Netter's Head and Neck Anatomy for Dentistry [3 ed.] 9780323462105, 9780323462099, 9780323462082, 9780323392280, 2016012134

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N EIL S. N O RT O N

NETTER’S

HEAD AND NECK ANATO MY FO R DENTISTRY 3RD EDITION

NEIL S. NORTON, PhD Associate Dean for Admissions Professor of Oral Biology School of Dentistry Creighton University Omaha, Nebraska

Illustrations by Frank H. Netter, MD Contributing Illustrators Carlos A.G. Machado, MD Kip Carter, MS, CMI Andrew E. B. Swift, MS, CMI William M. Winn, MS, FAMI Tiffany S. DaVanzo, MA, CMI James A. Perkins, MS, MFA John A. Craig, MD

1600 Joh n F. Ken n ed y Blvd . Ste 1800 Ph ilad elp h ia, PA 19103-2899 Netter’s Head an d Neck An atom y or Den tistry Co p y ri g h t © 2 0 1 7 b y El se v i e r, In c . Al l ri g h t s re se rv e d .

ISBN: 978-0-323-39228-0

No p art o th is p u blication m ay be rep rod u ced or tran sm itted in an y orm or by an y m ean s, electron ic or m ech an ical, in clu d in g p h otocop yin g, recordin g, or an y in orm ation storage an d retrieval system , with ou t p erm ission in writin g rom th e p u blish er. Details on h ow to seek p erm ission , u rth er in orm ation abou t th e Pu blish er’s p erm ission s p olicies an d ou r arran gem en ts with organ ization s su ch as th e Cop yrigh t Clearan ce Cen ter an d th e Cop yrigh t Licen sin g Agen cy, can be ou n d at ou r website: www.elsevier.com / p erm ission s. Th is book an d th e in d ivid u al con tribu tion s con tain ed in it are p rotected u n d er cop yrigh t by th e Pu blish er (oth er th an as m ay be n oted h erein ).

No t i c e s Kn owled ge an d best p ractice in th is f eld are con stan tly ch an gin g. As n ew research an d exp erien ce broaden ou r u n d erstan din g, ch an ges in research m eth od s, p ro ession al p ractices, or m ed ical treatm en t m ay becom e n ecessary. Practition ers an d research ers m u st always rely on th eir own exp erien ce an d kn owled ge in evalu atin g an d u sin g an y in orm ation , m eth od s, com p ou n d s, or exp erim en ts described h erein . In u sin g su ch in orm ation or m eth od s th ey sh ou ld be m in d u l o th eir own sa ety an d th e sa ety o oth ers, in clu d in g p arties or wh om th ey h ave a p ro ession al resp on sibility. With resp ect to an y d ru g or p h arm aceu tical p rod u cts id en tif ed , read ers are ad vised to ch eck th e m ost cu rren t in orm ation p rovid ed (i) on p roced u res eatu red or (ii) by th e m an u actu rer o each p rod u ct to be ad m in istered , to veri y th e recom m en ded d ose or orm u la, th e m eth od an d d u ration o ad m in istration , an d con train d ication s. It is th e resp on sibility o p ractition ers, relyin g on th eir own exp erien ce an d kn owledge o th eir p atien ts, to m ake d iagn oses, to d eterm in e d osages an d th e best treatm en t or each in d ivid u al p atien t, an d to take all ap p rop riate sa ety p recau tion s. To th e u llest exten t o th e law, n eith er th e Pu blish er n or th e au th ors, con tribu tors, or ed itors, assu m e an y liability or an y in ju ry an d / or d am age to p erson s or p rop erty as a m atter o p rod u cts liability, n egligen ce or oth erwise, or rom an y u se or op eration o an y m eth od s, p rod u cts, in stru ction s, or ideas con tain ed in th e m aterial h erein .

Previou s ed ition s cop yrigh ted 2012 an d 2007 by Sau n d ers, an im p rin t o Elsevier In c. Li b ra r y o f Co n g re ss Ca t a l o g i n g -i n -P u b l i c a t i o n D a t a Nam es: Norton , Neil Scott, au th or. | Netter, Fran k H. (Fran k Hen ry), 1906-1991, illu strator. Title: Netter’s h ead an d n eck an atom y or den tistry / Neil S. Norton ; illu stration s by Fran k H. Netter ; con tribu tin g illu strators, Carlos A.G. Mach ado [an d 6 oth ers]. Oth er titles: Head an d n eck an atom y or d en tistry Descrip tion : 3rd edition . | Ph ilad elp h ia, PA : Elsevier, [2017] | In clu d es in d ex. Id en tif ers: LCCN 2016012134 | ISBN 9780323392280 (p bk. : alk. p ap er) Su bjects: | MESH: Den tistry | Head –an atom y & h istology | Neck–an atom y & h istology | Atlases Classif cation : LCC RK280 | NLM W U 17 | DDC 611/ .91–d c23 LC record available at h ttp :/ / lccn .loc.gov/ 2016012134 Executive Content Strategist: Elyse O’Grad y Senior Content Developm ental Specialist: Marybeth Th iel Publishing Services Manager: Patricia Tan n ian Project Manager: Step h an ie Tu rza Design Direction: Ju lia Du m m it Prin ted in Ch in a Last d igit is th e p rin t n u m ber:

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I dedicate this book to the ollowing in uential people in m y li e, To m y late m other Chari, who worked tirelessly and sacrif ced everything throughout her li e so that her children would not be without. To Elizabeth, who m ade m e a better m an. I owe you everything or all that you have done or m e. To m y brother John, who helped raise m e. And to m y m entors, the late Frs. John G. Holbrook, S.J., and John P. Schlegel, S.J., who helped m e appreciate the im portance o service to others. They taught m e the dedicated ways o cu ra p erson alis, or care or the individual. I have tried to live by those words every day o m y li e.

Ab o u t th e Au th o r Ne i l S. No r t o n , P h D , join ed Creigh ton Un iversity in 1996 an d is cu rren tly th e Associate Dean for Ad m ission s an d Professor of Oral Biology in th e Sch ool of Den tistry. After grad u atin g Ph i Beta Kap p a from Ran d olp h -Macon College with a BA in Biology, h e wen t on to receive h is Ph D train in g in An atom y from th e Un iversity of Nebraska Med ical Cen ter. Dr. Norton h as been th e recip ien t of over 25 teach in g award s, in clu d in g m u ltip le Ou tstan d in g In stru ctor of th e Year Awards from Fresh m an classes an d Dr. Th eod ore J. Urban Pre-Clin ical Award s, p resen ted by grad u atin g Sen ior classes for ou tstan d in g Basic Scien ce in stru ction . Dr. Norton is th e th ird p rofessor in th e h istory of th e Sch ool of Den tistry to receive th e p restigiou s Robert F. Ken n ed y Mem orial Award for Teach in g Ach ievem en t, th e h igh est teach in g recogn ition offered by th e Un iversity. In 2007 Dr. Norton received th e GlaxoSm ith Klin e Sen sod yn e Teach in g Award , th e h igh est n ation al teach in g award given by th e Am erican Den tal Ed u cation Association (ADEA). An active m em ber of th e Sch ool of Den tistry facu lty, h e was elected by colleagu es to h on orary m em bersh ip in Om icron Kap p a Up silon , th e Nation al Den tal Hon or Society wh ose regu lar m em bersh ip is reserved for d en tists. His teach in g resp on sibilities in clu d e Head an d Neck An atom y, Gen eral An atom y, Neu roscien ce, an d Pain Con trol. Dr. Norton served fou r years as Presid en t of th e Un iversity Facu lty an d ch aired m an y com m ittees, in clu d in g th e Un iversity Com m ittee on Ran k an d Ten u re an d th e Un iversity Com m ittee on Acad em ic Freed om an d Resp on sibility. Cu rren tly h e serves as th e Facu lty Ath letic Rep resen tative for Creigh ton to th e BIG EAST Con feren ce. He con tin u es to actively p u blish on a variety of an atom ical top ics in ad d ition to h is ad m in istrative du ties. He is an active m em ber of th e Am erican Association of Clin ical An atom ists (AACA), h avin g served as th e Treasu rer for seven years an d as Presid en t from 2015–2017.

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Ab o u t th e Artists Fra n k H . Ne t t e r, MD Fran k H. Netter was born in 1906, in New York City. He stu died art at th e Art Stu d en t’s Leagu e an d th e Nation al Acad em y of Design before en terin g m ed ical sch ool at New York Un iversity, wh ere h e received h is MD in 1931. Du rin g h is stu d en t years, Dr. Netter’s n otebook sketch es attracted th e atten tion of th e m ed ical facu lty an d oth er p h ysician s, allowin g h im to au gm en t h is in com e by illu stratin g articles an d textbooks. He con tin u ed illu stratin g as a sid elin e after establish in g a su rgical p ractice in 1933, bu t h e u ltim ately op ted to give u p h is p ractice in favor of a fu ll-tim e com m itm en t to art. After service in th e Un ited States Arm y d u rin g World War II, Dr. Netter began h is lon g collaboration with th e CIBA Ph arm aceu tical Com p an y (n ow Novartis Ph arm aceu ticals). Th is 45-year p artn ersh ip resu lted in th e p rodu ction of th e extraord in ary collection of m ed ical art so fam iliar to p h ysician s an d oth er m ed ical p rofession als world wid e. In 2005, Elsevier, In c., p u rch ased th e Netter Collection an d all p u blication s from Icon Learn in g System s. Th ere are n ow over 50 p u blication s featu rin g th e art of Dr. Netter available th rou gh Elsevier, In c. (in th e Un ited States: www.u s.elsevierh ealth .com / Netter an d ou tsid e th e Un ited States: www.elsevierh ealth .com ). Dr. Netter’s works are am on g th e n est exam p les of th e u se of illu stration in th e teach in g of m edical con cep ts. Th e 13-book Netter Collection of Medical Illustrations, wh ich in clu d es th e greater p art of th e m ore th an 20,000 p ain tin gs created by Dr. Netter, becam e an d rem ain s on e of th e m ost fam ou s m ed ical works ever p u blish ed . The Netter Atlas of Hum an Anatom y, rst p u blish ed in 1989, p resen ts th e an atom ical p ain tin gs from th e Netter Collection . Now tran slated in to 16 lan gu ages, it is th e an atom y atlas of ch oice am on g m ed ical an d h ealth p rofession s stu den ts th e world over. Th e Netter illu stration s are ap p reciated n ot on ly for th eir aesth etic q u alities, bu t, m ore im p ortan t, for th eir in tellectu al con ten t. As Dr. Netter wrote in 1949, “… clari cation of a su bject is th e aim an d goal of illu stration . No m atter h ow beau tifu lly p ain ted , h ow d elicately an d su btly ren d ered a su bject m ay be, it is of little valu e as a m edical illustration if it d oes n ot serve to m ake clear som e m ed ical p oin t.” Dr. Netter’s p lan n in g, con cep tion , p oin t of view, an d ap p roach are wh at in form h is p ain tin gs an d wh at m ake th em so in tellectu ally valu able. Fran k H. Netter, MD, p h ysician an d artist, d ied in 1991. Learn m ore abou t th e p h ysician -artist wh ose work h as in sp ired th e Netter Referen ce collection at www.n etterim ages.com / artist/ n etter.h tm .

Ca rl o s Ma c h a d o , MD Carlos Mach ad o was ch osen by Novartis to be Dr. Netter’s su ccessor. He con tin u es to be th e m ain artist wh o con tribu tes to th e Netter collection of m ed ical illu stration s. Self-tau gh t in m ed ical illu stration , card iologist Carlos Mach ad o h as con tribu ted m eticu lou s u p d ates to som e of Dr. Netter’s origin al p lates an d h as created m an y p ain tin gs of h is own in th e style of Netter as an exten sion of th e Netter collection . Dr. Mach ad o’s p h otorealistic exp ertise an d h is keen in sigh t in to th e p h ysician / p atien t relation sh ip in form h is vivid an d u n forgettable visu al style. His d edication to research in g each top ic an d su bject h e p ain ts p laces h im am on g th e p rem ier m ed ical illu strators at work tod ay. Learn m ore abou t h is backgrou n d an d see m ore of h is art at www.n etterim ages. com / artist/ m ach ad o.h tm .

Ab o u t t h e Ar t is t s

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Ackn o wle d gm e n ts It is h ard to believe th at it h as been over a d ecad e sin ce th e seed s of Netter’s Head & Neck Anatom y for Dentistry were p lan ted . Th e 3rd ed ition , like th e p reviou s ed ition s, is th e resu lt of m an y lon g h ou rs of work. I wou ld n ot h ave been able to accom p lish su ch a task with ou t th e h elp of m an y talen ted an d ded icated in divid u als. Begin n in g m y acad em ic career at th e Creigh ton Un iversity Sch ool of Den tistry in 1996, I was overwh elm ed by th e com rad ery th at existed at both th e Sch ool an d Un iversity level. Twen ty years later – it still exists. I am gratefu l every d ay to be p art of su ch a n e in stitu tion th at is com m itted to th e ed u cation of stu d en ts. Th e su p p ort an d assistan ce m y fellow colleagu es h ave p rovid ed to h elp in th e creation of each ed ition h ave been im m easu rable. I wou ld esp ecially like to th an k for th eir review of ch ap ters, su ggestion s, an d willin gn ess to p rovid e m aterials th e followin g m em bers of th e Creigh ton Sch ool of Den tistry fam ily (p ast an d p resen t): Drs. David Blah a, W. Th om as Cavel, Pau l Ed wards, Jam es Howard, Terry Lan p h ier, Joh n McCabe, Kirstin McCarville, Tim oth y McVan ey, Takan ari Miyam oto, Barbara O’Kan e, Cyn d i Ru ssell, an d Tarjit Sain i. I owe a very sp ecial th an ks to m y form er Dean , Dr. Wayn e W. Barkm eier. He was th e p erson willin g to give a you n g an atom ist an op p ortu n ity at Creigh ton , an d I owe m y career to Dr. Barkm eier. It was h e an d Dr. Fran k J. Ayers wh o p u sh ed m e an d p rovided m e th e op p ortu n ity in Ad m ission s an d Stu d en t Affairs. For th at, I’ll always be gratefu l. Sin ce th e p u blication of th e 2n d ed ition , I wou ld n ot h ave been able to con tin u e to d evelop th is book with ou t th e su p p ort of m y cu rren t Dean , Dr. Mark A. Latta. Ad d ition ally, I am extrem ely gratefu l to Dr. Lau ra C. Barritt wh o p rovid ed excellen t su ggestion s an d reviews th at were in stru m en tal in th e creation of th e Develop m en t section of th e book, as well as p rovid in g variou s su ggestion s in m an y oth er ch ap ters. Sp ecial th an ks go to Dr. Margaret A. Jergen son , ch air of th e Dep artm en t of Oral Biology. Sin ce 1996, Dr. Jergen son an d I h ave tau gh t gen eral an atom y an d h ead an d n eck an atom y to fresh m an d en tal stu d en ts. Her clin ical backgrou n d as a d en tist h as been in valu able in h elp in g m e ap p reciate h ead an d n eck an atom y from a den tal p ersp ective. Alon g with Dr. Barbara O’Kan e, we h ave en joyed workin g togeth er as th e an atom ical team in th e Sch ool of Den tistry. I cou ld n ot ask for better colleagu es with wh om to teach an atom y. My sin cere ap p reciation to m y Creigh ton colleagu es ou tsid e of th e Sch ool of Den tistry. Creigh ton is a fam ily, an d I h ave been fortu n ate to sp en d m y career at su ch a n e u n iversity. Over th e years th ere h ave been a few in d ividu als wh o h ave h elp ed m e im m en sely. In p articu lar, I owe a sp ecial ackn owledgm en t of gratitu de to Frs. Rich ard Hau ser, S.J., an d Th om as Sh an ah an , S.J. My sin cere ap p reciation goes to m y frien d an d colleagu e Dr. Th om as Qu in n , wh o offered h elp fu l com m en ts an d word s of en cou ragem en t th rou gh ou t th e textu al writin g an d d evelop m en t of th e art. My th an ks to th e reviewers wh o exam in ed th e ch ap ters in th e rst edition an d p rovid ed excellen t feed back: Drs. Robert Sp ears, Kath leen M. Klu eber, an d Brian R. MacPh erson , an d Professor Cin d y Evan s. A very sp ecial th an ks to m y frien d an d colleagu e Dr. Vid h ya (Vid ) Persau d for h is h elp fu l com m en ts regard in g th e Develop m en t section of th e text. Over th e years, I h ave en listed th e h elp of m y d en tal stu den ts to m ake Netter’s Head and Neck Anatom y for Dentistry m ore stu d en t-frien d ly. Sp ecial th an ks go to Drs. Josep h Op ack, Ryan Dobbs, Steve Mid stokke, Pau l Men d es, Kyle D. Sm ith , an d Th om as Sp ellm an for th eir in valu able assistan ce. Th is book wou ld n ot be p ossible if n ot for th e beau tifu l n ew artwork created by th e in cred ible m ed ical illu strators at Elsevier. A very sp ecial th an ks to Carlos Mach ado, MD, wh o created n ew artwork sp eci cally for th is atlas. Qu ite sim p ly, Dr. Mach ado is on e of th e greatest m ed ical illu strators of ou r tim e an d it h as been a d istin ct h on or an d p rivilege to h ave worked with h im . A sin cere th an ks to Tiffan y DaVan zo, wh o was in stru m en tal in th e creation of th e n ew p ieces in both th e 2n d an d 3rd ed ition s. I am very gratefu l for th e work of Kip Carter, William Win n , an d

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An d rew Swift in th e 1st ed ition . All of th ese illu strators h elp ed p u t m y vision in to art. Th eir artistic in terp retation s are sim p ly m agn i cen t. I can n ever th an k th e am azin g Elsevier team en ou gh ! Two p eop le in p articu lar h ave always been th ere to h elp : Elyse O’Grad y an d Marybeth Th iel. Elyse h as been a con stan t sou rce of su p p ort an d fan tastic id eas for all ed ition s. Marybeth h as been th ere sin ce I su bm itted th e rst ch ap ter of th e 1st edition , always keep in g m e on track. Th is book wou ld n ot be p ossible with ou t th em . Th e Elsevier team h as been an absolu te p leasu re! In p articu lar, I sin cerely th an k m y Project Man ager, Step h an ie Tu rza, for h er atten tion to d etail an d keep in g everyth in g on tim e for th is book. Ad d ition ally, I wou ld like to ackn owled ge th e work of th ose wh o h elp ed m e com p lete th e rst ed ition of th e book: Jen n ifer Su rich , Carolyn Kru se, an d Jon ath an Dim es. Very sp ecial th an ks go to Pau l Kelly. I h ave h ad th e great h on or an d p rivilege of kn owin g Pau l for n early 20 years. Pau l en cou raged m e to p u t togeth er an an atom ical p roject for d en tistry. I p resen ted h im with th e rou gh ou tlin e an d p rosp ectu s for a text/ atlas th at evolved in to th e rst ed ition of th is book. Lastly, I th an k all of th e stu den ts wh om I h ave in stru cted over m y career. You h ave always served as a great in sp iration to m e. It h as been an h on or an d p rivilege to be a p art of you r ed u cation . Netter’s Head and Neck Anatom y for Dentistry is for you .

ACKNOw l EDg MENTS

vii

Pre fa ce Netter’s Head and Neck Anatom y for Dentistry is a text/ atlas written to h elp d en tal stu d en ts an d p ro ession als learn an d review h ead an d n eck an atom y. Design ed or f rst-year den tal stu d en ts, it also serves to teach an atom y to stu den ts o d en tal h ygien e as well as a review or th e p racticin g clin ician . Th e h ead an d n eck com p rise th e ou n d ation or den tal an atom ical stu d y. Th e m an y sm all, in terrelated stru ctu res are n ot easily observable, wh ich m akes h ead an d n eck an atom y on e o th e m ost d i f cu lt d iscip lin es or stu den ts to m aster. Th is 3rd ed ition h as received a bit o a aceli t. Elsevier h as redesign ed th e look o th e book, an d I h op e you are as p leased with th e ou tcom e as I am . Th ere are n u m erou s ad d ition s an d revision s to th e book. First is th e ap p en d ix on th e lym p h atics — with em p h asis on th e h ead an d n eck. Secon d, m ore th an 30 rad iograp h ic im ages h ave been ad d ed to th e existin g im age catalog to com p lem en t th e an atom y illu stration s th rou gh ou t th e text. Radiology is an im p ortan t p art o th e ed u cation o every d en tal stu d en t, an d it is a n atu ral ad d ition to an y an atom y text. Th ird , m ore clin ical correlates h ave been ad d ed to p rovide real world scen arios or th e stu d en t. Fou rth , m an y o th e tables an d artwork h ave been revised ollowin g th e su ggestion s o m an y o ou r read ers o th e p reviou s ed ition s. In th e 3rd edition , th ere are 50 n ew q u estion s th at cover th e ch ap ters in th e text. However, to give ou r read ers m ore, Elsevier h as created a test ban k o q u estion s on Stu d en t Con su lt. Th u s, stu d en ts can access all o th e q u estion s rom p reviou s edition s as well as oth er review q u estion s on Stu d en t Con su lt or a m ore robu st review o th e m aterial. An oth er p erk o Stu d en t Con su lt in clu d es th e ad d ition o sh ort an atom ical vid eo clip s u sin g th e im agin g rom th e 3rd ed ition . To u n d erstan d th e clin ical sign if can ce o an an atom ical con cep t is to u n d erstan d th e an atom y. It is with th at in m in d th at a series o clin ical correlates th at relate sp ecif cally to d en tistry are p rovided at th e en d o th e ch ap ters. Th ere are m an y an atom ical top ics covered in tradition al h ead an d n eck cou rses th at h ave been exp an d ed esp ecially or th is text. A ch ap ter h as been d ed icated to th e tem p orom an d ibu lar join t. In th e ch ap ter on th e oral cavity, m ore in orm ation h as been p rovid ed or th e read er on su ch top ics as d en tition . Ch ap ters on th e d evelop m en t o th e h ead an d n eck an d basic n eu roscien ce are in clu d ed to h elp con n ect with oth er related an atom ical areas. A ch ap ter on in traoral in jection s is in clu d ed to h elp teach an d rein orce an area o ten overlooked . Th e in ten t o th ese ch ap ters is to p rovid e th e read er with a brie overview o im p ortan t con cep ts related to h ead an d n eck an atom y. A su p erb team o m ed ical illu strators created n ew art to com p lem en t th e an atom ical illu stration s o Dr. Fran k H. Netter, wh ich resu lted in a m ore com p lete learn in g tool. In p articu lar, th e n ew illu stration s o Dr. Carlos Mach ado d em on strate wh y h e con tin u es to be th e p reem in en t m ed ical illu strator in h is f eld . Th e Tem p orom an d ibu lar Join t ch ap ter eatu res 6 n ew f gu res by Dr. Mach ad o, an d I kn ow you will f n d th em as sp ectacu lar as I d o. Essen tial in orm ation is p resen ted in tables an d brie text th at are in tegrated with th e Netter art to h elp brid ge gap s an d au gm en t th e read ers’ kn owled ge o h ead an d n eck an atom y. Netter’s Head and Neck Anatom y for Dentistry is or th ose in all stages o th e d en tal p ro ession . My h op e is th at th is book will p rovide an essen tial resou rce to readers in h elp in g th em to learn an d ap p reciate th e com p lex an atom y o th e h ead an d n eck.

viii

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

Co n te n ts 1

Development of the Head and

2

eck

steology

25

3

Basic

4

he

5

calp and Muscles of Facial xpression

6

eck

107 153 187 207

Muscles of Mastication

229

emporomandibular Joint

241

Pterygopalatine Fossa

11 12

65

emporal and Infratemporal Fossae

9 10

euroanatomy and Cranial erves

Parotid Fossa and Gland

7 8

1

ose and

257

asal Cavity

275

Paranasal inuses

13

311

ral Cavity

341

14

ongue

399

15

Pharynx

425

16

Larynx

445

17

Cervical Fascia

465

18

ar

19

ye and

483 rbit

509

20

Autonomics of the Head and

eck

543

21

Intraoral Injections

567

22

Introduction to the Upper Limb, Back, horax, and Abdomen

589

Appe ndix A Lymphatics

655

Appe ndix B

661

Questions and Answers

Inde x

669

C

ix

This pa ge inte ntiona lly le ft bla nk

CHAPTER 1

DEVELOPMENT OF THE HEAD AND NECK

Overview

2

Pharyngeal Arches

4

Pharyngeal Pouches, Membranes, and Clefts

7

Cranium

10

Face

13

Palate

15

Tongue

17

Thyroid Gland

18

Clinical Correlates

19

1

OVERVIEW • General Information •

•

•

•

•

3 m ajor germ layers form th e in itial develop in g em bryo: • Ectod erm • Mesod erm • En d od erm Mesod erm differen tiates in to: • Paraxial m esod erm • In term ed iate m esod erm • Lateral p late m esoderm Ectod erm gives rise to 3 layers: • Neu roectod erm • Neu ral crest • Ep id erm is Th e h ead an d n eck are form ed by: • Paraxial m esod erm • Lateral p late m esoderm • Neu ral crest • Ectod erm al p lacodes Most of th e h ead an d n eck is form ed from th e p h aryn geal region of th e em bryo

Human Embryo at 16 Days Midsagittal section Neural plate Notochord Amniotic sac

Hensen’s node (origin of notochord) Body stalk

Cardiac primordia Plane of cross section shown below

Roof of yolk sac

1.8 mm

Figu re 1-1

2

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

Allantois

OVERVIEW • General Information

1

Cross section of embryo Neural plate

Notochord Paraxial column (segmenting into somites)

Intermediate mesoderm

Lateral plate mesoderm The arrow passes through a temporary communication between the extraembryonic coelom and intraembryonic coelom

The intraembryonic coelom in the lateral plate is continuous with the coelom in the cardiogenic mesoderm

Vertebrate Body Plan after 4 Weeks Connecting stalk Amnion (cut) Neural plate

Neural crest Neural plate forming neural tube Somite Intermediate mesoderm Intraembryonic coelom

Paraxial column Intermediate mesoderm

Notochord

Lateral plate Notochord

Intermediate Intermediate mesoderm: Nephrogenic ridge mesoderm Nephrogenic cord dorsal to the intraembryonic Genital ridge coelom Splanchnopleure (endoderm plus lateral plate mesoderm) Somatopleure (ectoderm plus lateral plate mesoderm)

Formation of ventral mesentery Amnion fusing with chorion

Connecting stalk

Somatic mesoderm of lateral plate Amnion tucking around the sides of the folding embryo Splanchnic mesoderm of lateral plate

Yolk sac

Left and right dorsal aorta Lateral plate is a thin mesodermal coating of the coelom

Embryonic endoderm forming gastrointestinal (gut) tube

Somite sclerotome surrounds the neural tube and notochord to form vertebral column Spinal nerve Dermomyotome Aorta Dorsal mesentery Ventral mesentery

Gut tube

Umbilical cord

Yolk sac (stalk just out of the plane of section)

Amnion against chorion

Figu re 1-2

DEVELO P MENT O F THE HEAD AND NECK

3

1

PHARYNGEAL ARCHES • General Information • • • • •

•

• • •

Start form in g in th e 4th week of d evelop m en t Develop as blocks sep arated by p h aryn geal clefts (form ed by ectoderm ) In itially, 6 p h aryn geal arch es d evelop , bu t th e 5th regresses Arisin g from th e en d oderm are com p artm en ts called p h aryn geal p ou ch es th at exten d toward th e p h aryn geal clefts, sep arated by p h aryn geal m em bran es Help form 4 of th e 5 swellin gs (em bryon ic p rim ord ia) of th e face: • 2 m an dibu lar p rocesses (p h aryn geal arch ) • 2 m axillary p rocesses (p h aryn geal arch ) • 1 fron ton asal p rom in en ce Com p osed of: • Extern al su rface–ectoderm • In tern al su rface–en d oderm • Cen tral p art–lateral p late m esod erm , p araxial m esod erm , n eu ral crest Skeletal com p on en ts an d associated con n ective tissu e develop from th e n eu ral crest cells Mu scu lar stru ctu res develop collectively from th e m esod erm Each arch is in n ervated by a cran ial n erve th at m igrates with th e m u scles

O phthalmic division of trigeminal nerve (V1) Sensory for orbit, nose, and forehead

Preotic somitomeres

IV

O tic ganglion (V3)

Accessory nerve XI relates to somitic mesenchyme by arch 6

VIII III

Ciliary ganglion (V1) Pterygopalatine ganglion (V2) Lens placode

Postotic somites

V VI

VII

O tic vesicle IX

X

II XII

O ptic cup Submandibular ganglion (V3)

Head mesenchyme

I

O lfactory placode

XI Chorda tympani Taste to ant. 2/3 of tongue and parasympathetic to salivary glands

Heart bulge

Pharyngeal arches and their nerves: Arch 1—trigeminal nerve (V) Tympanic nerve Maxillary part of arch 1—maxillary nerve (trigeminal, V2) Mandibular part of arch 1—mandibular nerve (trigeminal, V3) Visceral sensory Arch 2—facial nerve (VII) for middle ear and Arch 3—glossopharyngeal nerve (IX) parasympathetic Arch 4—vagus n. (X) for parotid gland Arch 6—vagus n. (X)

Figu re 1-3

4

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

Parasympathetic and visceral sensory branch from X for foregut and midgut

PHARYNGEAL ARCHES • Derivatives of the Pharyngeal Arches Cartilage Structure(s) from Neural Crest

Cartilage Structure(s) from Mesoderm

Connective Tissue Structure(s) from Neural Crest

Arch

Muscle(s) from Mesoderm

1 (also called the Mandibular arch) Develops into: • Maxillary process • Mandibular process

Masseter Tem poralis Lateral pterygoid Medial pterygoid Mylohyoid Anterior digastric Tensor tym pani Tensor veli palatini

Malleus Incus (both from Meckel’s cartilage, which degenerates in adulthood)

Sphenom andibular ligam ent Anterior ligam ent of the m alleus (both from Meckel’s cartilage, which degenerates in adulthood)

Trigem inal

2 (also called the Hyoid arch)

Muscles of facial expression Posterior digastric Stylohyoid Stapedius

Lesser cornu of the hyoid Superior part of the hyoid body Styloid process Stapes (all from Reichert’s cartilage)

Stylohyoid ligam ent Connective tissue of the tonsil

Facial

3

Stylopharyngeus

Greater cornu of the hyoid Inferior part of the hyoid body

Connective tissue of the thym us and inferior parathyroid

Glossopharyngeal

4

Musculus uvulae Levator veli palatini Palatopharyngeus Palatoglossus Superior constrictor Middle constrictor Inferior constrictor Salpingopharyngeus Cricothyroid

Epiglottis Thyroid (both from lateral plate m esoderm )

Connective tissue of the superior parathyroid and the thyroid

Vagus

6

Thyroarytenoid Vocalis Lateral cricoarytenoid Oblique arytenoids Transverse arytenoids Posterior cricoarytenoid Aryepiglottis Thyroepiglottis

Arytenoid Cricoid Cuneiform Corniculate (all from lateral plate m esoderm )

1

Nerve

Vagus

DEVELO P MENT O F THE HEAD AND NECK

5

1

PHARYNGEAL ARCHES • Derivatives of the Pharyngeal Arches

Epicranial aponeurosis (galea aponeurotica) Temporalis Auricularis mm. O ccipitofrontalis (occipital belly) Masseter Styloid process Stylohyoid Digastric (posterior belly) Thyrohyoid Sternocleidomastoid Prevertebral fascia Trapezius O mohyoid Clavicle Platysma (mostly removed)

Superficial muscles

O ccipitofrontalis (frontal belly) O rbicularis oculi Procerus Nasalis Levator labii superioris Zygomaticus mm. O rbicularis oris Buccinator Mentalis Depressor labii inferioris Depressor anguli oris Mylohyoid Digastric (anterior belly) Sternohyoid Sternothyroid Deep muscles

Tensor veli palatini Levator veli palatini

Part of lateral pterygoid m. Extrinsic eyeball mm. Pterygomandibular raphe Part of buccinator Tongue Genioglossus Mandible Geniohyoid Hyoglossus Hyoid bone Thyroid cartilage Inferior pharyngeal constrictor Cricothyroid Trachea

Superior pharyngeal constrictor Styloid process Sternocleidomastoid Splenius capitis Carotid sheath Scalene mm. Levator scapulae Trapezius Stylopharyngeus Styloglossus Middle pharyngeal constrictor Esophagus

Embryo at 7 to 8 weeks Cartilage primordia

2nd pharyngeal arch territory Stapes Styloid process

1st pharyngeal arch territory

Stylohyoid ligament 3rd pharyngeal arch territory

Incus Meckel’s Malleus cartilage Future sphenomandibular ligament Portion mandibular bone surrounds Lesser cornu of hyoid cartilage Upper half of hyoid body Lower half of hyoid body

Greater cornu of hyoid cartilage 6th pharyngeal arch territory Cricoid cartilage 4th pharyngeal arch territory

Thyroid cartilage

PHARYNGEAL ARCH BONES AND CARTILAGE Arch # Derivatives of Arch Cartilages 1 Malleus, incus, sphenomandibular ligament, anterior ligament of malleus 2 Stapes, styloid process, stylohyoid ligament, upper half and lesser horn of hyoid 3 Lower half and greater horns of hyoid Thyroid and epiglottic cartilages of larynx 4 Cricoid, arytenoid, and corniculate cartilages of larynx 6

Figu re 1-4

6

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

PHARYNGEAL POUCHES, MEMBRANES, AND CLEFTS • General Information • • •

1

Ph aryn geal p ou ch es–4 d evelop from en d od erm Ph aryn geal clefts–each is a groove form ed from ectod erm Ph aryn geal m em bran es–each is com p osed of tissu e located between a p h aryn geal p ou ch an d a p h aryn geal cleft; com p osed of extern al ectoderm , m esod erm an d n eu ral crest in th e core, an d an in tern al en dod erm lin in g

Pharyngeal Pouches Pouch

Location

Embryonic Structure

Adult Structure

1

Opposite the 1st pharyngeal cleft, separated by the 1st pharyngeal m em brane

Tubotym panic recess

Epithelium of the (pharyngotym panic auditory) tube Tym panic cavity

2

Opposite the 2nd pharyngeal cleft, separated by the 2nd pharyngeal m em brane

Prim ordial palatine tonsils

Tonsillar (sinus fossa) Epithelium of the palatine tonsil

3

Opposite the 3rd pharyngeal cleft, separated by the 3rd pharyngeal m em brane

Divides into a dorsal and a ventral part Dorsal part m igrates inferiorly toward the thorax

Inferior parathyroid gland (from the dorsal part) Thym us (from the ventral part)

4

Opposite the 4th pharyngeal cleft, separated by the 4th pharyngeal m em brane

Divides into a dorsal and a ventral part Ventral part is invaded by neural crest to form the parafollicular or C cells

Superior parathyroid gland (from the dorsal part) Ultim obranchial body (from the ventral part)

Infundibulum (posterior lobe) Rathke’s pouch (anterior lobe) Pituitary gland

Sagittal section

Hypothalamus of brain

1st pharyngeal pouch Buccopharyngeal membrane (disintegrating)

Frontal prominence

Pharynx Laryngotracheal ridge or groove

Nasal placode

Esophagus Lung bud

Stomodeum 1st pharyngeal arch

Thyroid diverticulum

Figu re 1-5

DEVELO P MENT O F THE HEAD AND NECK

7

1

PHARYNGEAL POUCHES, MEMBRANES, AND CLEFTS • Pharyngeal Pouches

Mouth cavity

I

Thyroid gland II Pharyngeal pouches III

IV

Trachea

Lung bud

Esophagus

Tongue

Pharyngeal cavity Foramen cecum

1st pouch

2nd pouch Epithelium of larynx 3rd pouch Parathyroid III Lateral thyroid lobe Thymus

4th pouch Thyroid isthmus

Parathyroid IV Esophagus

Trachea

Figu re 1-6

8

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

PHARYNGEAL POUCHES, MEMBRANES, AND CLEFTS • Pharyngeal Membranes Membrane

Location

Adult Structure

1

Between the 1st pharyngeal cleft and the 1st pharyngeal pouch

Tym panic m em brane

2

Between the 2nd pharyngeal cleft and the 2nd pharyngeal pouch

3

Between the 3rd pharyngeal cleft and the 3rd pharyngeal pouch

4

Between the 4th pharyngeal cleft and the 4th pharyngeal pouch

1

Pharyngeal Clefts Cleft

Location

Adult Structure

1

A groove between the 1st and 2nd pharyngeal arches

External acoustic m eatus

2

A groove between the 2nd and 3rd pharyngeal arches

3

A groove between the 3rd and 4th pharyngeal arches

Obliterated cervical sinus by the 2nd pharyngeal arch, which grows over the clefts

4

A groove between the 4th and 6th pharyngeal arches

Source 1st pharyngeal pouch

Auditory tube Tympanic cavity Eardrum Pharyngeal fistula

1st pharyngeal groove

External acoustic meatus

1st and 2nd pharyngeal arches

Auricle

Supratonsillar fossa 2nd pharyngeal pouch

Epithelium of palatine tonsil Tongue (cut)

Ventral pharyngeal wall

Foramen cecum Persistent thyroglossal duct

3rd pharyngeal pouch

Aberrant parathyroid gland III

2nd pharyngeal pouch

Pharyngeal fistula

4th pharyngeal pouch Ventral pharyngeal wall 3rd pharyngeal pouch

3rd pharyngeal pouch

3rd pharyngeal pouch

Parathyroid gland IV Ultimobranchial body Pyramidal and lateral lobes of thyroid gland Parathyroid gland III Persistent cord of thymus Pharyngeal fistula

Aberrant parathyroid gland III Thymus gland

Figu re 1-7 DEVELO P MENT O F THE HEAD AND NECK

9

1

CRANIUM • General Information •

•

•

Cran iu m (sku ll) is form ed from : • Lateral p late m esoderm (n eck region ) • Paraxial m esod erm • Neu ral crest Cran iu m d evelop m en t is d ivided in to 2 p arts: • Viscerocran iu m –form s th e bon es of th e face (from th e p h aryn geal arch es) • Form s com p letely from n eu ral crest • Neu rocran iu m –form s th e bon es of th e cran ial base an d cran ial vau lt, an d th e fu n ction is to p rotect an d su rrou n d th e brain an d organ s of sp ecial sen se (olfaction , vision , au d itory, an d eq u ilibriu m ). It can be d ivid ed in to: • Mem bran ou s n eu rocran iu m (form s from n eu ral crest an d p araxial m esod erm ) • Cartilagin ou s n eu rocran iu m (form s from n eu ral crest an d p araxial m esod erm ) Bon y sku ll is form ed by eith er of 2 m ech an ism s: • In tram em bran ou s ossi cation • En d och on d ral ossi cation

Viscerocranium Germ Layers

Origins

Adult Structure(s)

Ossif cation

Neural crest

1st pharyngeal arch Maxillary process

Maxilla

Intram em branous

Tem poral bone Zygom a Palatine Lacrim al Vom er Nasal

1st pharyngeal arch Mandibular process

Inferior nasal concha

Endochondral

Mandible

Intram em branous (body) Endochondral (coronoid and condylar process)

Malleus

Endochondral

Incus 2nd pharyngeal arch

Styloid process

Endochondral

Stapes Hyoid

10

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

CRANIUM • Viscerocranium Chondrocranium at 9 weeks O rbitosphenoid (orbital, or lesser, wing of future sphenoid bone) (vision) Crista galli Nasal capsule (olfaction) Meckel’s cartilage Cartilaginous Styloid process pharyngeal Hyoid cartilage arch skeleton Thyroid cartilage Cricoid cartilage

Membrane bones at 9 weeks

Frontal bone Nasal bone Maxilla Mandible

Membrane bones at 12 weeks

1

O ptic foramen Greater wing of future sphenoid bone O tic capsule (audition) Incus Malleus

Interparietal part of occipital bone Zygomatic bone Squamous part of temporal bone Chondrocranium

Pharyngeal arch mesenchyme for viscerocranium Head mesenchyme for neurocranium Cartilage from pharyngeal arches for viscerocranium and neck cartilages Cartilage from somite sclerotomes and neural crest anteriorly for base of neurocranium

Intramembranous ossification (both from neural crest)

Endochondral ossification

Site of future anterior fonticulus (fontanelle) Site of future coronal suture Parietal bone

Frontal bone Nasal bone Lacrimal bone Maxilla Zygomatic bone Mandible

Interparietal part of occipital bone Greater wing of sphenoid bone Chondrocranium Squamous part and zygomatic process of temporal bone Tympanic ring of temporal bone

Figu re 1-8

Cranial Fontanelles Fontanelle

Time of Closure

Anterior fontanelle (bregm a)

4–26 m onths

Posterior fontanelle (lam bda)

1–2 m onths

Sphenoidal fontanelle (pterion)

2–3 m onths

Mastoid fontanelle (asterion)

12–18 m onths

DEVELO P MENT O F THE HEAD AND NECK

11

1

CRANIUM • Membranous Neurocranium Germ Layer

Portions of Neurocranium

Adult Structure

Ossi cation

Neural crest

Main portion of the roof and lateral sides of the cranial vault

Frontal bone Squam ous portion of the tem poral bone

Intram em branous

Paraxial m esoderm

Parietal bone Occipital bone (intraparietal portion)

Cartilaginous Neurocranium Germ Layer

Portions of Neurocranium

Adult Structure

Ossi cation

Neural crest

Prechordal Anterior to the sella turcica

Ethm oid Sphenoid

Endochondral

Paraxial m esoderm

Chordal Posterior to the sella turcica

Petrous portion of the tem poral bone Mastoid process of the tem poral bone Occipital bone

Lateral view

Cranium of Newborn Parietal bone Tuber (eminence) Squamous suture

Anterior fontanelle Coronal suture Sphenoidal fontanelle

Posterior fontanelle

Frontal bone Squamous part Supraorbital notch (foramen)

Lambdoid suture

Ethmoid bone

Occipital bone

O rbital plate Mastoid fontanelle

Lacrimal bone Nasal bone Zygomatic bone Maxilla Palatine bone Pyramidal process Sphenoid bone Greater wing Lateral plate of pterygoid process Hamulus of medial plate of pterygoid process Superior view

Temporal bone Squamous part Petrosquamous fissure Petrous part (mastoid process absent) Tympanic part (bony external acoustic meatus absent) O val (vestibular) window Round (cochlear) window Styloid process Mandibular fossa Zygomatic process

Frontal bone Anterior fontanelle Coronal suture Parietal bone

Sagittal suture Posterior fontanelle

Occipital bone

Lambdoid suture

Figu re 1-9

12

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

FACE • General Information •

•

•

1

Th e face is form ed m ain ly from n eu ral crest, wh ich m akes 3 swellin gs (p rom in en ces) th at su rrou n d th e stom od eu m : • Fron ton asal p rom in en ce • Maxillary p rom in en ce (from th e 1st p h aryn geal arch ) • Man dibu lar p rom in en ce (from th e 1st p h aryn geal arch ) Lateral to th e fron ton asal p rom in en ce, 2 ad d ition al areas of ectoderm form th e 2 n asal p lacod es th at in vagin ate in th e cen ter to form n asal p its, creatin g rid ges of tissu e on eith er side of th e p its: • Lateral n asal p rom in en ce • Med ial n asal p rom in en ce Fu sion of th e m ed ial n asal p rom in en ces at th e m id lin e resu lts in form ation of th e in term axillary segm en t

ADULT STRUCTURES OF THE FACE Structure

Develop(s) from

Forehead

Frontonasal prom inence

Upper lip

Maxillary prom inence (lateral part of upper lip) Medial nasal prom inence (m iddle part of upper lip)

Lower lip

Mandibular prom inence

Lacrim al sac Nasolacrim al duct

A nasolacrim al groove that separates the lateral nasal prom inence and the m axillary prom inence

Nose

Frontonasal prom inence (bridge of nose) Medial nasal prom inence (nose attaching at philtrum ) Lateral nasal prom inence (alae of nose)

Cheeks

Maxillary prom inence

Philtrum

Medial nasal prom inence

Prim ary palate Upper jaw containing the central and lateral incisors

Interm axillary segm ent (fusion of m edial nasal prom inences)

Lateral view at 5 to 6 weeks 4.0 mm Left eye Maxillary process of 1st arch Nasolacrimal groove Nasal pit 1st pharyngeal arch Cardiac prominence 2nd pharyngeal arch Pharyngeal arches 3 and 4

Ventral view at 5 to 6 weeks Location of otic vesicle (future membranous Right labyrinth of nasal inner ear) pit 1st pharyngeal Right groove eye 1st cervical Nasolacrimal somite (myotome groove portion) Stomodeum Arm bud 1st pharyngeal groove Site of future hyoid bone

Frontonasal process Medial nasal prominence Lateral nasal prominence Maxillary process of 1st arch 1st pharyngeal arch (mandibular part) 2nd pharyngeal arch 3rd and 4th pharyngeal arches (sites of future laryngeal cartilages)

Figu re 1-10 DEVELO P MENT O F THE HEAD AND NECK

13

1

FACE • General Information

Lateral view at 6 to 7 weeks 7.0 mm 1st pharyngeal groove

Left eye

Nodules that will merge to form auricle of ear

Nasolacrimal groove Maxillary process

2nd pharyngeal arch

O pening of left nasal sac (future naris)

3rd and 4th pharyngeal arches in cervical sinus

O ral opening Cardiac prominence

1st pharyngeal arch

Ventral view at 6 to 7 weeks Intermaxillary segment

O pening of right nasal sac (future naris)

Medial nasal prominence

Maxillary process of 1st arch

Lateral nasal prominence Right eye Nasolacrimal groove 1st pharyngeal arch

O ral opening Nodules that merge to form auricle of ear

1st pharyngeal cleft (future external acoustic meatus)

3rd and 4th pharyngeal arches in cervical sinus (sites of future laryngeal cartilages)

2nd pharyngeal arch

Ventral view at 7 to 8 weeks

Site of nasolacrimal groove (fusion of lateral nasal and maxillary processes) Site of fusion of medial nasal and maxillary processes (site of cleft lip) Philtrum of upper lip (fusion of medial nasal processes)

Auricle of ear

Lateral view at 7 to 8 weeks

Lateral view at 8 to 10 weeks

10.0 mm

24.0 mm

Auricle of ear Auricle of ear Lateral nasal process Medial nasal process

Fused eyelids Philtrum of upper lip

Philtrum

Figu re 1-11

14

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

PALATE • General Information • • • • • •

1

Form ed by th e: • Prim ary p alate (in term axillary segm en t) • Secon dary p alate (p rotru sion s from th e m axillary p rom in en ces) In term axillary segm en t: th e in itial p ortion of th e p alate in develop m en t; con tain s th e cen tral an d lateral in cisors Swellin gs of th e m axillary p rom in en ce form sh elves (lateral p alatin e p rocesses) th at p roject m ed ially an d are sep arated by th e ton gu e W h en th e ton gu e n o lon ger occu p ies th e sp ace between th e p alatal sh elves, th ese lateral p alatin e p rocesses fu se togeth er to form th e secon dary p alate Th e p rim ary an d secon d ary p alatal tissu es all m eet at th e incisive foram en Prim ary an d secon d ary p alates an d th e n asal sep tu m fu se to form th e de n itive p alate

Frontal (coronal) section at 7 to 8 weeks Right olfactory bulb

Ethmoid cartilage Frontal bone

O cular muscles

Septal cartilage

Eyeball

Eyelid Maxilla

Nasal septum Tongue

Right lateral palatine process of secondary palate

Muscles of facial expression

Meckel’s cartilage

Mandible

Submandibular salivary gland

Hypoglossal (XII) nerve

Hyoid cartilage

Platysma

Thyroid cartilage

Lumen of larynx Esophagus Frontal (coronal) section at 8 to 10 weeks Septal cartilage Superior concha and meatus Ethmoid cartilage Eyeball

Frontal bone

Lens

O cular muscles

Middle concha and meatus

Fused eyelids

Right nasal cavity

Maxilla Zygomatic bone

Inferior concha and meatus

Muscles of facial expression

Enamel organs of deciduous molar teeth

Sites of fusion of lateral palatine processes and nasal septum O ral cavity

Meckel’s cartilage Submandibular salivary gland

Mandible

Hyoid cartilage

Tongue

Infrahyoid muscles

Platysma

Figu re 1-12

DEVELO P MENT O F THE HEAD AND NECK

15

1

PALATE • General Information

Roof of stomodeum (inferior view; 6 to 7 weeks)

Frontal area

O pening of right nasal sac

Medial nasal process Right eye

Lateral nasal process

Primitive or primary palate (median palatine process)

Nasolacrimal groove Definitive nasal septum

O ronasal membrane (primitive posterior naris or choana)

Maxillary process of 1st arch Lateral palatine process (secondary palate)

Roof of stomodeum (base of skull)

O pening of Rathke’s pouch

Palate formation (inferior view; 7 to 8 weeks)

Left naris Philtrum of upper lip (fusion of medial nasal processes)

Site of fusion of medial nasal and maxillary processes (cleft lip site)

Primary palate (median palatine process)

Primitive posterior naris or choana (former site of oronasal membrane)

Definitive nasal septum

Left lateral palatine process Site of evagination of Rathke’s pouch

Mucosa covering base of skull

Roof of oral cavity (inferior view; 8 to 10 weeks)

Left naris

Broken lines border area formed from medial nasal processes and primary palate

Upper lip

Medial palatine process (primary palate contribution to definitive palate)

Gingiva (gum) Palatine raphe (cleft palate site)

Lateral palatine process (secondary palate contribution to definitive palate)

Palatoglossal arch Palatopharyngeal arch

Arrow emerging from choana (posterior naris of right nasal cavity)

Uvula

Figu re 1-13

16

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

TONGUE • General Information •

1

Th e GSA bers th at su p p ly th e ep ith eliu m of th e ton gu e m irror th e develop m en t of th e ton gu e by th e p h aryn geal arch es (arch es 1, 3, an d 4) Alth ou gh th e 2n d p h aryn geal arch does n ot con tribu te to th e ton gu e, th e SVA bers (taste) th at travel to th e an terior two-th irds of th e ton gu e com e from th e ch ord a tym p an i (a bran ch of th e facial n .), wh ich join s th e lin gu al n . in th e in fratem p oral fossa, allowin g th e SVA bers to be d istribu ted to th e an terior two-th irds of th e ton gu e

•

Pharyngeal Arch

Embryonic Structure(s)

Adult Structure

Innervation

1

2 lateral lingual swellings Tuberculum im par

Anterior 2/ 3 of the tongue

GSA: Lingual branch of the m andibular division of the trigem inal n.

2

Is overgrown by the 3rd arch; does not contribute to the adult tongue Very little contributes to the hypopharyngeal em inence

Does not contribute to the adult tongue

3

Hypopharyngeal em inence

Posterior 1/ 3 of the tongue

GSA: Glossopharyngeal n. SVA: Glossopharyngeal n.

4

Hypopharyngeal em inence Epiglottic swelling Arytenoid swelling Laryngotracheal groove

Root of the tongue

GSA: Internal laryngeal branch of the vagus n. SVA: Internal laryngeal branch of the vagus n.

Muscles •

Mesod erm from th e occip ital som ites m igrates an teriorly with th e h yp oglossal n erve to give rise to th e extrin sic an d in trin sic m u scles of th e ton gu e, excep t th e p alatoglossu s, wh ich is from m esod erm from th e 4th p h aryn geal arch (an d th u s is in n ervated by th e vagu s n erve)

Floor of oral cavity and pharynx (superior view; 5 to 6 weeks) Lower lip portion of 1st pharyngeal arch Foramen cecum 2nd pharyngeal arch (diminishes) Hypobranchial eminence 3rd and 4th pharyngeal arches

Lateral lingual Future anterior swelling Tuberculum two-thirds of tongue impar 1st pharyngeal arch Future posterior one-third of tongue Epiglottis Arytenoid Oral cavity and fauces (36 weeks) swelling

Laryngotracheal groove opening

Median lingual sulcus Sulcus terminalis Lingual tonsil of posterior one-third of tongue Epiglottis

Foramen cecum Palatoglossal arch Palatine tonsil Palatopharyngeal arch

Figu re 1-14 DEVELO P MENT O F THE HEAD AND NECK

17

1

THYROID GLAND • General Information • • • • •

Begin s in th e oor of th e p h aryn x as an in vagin ation at th e foram en cecu m Descen d s in feriorly to its n al p osition alon gsid e th e laryn x May be con n ected to th e foram en cecu m by th e th yroglossal du ct (wh ich n orm ally atrop h ies an d d isap p ears; rem n an ts m ay p ersist an d form cysts) Divid ed in to 2 lateral lobes con n ected by an isth m u s, from wh ich a p yram id al lobe som etim es d evelop s Follicu lar cells are d erived from th e en d oderm ; p arafollicu lar cells are d erived from th e u ltim obran ch ial bod y

Soft palate (velum) O ropharynx

Epithelium of palatine tonsil Tongue (cut) Foramen cecum Persistent thyroglossal duct

Hyoid bone (cut)

Common carotid artery Parathyroid gland IV Ultimobranchial body Pyramidal and lateral lobes of thyroid gland

Figu re 1-15

18

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

CLINICAL CORRELATES • Pharyngeal Pouch Abnormalities

1

ECTOPIC THYROID

• • • • • •

Th yroid tissu e in an aberran t location Often th e on ly th yroid tissu e in th e affected p erson Su scep tible to th yroid d iseases like n orm al th yroid tissu e May occu r an ywh ere alon g th e m igratory p ath way of th e th yroid glan d begin n in g at th e foram en cecu m Usu ally located at th e base of th e ton gu e (lin gu al th yroid) Com m on location s in clu d e: • Lin gu al th yroid • Su blin gu al th yroid • Th yroglossal du ct rem n an t • An terior m ed iastin u m • Prelaryn geal • In tralin gu al • In tratrach eal

Lingual Intralingual Thyroglossal tract Sublingual Thyroglossal cyst Prelaryngeal Normal Intratracheal Substernal

Ectopic lingual thyroid

Figu re 1-16

DEVELO P MENT O F THE HEAD AND NECK

19

1

CLINICAL CORRELATES • Pharyngeal Arch Abnormalities PIERRE ROBIN

• • • • • • •

First rep orted as a con d ition ch aracterized by m icrogn ath ia, cleft p alate, an d glossop tosis Now in clu des an y con dition with a series of an om alies cau sed by even ts in itiated by a sin gle m alform ation In th is m icrogn ath ia, th e in ferior d en tal arch is p osterior to th e su p erior arch Th e cleftin g m ay affect th e h ard an d th e soft p alate Glossop tosis (p osterior d isp lacem en t of th e ton gu e) m ay cau se airway obstru ction or ap n ea Th e m an d ible u su ally grows fairly q u ickly du rin g ch ild h ood Mu ltip le su rgeries typ ically n eeded to correct th e cleft p alate an d to aid sp eech d evelop m en t in ch ildren

Sequence (anomalad) Intrinsic cause

Primary anomaly

Robin sequence

Secondary anomaly

Malformation

Secondary anomaly

Deformation Extrinsic cause

Secondary anomaly

Distribution

Multiple anomalies resulting from single primary anomaly or mechanical factor

Typical Robin facies with micrognathia

Tongue obstructs palatal fusion (secondary anomaly)

Hypoplastic mandible (primary anomaly)

Glossoptosis (secondary anomaly)

Airway obstruction

Sequence of anomalies initiated by hypoplastic mandible that causes glossoptosis. With palatal defect resulting from glossoptosis, airway obstruction is common.

Figu re 1-17

20

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

U-shaped palate, (secondary anomaly)

CLINICAL CORRELATES • Pharyngeal Arch Abnormalities

1

TREACHER COLLINS

• • • • •

•

A h ered itary con d ition affectin g th e h ead an d n eck Cau sed by h ap loin su f cien cy of th e gen e TCOF1 (Treach er Collin s–Fran cesch etti syn d rom e 1) wh ich is of cially kn own as Treacle Ribosom e Biogen esis Factor 1. Th e gen e p rod u ct is th e treacle p rotein , wh ich con tribu tes to d evelop m en t of cartilage an d bon e of th e face Ch ildren of an affected p aren t h ave a 50% risk of h avin g th e syn d rom e Clin ical m an ifestation s in clu de: • Down slan tin g eyes • In com p lete orbits • Notch in g of th e lower eyelid s • Hyp op lastic m an dible • Hyp op lastic zygom atic bon es (m alar h yp op lasia) • Un d erd evelop ed or m alform ed ears or “sidebu rn s,” or both , are p rom in en t Com m on associated p roblem s in clu d e: • Hearin g loss • Eatin g/ breath in g dif cu lties • Cleft p alate

Treacher Collins syndrome

Figu re 1-18

DEVELO P MENT O F THE HEAD AND NECK

21

1

CLINICAL CORRELATES • Pharyngeal Arch Abnormalities DIGEORGE SYNDROME

• • • • •

A rare con d ition cau sed by a d eletion on ch rom osom e 22, ch aracterized by a wid e array of clin ical m an ifestation s Possible exp lan ation : Prop er d evelop m en t is dep en den t on m igration of n eu ral crest cells to th e area of th e p h aryn geal p ou ch es Alth ou gh research ers d escribed th e syn drom e as abn orm al develop m en t of th e 3rd an d 4th p h aryn geal p ou ch es, d efects in volvin g th e 1st to th e 6th p ou ch es h ave been observed Th u s, th e affected in d ividu al is born with ou t a th ym u s an d p arath yroid glan d s Possible associated p roblem s in clu de: • Con gen ital h eart d efects (su ch as tetralogy of Fallot, righ t in fu n dibu lar sten osis, tru n cu s arteriosu s, aberran t left su bclavian artery, an d ven tricu lar sep tal defect) • Facial d efects (su ch as cleft p alate, m icrostom ia, d own slan tin g eyes, low-set ears, or h yp ertelorism ) • In creased vu ln erability to in fection s (du e to im p aired im m u n e system from th e loss of T cells associated with absen ce or h yp op lasia of th e th ym u s)

DiGeorge syndrome

Figu re 1-19

22

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

CLINICAL CORRELATES • Cleft Lip and Palate • • •

• •

1

Cl e f t l i p : a gap in th e u p p er lip Cl e f t p a l a t e : a gap in th e p alate Classi cation of th e develop m en tal d efect is with referen ce to th e in cisive foram en : • Prim ary cleft • Secon dary cleft • Com p lete cleft Both cleft lip an d cleft p alate often cau se d if cu lty with feed in g an d even tu ally sp eech Su rgery is th e m ost com m on form of treatm en t for both

PRIMARY

•

•

Occu rs an terior to th e in cisive foram en an d resu lts from a failu re of th e m esen ch ym e in th e lateral p alatin e p rocess (d erived from m axillary p rom in en ce) to fu se with th e in term axillary segm en t (or p rim ary p alate, wh ich is d erived from th e fu sion of th e righ t an d left m edial n asal p rom in en ces) Com m on typ es of p rim ary cleft: • Un ilateral cleft lip • Un ilateral cleft alveolu s • Un ilateral cleft lip an d p rim ary p alate • Bilateral cleft lip an d p rim ary p alate

SECONDARY

• •

Occu rs p osterior to th e in cisive foram en ; resu lts from failu re of th e lateral p alatin e p rocess (d erived from m axillary p rom in en ce) to fu se togeth er Com m on typ es of secon dary cleft: • Cleft in soft p alate • Un ilateral cleft in h ard an d soft p alate • Bilateral cleft of h ard an d soft p alate

COMPLETE

•

•

Exten ds th rou gh th e lip , th e p rim ary p alate, an d th e lateral p alatin e p rocess; resu lts from a failu re of th e lateral p alatin e p rocess (d erived from m axillary p rom in en ce) to fu se with each oth er, as well as with th e n asal sep tu m an d p rim ary p alate (d erived from in term axillary segm en t) Com m on typ es of com p lete cleft: • Un ilateral cleft lip an d cleft p alate • Bilateral cleft lip an d cleft p alate

Cleft

Cleft

Palatal obturator

Note the communication between nasal cavity and oral cavity.

Figu re 1-20 See next page. DEVELO P MENT O F THE HEAD AND NECK

23

1

CLINICAL CORRELATES • Cleft Lip and Palate

Unilateral cleft lip—partial

Partial cleft of palate

Unilateral cleft of primary palate— complete, involving lip and alveolar ridge

Complete cleft of secondary palate and unilateral cleft of primary palate

Bilateral cleft lip

Figu re 1-21

24

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

CHAPTER 2

OSTEOLOGY

Overview

26

Bones of the Skull

28

Views and Sutures

46

Major Foramina and Fissures

50

Cervical Vertebrae

56

Clinical Correlates

61

2

OVERVIEW • General Information • • • •

Most com p licated bon y stru ctu re in th e h u m an bod y Th e com p lete bon y fram ework of th e h ead ; in clu des th e m an dible 28 in dividu al bon es m ake u p th e sku ll: • 11 are p aired • 6 are sin gle Worm ian bon es, or su tu ral bon es, are irregu larly sh ap ed sm all bon es fou n d alon g su tu res th at occu r n atu rally

FUNCTIONS

• •

Most im p ortan t fu n ction : to p rotect th e brain Also p rotects th e 5 organ s of sp ecial sen se: • Olfaction • Vision • Taste • Vestibu lar fu n ction • Au ditory fu n ction

DIVISIONS

• • •

•

•

•

26

2 m ajor ways to d ivide th e bon es of th e sku ll: • Region al • Develop m en tal Re g i o n a l l y , th e sku ll is d ivid ed in to th e m an d ible (lower jaw) an d cran iu m (sku ll with ou t th e m an d ible) Cran iu m is fu rth er divided in to: • Cran ial vau lt–u p p er p ortion of th e sku ll • Cran ial base–in ferior p ortion of th e sku ll • Cran ial cavity–in terior of th e sku ll • Facial skeleton –bon es th at m ake u p th e face • Acou stic skeleton –ear ossicles D e v e l o p m e n t a l l y , th e sku ll is d ivid ed in to: • Viscerocran iu m –th e p ortion of th e sku ll related to th e d igestive an d resp iratory system s • Neu rocran iu m –th e p ortion of th e sku ll th at p rotects th e brain an d th e 5 organ s of sp ecial sen se Cran ial cavity d ivision s: • An terior cran ial fossa–con tain s th e fron tal lobe of th e brain • Mid dle cran ial fossa–con tain s th e tem p oral lobe of th e brain • Posterior cran ial fossa–con tain s th e cerebellu m Sku ll is d ep icted by observin g it from 5 views: • Norm a fron talis–th e an terior view • Norm a lateralis–th e lateral view • Norm a occip italis–th e p osterior view • Norm a basalis–th e in ferior view • Norm a verticalis–th e su p erior view

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

OVERVIEW • Articulations Bone

Single

Frontal

Paired

X

Articulates With Parietal, sphenoid, zygom atic, m axilla, ethm oid, nasal, lacrim al

Parietal

X

Frontal, parietal, tem poral, occipital, sphenoid

Tem poral

X

Parietal, occipital, sphenoid, zygom atic, m andible

Occipital

X

Parietal, tem poral, sphenoid, and atlas (C1)

Sphenoid

X

Frontal, parietal, tem poral, occipital, zygom atic, m axilla, ethm oid, palatine, vom er

Zygom atic

X

Frontal, tem poral, m axilla

Maxilla

X

Frontal, sphenoid, zygom atic, m axilla, ethm oid, palatine, vom er, nasal, lacrim al, inferior nasal concha

Ethm oid

X

Palatine

Frontal, sphenoid, m axilla, palatine, vom er, nasal, lacrim al, inferior nasal concha X

Vom er

X

Sphenoid, m axilla, ethm oid, palatine, vom er, inferior nasal concha Sphenoid, m axilla, ethm oid, palatine

Nasal

X

Frontal, m axilla, nasal

Lacrim al

X

Frontal, m axilla, ethm oid, inferior nasal concha

Inferior nasal concha

X

Maxilla, ethm oid, palatine, lacrim al

Mandible

2

X

Tem poral

Frontal bone Glabella

Coronal suture Parietal bone

Supraorbital notch (foramen) Sphenoid bone

O rbital surface

Lesser wing Nasal bone

Greater wing Temporal bone

Lacrimal bone

Ethmoid bone O rbital plate

Zygomatic bone Frontal process

Perpendicular plate

O rbital surface

Middle nasal concha

Temporal process Zygomaticofacial foramen

Inferior nasal concha Vomer

Maxilla Zygomatic process

Mandible

O rbital surface

Ramus

Infraorbital foramen Body Mental foramen

Frontal process Alveolar process

Mental tubercle

Anterior nasal spine

Mental protuberance

Figu re 2-1 O STEO LO GY

27

2

BONES OF THE SKULL • Frontal Bone Characteristics

Parts

Ossif cation

Comments

Contains the frontal paranasal sinuses Has 2 prim ary centers that ossify along the frontal suture (m etopic) in the 2nd year Helps form the foram en cecum , which allows passage of an em issary vein that connects to the superior sagittal sinus There is 1 frontal bone

Squam ous portion

Intram em branous (for all 3 parts)

The largest part of the frontal bone Form s the m ajority of the forehead Form s the supraorbital m argin and the superciliary arch The zygom atic process of the frontal bone extends from the posterior part of the supraorbital m argin Arachnoid foveae—depressions caused by arachnoid granulations that push on the dura m ater, causing bone resorption on the endocranial surface

Orbital portion

Form s the roof of the orbit and the oor of the anterior cranial fossa

Nasal portion

The trochlea of the orbit articulates with the orbital portion Articulates with the nasal bones and the frontal process of the m axilla to form the root of the nose

Parietal bone Coronal suture Pterion Frontal bone Supraorbital notch (foramen) Glabella Ethmoid bone Lacrimal bone Nasal bone Sphenoid bone Zygomatic bone Maxilla

Temporal fossa Superior temporal line Inferior temporal line Temporal bone

O ccipital bone

Frontal bone Groove for anterior meningeal vessels Foramen cecum Superior surface of orbital part Ethmoid bone Crista galli

Mandible

Cribriform plate

Frontal bone Glabella

Coronal suture Parietal bone

Supraorbital notch (foramen) O rbital surface Nasal bone Lacrimal bone

Sphenoid bone Temporal bone Ethmoid bone

Zygomatic bone Maxilla

Inferior nasal concha Vomer

Figu re 2-2

28

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

Groove for superior sagittal sinus Frontal crest

BONES OF THE SKULL • Parietal Bone Characteristics

Parts

Ossif cation

Comments

Form s the m ajority of the cranial vault Provides for the attachm ent of the tem poralis m uscle The 4 corners of the parietal are not ossi ed at birth and give rise to the fontanelles There are 2 parietal bones

The 4 corners: • Frontal–located at bregm a • Sphenoid–located at pterion • Occipital–located at lam bda • Mastoid–located at asterion

Intram em branous

Relatively square, form ing the roof and sides of the cranial vault Endocranial surface is lled with grooves m ade by branches of the m iddle m eningeal a. Sigm oid sulcus is a groove caused by the beginning of the transverse sinus, located at the m astoid angle

2

Superior view Frontal bone Coronal suture Bregma Parietal bone

Inferior view

Sagittal suture

Frontal crest Frontal bone

Parietal foramen (for emissary vein)

Groove for superior sagittal sinus

Lambda Lambdoid suture

Coronal suture Parietal bone Granular foveolae (for arachnoid granulations) Diploë Grooves for branches of middle meningeal vessels

O ccipital bone

Grooves for Parietal bone branches of middle Temporal bone meningeal vessels

Sagittal suture

Lambdoid suture O ccipital bone Coronal suture

Internal acoustic meatus

Sphenoid bone Lambdoid suture

Frontal bone Frontal sinus Ethmoid bone Crista galli Cribriform plate Perpendicular plate

Occipital bone

Nasal bone Inferior nasal concha Palatine bone

Maxilla Vomer

Figu re 2-3

O STEO LO GY

29

2

30

BONES OF THE SKULL • Occipital Bone Characteristics

Parts

Ossif cation

Comments

Form s the posterior part of the cranial vault Articulates with the atlas The squam ous and lateral portions norm ally ossify together by year 4 The basilar portion unites to this section at year 6 There is 1 occipital bone

Squam ous portion

Intram em branous

Articulates with the tem poral and parietal bones The largest portion of the occipital bone Located posterior and superior to the foram en m agnum Has the external occipital protuberance (m ore pronounced in m ales) Has the superior and the inferior nuchal lines Has grooves on the internal surface for 3 of the sinuses form ing the con uence of the sinuses (the superior sagittal and the right and left transverse sinuses) The depression superior to the transverse sinus is for the occipital lobes of the brain The depression inferior to the transverse sinus is for the cerebellum

Lateral portion

Endochondral

Articulates with the tem poral bone Is the portion lateral to the foram en m agnum Has the occipital condyles that articulate with the atlas Contains the hypoglossal canal Form s a portion of the jugular foram en

Basilar portion

Endochondral

Articulates with the petrous part of the tem poral and the sphenoid bones Is the portion im m ediately anterior to the foram en m agnum Pharyngeal tubercle is part of the basilar portion that provides attachm ent for the superior constrictor Internal surface of the basilar portion is called the clivus, and part of the brainstem lies against it

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

BONES OF THE SKULL • Occipital Bone

2

Parietal bone Frontal bone Temporal bone Ethmoid bone

O ccipital bone

Lacrimal bone Nasal bone

External occipital protuberance

Sphenoid bone Zygomatic bone Maxilla Mandible

Transverse palatine suture Zygomatic bone

Maxilla

Frontal bone

Palatine bone

Sphenoid bone

Vomer

Temporal bone Pharyngeal tubercle

Jugular fossa (jugular foramen in its depth)

Foramen magnum Parietal bone External occipital crest

Occipital bone Hypoglossal canal O ccipital condyle Condylar canal and fossa Basilar part Inferior nuchal line Superior nuchal line External occipital protuberance

Parietal bone

Lambdoid suture O ccipital bone

Temporal bone

Groove for transverse sinus

Internal acoustic meatus

External occipital protuberance

Groove for sigmoid sinus

Jugular foramen Groove for inferior petrosal sinus Hypoglossal canal Basilar part

Foramen magnum O ccipital condyle

Figu re 2-4

O STEO LO GY

31

2

BONES OF THE SKULL • Temporal Bone Characteristics

Parts

Ossif cation

Comments

The paired tem poral bones: Help form the base and the lateral walls of the skull House the auditory and vestibular apparatuses Contain m astoid air cells Each bone has 8 centers of ossi cation that give rise to the 3 m ajor centers observed before birth There are 2 tem poral bones

Squam ous part

Intram em branous Endochondral

The largest portion of the bone 3 portions to the squam ous part: • Tem poral • Zygom atic process • Glenoid fossa Tem poral portion is the thin large area on the squam ous part of the tem poral On the internal surface of the tem poral portion lies a groove for the m iddle m eningeal a. The zygom atic process extends laterally and anteriorly from the squam ous portion; it articulates with the tem poral process of the zygom atic bone to m ake the zygom atic arch Glenoid fossa is inferior and m edial to the zygom atic process; it articulates with the m andibular condyle, form ing the tem porom andibular joint

Petrous part

32

Form s the solid portion of bone The auditory and vestibular apparatuses are located within the petrous part Helps separate the tem poral and the occipital lobes of the brain; it extends anteriorly and m edially The m edial part articulates with the sphenoid bone to form the foram en lacerum Internal acoustic m eatus is observed on the m edial side of the petrous part Carotid canal lies on the inferior part of the petrous part Petrotym panic ssure lies between the petrous part of the tem poral bone and the tym panic part of the tem poral bone On the m edial portion of the petrous part lie grooves for the superior and inferior petrosal sinuses On the posterior inferior surface of the petrous part lies the jugular fossa Between the jugular fossa and the carotid canal is the tym panic canaliculus The m astoid process extends posteriorly and has large m astoid air cells

Tym panic part

Intram em branous

A plate of bone form ing the anterior, posterior, and inferior portions of the external acoustic m eatus Anterior part form s the posterior portion of the glenoid fossa

Styloid process

Endochondral

A projection from the tem poral bone The stylom astoid foram en lies posterior to this process

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

BONES OF THE SKULL • Temporal Bone

Pterion Frontal bone

Parietal bone

2

Temporal bone Squamous part Zygomatic process Articular tubercle External acoustic meatus

Sphenoid bone

Mastoid process Lambdoid suture

Ethmoid bone Lacrimal bone

Occipital bone

Nasal bone Maxilla Zygomatic bone

Temporal bone

Mandible

Squamous part Petrous part Groove for lesser petrosal n. Groove for greater petrosal n. Trigeminal impression Arcuate eminence Groove for superior petrosal sinus Groove for sigmoid sinus Zygomatic bone Frontal bone Sphenoid bone

Maxilla

Temporal bone Zygomatic process Articular tubercle Mandibular fossa Styloid process Petrotympanic fissure Carotid canal (external opening) Tympanic canaliculus External acoustic meatus Mastoid process Stylomastoid foramen Petrous part Mastoid notch (for digastric m.) O ccipital groove (for occipital a.) Jugular fossa (jugular foramen in its depth) Mastoid foramen Parietal bone

Palatine bone Vomer Foramen lacerum Groove for pharyngotympanic (auditory) tube

Occipital bone

Sigmoid sulcus

Middle meningeal grooves

Zygomatic process Groove for middle meningeal artery Groove for greater petrosal nerve

Groove for the greater petrosal nerve

Internal acoustic meatus Styloid process Temporal bone portion of the foramen lacerum

Zygomatic process Groove for the lesser petrosal nerve

Temporal bone portion of the foramen lacerum O pening to the auditory tube Styloid process

Figu re 2-5

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34

BONES OF THE SKULL • Sphenoid Bone Characteristics

Parts

Ossif cation

Comments

Form s the m ajority of the m iddle portion of the cranial base Form s the m ajority of the m iddle cranial fossa Contains the sphenoid paranasal sinus There is 1 sphenoid bone

Body

Endochondral

The center of the sphenoid Anterior portion of the body helps form part of the nasal cavity Superior part of the body, known as the sella turcica, is saddle-shaped and possesses the anterior and posterior clinoid processes Hypophyseal fossa, the deepest part of the sella turcica, houses the pituitary gland Dorsum sellae is a square-shaped part of the bone that lies posterior to the sella turcica Clivus is the portion that slopes posterior to the body Body contains the sphenoid paranasal sinuses Lateral portion of the body is covered by the cavernous sinus Optic canal is found in the body of the sphenoid

Greater wing

Endochondral and intram em branous

Extends laterally and anteriorly from the posterior portion of the body of the sphenoid Endocranial portion helps form a large part of the m iddle cranial fossa Lateral portion is the infratem poral surface Anterior portion lies in the orbit Contains 3 foram ina: • Foram en spinosum • Foram en rotundum • Foram en ovale

Lesser wing

Endochondral

Extends laterally and anteriorly from the superior portion of the sphenoid body Separated from the greater wing by the superior orbital ssure

Pterygoid process

Intram em branous

Arises from the inferior surface of the body There are 2 pterygoid processes Each has a: • Lateral pterygoid plate • Medial pterygoid plate Pterygoid ham ulus extends from the m edial pterygoid plate 2 canals are associated with the pterygoid process: • Pterygoid canal • Pharyngeal canal

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

Bo n es o f t h e s k u l l • Sphenoid Bone Sphenoid bone Greater wing Lesser wing Anterior clinoid process O ptic canal Sella turcica Sphenoidal sinus

2

Parietal bone Temporal bone

Body Medial and lateral plates of pterygoid process Frontal bone Ethmoid bone

Occipital bone

Nasal bone Inferior nasal concha Vomer Maxilla Palatine bone Frontal bone

Sphenoid bone Lesser wing Anterior clinoid process Greater wing Groove for middle meningeal vessels (frontal branches) Jugum Body Sella turcica

Ethmoid bone

Prechiasmatic groove Tuberculum sellae Hypophyseal fossa Dorsum sellae Posterior clinoid process

Occipital bone

Carotid groove (for int. carotid a.)

Clivus

Parietal bone

Temporal bone

Frontal bone

Zygomatic bone Maxilla

Sphenoid bone

Pterygoid process

Hamulus Medial plate Pterygoid fossa Lateral plate Scaphoid fossa

Palatine bone Vomer

Greater wing Foramen ovale Foramen spinosum Spine

Occipital bone

Temporal bone Sphenoid sinus within body

Superior orbital fissure

Lesser wing

Greater wing

Foramen rotundum Pterygoid canal

O rbital surface Pterygoid process Pharyngeal canal

O ptic canal

Body Lesser wing

Foramen rotundum Foramen ovale Pterygoid fossa Medial pterygoid plate

Superior orbital fissure

Greater wing Lateral pterygoid plate Pterygoid hamulus

Figu re 2-6

Os t e Ol Og y

35

2

BONES OF THE SKULL • Lacrimal Bone Characteristics

Parts

Lacrim al bone is sm all and rectangular in shape and very thin and fragile There are 2 lacrim al bones

Ossif cation

Comments

Intram em branous

Form s a sm all portion of the m edial wall of the orbit Articulates with the frontal process of the m axilla, orbital plate of the ethm oid bone, the frontal bone, and the inferior nasal concha The region that articulates with the frontal process of the m axilla form s the lacrim al fossa, the location of the lacrim al sac The inferior part of the lacrim al form s a sm all portion of the lateral wall of the nasal cavity

Ossif cation

Comments

Intram em branous

Articulates with the nasal bone of the opposite side, the nasal portion of the frontal bone, the frontal process of the m axilla, and the perpendicular plate of the ethm oid Inferior portion of the nasal bones attaches with the lateral nasal cartilages and septal cartilage

Nasal Bone Characteristics

Parts

Inferior portion form s the superior m argin of the nasal aperture Form s the bridge of the nose There are 2 nasal bones

Frontal bone

Sphenoid bone

Lacrimal bone Ethmoid bone

Frontal bone

Sphenopalatine foramen

Nasal bone Lacrimal bone

Lateral process of septal nasal cartilage

Nasal bone

Major alar cartilage

Zygomatic bone Maxilla

Alar fibrofatty tissue

*Superficially, mastoid process forms posterior boundary

Maxilla

Temporal bone

Inferior nasal concha

O rbital surface of frontal bone O rbital surface of lesser wing

O rbital plate of ethmoid bone

Superior orbital fissure

Nasal bone

O ptic canal (foramen)

Lacrimal bone Fossa for lacrimal sac

O rbital surface of greater wing of sphenoid bone

O rbital process of palatine bone

O rbital surface of zygomatic bone

O rbital surface of maxilla

Inferior orbital fissure

Figu re 2-7

36

Sphenoid bone Palatine bone

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

Bo n es o f t h e s k u l l • Zygomatic Bone (Zygoma) Characteristics

Parts

Ossif cation

Comments

Form s the m ajority of the skeleton of the cheek Provides for attachm ent of the m asseter 3 foram ina in the zygom a: • Zygom atico-orbital foram en • Zygom aticofacial foram en • Zygom aticotem poral foram en There are 2 zygom atic bones

Frontal process

Intram em branous

Articulates with the frontal bone to help form the orbit

Tem poral process

Articulates with the zygom atic process of the tem poral bone to form the zygom atic arch

Maxillary process

Articulates with the zygom atic process of the m axillary bone to help form the orbit

Sphenoid bone Greater wing Frontal bone

2

Parietal bone Temporal bone

Supraorbital notch (foramen) Glabella Ethmoid bone O rbital plate Lacrimal bone Fossa for lacrimal sac Nasal bone

O ccipital bone

Maxilla Maxilla Incisive fossa

Zygomatic bone Zygomaticofacial foramen Temporal process Zygomatic arch

Palatine process Median palatine suture Zygomatic process Maxillary process Zygomatic bone

Mandible

Frontal bone Palatine bone Vomer Sphenoid bone Temporal bone

Occipital bone

Frontal bone Nasal bone Lacrimal bone Zygomatic bone Frontal process

Sphenoid bone Temporal bone Ethmoid bone

O rbital surface Temporal process

Inferior nasal concha

Zygomaticofacial foramen Vomer

Maxillary process

Mandible

Maxilla

Figu re 2-8 Os t e Ol Og y

37

2

38

BONES OF THE SKULL • Ethmoid Bone Characteristics

Parts

Ossif cation

Comments

A porous bone that form s the m ajor portion of the m iddle part of the face between the orbits Helps form the orbit, nasal cavity, nasal septum , and anterior cranial fossa There is 1 ethm oid bone

Perpendicular plate

Endochondral

A at plate that descends from the cribriform plate to form part of the nasal septum Articulates with the vom er inferiorly

Cribriform plate

A horizontal bone that form s the superior surface of the ethm oid Contains num erous foram ina for the olfactory n. Crista galli is a vertical plate that extends superiorly from the cribriform plate, providing attachm ent for the falx cerebri of the m eninges Associated with a sm all foram en cecum

Ethm oid labyrinth

The largest part of the ethm oid bone Descends inferiorly from the cribriform plate Ethm oid paranasal sinuses are located within the ethm oid labyrinth Ethm oid labyrinth form s 2 m ajor structures within the nasal cavity: • Superior nasal concha • Middle nasal concha Ethm oid bulla is the large elevation of bone located by the m iddle ethm oid paranasal sinuses Uncinate process is a curved piece of bone Between the uncinate process and the ethm oid bulla is the hiatus sem ilunaris

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

BONES OF THE SKULL • Ethmoid Bone

2

Sphenoid bone Frontal bone Ethmoid bone O rbital plate

Nasal bone

Perpendicular plate

Lacrimal bone

Middle nasal concha

Zygomatic bone

Inferior nasal concha Maxilla

Vomer

Ethmoidal bulla O pening of middle ethmoidal cells Superior nasal concha (cut away) Middle nasal concha (cut away)

O penings of posterior ethmoidal cells

Semilunar hiatus with opening

O penings into maxillary sinus

Uncinate process Inferior nasal concha (cut aw ay)

Ethmoidal process of inferior nasal concha

O pening of nasolacrimal canal

Frontal bone

Lacrimal bone Middle nasal concha Uncinate process Cribriform plate Superior nasal concha Highest nasal concha

Nasal bone

Ethmoid bone

Sphenoethmoidal recess

Inferior nasal concha Sphenoid bone Maxilla

Palatine bone

Figu re 2-9

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BONES OF THE SKULL • Vomer Characteristics

Parts

Shaped like a plow Form s the posterior inferior part of the nasal septum There is 1 vom er bone

Ossif cation

Comments

Intram em branous

Articulates with the perpendicular plate of the ethm oid, m axilla, palatine, and sphenoid bones and septal cartilage Posterior border does not articulate with any other bone

Parietal bone

Temporal bone

Frontal bone Sphenoid bone Ethmoid bone Crista galli Cribriform plate Perpendicular plate

O ccipital bone

Nasal bone Inferior nasal concha Maxilla Palatine bone Vomer

Crista galli Frontal bone

Cribriform plate

Ethmoid bone

Perpendicular plate Nasal bone Vomer Sphenoid bone

Septal cartilage Vomerine groove for nasopalatine n. and vessels

Palatine bone Maxilla

Figu re 2-10

40

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

BONES OF THE SKULL • Inferior Nasal Concha Characteristics

Parts

Is described as a curved bone that form s part of the lateral wall of the nasal cavity There are 2 inferior nasal conchae

Ossif cation

Comments

Endochondral

Lies within a curve in the lateral wall of the nasal cavity Articulates with the m axilla and perpendicular plate of the palatine, lacrim al, and ethm oid bones

2

Palatine Bone Characteristics

Parts

Ossif cation

Comments

Form s part of the nasal cavity and the hard palate Is L-shaped There are 2 palatine bones

Perpendicular plate

Intram em branous

Is in the shape of a vertical rectangle On the superior border is a notch that articulates with the sphenoid bone, form ing the sphenopalatine foram en A sm all orbital process helps form part of the orbit Form s part of the wall of the pterygopalatine fossa and the lateral wall of the nasal cavity Lateral wall articulates with the m axilla to form the palatine canal

Horizontal plate

Form s the posterior portion of the hard palate Superior to the horizontal plate is the nasal cavity On the m edial part, form ed by both of the horizontal plates, is the posterior nasal spine Greater palatine foram en is on this plate

Pyram idal process

Extends posteriorly and inferiorly from the junction of the perpendicular and horizontal plates of the palatine Lesser palatine foram ina are located here

Sphenopalatine foramen

Inferior nasal concha Sphenoid bone Maxilla Perpendicular plate Horizontal plate

Palatine plate

Figu re 2-11 O STEO LO GY

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2

BONES OF THE SKULL • Maxilla Characteristics

Parts

Ossif cation

Comments

Form s the m ajority of the skeleton of the face and the upper jaw Contains the m axillary paranasal sinus Articulates with the opposite m axilla and the frontal, sphenoid, nasal, vom er, and ethm oid bones; inferior nasal concha; palatine, lacrim al, and zygom atic bones; and the septal and nasal cartilages There are 2 m axilla bones (m axillae)

Body

Intram em branous

Major part of the bone Shaped like a pyram id Contains the m axillary paranasal sinus Gives rise to 4 different regions: • Orbit • Nasal cavity • Infratem poral fossa • Face Infraorbital canal and foram en pass from the orbit region to the face region

Frontal process

Extends superiorly to articulate with the nasal, frontal, ethm oid, and lacrim al bones Form s the posterior boundary of the lacrim al fossa

Zygom atic process

Extends laterally to articulate with the m axillary process of the zygom atic bone

Palatine process

Extends m edially to form the m ajority of the hard palate Articulates with the palatine process of the opposite side and the horizontal plate of the palatine bone Incisive foram en is located in the anterior portion

Alveolar process

The part of the m axilla that supports all of the m axillary teeth Extends inferiorly from the m axilla Each m axilla contains 5 prim ary and 8 perm anent teeth Alveolar bone is resorbed when a tooth is lost

Central incisor Lateral incisor Incisive fossa

Canine 1st premolar 2nd premolar

Palatine process of maxilla

1st molar

2nd molar 3rd molar Horizontal plate of palatine bone Greater and lesser palatine foramina Upper permanent teeth

Figu re 2-12

42

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

BONES OF THE SKULL • Maxilla

Parietal bone

2

Temporal bone

Sphenoid bone

Frontal bone O ccipital bone Ethmoid bone Nasal bone Inferior nasal concha Maxilla Vomer

Palatine bone

Frontal bone Parietal bone

Nasal bone

Sphenoid bone Temporal bone

Lacrimal bone

Ethmoid bone

Zygomatic bone

Inferior nasal concha Vomer Maxilla

Mandible

Zygomatic process O rbital surface Infraorbital foramen Frontal process Alveolar process Anterior nasal spine

Figu re 2-13

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44

BONES OF THE SKULL • Mandible Characteristics

Parts

Ossif cation

Comments

Form s the lower jaw Described as horseshoe-shaped All m uscles of m astication attach to the m andible There is 1 m andible

Body

Intram em branous (ossi es around Meckel’s cartilage)

Mental foram en lies on the anterior part of the lateral surface of the body External oblique line is observed on the lateral side of the m andible On the m edial side of the body lies the m ylohyoid line Mylohyoid line helps divide a sublingual from a subm andibular fossa Posterior border of the m ylohyoid line provides for attachm ent of the pterygom andibular raphe At the m idline on the m edial side are the superior and inferior genial tubercles, as well as the digastric fossa A sm all lingual foram en (or foram ina) is located by the genial tubercles

Ram us

Meets the body of the m andible at the angle of the m andible on each side Masseter m . attaches to the lateral side Medial pterygoid m . and sphenom andibular lig. attach to the m edial aspect Mandibular foram en is located on the m edial aspect of the ram us Superior part divides into a coronoid process anteriorly and a condylar process posteriorly, separated by a m andibular notch

Coronoid process

The anteriorm ost superior extension of each ram us Tem poralis m . attaches to the coronoid process

Condylar process

Articulates with the tem poral bone in the tem porom andibular joint Has a neck that form s a condyle superiorly Lateral pterygoid m uscle attaches to pterygoid fovea on the neck

Alveolar process

Extends superiorly from the body Created by a thick buccal and a thin lingual plate of bone The part of the m andible that supports the m andibular teeth Each side of the m andible contains 5 prim ary and 8 perm anent teeth Alveolar bone is resorbed when a tooth is lost

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

BONES OF THE SKULL • Mandible

2

Head Pterygoid fovea Neck Mandibular notch Lingula Mandibular foramen

Condylar process Coronoid process

Mylohyoid groove O blique line Submandibular fossa Mylohyoid line Sublingual fossa Interalveolar septa

Ramus Alveolar part (crest) Mental foramen Mental protuberance Mental tubercle Base of mandible

Angle

Body

Coronoid process Head Neck

Mandible of adult: anterolateral superior view

Condylar process Lingula Mandibular foramen Mylohyoid groove

Mandibular notch Pterygoid fovea Mylohyoid line

Ramus Lingual tuberosity

Mandible of adult: left posterior view

Angle Submandibular fossa y d Bo Sublingual fossa Lingual foramen Digastric fossa Mental spines Condyle Mandibular foramen Lingula

Coronoid process

3rd molar

Buccal shelf

2nd molar 1st molar 2nd premolar 1st premolar Mental foramen

Canine Lateral incisor Central incisor

Figu re 2-14

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VIEWS AND SUTURES • Norma Frontalis Bones

Major Sutures

Frontal Nasal Maxilla Zygom atic Mandible Vom er Ethm oid Sphenoid Palatine Lacrim al

Frontonasal Frontozygom atic Zygom aticom axillary Metopic

Frontal bone

Frontonasal suture

Nasal bone Lacrimal bone

Frontozygomatic suture

Zygomatic bone

Zygomaticomaxillary suture Mandible

Maxilla

Figu re 2-15 Norma Occipitalis Bones

Major Sutures

Parietal Occipital Tem poral

Sagittal Lam bdoid

Sagittal suture Parietal bone

Lambda Lambdoid suture O ccipital bone

Temporal bone

Figu re 2-16

46

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

VIEWS AND SUTURES • Norma Verticalis Bones

Major Sutures

Frontal Parietal Occipital

Coronal Sagittal Lam bdoid

2

Superior view Frontal bone

Coronal suture Bregma Parietal bone Sagittal suture

Lambda Lambdoid suture O ccipital bone

Superior view

Frontal bone Anterior fontanelle

Coronal suture

Parietal bone

Sagittal suture

Posterior fontanelle

Lambdoid suture

O ccipital bone

Figu re 2-17 O STEO LO GY

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2

VIEWS AND SUTURES • Norma Lateralis Bones

Major Sutures

Frontal Parietal Tem poral Zygom atic Maxilla Nasal Occipital Greater wing of the sphenoid Mandible

Coronal Squam osal Sphenofrontal Sphenoparietal Lam bdoid Occipitom astoid Tem porozygom atic Frontozygom atic

Sphenofrontal suture Sphenoid bone Greater wing Frontal bone Frontozygomatic suture

Sphenoparietal suture

Parietal bone

Temporal bone

Squamosal suture

Squamous part Zygomatic process Articular tubercle

Coronal suture

Groove for posterior deep temporal artery External acoustic meatus Mastoid process

Lacrimal bone Lambdoid suture Nasal bone

Occipital bone

Maxilla O ccipitomastoid suture

Mandible Zygomatic bone Temporozygomatic suture

Figu re 2-18

48

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

VIEWS AND SUTURES • Norma Basalis Bones

Major Sutures

Maxilla (Palatine process) Occipital Tem poral Palatine (Horizontal plate) Vom er Zygom atic Sphenoid: Greater wing Medial pterygoid plate Lateral pterygoid plate

Interm axillary Transverse palatine Petro-occipital Spheno-occipital Petrosquam ous Petrotym panic Squam otym panic

2

Intermaxillary suture

Maxilla Palatine process

Transverse palatine suture

Sphenoid bone

Palatine bone Horizontal plate

Temporal bone

Vomer

Foramen lacerum

Occipital bone

Figu re 2-19

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2

MAJOR FORAMINA AND FISSURES • Anterior View Foramen/Fissure/Opening

Located in or Formed by

Vessels Passing Through

Nerves Passing Through

Supraorbital foram en

Frontal

Supraorbital a. & v.

Supraorbital n.

Optic canal

Sphenoid

Ophthalm ic a.

Optic n.

Superior orbital ssure

Between the: • Greater wing of the sphenoid and • Lesser wing of the sphenoid

Superior ophthalm ic v. Inferior ophthalm ic v.

Nasociliary, frontal, and lacrim al branches of the ophthalm ic division of the trigem inal n. Oculom otor n. Trochlear n. Abducens n.

Inferior orbital ssure

Between the: • Greater wing of the sphenoid and • Maxilla and orbital portion of the palatine bones

Infraorbital a. & v. Inferior ophthalm ic v. (portion com m unicating to pterygoid plexus)

Infraorbital n. Zygom atic n.

Anterior ethm oid foram en

Between the: • Frontal and • Ethm oid

Anterior ethm oid a. & v.

Anterior ethm oid n.

Posterior ethm oid a. & v.

Posterior ethm oid n.

Zygom aticofacial foram en

Zygom atic

Zygom aticotem poral a. & v.

Zygom aticofacial n.

Infraorbital foram en

Maxilla

Infraorbital a. & v.

Infraorbital n.

Mental foram en

Mandible

Mental a. & v.

Mental n.

Posterior ethm oid foram en

Supraorbital notch (foramen)

Posterior and anterior ethmoidal foramina

Superior orbital fissure

O ptic canal

Zygomaticofacial foramen Inferior orbital fissure Maxilla Body Mental foramen

Infraorbital foramen

Figu re 2-20

50

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

MAJOR FORAMINA AND FISSURES • Mandible Foramen/Fissure

Located in or Formed by

Vessels Passing Through

Nerves Passing Through

Mandibular foram en

Mandible

Inferior alveolar a. & v.

Inferior alveolar n.

Mental foram en

Mental a. & v.

Mental n.

Lingual foram en

Arterial branch from the anastom osis of the sublingual aa.

Branches of the m ylohyoid n. have been observed to enter the foram en occasionally

2

Mandibular foramen

Ramus

Mental foramen

Angle

Body

Mandible of adult: anterolateral superior view

Mandibular foramen

Ramus

Angle y Bo d Lingual foramen

Mandible of adult: left posterior view

Figu re 2-21 Superior View of the Cranial Base Foramen/Fissure

Located in or Formed by

Cribriform plate foram ina

Ethm oid

Foram en cecum

Between the: • Frontal and • Ethm oid

Vessels Passing Through

Nerves Passing Through Olfactory nn. from the olfactory bulb

Em issary v. from nasal cavity to the superior sagittal sinus

Anterior ethm oid foram en

Anterior ethm oid a. & v.

Anterior ethm oid n.

Posterior ethm oid foram en

Posterior ethm oid a. & v.

Posterior ethm oid n. Continued on next page

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2

MAJOR FORAMINA AND FISSURES • Superior View of the Cranial Base Foramen/Fissure

Located in or Formed by

Vessels Passing Through

Nerves Passing Through

Optic canal

Sphenoid

Ophthalm ic a.

Optic n.

Superior orbital ssure

Between the: • Greater wing of the sphenoid and • Lesser wing of the sphenoid

Superior ophthalm ic v. Inferior ophthalm ic v.

Nasociliary, frontal, and lacrim al branches of the ophthalm ic division of the trigem inal n. Oculom otor n. Trochlear n. Abducens n.

Foram en rotundum

Sphenoid

Maxillary division of the trigem inal n.

Foram en ovale

Accessory m eningeal a. Em issary v.

Mandibular division of the trigem inal n. Lesser petrosal n.

Foram en spinosum

Middle m eningeal a. & v.

Meningeal branch of the m andibular division of the trigem inal n.

Sphenoid foram en

Em issary v.

Foram en lacerum

Articulation of the: • Sphenoid (greater wing and body) • Tem poral (petrous portion) • Occipital (basilar portion) bones

Carotid canal

Tem poral (petrous portion)

*Nothing passes through it–but within the foram en, the greater petrosal n. joins the deep petrosal n. Filled with brocartilage during life (although the anterior wall of the foram en has an opening for the pterygoid canal and the posterior wall has an opening for the carotid canal) Internal carotid a.

Hiatus for the lesser petrosal n.

Lesser petrosal n.

Hiatus for the greater petrosal n.

Greater petrosal n.

Internal acoustic m eatus

Labyrinthine a.

Opening of the vestibular aqueduct

*(No nerves or vessels–transm its the Endolym phatic duct)

Mastoid foram en

Tem poral (m astoid portion)

Mastoid em issary v Posterior m eningeal a. from the occipital a.

Jugular foram en

Tem poral (petrous portion) and occipital

Inferior petrosal sinus Sigm oid sinus Posterior m eningeal a.

Condylar canal

Occipital

Em issary v. Meningeal branch of ascending pharyngeal a.

Hypoglossal canal Foram en m agnum

52

Internal carotid n. plexus (sym pathetics)

Facial n. Vestibulocochlear n.,

Glossopharyngeal n. Vagus n. Accessory n.

Hypoglossal n. Vertebral aa. Venous plexus

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

Medulla oblongata Accessory n. (Spinal roots)

MAJOR FORAMINA AND FISSURES • Superior View of the Cranial Base

2

Foramen cecum Nasal slit Anterior ethmoidal foramen Foramina of cribriform plate Posterior ethmoidal foramen

O ptic canal Superior orbital fissure Foramen rotundum Foramen ovale

Foramen spinosum Sphenoid emissary foramen (Vesalius) (inconstant) Foramen lacerum Carotid canal for

carotid artery {Internal Internal carotid nerve plexus

Hiatus for

Lesser petrosal nerve

Hiatus for

Greater petrosal nerve

Internal acoustic meatus External opening of vestibular aqueduct Mastoid foramen (inconstant) Jugular foramen Condylar canal (inconstant) Hypoglossal canal Foramen magnum

Figu re 2-22

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2

MAJOR FORAMINA AND FISSURES • Inferior View of the Cranial Base Foramen/Fissure

Located in or Formed by

Vessels Passing Through

Nerves Passing Through

Incisive foram en

Maxilla (palatine process)

Sphenopalatine a. & v.

Nasopalatine n.

Greater palatine foram en

Palatine

Greater palatine a. & v.

Greater palatine n.

Lesser palatine foram ina

Palatine

Lesser palatine a. & v.

Lesser palatine n.

Foram en ovale

Sphenoid

Accessory m eningeal a. Em issary v.

Mandibular division of the trigem inal n. Lesser petrosal n.

Foram en spinosum

Sphenoid

Middle m eningeal a. & v.

Meningeal branch of the m andibular division of the trigem inal n.

Foram en lacerum

Articulation of the: • Sphenoid (greater wing and body) • Tem poral (petrous portion) • Occipital (basilar portion) bones

Opening for auditory tube

Tem poral and sphenoid

*(No nerves or vessels–transm its the cartilaginous portion of the auditory tube)

Carotid canal

Tem poral (petrous portion)

Internal carotid a.

Tym panic canaliculus

Tem poral

Jugular foram en

Tem poral (petrous portion) and occipital

Mastoid canaliculus

Tem poral (within the jugular fossa)

Petrotym panic ssure

Tem poral

Internal carotid n. plexus (sym pathetics) Tym panic branch of the glossopharyngeal n.

Inferior petrosal sinus Sigm oid sinus Posterior m eningeal a.

Glossopharyngeal n. Vagus n. Accessory n. Auricular branch of the vagus n.

Anterior tym panic a.

Chorda tym pani n.

Stylom astoid foram en

Stylom astoid a.

Facial n.

Mastoid foram en

Mastoid em issary v. Posterior m eningeal a. from the occipital a.

Hypoglossal canal

54

*Nothing passes through it—but within the foram en, the greater petrosal n. joins the deep petrosal n. Filled with brocartilage during life (although the anterior wall of the foram en has an opening for the pterygoid canal and the posterior wall has an opening for the carotid canal)

Occipital

Hypoglossal n.

Condylar canal

Em issary v. Meningeal branch of ascending pharyngeal a.

Foram en m agnum

Vertebral aa. Venous plexus

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

Medulla oblongata Accessory n. (Spinal roots)

MAJOR FORAMINA AND FISSURES • Inferior View of the Cranial Base

2

Incisive fossa Greater palatine foramen Lesser palatine foramen Foramen lacerum Foramen ovale

Foramen spinosum

Carotid canal Petrotympanic fissure Tympanic canaliculus Mastoid canaliculus Stylomastoid foramen

Jugular fossa

Mastoid foramen Hypoglossal canal

Foramen magnum

Figu re 2-23

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2

CERVICAL VERTEBRAE • General Information • • •

7 cervical vertebrae (C1 to C7) Th e sm allest vertebrae in th e bod y Th e 1st, 2n d , an d 7th cervical vertebrae are u n iq u e in th eir sh ap e; th e 3rd to th e 6th are sim ilarly sh ap ed Vertebra

Characteristics

Atlas (C1)

Supports the skull No body No spinous process Has an anterior arch and a posterior arch Large lateral m asses support the occipital condyles of the skull superiorly and articulate with the axis inferiorly Foram en transversarium located in the large transverse process

Axis (C2)

Dens (odontoid process) located on the body’s superior surface Foram en transversarium located in the sm all transverse process Spinous process is large and bi d

C3–C6

Cervical vertebrae have sm all bodies Pedicles project posteriorly and laterally Spinous processes are short and bi d Vertebral foram ina are large and triangular Each foram en transversarium is located in the transverse process Vertebral a. enters the foram en transversarium at C6 Transverse processes each have an anterior and a posterior portion called the anterior tubercle and the posterior tubercle

C7

Also called “vertebra prom inens” because its long spinous process m akes it visible under the skin Long spinous process is not bi d Foram en transversarium located in the large transverse process Norm ally, the vertebral vessels do not pass through the foram en transversarium of C7 (the veins pass through m ore frequently than the arteries) Posterior tubercle

Posterior arch

Superior articular facet for atlas

Vertebral foramen

Transverse process

Transverse foramen Inferior articular surface of lateral mass for axis

Dens

Interarticular part

Anterior arch

Articular facet for dens Anterior tubercle

Inferior articular process

Atlas (C1): inferior view

Superior articular surface for occipital condyle Posterior articular facet (for transverse ligament of atlas) Upper cervical vertebrae, assembled: posterosuperior view

Spinous process Axis (C2): posterosuperior view

Dens Atlas (C1)

Axis (C2) C3 C4

Figu re 2-24

56

Posterior articular facet (for transverse ligament of atlas) Transverse process

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

CERVICAL VERTEBRAE • General Information Anterior tubercle

Body

Transverse process

Body

Groove for spinal nerve

Posterior tubercle

2

Anterior tubercle Posterior tubercle

Transverse foramen Pedicle Superior articular facet Inferior articular process

Lamina

Vertebral foramen

Lamina

Spinous process 4th cervical vertebra: superior view 7th cervical vertebra: superior view

Dens

Cervical curvature C2 Intervertebral foramina for spinal nerves

Spinous processes

C3

C4

C5

C6 Zygapophyseal joints

C7

Intervertebral joint (symphysis) (disc rem oved) Costal facets (for 1st rib)

T1

2nd cervical to 1st thoracic vertebrae: right lateral view

Figu re 2-25

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2

CERVICAL VERTEBRAE • Major External Ligaments Ligament(s)/Membrane(s)

Comments

Anterior longitudinal ligam ent

Attached to the anterior surfaces of the vertebral bodies, extending from the axis to the sacrum Superior to the axis, it is continuous with the anterior atlantoaxial lig.

Ligam enta ava

Attached to the anterior surfaces of the lam ina within the vertebral foram en, extending from the axis to the 1st sacral vertebra

Ligam entum nuchae

Extends from the external occipital protuberance and m edian nuchal line to the spinous process of C7 Between these attachm ents, it attaches to the posterior tubercle of the atlas and the spinous processes of the axis and C3–C6

Anterior atlanto-occipital m em brane

Extends from the anterior m argin of the foram en m agnum superiorly and the anterior arch of the atlas inferiorly Continuous with the capsule of the atlanto-occipital joint laterally

Posterior atlanto-occipital m em brane

Extends from the posterior m argin of the foram en m agnum superiorly to the posterior arch of the atlas inferiorly Allows passage of the vertebral a. on the lateral m argin

Anterior view Basilar part of occipital bone Anterior atlanto-occipital membrane Capsule of atlanto-occipital joint Posterior atlanto-occipital membrane

Atlas (C1)

Lateral atlantoaxial joint (opened up) Anterior longitudinal ligament

Capsule of lateral atlantoaxial joint

Posterior view

Axis (C2)

Posterior atlanto-occipital membrane

Skull

Capsule of zygapophyseal joint (C3–4)

Capsule of atlanto-occipital joint Transverse process of atlas (C1) Capsule of lateral atlantoaxial joint Axis (C2)

Anterior atlanto-occipital membrane Capsule of atlanto-occipital joint

Ligamenta flava Vertebral Suboccipital nerve (dorsal artery ramus of C1 spinal nerve) Atlas (C1)

Posterior atlanto-occipital membrane Ligamenta flava

Body of axis (C2) Ligamentum nuchae

Intervertebral discs (C2–3 and C3–4)

Zygapophyseal joints (C4–5 and C5–6) Anterior tubercle of C6 vertebra (carotid tubercle) Spinous process of C7 vertebra (vertebra prominens)

Vertebral artery T1 vertebra

Right lateral view

Figu re 2-26

58

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

CERVICAL VERTEBRAE • Major Internal Ligaments Ligament(s)/Membrane(s)

2

Comments DEEP LIGAMENTS/MEMBRANES

Alar ligam ent

Extends from the dens to the m edial portions of the occipital condyles Also known as “check ligam ents” because they lim it skull rotation

Apical ligam ent of the dens

Extends from the dens to the anterior m argin of the foram en m agnum

Cruciate ligam ent Superior longitudinal band

Part of the transverse lig. of the atlas, which extends superiorly to attach to the basilar portion of the occipital bone

Transverse ligam ent of atlas

Thick ligam ent extending from one side of the internal surface of the anterior arch of the atlas to the other side, holding the dens in contact with the anterior arch

Inferior longitudinal band

Part of the transverse lig. of the atlas that extends inferiorly, attaching to the posterior body of the axis

SUPERFICIAL LIGAMENTS/MEMBRANES Tectorial m em brane

Extends from the basilar portion of the occipital bone, where it blends with the dura m ater, to the posterior portion of the body of the axis Continuous inferiorly with the posterior longitudinal lig.

Posterior longitudinal ligam ent

Attached to the posterior surfaces of the bodies of the vertebrae extending within the vertebral foram en from the axis to the sacrum Superior to the axis, it is continuous with the tectorial m em brane

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CERVICAL VERTEBRAE • Major Internal Ligaments Clivus of occipital bone

Tectorial membrane Capsule of atlantooccipital joint

Deeper (accessory) part of tectorial membrane

Atlas (C1)

Posterior longitudinal ligament

Capsule of lateral atlantoaxial joint Axis (C2) Capsule of zygapophyseal joint (C2-3) Upper part of vertebral canal with spinous processes and parts of vertebral arches removed to expose ligaments of posterior vertebral bodies: posterior view Alar ligaments

Atlas (C1) Superior longitudinal band Cruciate ligament Transverse ligament of atlas Axis (C2)

Inferior longitudinal band Deeper (accessory) part of tectorial membrane

Principal part of tectorial membrane removed to expose deeper ligaments: posterior view

Apical ligament of dens Alar ligament Posterior articular facet of dens (for transverse ligament of atlas)

Atlas (C1)

Axis (C2)

Cruciate ligament removed to show deepest ligaments: posterior view Alar ligament

Synovial cavities

Dens Transverse ligament of atlas Median atlantoaxial joint: superior view

Figu re 2-27

60

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

CLINICAL CORRELATES • Zygomatic Fractures • • • • • •

2

Zygom a is th e 2n d m ost com m on ly fractu red bon e of th e face after th e n asal bon e Su scep tible to fractu re, u su ally d u e to a facial blow from a st or trau m a in cu rred in a m otor veh icle crash In fractu res du e to blows from a st, th e left zygom atic bon e is m ore freq u en tly fractu red th an th e righ t Most fractu res are u n ilateral May disp lace th e zygom atic bon e alon g th e su tu res, or m ore severe disp lacem en t in a p osterior, m edial, or in ferior d irection m ay occu r Com m on clin ical m an ifestation s in clu d e: • Pain • Swellin g • Dip lop ia • Paresth esia • Dep ressed ch eek

Lowered lateral portion of palpebral fissure

Subconjunctival hemorrhage

Flattened cheekbone

Lateral canthal lig. displaced downward with dislocation of zygomatic bone

Ecchymosis

Dislocated zygomatic bone

Displaced segment

Fracture at zygomaticomaxillary suture line

Figu re 2-28 O STEO LO GY

61

2

CLINICAL CORRELATES • Le Fort Fractures •

Trau m a to • Le Fort • Le Fort • Le Fort

th e m id face u su ally follows 1 of 3 p attern s of fractu re: I II III

LE FORT I

• •

Horizon tal, exten d in g from th e lateral m argin of th e p iriform ap ertu re to th e p terygoid p lates ju st su p erior to th e ap ices of th e teeth Gives rise to a d etach ed u p p er jaw relative to th e rest of th e m axillofacial skeleton

LE FORT II

•

Pyram id al in ou tlin e, exten d in g from th e brid ge of th e n ose at or in ferior to th e n asofron tal su tu re or m axilla, th en in feriorly an d laterally th rou gh th e in ferior orbital oor n ear th e in fraorbital foram en , th rou gh th e an terior wall of th e m axillary sin u s, to th e p terygoid p lates

LE FORT III

•

• •

Tran sverse, exten d in g from th e n asofron tal su tu re an d fron tom axillary su tu re an d p assin g p osteriorly alon g th e m edial wall of th e orbit th rou gh th e n asolacrim al groove an d eth m oid , th en followin g th e in ferior orbital ssu re to th e lateral wall of th e orbit, an d exten d in g th rou gh th e fron tozygom atic su tu re With in th e n ose, th e fractu re exten d s alon g th e p erp en d icu lar p late, vom er, an d p terygoid p lates In a Le Fort III fractu re, th e facial skeleton is detach ed from th e base of th e sku ll Le Fort I fracture: horizontal detachment of maxilla at level of nasal floor Anterior view

Le Fort II fracture: fracture through maxillae, antra, nasal bones, and infraorbital rims Anterior view

Posterior view

Fracture line

Posterior view

Fracture line Anterior view

Posterior view

Free-floating maxillary segment

Free-floating maxillary segment

Le Fort III fracture: fracture through zygomatic bones and orbits, separating facial bones from cranial vault

Fracture line

Fracture in cranial vault

Edema

Free-floating maxilla

Facial asymmetry, especially elongation

CSF leakage

Ecchymosis over midface Hematoma and massive edema may occlude nasal airway, necessitating tracheostomy

Malocclusion Craniofacial dysjunction in Le Fort III fracture distorts facial symmetry

Figu re 2-29

62

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

CLINICAL CORRELATES • Mandible Fractures • • •

•

2

Man dible is a freq u en tly fractu red bon e Fractu res resu lt from blow from a st or trau m a in cu rred in m otor veh icle crash Com m on sites (in d ecreasin g ord er of freq u en cy): • Con d yle • An gle • Bod y • Sym p h ysis • Ram u s • Alveolu s • Coron oid p rocess With d ou ble m an d ibu lar fractu res, th e 2n d u su ally is con tralateral

Anatomy of mandible predisposes it to multiple fractures 3rd molar area may be weakened by partially erupted molar

Distorted soft tissue contours

Subcondylar area can fracture from blow to chin

Condyle

Ecchymosis or laceration of chin (in children)

Malocclusion

Displaced segment

Cuspid area is weakened by long tooth

Step defects

Bleeding

Mylohyoid m.

Displaced segment Step defect

Geniohyoid m. Bleeding caused by fracture is trapped by fanlike attachment of mylohyoid musculature to mandible, and presents clinically as ecchymosis in floor of mouth

Figu re 2-30 O STEO LO GY

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2

CLINICAL CORRELATES • Cervical Fractures •

2 com m on typ es of cervical fractu res: • Jefferson fractu re (at C1) • Han gm an ’s fractu re (at C2)

JEFFERSON FRACTURE

• • • • •

In volves th e atlas Resu lts from sku ll com p ression d u e to axial load in g, cau sin g th e atlas to bu rst Most p atien ts are n eu rologically in tact bu t h ave severe n eck p ain Vertebral artery can be com p rom ised Classi ed as stable or u n stable accordin g to wh eth er th e tran sverse ligam en t of th e atlas is in tact: • Stable fractures can be treated with an orth osis su ch as a soft collar • Unstable fractures are m ore p roblem atic; m ay req u ire cran ial traction ap p lied with u se of a h alo, as well as cervical fu sion

HANGMAN’S FRACTURE

• • •

Occu rs th rou gh th e vertebral arch of th e axis between th e su p erior an d th e in ferior articu latin g facets A trau m atic sp on dylolisth esis often is cau sed by exten sion of th e n eck with axial com p ression , com m on in car accid en ts Th e h istorical h an gm an ’s fractu re is cau sed by exten sion an d distraction of th e n eck

ODONTOID FRACTURE

• •

In volves th e axis Classi cation in to 3 typ es: • Typ e I–fractu re at th e tip of th e od on toid p rocess • Typ e II–fractu re alon g th e base or th e n eck of th e od on toid • Typ e III–fractu re th at p asses th rou gh th e bod y of th e axis

Fracture of dens

Type I. Fracture of tip Type II. Fracture of base or neck Type III. Fracture extends into body of axis

Superior articular facet

Jefferson fracture of atlas (C1). Each arch may be broken in one or more places Inferior articular facet

Fracture of anterior arch

Superior articular facet

Superior articular facet

Inferior articular process

Hangman′s fracture Fracture through neural arch of axis (C2), between superior and inferior articular facets

Fracture of posterior arch

Superior articular facet

Inferior articular facet

Figu re 2-31

64

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

CHAPTER 3

BASIC NEUROANATOMY AND CRANIAL NERVES

Nervous Tissue

66

Central Nervous System

68

Peripheral Nervous System

72

Cranial Nerves

74

Clinical Correlates

104

3

NERVOUS TISSUE • General Information •

Nervou s tissu e is d ivid ed in to 2 m ajor cell typ es: • Neu ron s • Neu roglial cells (th e n eu roglia)

NEURONS

• • • •

•

•

•

Th e stru ctu ral an d fu n ction al cells in th e n ervou s system Resp on d to a n ervou s stim u lu s an d con du ct th e stim u lu s alon g th e len gth of th e cell A n eu ron ’s cell body is called th e p erikaryon , or som a Cell bod ies are classi ed by th eir location : • Gan glion : a collection of n erve cell bod ies located in th e p erip h eral n ervou s system (e.g., d orsal root gan glion , trigem in al gan glion , ciliary gan glion ) • Nu cleu s: a collection of n erve cell bod ies located in th e cen tral n ervou s system (e.g., Ed in ger-Westp h al n u cleu s, ch ief sen sory n u cleu s of cran ial n erve [CN] V, m otor n u cleu s of CN VII) Neu ron ’s cell bod ies con tain typ ical cellu lar organ elles with in th eir cytop lasm : • Mitoch on d ria • Nu cleu s • Nu cleolu s • Ribosom es • Rou gh en d op lasm ic reticu lu m (Nissl su bstan ce) • Neu rotu bu les • Golgi ap p aratu s • Lysosom es Neu ron s h ave 2 typ es of p rocesses th at exten d from th e n erve cell body: • Den d rite: p rocess th at carries n erve im p u lses toward th e n erve cell bod y; n eu ron s m ay h ave m u ltip le den d rites • Axon : p rocess th at carries n erve im p u lses away from th e n erve cell body; n eu ron s can h ave only 1 axon 3 m ajor typ es of n eu ron s: • Un ip olar: h as on ly 1 p rocess from th e cell bod y (sen sory n eu ron s) • Bip olar: h as 2 p rocesses from th e cell body: 1 d en d rite an d 1 axon (sen sory n eu ron s; located on ly in th e retin a, olfactory ep ith eliu m , an d th e vestibu lar an d coch lear gan glia) • Mu ltip olar: h as 3 or m ore p rocesses from th e cell bod y: 2 or m ore d en drites an d 1 axon (m otor n eu ron s an d in tern eu ron s)

Dendrites Rough endoplasmic reticulum (Nissl substance)

Dendritic spines Interneurons (gemmules) Ribosomes Blood vessel Nucleus Nucleolus Axon Axon hillock Neurotubules Golgi apparatus Cell body (soma) Lysosome

Mitochondrion

Striated (voluntary) muscle

Bipolar cell of cranial n. VIII Unipolar cell of sensory ganglia Satellite cells Schwann cell Myelinated fibers Free nerve endings Multipolar Encapsulated ending neuron Specialized ending O ligodendrocyte

Multipolar somatic motor cell Astrocyte Collateral Myelinated somatic motor fiber Myelin sheath Red: Motor neuron Blue: Sensory neuron Purple: Interneuron Gray: Glial and Motor end neurilemmal plate with cells and myelin Schwann cell cap

Figu re 3-1

66

Muscle spindle

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

NERVOUS TISSUE • Neuroglia • • •

3

Neu roglia is th e su p p ortin g n ervou s tissu e for n eu ron s, alth ou gh n eu roglial cells also h ave assistive roles in n eu ron fu n ction Neu roglial cells h ave on ly 1 typ e of p rocess Classi cation : • Astrocytes: located in th e cen tral n ervou s system ; h elp keep n eu ron s in p lace, p rovid e n u trition al su p p ort, regu late th e extracellu lar m atrix, form p art of th e blood -brain barrier • Oligod en d rocytes: located in th e cen tral n ervou s system ; resp on sible for axon m yelin ation in th e cen tral n ervou s system ; 1 oligod en d rocyte can m yelin ate 1 segm en t of m u ltip le axon s • Microglial cells: located in th e cen tral n ervou s system ; resp on sible for p h agocytosis to rem ove waste • Sch wan n cells: located in th e p erip h eral n ervou s system ; resp on sible for axon m yelin ation in th e p erip h eral n ervou s system ; 1 Sch wan n cell can m yelin ate 1 segm en t of 1 axon • Satellite cells: located in th e p erip h eral n ervou s system ; su rrou n d th e n erve cell bod ies of gan glia

Ventricle

Microglial cell

Ependyma Tanycyte

Neuron Oligodendrocyte

Axon Astrocyte Astrocyte foot process Perivascular pericyte

Pia mater

Capillary

Figu re 3-2 BASIC NEUROANATO MY AND CRANIAL NERVES

67

3

CENTRAL NERVOUS SYSTEM • General Information •

Th e cen tral n ervou s system is com p osed of th e: • Brain • Sp in al cord

Precentral gyrus Precentral sulcus

Central sulcus Postcentral gyrus

Superior frontal gyrus

Superior parietal lobule Intraparietal sulcus Inferior parietal lobule

Middle frontal gyrus

Angular gyrus

Inferior frontal gyrus Frontal pole Lateral (sylvian) fissure

O ccipital pole Anterior ramus Ascending ramus Posterior ramus Temporal pole

Inferior temporal gyrus Superior temporal gyrus

Parietal lobe

Frontal lobe Occipital lobe

Temporal lobe

Central sulcus of insula

Circular sulcus of insula

Insula

Short gyri Limen Long gyrus

Figu re 3-3

68

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

CENTRAL NERVOUS SYSTEM • Brain

3

CEREBRUM

• •

•

Th e su rface of th e cerebral cortex of th e brain is divided by: • Gyri (sin gu lar gyrus): th e elevation s of brain tissu e on th e su rface • Su lci (sin gu lar sulcus): th e grooves or ssu res located between th e gyri Th ere are 3 large su lci th at h elp d ivid e th e cerebral h em isp h eres in to 4 of its lobes: • Cen tral su lcu s (of Rolan d o): divid es fron tal lobe from p arietal lobe • Lateral su lcu s (of Sylviu s): d ivid es th e fron tal an d p arietal lobes from th e tem p oral lobe • Parieto-occip ital su lcu s: divid es th e p arietal lobe from th e occip ital lobe Th e brain is d ivid ed in to 5 lobes: • Fron tal: m otor m ovem en t, m otor asp ect of sp eech (Broca’s area), reason in g, em otion s, p erson ality, an d p roblem solvin g • Parietal: sen sory p ercep tion s related to p ain , tem p eratu re, tou ch an d p ressu re, sp atial orien tation an d p ercep tion , sen sory asp ect of lan gu age (Wern icke’s area) • Tem p oral: au d itory p ercep tion s, learn in g, an d m em ory • Occip ital: vision • In su la: associated with visceral fu n ction s in clu din g taste

DIENCEPHALON

•

Com p osed of 4 p arts: • Th alam u s: m ajor relay cen ter of th e som atosen sory system an d p arts of th e m otor system • Hyp oth alam u s: con trols th e au ton om ic n ervou s system an d en d ocrin e system • Ep ith alam u s: m ajor stru ctu res in clu de th e p in eal glan d (circad ian rh yth m s) an d th e h aben u la • Su bth alam u s: an extrap yram id al n u cleu s of th e m otor system ; lesion s of th is n u cleu s will resu lt in a con tralateral h em iballism u s

BRAINSTEM

•

Com p osed of 3 p arts: • Mid brain • Pon s • Med u lla

CEREBELLUM

• • •

Part of th e m otor system Receives sen sory in p u t of all form s th at u se th e d eep cerebellar n u clei Associated with : • Eq u ilibriu m • Postu re • Ton e of axial m u scles • Gait

Corpus callosum Interthalamic adhesion

Cuneus

Thalamus

Pineal gland Lingual gyrus

Hypothalamic sulcus O ptic chiasm

AP

Pituitary gland (anterior and posterior)

Cerebellum Medulla oblongata Midbrain Pons

Figu re 3-4 BASIC NEUROANATO MY AND CRANIAL NERVES

69

3

CENTRAL NERVOUS SYSTEM • Spinal Cord • • •

• •

Th e cau dal con tin u ation of th e cen tral n ervou s system Begin s at th e cau d al en d of th e m ed u lla an d en ds at vertebral level L1–2, tap erin g in to th e con u s m ed u llaris Has 2 en largem en ts associated with th e lim bs: • Cervical—associated with th e u p p er lim b an d fou n d between th e sp in al cord at levels C4 to T1 • Lu m bosacral—associated with th e lower lim b an d fou n d between th e sp in al cord at levels L1 to S2 Com p osed of: • Gray m atter—location of n erve cell bod ies an d n eu roglial cells • W h ite m atter—location of th e axon s an d n eu roglial cells Has 5 levels: • Cervical—8 sp in al n erves • Th oracic—12 sp in al n erves • Lu m bar—5 sp in al n erves • Sacral—5 sp in al n erves • Coccygeal—1 sp in al n erve

C1 1st cervical n. Cervical enlargement C7 8th cervical n. T1 1st thoracic n. Spinal dura mater Filaments of nerve root

T12 Lumbosacral enlargement 12th thoracic n. L1 1st lumbar n. Conus medullaris Cauda equina L5 5th lumbar n. S1 1st sacral n. Filum terminale 5th sacral n. Coccygeal n. Coccyx

Figu re 3-5

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NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

CENTRAL NERVOUS SYSTEM • Spinal Cord

3

Posterior view Rami communicantes Dura mater Dorsal root Dorsal root (spinal) ganglion

Arachnoid

Subarachnoid space Pia mater (overlying spinal cord) Filaments of dorsal root Denticulate ligament

Anterior view Gray matter Filaments of dorsal root White matter Dorsal root Dorsal root (spinal) ganglion Ventral root Spinal nerve Filaments of ventral root Anterior median fissure

Sections through spinal cord at various levels C5

L1

T2

T8

L3

S1 S3

Figu re 3-6

BASIC NEUROANATO MY AND CRANIAL NERVES

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PERIPHERAL NERVOUS SYSTEM • General Information • • •

Perip h eral n ervou s system is th e p ortion of th e n ervou s system located extern al to th e cen tral n ervou s system Con sists of: • Cran ial n erves—12 p airs • Sp in al n erves—31 p airs Can be su bdivid ed in to: • Som atic n ervou s system —volu n tary system associated with afferen t (sen sory) an d efferen t (m otor) bers • Au ton om ic n ervou s system —in volu n tary system associated with h om eostasis of th e bod y

Pacinian corpuscle

Dorsal column

Dorsal root

Sensory Motor Preganglionic sympathetic Postganglionic sympathetic

Dorsal root ganglion

Vascular sm ooth m uscle, sw eat glands, and arrector pili m uscles in skin

Dorsal ramus Skeletal m uscle Ventral ramus Gray ramus communicans

Ventral root

Sympathetic chain ganglion Free endings

Splanchnic nerve Collateral sympathetic ganglion

Skeletal m uscle

Sympathetic chain Preganglionic sym pathetic neurons passing to synapse in another sym pathetic chain ganglion N euroeffector junctions on sm ooth m uscle, cardiac m uscle, secretory glands, m etabolic cells, im m une cells

Sensory neuron of abdom inal viscera

Figu re 3-7

72

White ramus communicans

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

PERIPHERAL NERVOUS SYSTEM • Spinal Nerves and Cranial Nerves

3

O culomotor (III) n. Facial (VII) n.

Intracranial vessels

Glossopharyngeal (IX) n. Medulla oblongata

Lacrimal gland

Vagus (X) n.

Pterygopalatine ganglion

C1 C2

Bronchi and lungs Heart s

Greater thoracic splanchnic n.

te

T8 T9

Le sp sse L la r sp o w n th c o la e h ra s n t n c c th ic i h n or n c ic a . n c ic .

T6 T7

Hair follicle

Trachea

n

T5

T10 T11

Celiac ganglion Stomach Liver Gallbladder Bile ducts S ga u p n .m gl io e s n en

T12 L1

S1 S2 S3 S4 S5 Coccyx

Sympathetic fibers preganglionic postganglionic

G

ra

y

L3 L5

Pancreas

te

ri c

Lumbar splanchnic nn.

L2 L4

Peripheral cranial blood vessels Larynx

R a m gr i a y c o a m n d m w u n h ic it e a

Peripheral vessel

Submandibular ganglion

r ay

Shown for only 1 segment

Parotid gland Sublingual and submandibular glands

O tic ganglion

C3 C4 C5 C6 C7 C8 T1 T2 T3 T4

G

Sweat gland

Eye

Ciliary ganglion

Sup. hypogastric plexus Hypogastric nn.

Adrenal glands Brown fat Kidneys

Intestines Inf. mesenteric ganglion

Lymphoid organs Distal colon Bladder

Pelvic splanchnic nn. Sympathetic trunk

Inf. hypogastric (pelvic) plexus

External genitalia

Parasympathetic fibers preganglionic postganglionic

Figu re 3-8

BASIC NEUROANATO MY AND CRANIAL NERVES

73

3

CRANIAL NERVES • General Information • •

•

Cran ial n erves or cerebral n erves are p erip h eral n erves th at leave th e brain or brain stem Th e cran ial n erves cu stom arily are su bd ivid ed in to 12 p airs: I: Olfactory n erve VII: Facial n erve II: Op tic n erve VIII: Vestibu lococh lear n erve III: Ocu lom otor n erve IX: Glossop h aryn geal n erve IV: Troch lear n erve X: Vagu s n erve V: Trigem in al n erve XI: Accessory n erve VI: Abd u cen s n erve XII: Hyp oglossal n erve Becau se of th e h igh d egree of d ifferen tiation in th e brain of h u m an s, cran ial n erves are m ore com p lex in stru ctu re an d fu n ction th an sp in al n erves

Spinal nerve fibers Efferent (motor) fibers Afferent (sensory) fibers

I Olfactory

III Oculomotor Ciliary muscle, sphincter of II pupil and all external eye Optic muscles except those below IV Trochlear V Superior oblique muscle Trigeminal VI Sensory—face Abducent sinuses, teeth Lateral rectus muscle

O

p

M

h ht

ax

n Ma

al

i ll

m

ar

d ib

ic

y

u la

r

Motor—muscles of mastication

Intermediate nerve Motor—submandibular, sublingual, lacrimal glands Taste—anterior 2 ⁄3 of tongue, sensory soft palate

VII Facial Muscles of face

VIII Vestibulocochlear Cochlear Vestibular IX Glossopharyngeal Taste—posterior 1 ⁄3 of tongue Sensory—tonsil, pharynx, middle ear Motor—stylopharyngeus, upper pharyngeal muscles, parotid gland

XII Hypoglossal Tongue muscles

X Vagus Motor—heart, lungs, palate, pharynx, XI larynx, trachea, bronchi, GI tract Accessory Sensory—heart, lungs, trachea, Sternocleidomastoid, bronchi, larynx, pharynx, trapezius muscles GI tract, external ear

Strap muscles (C1, 2, 3 fibers)

Figu re 3-9

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NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

CRANIAL NERVES • Functional Columns •

• •

•

3

7 fu n ction al com p on en ts (or fu n ction al colu m n s) of th e cran ial n erves are recogn ized • Con cep t of fu n ction al colu m n s com es from stu d ies of sp in al n erves—fu n ction s associated with d ifferen t n eu rologic p ath ways alon g sp in al colu m n are assign ed corresp on din g “colu m n s” A given cran ial n erve m ay h ave 1 to 5 fu n ction al colu m n s Th e fu n ction al colu m n s are classi ed as general or special: • Gen eral—th ese fu n ction al colu m n s h ave th e sam e fu n ction s as th ose for sp in al n erves • Sp ecial—th ese fu n ction al colu m n s are sp eci c on ly to cran ial n erves Gen eral an d sp ecial fu n ction al colu m n s each are su bd ivided in to 2 ad dition al categories: • Afferent (sen sory) an d efferent (m otor) • Som atic (bod y-related ) an d visceral (organ -related )

SUMMARY OF FUNCTIONS*

GSA: Exterocep tors an d p rop riocep tors (e.g., for p ain , tou ch , an d tem p eratu re, or with in ten d on s an d join ts). Th ese are th e sam e as in sp in al n erves. SSA: Sp ecial sen ses in eye an d ear (vision ; h earin g an d eq u ilibriu m ) GVA: Sen sory from viscera (e.g., gu t). Th ese are th e sam e as in sp in al n erves. SVA: Olfaction an d taste GVE: Au ton om ic n ervou s system (in n ervates card iac m u scle, sm ooth m u scle, an d glan d s). Th ese are th e sam e as in sp in al n erves. GSE: Skeletal (som atic) m u scle. Th ese are th e sam e as in sp in al n erves. SVE: Skeletal m u scle, wh ich d evelop s from th e p h aryn geal (bran ch ial) arch es (h om ologou s to GSE) *W ithin each designation: G or S, gen eral or sp ecial; S or V, som atic or visceral; A or E, afferen t or efferen t.

Posterior phantom view

O culomotor nerve (III) Red nucleus O culomotor nucleus

Mesencephalic nucleus of trigeminal nerve

Edinger-Westphal nucleus Trochlear nucleus

Trigeminal nerve (V) and ganglion Principal sensory nucleus of trigeminal nerve Facial nerve (VII) and geniculate ganglion Vestibulocochlear nerve (VIII) Cochlear nuclei

Trochlear nerve (IV) Trigeminal nerve (V) and ganglion Motor nucleus of trigeminal nerve Abducens nucleus (Geniculum) of facial nerve Facial nucleus Superior and inferior salivatory nuclei

Anterior Posterior

Vestibular nuclei

Glossopharyngeal nerve (IX)

Glossopharyngeal nerve (IX) Vagus nerve (X) Spinal tract and spinal nucleus of trigeminal nerve

Vagus nerve (X) Accessory nerve (XI)* Nucleus ambiguus

Solitary tract nucleus

Dorsal motor nucleus of vagus nerve (X) Hypoglossal nucleus

Dorsal motor vagal nucleus Efferent fibers Afferent fibers Mixed fibers

Spinal nucleus of accessory nerve

*Recent evidence suggests that the accessory nerve lacks a cranial root and has no connection to the vagus nerve. Verification of this finding awaits further investigation

Figu re 3-10

BASIC NEUROANATO MY AND CRANIAL NERVES

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3

CRANIAL NERVES • CN I: Olfactory Nerve Functional Column SVA

Origin of Fibers

Termination of Fibers

Summary

Comment

Fibers originate in the neurosensory cells o the ol actory epithelium The prim ary f bers (which are bipolar neurons) travel through the cribri orm plate to synapse on the secondary f bers within the ol actory bulb These f bers continue posteriorly as the ol actory tract that carries the f bers to the ol actory areas

The secondary f bers continue to synapse in the ol actory areas: • Lateral ol actory area • Anterior ol actory nucleus • Interm ediate ol actory area • Medial ol actory area • Am ygdala • Entorhinal cortex • Piri orm cortex

The SVA f bers are responsible or the sense o sm ell

Tum ors o the ol actory lobe can a ect the ol actory system Traum a to the head can cause a shearing o the prim ary f bers as they pass through the cribri orm plate

Subcallosal (parolfactory) area Septal area and nuclei

Olfactory bulb cells: schema

Fibers from Contralateral Fibers to olfactory bulb

Efferent fibers to olfactory bulb Afferent fibers from bulb to central connections and contralateral bulb

Anterior commissure Medial olfactory stria

Granule cell (excited by and inhibiting to mitral and tufted cells) Mitral cell Recurrent process Tufted cell Periglomerular cell Glomerulus O lfactory nerve fibers

O lfactory tract

O lfactory cells O lfactory mucosa Olfactory nerves (I)

O lfactory trigone and olfactory tubercle

O lfactory bulb Cribriform plate of ethmoid bone Anterior olfactory nucleus

Lateral olfactory stria

Uncus

Lateral olfactory tract nucleus Anterior perforated substance Amygdaloid body (phantom ) Piriform lobe

Figu re 3-11

76

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

Hippocampal fimbria Dentate gyrus Parahippocampal gyrus

CRANIAL NERVES • CN I: Olfactory Nerve

3

Cribriform plate of ethmoid bone O lfactory bulb

Distribution of olfactory epithelium (blue area)

Lateral nasal wall

Septum Schema of section through olfactory mucosa Cribriform plate Schwann cell O lfactory gland Unmyelinated olfactory axons Basement membrane Sustentacular cells Endoplasmic reticulum Nucleus O lfactory cells Dendrites Terminal bars (desmosomes) O lfactory rod (vesicle) Villi Cilia Mucus

Figu re 3-12

BASIC NEUROANATO MY AND CRANIAL NERVES

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3

CRANIAL NERVES • CN II: Optic Nerve Functional Column SSA

Origin of Fibers

Termination of Fibers

Summary

Comment

Begins in the retina with the receptors o rods and cones that synapse on bipolar cells, which synapse with ganglion cells

Ganglionic axons orm the optic nerve that m eets in an incom plete crossing at the optic chiasm where: • Nasal retinal f bers decussate to the opposite side • Tem poral retinal f bers rem ain on the ipsilateral side These orm an optic tract that term inates on the lateral geniculate nucleus Fibers rom the lateral geniculate travel to synapse in the occipital lobe

The SSA f bers are responsible or vision

Lesions o the optic nerve lead to blindness Lesions o the optic chiasm lead to bitem poral hem ianopsia Lesions o the optic tract lead to hom onym ous hem ianopsia

Central darker circle represents macular zone. O verlapping visual fields

Lightest shades represent monocular fields. Each quadrant is a different color.

Projection on left retina

Projection on right retina O ptic (II) nerves O ptic chiasm

Projection on left dorsal lateral geniculate nucleus

Meyer loop

O ptic tracts

Meyer loop

Projection on right dorsal lateral geniculate nucleus

Lateral geniculate bodies

Projection on left occipital lobe

Projection on right occipital lobe

Calcarine fissure

Figu re 3-13

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NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

CRANIAL NERVES • CN II: Optic Nerve

Section through retina

Eyeball Iris

Lens Cornea

Suspensory lig.

Ciliary body

Anterior chamber

Inner limiting membrane Axons at surface of retina passing via optic nerve, chiasm, and tract to lateral geniculate body Ganglion cell

Posterior chamber

Müller cell (supporting glial cell) Amacrine cell Bipolar cell Horizontal cell

containing aqueous humor

O ra serrata

3

Vitreous humor Rod Cone

Retina

O ptic nerve

Choroid Sclera Fovea

Rod in dark

Pigment cells of choroid

Rod in light

Synaptic ending depolarized

Synaptic bar

Photons of light Rhodopsin

Na + permeability increased

Nucleus

Lumirhodopsin

Metabolic energy Current flow

Synaptic ending fully polarized

Metarhodopsin Retinene + O psin

Retinene + O psin Vitamin A

Vitamin A

Centriole (basal body) Na + permeability decreased

Circulation

Figu re 3-14

BASIC NEUROANATO MY AND CRANIAL NERVES

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3

CRANIAL NERVES • CN III, IV, VI: Oculomotor, Trochlear, Abducens Nerves Functional Column

Origin of Fibers

Termination of Fibers

Summary

Comment

OCULOMOTOR NERVE GSE

Begins in the oculom otor nucleus (o the m idbrain)

Enters orbit through superior orbital f ssure and divides into: • Superior division, which innervates the superior rectus and levator palpebrae superioris m m . • In erior division, which innervates the in erior rectus, m edial rectus, and in erior oblique m m .

GSE f bers are responsible or innervating the m ajority o the extraocular eye m uscles

Lesions o the oculom otor nerve result in diplopia (GSE), lateral strabism us (GSE), ptosis (GVE), and m ydriasis (GVE)

GVE

Preganglionic parasym pathetic f bers begin in the EdingerWestphal nucleus (o the m idbrain)

Preganglionic parasym pathetic f bers synapse with postganglionic parasym pathetic f bers at the ciliary ganglion Postganglionic f bers travel through the short ciliary nn. to innervate the sphincter pupillae and ciliary m m .

GVE f bers are responsible or providing the parasym pathetic innervation to the intrinsic eye m uscles: • Ciliary m uscle • Sphincter pupillae

GVE f bers utilize 1 ganglion: • Ciliary ganglion

TROCHLEAR NERVE GSE

Begins in the trochlear nucleus (o the m idbrain)

Enters orbit through superior orbital f ssure and innervates the superior oblique m .

GSE f bers are responsible or innervating 1 extraocular m uscle o the eye: the superior oblique

The trochlear nerve exits the brainstem dorsally Lesions o the trochlear n. result in diplopia In trochlear n. lesions, the eye is adducted and elevated

ABDUCENS NERVE GSE

Begins in the abducens nucleus (o the pons)

Sensory root of ciliary ganglion

Enters orbit through superior orbital f ssure and innervates the lateral rectus m .

Sympathetic root of ciliary ganglion

Superior oblique m. Levator palpebrae superioris m. Superior rectus m. Ciliary ganglion Short ciliary nn.

GSE f bers are responsible or innervating 1 extraocular m uscle o the eye: the lateral rectus

Lesions o the abducens nerve result in diplopia and m edial strabism us

Superior division of oculomotor n. Edinger-Westphal Lateral rectus m. and nucleus abducens n. (turned back) (parasympathetic) O phthalmic n. (V1 ) O culomotor nucleus Trochlear nucleus Oculomotor n. (III) Trochlear n. (IV) Abducens nucleus

Sphincter m. of pupil

Abducens n. (VI)

Dilator muscle of pupil Ciliary m. Inferior oblique m. Infraorbital n. Efferent fibers Zygomatic n. (cut) Afferent fibers Sympathetic fibers Parasympathetic root Parasympathetic fibers of ciliary ganglion

Internal carotid a. and n. plexus Medial rectus m. Inferior division of oculomotor n. Inferior rectus m.

Figu re 3-15

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NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

CRANIAL NERVES • CN III, IV, VI: Oculomotor. Trochlear, Abducens Nerves

Sphincter of pupil

Accessory oculomotor (Edinger-Westphal) nucleus (autonomic)

O culomotor n. root of ciliary ganglion (motor)

Dilator of pupil Ciliary m.

Short ciliary nn.

3

O culomotor (III) n.

Ciliary ganglion

Nasociliary n.

O phthalmic n.

O ptic (II) n.

Trigeminal ganglion Internal carotid plexus

Long ciliary n. Nasociliary n. root of ciliary ganglion Sympathetic root of ciliary ganglion O phthalmic a.

Internal carotid a.

Middle ear Thoracic part of spinal cord

Tectospinal tract

Superior cervical sympathetic trunk ganglion

1st thoracic sympathetic trunk ganglion White ramus communicans Presynaptic Postsynaptic Presynaptic Postsynaptic

{ {

T1 Gray ramus communicans

Sympathetic fibers Parasympathetic fibers T2

Afferent fibers Visual pathway Descending pathway

T3

Figu re 3-16

BASIC NEUROANATO MY AND CRANIAL NERVES

81

3

CRANIAL NERVES • CN V: Trigeminal Nerve OVERVIEW

• •

•

•

Con sists of a large sen sory root an d a sm all m otor root wh ich join s th e m an d ibu lar d ivision at th e level of th e foram en ovale Th e sen sory root is created by 3 division s th at com e togeth er at th e trigem in al gan glion with in th e m id d le cran ial fossa: • Op h th alm ic division of th e trigem in al, wh ich p asses th rou gh th e su p erior orbital ssu re (con n ects to orbit) • Maxillary d ivision of th e trigem in al, wh ich p asses th rou gh th e foram en rotu n d u m (con n ects to p terygop alatin e fossa) • Man dibu lar d ivision of th e trigem in al, wh ich p asses th rou gh th e foram en ovale (con n ects to in fratem p oral fossa) Each division carries th e p rim ary n eu ron s for: • Pain an d tem p eratu re (th e cell body of th e p rim ary n eu ron is located in th e trigem in al gan glion ) • Discrim in ative tou ch (th e cell body of th e p rim ary n eu ron is located in th e trigem in al gan glion ) • Prop riocep tion (th e cell bod y of th e p rim ary n eu ron is located in th e m esen cep h alic n u cleu s of V) Parasym p ath etics u se all of th e d ivision s of th e trigem in al n erve to d istribu te th eir bers th rou gh ou t th e h ead an d n eck

Mesencephalic nucleus Motor nucleus

Trigeminal n. (V) ganglion and nuclei

Ophthalmic n. (V1 )

Maxillary n. (V2 )

Mandibular n. (V3 )

Facial n. (VII)

Efferent fibers (SVE) Afferent fibers (GSA) Proprioceptive fibers (GSK)

Figu re 3-17

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NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

Principal sensory nucleus Spinal tract and nucleus

CRANIAL NERVES • CN V: Trigeminal Nerve Functional Column

Origin of Fibers

Termination of Fibers

Summary

Comment Provides sensory innervation through 3 m ain divisions: • Ophthalm ic • Maxillary • Mandibular The nerve cell bodies or the prim ary f bers or pain and tem perature and touch are located in the trigem inal ganglion The nerve cell bodies or the prim ary f bers or proprioception are located in the m esencephalic nucleus

GSA

A erent f bers begin in the various receptors (nociceptors, m echanoceptors, proprioceptors) o the skin and deep tissues o the head

Pain and tem perature and light touch f bers term inate in the spinal nucleus o V Discrim inative touch f bers term inate in the m ain sensory nucleus o V Proprioception f bers have their cell bodies in the m esencephalic nucleus o V

GSA f bers are responsible or providing sensory innervation to the m ajor part o the head GSA f bers utilize the trigem inothalam ic lem niscus to carry their sensory im pulses to consciousness

SVE

Begins in the m otor nucleus o the trigem inal (located in the pons)

Innervates the m uscles o m astication: • Masseter • Tem poralis • Medial pterygoid • Lateral pterygoid Also innervates: • Mylohyoid • Anterior digastric • Tensor tym pani • Tensor veli palatini

The SVE f bers are responsible or innervating the m uscles o the 1st pharyngeal arch

3

Mesencephalic nucleus of V Principal sensory nucleus of V O phthalmic Maxillary Divisions of Mandibular trigeminal nerve V

Motor nucleus of V Nucleus of VII Nucleus of tractus solitarius Nucleus of XII

VII

C1 IX

C2 Spinal tract and nucleus of V

X XII

Figu re 3-18 BASIC NEUROANATO MY AND CRANIAL NERVES

83

3

CRANIAL NERVES • CN V: Trigeminal Nerve OPHTHALMIC DIVISION OF THE TRIGEMINAL NERVE • The ophthalm ic division (V1 ), being a branch o the trigem inal n., is sensory in unction • Arises rom the m ain nerve in the m iddle cranial ossa • Passes anterior on the lateral wall o the cavernous sinus im m ediately in erior to the oculom otor and trochlear nn., but superior to the m axillary division o the trigem inal n. • Be ore entering the orbit, it gives rise to a sm all tentorial branch • Im m ediately be ore entering the orbit, through the superior orbital f ssure, it divides into 3 m ajor branches: • Lacrim al • Frontal • Nasociliary

Branches Within the Middle Cranial Fossa Nerve

Source

Course

Tentorial (m eningeal)

Ophthalm ic division o the trigem inal

Is recurrent in nature and passes posteriorly to provide innervation to sm all parts o the dura m ater: • Falx cerebri • Tentorium cerebelli

Lacrim al

1 o the 3 m ajor branches o the ophthalm ic division o the trigem inal n.

Sm allest o the m ajor branches o the ophthalm ic division o the trigem inal n. Passes anteriorly to enter the orbit through the superior orbital f ssure In the orbit it travels superolaterally on the superior border o the lateral rectus with the lacrim al a. Be ore reaching the lacrim al gland, it com m unicates with the zygom atic branch o the m axillary division o the trigem inal n. to receive autonom ic nervous f bers Enters the lacrim al gland and supplies it and the conjunctiva be ore piercing the orbital septum to supply the skin o the upper eyelid

Frontal

1 o the 3 m ajor branches o the ophthalm ic division o the trigem inal n.

Largest branch o the ophthalm ic division o the trigem inal n. Passes anteriorly to enter the orbit through the superior orbital f ssure In the orbit it passes anteriorly between the periosteum o the orbit and the levator palpebrae superioris m . About hal way in the orbit, it divides into its 2 term inal nerves: • Supraorbital n. • Supratrochlear n.

 Supraorbital

Frontal n.

1 o the 2 term inal branches o the rontal n. in the orbit Passes between the levator palpebrae superioris m . and periosteum o the orbit Continues anteriorly to the supraorbital oram en (notch) At the level o the supraorbital m argin, it sends nerve supply to the rontal sinus, skin, and conjunctiva o the upper eyelid Continues to ascend superiorly along the scalp Divides into m edial and lateral branches, which travel up to the vertex o the scalp

 Supratrochlear

Nasociliary

1 o the 2 term inal branches o the rontal n. in the orbit Once the supratrochlear a. joins it within the orbit, it continues to pass anteriorly toward the trochlear n. In the trochlear region, it exits the orbit at the rontal notch Ascends along the scalp, at f rst deep to the m usculature in the region, be ore piercing these m uscles to reach the cutaneous innervation along the scalp 1 o the 3 m ajor branches o the ophthalm ic division o the trigem inal n.

Passes anteriorly to enter the orbit through the superior orbital f ssure Enters the orbit lateral to the optic n. Travels across the optic n. anteriorly and m edially to lie between the m edial rectus m . and the superior oblique m . along the m edial wall o the orbit All along its path, it gives rise to other nerves, including the sensory root o the ciliary ganglion and the long ciliary and posterior ethm oid nn., until term inating into the anterior ethm oid and in ratrochlear nn. near the anterior ethm oid oram en Continued  on  next  page

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NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

CRANIAL NERVES • CN V: Trigeminal Nerve Nerve

Source

Course

 Sensory  root  Nasociliary n. of  the  ciliary  ganglion

Travels anteriorly on the lateral side o the optic n. to enter the ciliary ganglion Carries general sensory f bers, which are distributed by the short ciliary nn.

  • Short  ciliary

Ciliary ganglion

Arises rom the ciliary ganglion to travel to the posterior sur ace o the eye Supplies the sensory f bers to the eye and helps carry the postganglionic parasym pathetic f bers to the sphincter pupillae and the ciliary m uscle

 Long  ciliary

Nasociliary n.

Has 2 to 4 branches that travel anteriorly to enter the posterior part o the sclera o the eye Postganglionic sym pathetics traveling to the dilator pupillae will join the long ciliary to get to the eye

 Posterior  ethm oid

Travels deep to the superior oblique m . to pass through the posterior ethm oid oram en Supplies the sphenoid sinus and the posterior ethm oid sinus

 Anterior  ethm oid

Arises on the m edial wall o the orbit Enters the anterior ethm oid oram en and travels through the canal to enter the anterior cranial ossa Supplies the anterior and m iddle ethm oid sinus be ore entering and supplying the nasal cavity via internal nasal n. (m edial and lateral branches) Term inates as the external nasal n. on the nose

  • External  nasal

A term inal branch o the anterior ethm oid n.

  • Internal  nasal  Infratrochlear

3

Exits between the lateral nasal cartilage and the in erior border o the nasal bone Supplies the skin o the ala and apex o the nose around the nares Upon entering the nasal cavity, it divides into m edial (septal) and lateral branches, which supplies the skin on the internal sur ace o the vestibule

Nasociliary n.

1 o the term inal branches o the nasociliary branch o the ophthalm ic division o the trigem inal n. Passes anteriorly on the superior border o the m edial rectus m . Passes in erior to the trochlea toward the m edial angle o the eye Supplies the skin o the eyelids and the bridge o the nose, the conjunctiva, and all o the lacrim al structures

Supraorbital a. and n. Supratrochlear a. and n.

Infratrochlear n.

External nasal a. and n. Nasalis m. (transverse part) Infraorbital a. and n.

Figu re 3-19 BASIC NEUROANATO MY AND CRANIAL NERVES

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CRANIAL NERVES • CN V: Trigeminal Nerve

Superior view Medial branch Supraorbital n. Lateral branch Levator palpebrae superioris m. Superior rectus m. Lacrimal gland

Supratrochlear n. Medial rectus m. Superior oblique m.

Lacrimal n.

Infratrochlear n.

Lateral rectus m.

Nasociliary n.

Frontal n.

Trochlear n. (IV) O phthalmic n. (V1)

Maxillary n. (V2 )

O ptic n. (II) Internal carotid a. and n. plexus

Mandibular n. (V3 ) Lesser petrosal n. Meningeal branch of mandibular n. Greater petrosal n.

O culomotor n. (III) Trochlear n. (IV) Abducens n. (VI)

Trigeminal (semilunar) ganglion

Tentorium cerebelli Superior view: levator palpebrae superioris, superior rectus and superior oblique muscles partially cut away

Long ciliary nn. Short ciliary nn. Lacrimal n.

Supratrochlear n. (cut)

Ciliary ganglion

Supraorbital n. branches (cut)

Parasympathetic root of ciliary ganglion (from inferior branch of oculomotor n.) Sympathetic root of ciliary ganglion (from internal carotid plexus) Sensory root of ciliary ganglion (from nasociliary n.)

Infratrochlear n. Anterior ethmoidal n. O ptic n. (II) Posterior ethmoidal n. Superior branch of oculomotor n. (III) (cut)

Branches to inferior and medial rectus mm. Abducens n. (VI)

Nasociliary n.

Inferior branch of oculomotor n. (III)

Internal carotid plexus

Lacrimal n.

Trochlear n. (IV) (cut)

Frontal n. (cut)

O culomotor n. (III)

O phthalmic n. (V1 )

Abducens n. (VI)

Figu re 3-20

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3

MAXILLARY DIVISION OF THE TRIGEMINAL NERVE • • • • •

The m axillary division (V2 ), being a branch o the trigem inal n., is sensory in unction Branches rom the trigem inal n. and travels along the lateral wall o the cavernous sinus Passes rom the m iddle cranial ossa into the pterygopalatine ossa via the oram en rotundum Within the pterygopalatine ossa, it gives rise to 4 branches 1 o those nerves, the in raorbital n., is considered the continuation o the m axillary division o the trigem inal n.

Nerve

Course Branches Within the Middle Cranial Fossa

Meningeal

A sm all m eningeal branch is given o The nerve supplies the m eninges

within the m iddle cranial ossa

Branches Within the Pterygopalatine Fossa Posterior superior alveolar

Passes through the pterygom axillary f ssure to enter the in ratem poral ossa In the in ratem poral ossa, it passes on the posterior sur ace o the m axilla along the region o the m axillary tuberosity Gives rise to a gingival branch alongside the m axillary m olars Enters the posterior sur ace o the m axilla and supplies the m axillary sinus and the m axillary m olars, with the possible exception o the m esiobuccal root o the 1st m axillary m olar, and the gingiva and m ucosa alongside the sam e teeth

Zygom atic

Passes through the in erior orbital f ssure to enter the orbit Passes on the lateral wall o the orbit and branches into the zygom aticotem poral (supplies sensory to skin o the tem ple) and zygom atico acial branches (supplies sensory to skin over the cheek) A com m unicating branch rom it joins the lacrim al n. rom the ophthalm ic division o the trigem inal n. to carry autonom ics to the lacrim al gland

Ganglionic branches

Usually 2 ganglionic branches that connect the m axillary division o the trigem inal n. to the pterygopalatine ganglion Contain sensory f bers that pass through the pterygopalatine ganglion (without synapsing) to be distributed with the nerves that arise rom the pterygopalatine ganglion Also contain postganglionic autonom ic f bers to the lacrim al gland that pass through the pterygopalatine ganglion (parasym pathetic f bers orm a synapse here between the preganglionic f bers rom the vidian n. and the postganglionic f bers)

In raorbital

Considered the continuation o the m axillary division o the trigem inal n. Passes through the in erior orbital f ssure to enter the orbit Passes anteriorly through the in raorbital groove and in raorbital canal and exits onto the ace via the in raorbital oram en While in the in raorbital canal it gives rise to 2 branches: • Anterior superior alveolar n • Middle superior alveolar n.

Branches Associated With the Pterygopalatine Ganglion Pharyngeal

Passes through the palatovaginal (pharyngeal) canal to enter and supply the nasopharynx

Orbital

Sm all branches that enter the orbit through the in erior orbital f ssure Provide sensory to the orbital periosteum and send branches that supply the sphenoid sinus

Posterior superior nasal

A branch o the m axillary division o the trigem inal n. Arises rom the pterygopalatine ganglion in the pterygopalatine ossa Passes through the sphenopalatine oram en to enter the nasal cavity and branches into the: • Posterior superior m edial nasal n. • Posterior superior lateral nasal n. Continued  on  next  page

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Course Branches Associated With the Pterygopalatine Ganglion Continued

Posterior superior lateral nasal

A branch of the posterior superior nasal n. that supplies the posterosuperior portion of the lateral wall of the nasal cavity in the region of the superior and m iddle concha and the posterior ethm oid air cells

Posterior superior m edial nasal

Arises from the posterior superior nasal n. from the m axillary division of the trigem inal n. This nerve supplies the posterior portion of the nasal septum and nasal roof

Greater palatine

Passes through the palatine canal to enter the hard palate via the greater palatine foram en Supplies the palatal gingiva and m ucosa from the area in the prem olar region to the posterior border of the hard palate to the m idline

Posterior inferior nasal branch of the greater palatine

While descending in the palatine canal, the greater palatine n. gives rise to a posterior inferior nasal branch Supplies the posterior part of the lateral wall of the nasal cavity in the region of the m iddle m eatus

Lesser palatine

Passes through the palatine canal to enter and supply the soft palate via the lesser palatine foram en

Nasopalatine

Branches from the pterygopalatine ganglion in the pterygopalatine fossa Passes through the sphenopalatine foram en to enter the nasal cavity Passes along the superior portion of the nasal cavity to the nasal septum , where it travels anteroinferiorly to the incisive canal, supplying the septum Passes through the incisive canal to supply the gingiva and m ucosa of the hard palate from central incisor to canine

Branches Within the Infraorbital Canal Middle superior alveolar

A variable nerve, present in about 30% of individuals When present, it branches off the infraorbital n. as it travels in the infraorbital canal As the nerve descends to form the superior dental plexus, it innervates part of the m axillary sinus; the prem olars and possibly the m esiobuccal root of the 1st m olar; and the gingiva and m ucosa alongside the sam e teeth

Anterior superior alveolar

While in the infraorbital canal, it gives rise to the anterior superior alveolar n., which has a sm all branch that supplies the nasal cavity in the region of the inferior m eatus and inferior corresponding portion of the nasal septum , the m axillary sinus As the nerve descends to form the superior dental plexus, it innervates part of the m axillary sinus; m axillary central incisor, lateral incisor, and canine teeth; and the gingiva and m ucosa alongside the sam e teeth

Branches After Infraorbital Nerve Emerges From the Infraorbital Foramen

88

Superior labial branch of the infraorbital

Supplies the skin of the upper lip

Nasal branch of the infraorbital

Supplies the skin along the ala of the nose

Inferior palpebral branch of the infraorbital

Supplies the skin of the lower eyelid

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

CRANIAL NERVES • CN V: Trigeminal Nerve

Ciliary ganglion

3

Lacrimal gland

Lacrimal n. Nasociliary n.

Zygomaticotemporal n.

Frontal n.

Zygomaticofacial n.

O phthalmic n. (V1 ) Trigeminal (semilunar) ganglion

External nasal branch of anterior ethmoidal n.

Trigeminal n. (V) Meningeal branch Foramen rotundum Foramen ovale

Infraorbital n.

Mandibular n. (V3 )

Anterior superior alveolar n.

Maxillary nerve (V2 )

Nasal branch Mucous membrane of maxillary sinus Middle superior alveolar n. Dental and gingival branches

Zygomatic n. Nerve (vidian) of pterygoid canal Pterygopalatine ganglion

Superior dental plexus

Greater and lesser palatine nn.

Infraorbital nerve entering infraorbital canal

Ganglionic branches to pterygopalatine ganglion

Posterior superior alveolar n.

Medial wall of nasal cavity (nasal septum) Sphenopalatine foramen (dissected aw ay)

Nasopalatine nerve (V2 )

Pterygopalatine ganglion Nerve (Vidian) of pterygoid canal

Posterior superior lateral nasal branch of maxillary nerve (V2 ) Posterior inferior lateral nasal branch of greater palatine nerve (V2 ) Lesser palatine nerves (V2 ) Greater palatine nerve (V4 )

Lateral wall of nasal cavity

Figu re 3-21

BASIC NEUROANATO MY AND CRANIAL NERVES

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CRANIAL NERVES • CN V: Trigeminal Nerve MANDIBULAR DIVISION OF THE TRIGEMINAL NERVE Divisions Description

Source

Course

Anterior

Posterior

Mandibular division (V3 ) is the largest of the 3 divisions of the trigem inal n. Has m otor and sensory functions

Created by a large sensory root and a sm all m otor root that unite just after passing through the foram en ovale to enter the infratem poral fossa

Im m ediately gives rise to a m eningeal branch and a m edial pterygoid branch before dividing into anterior and posterior divisions

Sm aller; m ainly m otor, with 1 sensory branch (buccal): • Masseteric • Anterior and posterior deep tem poral • Lateral pterygoid • Buccal

Larger; m ainly sensory, with 1 m otor branch (nerve to the m ylohyoid): • Auriculotem poral • Lingual • Inferior alveolar • Mylohyoid nerve

BRANCHES FROM THE UNDIVIDED TRUNK Branch

Course

Meningeal (nervus spinosum )

After passing through the foram en ovale, the undivided trigem inal trunk is located between the tensor veli palatini and the lateral pterygoid The undivided trunk then gives rise to a lateral branch called the m eningeal nerve The branch travels through the foram en spinosum to enter the m iddle cranial fossa and innervate the dura m ater

Medial pterygoid

After passing through the foram en ovale, the undivided trigem inal trunk is located between the tensor veli palatini and the lateral pterygoid The undivided trunk then gives rise to a m edial branch to the m edial pterygoid This branch continues to supply the tensor veli palatini and the tensor tym pani

Anterior Division of the Mandibular Division Branch

Course

Masseteric

Passes laterally superior to the lateral pterygoid m . Lies anterior to the tem porom andibular joint and posterior to the tendon of the tem poralis m . Crosses the m andibular notch with the m asseteric a. to innervate the m asseter m . Also provides a sm all branch to the tem porom andibular joint

Anterior and posterior deep tem poral

Pass superior to the lateral pterygoid m . between the skull and the tem poralis m . while passing deep to the m uscle to innervate it Provides a sm all branch to the tem porom andibular joint

Lateral pterygoid

Passes into the deep surface of the m uscle Often arises from the buccal n.

Buccal

Passes anteriorly between the 2 heads of the lateral pterygoid m . Descends inferiorly along the lower part of the tem poralis m . to appear from deep to the anterior border of the m asseter m . Supplies the skin over the buccinator m . before passing through it to supply the m ucous m em brane lining its inner surface and the gingiva along the m andibular m olars Continued  on  next  page

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3

Posterior Division of the Mandibular Division Branch

Course

Auriculotem poral

Norm ally arises by 2 roots, between which the m iddle m eningeal a. passes Runs posteriorly just in erior to the lateral pterygoid and continues to the m edial side o the neck o the m andible Then it turns superiorly with the superf cial tem poral vessels between the auricle and condyle o the m andible deep to the parotid gland On exiting the parotid gland, it ascends over the zygom atic arch and divides into superf cial tem poral branches

Lingual

Lies in erior to the lateral pterygoid and m edial and anterior to the in erior alveolar n. The chorda tym pani n. also joins the posterior part The lingual n. passes between the m edial pterygoid and the ram us o the m andible, then passes obliquely to enter the oral cavity bounded by the superior pharyngeal constrictor m ., m edial pterygoid, and the m andible Supplies the m ucous m em brane o the anterior 2/ 3 o the tongue and gingiva on the lingual aspect o the m andibular teeth

In erior alveolar

The largest branch o the m andibular division Descends ollowing the in erior alveolar a. in erior to the lateral pterygoid and f nally between the sphenom andibular lig. and the ram us o the m andible until it enters the m andibular oram en A ter entering the m andibular oram en, it travels in the m andibular canal until it term inates as the m ental and incisive nn. in the area o the 2nd prem olar Innervates all m andibular teeth (via in erior alveolar and incisive nn.), periodontal ligam ents (via in erior alveolar and incisive nn.), and the gingiva rom the prem olars anteriorly to the m idline (via the m ental n.)

Mylohyoid

Branches rom the in erior alveolar n. im m ediately be ore it enters the m andibular oram en Descends in a groove on the deep side o the ram us o the m andible until it reaches the superf cial sur ace o the m ylohyoid Supplies the m ylohyoid and the anterior belly o the digastric m .

Zygomaticotemporal n. (V2 ) Deep temporal nn. (V3 ) Masseteric n. (V3 ) Mandibular n. (V3 ) Nerve to medial pterygoid and tensor veli palatini mm. (V3 ) (cut) Zygomaticofacial n. (V2 ) Maxillary n. (V2 ) Infraorbital n. (V2 ) Pterygopalatine ganglion Auriculotemporal n. (V3 ) Middle meningeal a. Superficial temporal a. (cut) Facial n. (VII) (cut)

Nerve to lateral pterygoid m. (V3 ) (cut) Buccal n. (V3 ) Chorda tympani n. (VII)

Maxillary a. Inferior alveolar n. (V3 )

Lingual n. (V3 ) Medial pterygoid m. (cut) (lateral pterygoid removed)

Nerve to mylohyoid (V3 ) Submandibular ganglion

Mental n. (V3 )

Internal carotid a.

Figu re 3-22 BASIC NEUROANATO MY AND CRANIAL NERVES

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CRANIAL NERVES • CN V: Trigeminal Nerve TRIGEMINAL NERVE PATHWAYS • Responsible or carrying to conscious level: • Pain and tem perature • Light touch • Discrim inative touch • Pressure • Utilizes a 3-neuron sensory system : • Prim ary neuron • Secondary neuron • Tertiary neuron • Utilizes the contralateral ventral trigem inothalam ic tract • Som e discrim inative touch and pressure f bers utilize the ipsilateral dorsal trigem inothalam ic tract, but this contribution is very m inor • Proprioception f bers are unique in that the cell body or the sensory nerve f ber is located in the central nervous system (m esencephalic nucleus)

Types of Fibers

Trigeminal Sensory Nucleus

Ascending Pathway

Pain and tem perature Light touch

Spinal (descending) nucleus

Ventral trigem inothalam ic tract

Discrim inative touch Pressure

Principal (m ain) sensory nucleus

Ventral trigem inothalam ic tract (dorsal trigem inothalam ic tract subserves discrim inative touch and pressure)

Proprioception

Mesencephalic nucleus

Projects to m otor nucleus o V to control the jaw jerk re ex and orce o bite

Cerebral cortex: postcentral gyrus Internal capsule

Centromedian nucleus (intralaminar) Ventral posteromedial (VPM) nucleus of thalamus

Midbrain Dorsal trigeminal lemniscus (dorsal trigeminothalamic tract) Ventral trigeminal lemniscus (ventral trigeminothalamic tract) Pontine reticular formation Pons

Medullary reticular formation: Lateral reticular formation Medial reticular formation Ventral trigeminal lemniscus

Trigeminal mesencephalic nucleus Trigeminal motor nucleus Principal sensory trigeminal nucleus Touch, pressure Pain, temperature Proprioception - from muscle spindles Trigeminal (semilunar) ganglion O phthalmic n. Maxillary n. Sensory root and motor root of mandibular n.

Facial (VII) n.

Spinal (descending) trigeminal tract Spinal (descending) trigeminal nucleus Dorsolateral fasciculus (of Lissauer) Cervical spinal cord Substantia gelatinosa (lamina II)

Vagus (X) n.

Glossopharyngeal (IX) n.

Figu re 3-23

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3

MAJOR ASCENDING PATHWAYS OF THE TRIGEMINAL NERVE Types of Neurons

Path of Pain and Temperature

Prim ary neuron

Fibers (Aδ or C) travel rom the receptor rom the ophthalm ic, m axillary, and m andibular divisions o the trigem inal n. The nerve cell body o the prim ary neuron is located in the trigem inal ganglion Fibers enter the pons Fibers descend in the spinal (descending) tract located rom the pons to the upper cervical spinal cord Fibers synapse on the nerve cell body o the secondary neuron

Fibers (Aβ) travel rom the receptor rom the ophthalm ic, m axillary, and m andibular divisions o the trigem inal n. The nerve cell body o the prim ary neuron is located in the trigem inal ganglion Fibers enter the pons Fibers m ay have either o 2 courses: • May descend in the spinal (descending) tract located rom the pons to the upper cervical spinal cord • May ascend to synapse on the nerve cell body o the secondary neuron Fibers synapse on the nerve cell body o the secondary neuron

Fibers (Aβ) travel rom the receptor rom the ophthalm ic, m axillary, and m andibular divisions o the trigem inal n. The nerve cell body o the prim ary neuron is located in the trigem inal ganglion Fibers enter the pons Fibers ascend to synapse on the nerve cell body o the secondary neuron

Secondary neuron

Secondary nerve cell bodies begin in the spinal (descending) nucleus located rom the pons to the upper cervical spinal cord (pars caudalis) Fibers decussate and ascend in the ventral trigem inothalam ic tract (lem niscus) to the thalam us Fibers synapse on the nerve cell body o the tertiary neuron

Secondary nerve cell bodies m ay reach the thalam us along either o 2 courses: • May begin in the spinal (descending) nucleus (pars interpolaris and pars oralis) and decussate and ascend in the ventral trigem inothalam ic tract (lem niscus) to the thalam us • May begin in the principal (m ain) sensory nucleus and decussate and ascend in the ventral trigem inothalam ic tract (lem niscus) to the thalam us (Note: som e f bers ascend in the ipsilateral dorsal trigem inothalam ic tract) Fibers synapse on the nerve cell body o the tertiary neuron

Secondary nerve cell bodies begin in the principal (m ain) sensory nucleus located in the pons Fibers decussate and ascend in the ventral trigem inothalam ic tract (lem niscus) to the thalam us (Note: som e f bers ascend in the ipsilateral dorsal trigem inothalam ic tract) Fibers synapse on the nerve cell body o the tertiary neuron

Tertiary neuron

Tertiary nerve cell bodies begin in the ventral posterom edial nucleus o the thalam us (VPM) Fibers ascend through the posterior lim b o the internal capsule to term inate in the postcentral gyrus

Tertiary nerve cell bodies begin in the VPM Fibers ascend through the posterior lim b o the internal capsule to term inate in the postcentral gyrus

Tertiary nerve cell bodies begin in the VPM Fibers ascend through the posterior lim b o the internal capsule to term inate in the postcentral gyrus

Path of Light Touch

Path of Discriminative Touch and Pressure

PROPRIOCEPTION OF THE TRIGEMINAL NERVE • Sensory f bers carry input rom the neurom uscular spindles along the m andibular division o the trigem inal n. • The nerve cell bodies o these sensory neurons are located in the m esencephalic nucleus o the m idbrain • These f bers project to the m otor nucleus o the trigem inal n. and innervate the m uscles o m astication, to control the jaw jerk re ex and orce o bite

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CRANIAL NERVES • CN VII: Facial Nerve Functional Column

94

Origin of Fibers

Termination of Fibers

Summary

Comment

GSA

A erent f bers begin in the various receptors (nociceptors, m echanoceptors, proprioceptors) o the skin o the external ear and tym panic m em brane

Pain and tem perature f bers term inate in the spinal nucleus o V

GSA f bers are carried in the nervus interm edius portion o the acial n. GSA f bers are responsible or providing sensory innervation to a portion o the external ear and tym panic m em brane GSA f bers o the acial n. utilize the trigem inothalam ic lem niscus to carry their sensory im pulses to consciousness

Facial nerve provides a very sm all area o GSA distribution Nerve cell bodies or the prim ary f bers are located in the geniculate ganglion

SVA

A erent f bers begin in the taste receptors o the anterior 2/ 3 o the tongue

Prim ary a erent f bers travel in the tractus solitarius and term inate in the nucleus solitarius

SVA f bers are carried in the nervus interm edius portion o the acial n. SVA f bers are responsible or carrying the taste f bers rom the taste buds on the anterior 2/ 3 o the tongue

Nerve cell bodies or the prim ary f bers are located in the geniculate ganglion

GVA

A erent f bers begin in the various receptors (such as nociceptors) o the m ucous m em branes o the nasopharynx

Prim ary a erent f bers travel in the tractus solitarius and term inate in the nucleus solitarius

GVA f bers are carried in the nervus interm edius portion o the acial n. GVA f bers utilize the sam e pathway as the SVA f bers

Nerve cell bodies or the prim ary f bers are located in the geniculate ganglion

GVE

Preganglionic parasym pathetic f bers begin in the superior salivatory nucleus

Postganglionic parasym pathetic f bers innervate the lacrim al, nasal, subm andibular, and sublingual glands

GVE f bers are carried in the nervus interm edius portion o the acial n.

GVE f bers utilize 2 ganglia: • Pterygopalatine • Subm andibular

SVE

Begins in the m otor nucleus o the acial n.

Innervates the m uscles o acial expression, stylohyoid, posterior digastric, and stapedius mm.

SVE f bers are carried in the m otor root o the acial n. SVE f bers are responsible or innervating the m uscles o the 2nd pharyngeal arch

In Bell’s palsy, the easiest sym ptom to observe is that the m uscles innervated by the SVE f bers are paralyzed

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

CRANIAL NERVES • CN VII: Facial Nerve

Greater petrosal n. Deep petrosal n. (from internal carotid plexus) Lesser petrosal n. Nerve (vidian) of pterygoid canal O tic ganglion Pterygopalatine ganglion

Facial n. (VII) Geniculate ganglion Internal carotid plexus (on internal carotid a.)

3

Internal acoustic meatus Intermediate n. Motor nucleus of facial n. Superior salivatory nucleus Solitary tract nucleus

e

T

m

p

o

ra

l

b

ra

n

c

h

e

s

e : a n te rio r /3 2

m a ti c b r a n c h es

Buccal branches ch

st Ta o f to n gu e

go Zy

n

O ccipital branch of posterior auricular n. Branches to auricular mm. Posterior auricular n. Nerve to stapedius m. Stylomastoid foramen Tympanic plexus Tympanic n. (Jacobson) (from glossopharyngeal n.) Glossopharyngeal n. (IX) Digastric m. (posterior belly) Stylohyoid m.

ra C

er

v

ic

a

l

b

Submandibular ganglion

Sublingual gland Submandibular gland

al Ma rgin la r u m a n d ib b ra n c h

Lingual n. (from trigeminal n.) Chorda tympani n. Efferent fibers Afferent fibers Parasympathetic fibers Sympathetic fibers

Figu re 3-24

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CRANIAL NERVES • CN VIII: Vestibulocochlear Nerve Functional Column SSA

Origin of Fibers

Termination of Fibers

Summary

Comment

Organ o Corti Cristae o sem icircular canals Maculae o utricle and saccule

Cochlear and vestibular nuclei

SSA f bers travel rom the various vestibulocochlear receptors to their respective nuclei in the brainstem

Vestibulocochlear and acial nn. both enter the internal acoustic m eatus and can be a ected by tum ors in the region

Cochlear n. Utricle

Membranous labyrinth within bony labyrinth (path of sound waves)

Semicircular canals

Saccule

Scala vestibuli Cochlear duct (scala media) Scala tympani Section through turn of cochlea

Round window

Scala vestibuli (perilymph); weakly +80 mV positive

Efferent n. fibers

O val window and stapes Vestibular (Reissner’s) membrane Cochlear duct (scala media; endolymph) Tectorial membrane Spiral lig. Bone

Scala tympani (perilymph); 0 mV

Afferent n. fibers

O uter hair cells; Basilar membrane

Spiral ganglion Spiral organ of Corti

60 mV

Inner hair cell;

60 mV

Hair cells Inner

Tectorial membrane

O uter

Stereocilia

Rods and tunnel of Corti

Basilar membrane Supporting cells Spiral lamina Spiral ganglion

Afferent n. fibers Efferent n. fibers

As basilar membrane moves up, hairs are deflected outward, causing depolarization of hair cells and increased firing of afferent nerve fibers

Figu re 3-25

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NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

CRANIAL NERVES • CN VIII: Vestibulocochlear Nerve Membranous labyrinth

Vestibular Utricle ganglion Saccule

Vestibular and cochlear divisions of vestibulocochlear n.

3

Position within base of skull

Superior semicircular canal

Canals superior

Plane of horizontal canal and utricle

Posterior

Horizontal semicircular canal

30 ˚ 60 ˚

Cochlear duct (scala media)

Plane of saccule

Maculae

Cristae within ampullae

Posterior semicircular canal

Plane of superior canal

Superior

Horizontal

90 ˚ Section of crista O pposite wall of ampulla

Plane of posterior canal

Posterior

Gelatinous cupula Hair tufts Hair cells Nerve fibers Basement membrane Section of macula O toconia Gelatinous otolithic membrane Hair tuft Hair cells Supporting cells Basement membrane Nerve fibers Structure and innervation of hair cells Excitation Kinocilium Stereocilia Cuticle

Inhibition Basal body Cuticle

Kinocilium Stereocilia Basal body Hair cell (type II)

Hair cell (type I)

Supporting cells

Supporting cells Afferent n. calyx

Efferent n. ending

Efferent n. ending

Afferent n. calyx

Basement membrane Myelin sheath

Myelin sheath

Figu re 3-26

BASIC NEUROANATO MY AND CRANIAL NERVES

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CRANIAL NERVES • CN IX: Glossopharyngeal Nerve Functional Column

98

Origin of Fibers

Termination of Fibers

Summary

Comment

GSA

A erent f bers begin in the various receptors o the skin o the external ear and the posterior 1/ 3 o the tongue

Pain and tem perature f bers term inate in the spinal nucleus o V

GSA f bers are responsible or providing sensory innervation to a sm all portion o the external ear and posterior 1/ 3 o the tongue GSA f bers o the glossopharyngeal n. utilize the trigem inothalam ic lem niscus to carry their sensory im pulses to consciousness

Nerve cell bodies or the prim ary f bers are located in the superior ganglion o IX

SVA

A erent f bers begin in the taste receptors o the posterior 1/ 3 o the tongue

Prim ary a erent f bers travel in the tractus solitarius and term inate in the nucleus solitarius

SVA f bers are responsible or carrying the taste f bers rom the circum vallate papillae and the taste buds on the posterior 1/ 3 o the tongue

Nerve cell bodies or the prim ary f bers are located in the in erior ganglion o IX

GVA

A erent f bers begin in the various receptors o the m ucous m em branes o the nasopharynx. oropharynx, m iddle ear, carotid body, and carotid sinus

Prim ary a erent f bers travel in the tractus solitarius and term inate in the nucleus solitarius

GVA f bers utilize the sam e pathway as the SVA f bers

The nerve cell bodies or the prim ary f bers are located in the in erior ganglion o IX GVA f bers are predom inantly the sensory portion o the pharyngeal plexus

GVE

Preganglionic parasym pathetic f bers begin in the in erior salivatory nucleus

Postganglionic parasym pathetic f bers innervate parotid gland

The GVE f bers are responsible or providing the parasym pathetic innervation to the parotid gland

GVE f bers utilize 1 ganglion: • Otic

SVE

Begins in the nucleus am biguus

Innervates the stylopharyngeus m.

SVE f bers are responsible or innervating the m uscles o the 3rd pharyngeal arch

Stylopharyngeus is the only m uscle innervated by the glossopharyngeal n.

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

CRANIAL NERVES • CN IX: Glossopharyngeal Nerve

3

Efferent fibers Afferent fibers Parasympathetic fibers

Spinal tract and spinal nucleus of trigeminal n. Solitary tract nucleus Tympanic n. (Jacobson) Nucleus ambiguus Tympanic cavity and plexus Inferior salivatory nucleus Geniculate ganglion Stylomastoid foramen of facial n. Caroticotympanic n. (from internal carotid plexus) Greater petrosal n. Deep petrosal n. Nerve (vidian) of pterygoid canal Lesser petrosal n. Mandibular n. (V3 ) O tic ganglion Auriculotemporal n. Parotid gland Tubal branch of tympanic plexus Pharyngotympanic (auditory) tube and pharyngeal opening Glossopharyngeal n. (IX)

Stylopharyngeus m. (and branch from glossopharyngeal n.)

Jugular foramen Communication to auricular branch of vagus n. Superior and Inferior ganglia of glossopharyngeal n. Communication to facial n. (VII)

Taste and somatic sensation: posterior 1 ⁄3 of tongue

Vagus n. (X) Superior cervical sympathetic ganglion Sympathetic trunk Carotid branch of glossopharyngeal n. Internal carotid a.

Pharyngeal plexus

Carotid sinus

Pharyngeal, tonsillar and lingual branches of glossopharyngeal n.

Carotid body Common carotid a. External carotid a.

Figu re 3-27

BASIC NEUROANATO MY AND CRANIAL NERVES

99

3

CRANIAL NERVES • CN X: Vagus Nerve Functional Column

100

Origin of Fibers

Termination of Fibers

Summary

Comment

GSA

A erent f bers begin in the various receptors on a sm all part o the skin o the external ear

Pain and tem perature f bers term inate in the spinal nucleus o V

The GSA f bers are responsible or providing sensory innervation to a very sm all portion o the external ear The GSA f bers o the glossopharyngeal n. utilize the trigem inothalam ic lem niscus to carry their sensory im pulses to consciousness

The nerve cell bodies or the prim ary f bers are located in the superior ganglion o X

SVA

A erent f bers begin in the taste receptors o the epiglottic region and are scattered on the palate

Prim ary a erent f bers travel in the tractus solitarius and term inate in the nucleus solitarius

The SVA f bers are responsible or carrying the taste f bers rom the epiglottic region and are scattered on the palate

The nerve cell bodies or the prim ary f bers are located in the in erior ganglion o X

GVA

A erent f bers begin in the various receptors o the m ucous m em branes o the laryngopharynx, larynx, thorax, and abdom en

Prim ary a erent f bers travel in the tractus solitarius and term inate in the nucleus solitarius

The GVA f bers utilize the sam e pathway as the SVA f bers

The nerve cell bodies or the prim ary f bers are located in the in erior ganglion o X

GVE

Preganglionic parasym pathetic f bers begin in the dorsal m otor nucleus o the vagus n.

Postganglionic parasym pathetic f bers innervate thoracic and abdom inal viscera

The GVE f bers are responsible or providing the parasym pathetic innervation to the thoracic and abdom inal viscera

The GVE f bers utilize: • Intram ural ganglia

SVE

Begins in the nucleus am biguus

Innervates the m uscles o the pharynx (via the pharyngeal plexus) and the larynx

The SVE f bers are responsible or innervating the m uscles o the 4th and 6th pharyngeal arches

The SVE f bers are the m otor com ponent to the pharyngeal plexus (m uscles o pharynx) and m uscles o the larynx Lesions o the vagus paralyze the m uscles o the larynx on the a ected side

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

CRANIAL NERVES • CN X: Vagus Nerve

3

Dorsal nucleus of vagus n. (parasympathetic)

Glossopharyngeal n. (IX)

Solitary tract nucleus (visceral afferents including taste) Spinal tract and spinal nucleus of trigeminal n. (somatic afferent) Nucleus ambiguus (motor to pharyngeal and laryngeal mm.) Cranial root of accessory n.

Meningeal branch of vagus n. Auricular branch of vagus n. Pharyngotympanic (auditory) tube Levator veli palatini m. Salpingopharyngeus m. Palatoglossus m. Palatopharyngeus m.

Vagus n. (X)

Superior pharyngeal constrictor m.

Jugular foramen Superior ganglion of vagus n.

Stylopharyngeus m.

Inferior ganglion of vagus n.

Middle pharyngeal constrictor m.

Pharyngeal branch of vagus n.

Inferior pharyngeal constrictor m.

Communicating branch of vagus n. to carotid branch of glossopharyngeal n.

Cricothyroid m. Trachea

Pharyngeal plexus Superior laryngeal n.: Internal branch (sensory and parasympathetic) External branch (motor to cricothyroid m.)

Esophagus Right subclavian a. Right recurrent laryngeal n. Heart Hepatic branch of anterior vagal trunk (in lesser omentum) Celiac branches from anterior and posterior vagal trunks to celiac plexus

Superior cervical cardiac branch of vagus n. Inferior cervical cardiac branch of vagus n. Thoracic cardiac branch of vagus n. Left recurrent laryngeal nerve Pulmonary plexus

Celiac and superior mesenteric ganglia and celiac plexus

Cardiac plexus Esophageal plexus

Hepatic plexus

Anterior vagal trunk Gastric branches of anterior vagal trunk (branches from posterior trunk behind stomach)

Gallbladder and bile ducts Liver Pyloric branch from hepatic plexus Pancreas

Vagal branches

Duodenum Small intestine Efferent fibers Afferent fibers Parasympathetic fibers

Ascending colon Cecum Appendix

Figu re 3-28

BASIC NEUROANATO MY AND CRANIAL NERVES

101

3

CRANIAL NERVES • CN XI: Accessory Nerve OVERVIEW

• • • •

Th e an atom y of th e accessory n erve is con troversial in th e literatu re It is trad ition ally d escribed as h avin g a cran ial root an d a sp in al root Th e cran ial bers are argu ed to be p art of th e vagu s n erve an d n ot th e accessory n erve Th e tradition al d escrip tion is n oted in th e table

Functional Column

Origin of Fibers

SVE/ GSE*

Cranial  part: Begins in the nucleus am biguus Spinal  part: Begins in the upper cervical levels o the spinal cord

Termination of Fibers

Summary

Comment

Innervates the trapezius and sternocleidom astoid mm.

These f bers o the cranial part travel with the vagus n. The spinal part begins in the cervical levels o the spinal cord and enters the skull via the oram en m agnum Once inside the cranium , the accessory n. exits the jugular oram en with the glossopharyngeal and vagus nn.

The cranial and spinal parts are described as separating so that the cranial part can ollow the vagus nerve and the spinal part can pass into the sternocleidom astoid m . and travel through the posterior triangle until reaching the trapezius m .

Nucleus ambiguus

Cranial root of accessory n. (joins vagus n.)* Spinal root of accessory n. Jugular foramen

Vagus n. (X)

Superior ganglion of vagus n. Foramen magnum Accessory n. (XI)* Inferior ganglion of vagus n. C1 spinal n. C2 spinal n. Accessory n. (to sternocleidomastoid and trapezius mm.) Sternocleidomastoid m. (cut) C3 spinal n. C4 spinal n. Trapezius m.

Efferent fibers Proprioceptive fibers *Recent evidence suggests that the accessory nerve lacks a cranial root and has no connection to the vagus nerve. There is disagreement whether the branchiomeric innervation to the trapezius and sternocleidomastoid is from SVE or GSE fibers.

Figu re 3-29

102

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

CRANIAL NERVES • CN XII: Hypoglossal Nerve Functional Column

Origin of Fibers

GSE

Begins in the hypoglossal nucleus

Termination of Fibers

Summary

Comment

Innervates the genioglossus, hyoglossus, and styloglossus m m . and the intrinsic m m . o the tongue

The GSE f bers are responsible or innervating the m ajor portion o the tongue m usculature

Lesions o the hypoglossal n. cause the tongue to deviate to the side o the lesion on protrusion

Hypoglossal n. (XII) Superior (in hypoglossal canal) longitudinal

Intrinsic mm. of tongue

3

Hypoglossal nucleus

Transverse and vertical Inferior longitudinal

Styloglossus m. Inferior ganglion of vagus n. Ventral rami of C1, 2, 3 form ansa cervicalis of cervical plexus Superior cervical sympathetic ganglion Superior root of ansa cervicalis

Genioglossus m. Internal carotid a.

Geniohyoid m.

Inferior root of ansa cervicalis

Hyoglossus m. Thyrohyoid m.

Ansa cervicalis

O mohyoid m. (superior belly)

Internal jugular v. Common carotid a.

Sternohyoid m. Sternothyroid m.

O mohyoid m. (inferior belly) Efferent fibers Afferent fibers

Figu re 3-30

BASIC NEUROANATO MY AND CRANIAL NERVES

103

3

CLINICAL CORRELATES • Lesions Affecting the Accessory Nerve • •

•

Th e accessory n erve p rovid es m otor in n ervation to th e stern ocleid om astoid an d trap eziu s m u scles Th e accessory n erve cou rses close to th e su p er cial cervical lym p h n odes • Th is cou rse m akes it vu ln erable to d am age du rin g biop sy or rad ical n eck d issection in th e p osterior trian gle • Dam age to th e accessory n erve also m ay resu lt from a carotid en d arterectom y In lesion s located in th e p osterior trian gle, th e stern ocleid om astoid m u scle is u n affected , bu t th e trap eziu s m u scle is d ein n ervated • Th e sh ou ld er d roop s, with m ild win gin g of th e scap u la • Abdu ction of th e arm also is affected wh en p atien t attem p ts to raise it above th e h orizon tal p lan e

Sternocleidomastoid m. (SCM) Lesion proximal to sternocleidomastoid (SCM) innervation

C1

Weakness of SCM

Weakness turning head to opposite side

C2

Spinal accessory n.

Lesion in posterior triangle of neck (distal to SCM innervation)

C3 C4 C5

Weakness of trapezius

Clinical presentation varies with location of damage.

Trapezius m.

Comparison of clinical findings in CN-XI and long thoracic nerve damage Spinal accessory nerve

Spinal accessory n. (CN-XI) Trapezius m. Scapula Upper trapezius atrophy Spinal accessory nerve palsy

Drooping of scapula

Atrophy of the trapezius demonstrates loss of the contour of the neck and prominence of the rhomboids as well as drooping of the scapula.

Figu re 3-31

104

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

Drooping of shoulder and midscapular winging; weakness in shoulder elevation and arm abduction above horizontal

CLINICAL CORRELATES • Lesions Affecting the Hypoglossal Nerve •

• • •

•

3

Th e h yp oglossal n erve p rovid es m otor in n ervation to a m ajority of th e m u scles of th e ton gu e, in clu d in g: • Gen ioglossu s • Hyoglossu s • Styloglossu s Protru sion of th e ton gu e is accom p lish ed by th e bilateral action s of th e gen ioglossu s m u scles Paralysis of a gen ioglossu s m u scle cau ses th e p rotru d ed ton gu e to d eviate to th e p aralyzed side Paralysis of th e h yp oglossal n erve can be cau sed by: • Tu m ors • Neck trau m a • Rad iation th erap y A sim ilar p aralysis can be cau sed by a stroke affectin g th e u p p er m otor n eu ron s on th e sid e con tralateral to th e p aralyzed m u scles, owin g to th e crossin g bers of th e u p p er m otor n eu ron s

Sites of lesions affecting hypoglossal n. (CN-XII)

Motor cortex

Lesion

Subtle weakness of tongue may be tested by asking patient to press tongue against cheek (shown) or against a tongue depressor. CN-XII Lesion

Nucleus CN-XII

CN-XII

Atrophy

Fasciculation

Lesions of nucleus of CN-XII or n. proper result in ipsilateral deficit.

Patient with right-sided CN-XII lesion

If hypoglossal nerve is affected on one side, the tongue often deviates toward the side of the lesion on protrusion (due to imbalance of genioglossus contraction). When hypoglossal nerve or its nucleus is damaged, atrophy and fasciculation of the tongue are noted on evaluation.

with

E. Ha tton

Figu re 3-32 BASIC NEUROANATO MY AND CRANIAL NERVES

105

This pa ge inte ntiona lly le ft bla nk

CHAPTER 4

THE NECK

Overview and Topographic Anatomy

10 8

Triangles of the Neck

111

Anterior Triangle

113

Posterior Triangle

120

Suboccipital Triangle

122

Visceral Contents

123

Root of the Neck

125

Muscles

126

Vascular Supply of the Neck

130

Nerve Supply of the Neck

139

Clinical Correlates

148

4

OVERVIEW AND TOPOGRAPHIC ANATOMY • General Information • •

• •

Th e neck is th e area between th e base of th e sku ll an d in ferior bord er of th e m an d ible an d th e su p erior th oracic ap ertu re Th e an terior p ortion of th e n eck con tain s th e m ajor visceral stru ctu res between th e h ead an d th e th orax: • Ph aryn x • Laryn x • Trach ea • Esop h agu s • Th yroid an d p arath yroid glan ds For descrip tive p u rp oses, th e n eck is divided in to 2 trian gles: • An terior trian gle • Posterior trian gle Skin is th e m ost su p er cial stru ctu re coverin g th e n eck

FASCIA

•

• • •

• • •

10 8

Th e n eck is su rrou n d ed by 2 m ain layers of cervical fascia th at can be fu rth er su bd ivid ed : • Su p er cial cervical fascia • Deep cervical fascia • Su p er cial layer of d eep cervical fascia (also kn own as th e in vestin g layer) • Mid dle layer of deep cervical fascia (in clu d es m u scu lar an d visceral p arts su ch as th e p retrach eal) • Deep layer of d eep cervical fascia (in clu des p revertebral an d alar) • Carotid sh eath (form ed by oth er layers of d eep cervical fascia) Th e con ten ts of th e su p er cial cervical fascia will vary d ep en d in g u p on location bu t in clu d e: Platysm a (an d cervical bran ch of facial n erve th at in n ervate th e m u scle) Cu tan eou s n erves of th e cervical p lexu s: • Lesser occip ital • Great au ricu lar • Tran sverse cervical (largest sen sory con tribu tion ) • Su p raclavicu lar Deep to th e su p er cial cervical fascia is th e in vestin g (or su p er cial) layer of d eep cervical fascia Th e su p er cial (or in vestin g) layer of deep cervical fascia attach es p osteriorly alon g th e m id lin e an d p asses an teriorly to su rrou n d th e en tire n eck Th e su p er cial (or in vestin g) layer of deep cervical fascia su rrou n d s th ese m u scles: • Trap eziu s • Stern ocleidom astoid

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

OVERVIEW AND TOPOGRAPHIC ANATOMY • General Information Parotid gland (cut) Ramus of mandible Styloglossus muscle Mastoid process

4

Masseter muscle Submandibular triangle Submandibular gland Hyoglossus muscle Mylohyoid muscle

Styloid process Stylohyoid muscle Digastric muscle (posterior belly) Middle pharyngeal constrictor muscle Splenius muscle Sternocleidomastoid muscle Levator scapulae muscle

Body of mandible Digastric muscle (anterior belly) Submental triangle (half) Hyoid bone

Posterior triangle

Thyrohyoid muscle

Posterior Scalene muscles Middle Anterior Brachial plexus

Carotid triangle

Trapezius muscle

Sternohyoid muscle

O mohyoid muscle (superior belly) Inferior pharyngeal constrictor muscle Sternothyroid muscle Muscular triangle

O mohyoid muscle (inferior belly) Clavicle Pectoralis major muscle

Sternal head Clavicular head Sternocleidomastoid muscle Digastric muscle (anterior belly) Mylohyoid muscle Submandibular gland Fibrous loop for intermediate digastric tendon

Platysma muscle (cut aw ay)

Stylohyoid muscle Digastric muscle (posterior belly) Submental triangle External carotid artery Internal jugular vein Thyrohyoid muscle O mohyoid muscle (superior belly) Sternohyoid muscle Sternothyroid muscle Scalene muscles Trapezius muscle

Hyoid bone Carotid sheath Fascia of infrahyoid muscles and cut edge Thyroid cartilage Investing layer of (deep) cervical fascia and cut edge Cricoid cartilage

Clavicle O mohyoid muscle (inferior belly) Pretracheal layer of (deep) cervical fascia over thyroid gland and trachea

Clavicular head Sternocleidomastoid Sternal head muscle

Figu re 4-1

THE NECK 109

4

OVERVIEW AND TOPOGRAPHIC ANATOMY • General Information

Temporal bone Sphenoid bone Condylar process of mandible Coronoid process of mandible Lateral pterygoid plate (broken line) Pterygomandibular raphe (broken line)

Mandible

Mastoid process External acoustic meatus

Ramus Angle Body

Atlas (C1) Styloid process

Stylohyoid ligament

Hyoid bone

Axis (C2) Stylomandibular ligament

Body Lesser horn Greater horn

C3 vertebra

Epiglottis

C7 vertebra

Thyroid cartilage Cricoid cartilage Trachea

T1 vertebra

1st rib Spine of sphenoid bone Foramen spinosum Foramen ovale

Sphenopalatine foramen Choanae (posterior nares) Lateral plate Medial plate Hamulus Tuberosity of maxilla Infratemporal fossa Alveolar process of maxilla

of pterygoid process

Pyramidal process of palatine bone Pterygomaxillary fissure leading into pterygopalatine fossa

Figu re 4-2

110

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

TRIANGLES OF THE NECK • Anterior Triangle •

•

• • •

•

4

Borders of th e an terior trian gle: • An terior bord er of th e stern ocleidom astoid • In ferior bord er of th e m an d ible (in clu d in g a lin e from th e an gle of th e m an d ible to th e m astoid p rocess) • Mid lin e of th e n eck (con tin u ou s from th e m an d ible to th e su p rastern al n otch ) Usin g th e h yoid as a keyston e, th e om oh yoid an d d igastric m u scles su bd ivid e th e an terior trian gle in to: • Su bm en tal trian gle • Su bm an d ibu lar trian gle • Carotid trian gle • Mu scu lar trian gle All of th e trian gles with in th e an terior trian gle are p aired excep t for th e su bm en tal trian gle, wh ich sp an s th e righ t an d th e left sides of th e n eck Hyoid bon e d ivides th e an terior trian gle in to 2 areas: su p rah yoid an d in frah yoid region s Th e suprahyoid region con tain s 4 m u scles: • Myloh yoid • Digastric • Styloh yoid • Gen ioh yoid Th e infrahyoid region con tain s 4 m u scles com m on ly called strap m u scles: • Om oh yoid • Stern oh yoid • Stern oth yroid • Th yroh yoid

Superior mental spine for origin of genioglossus muscle

Mylohyoid muscle Geniohyoid muscle

Body of hyoid bone Hyoglossus muscle (cut)

Figu re 4-3

THE NECK 111

4

TRIANGLES OF THE NECK • Anterior Triangle

Digastric muscle (anterior belly) Mylohyoid muscle

Hyoid bone Thyrohyoid membrane

Hyoglossus muscle

External carotid artery

Stylohyoid muscle

Internal jugular vein

Digastric muscle (posterior belly)

Thyrohyoid muscle

Fibrous loop for intermediate digastric tendon Sternohyoid and omohyoid muscles (cut)

Thyroid cartilage O mohyoid muscle (superior belly) Sternohyoid muscle

Thyrohyoid muscle

Median cricothyroid ligament

Cricothyroid muscle Sternothyroid muscle O mohyoid muscle (superior belly) (cut) Thyroid gland

Cricoid cartilage Scalene muscles

Trapezius muscle O mohyoid muscle (inferior belly)

Sternohyoid muscle (cut) Trachea

Clavicle

Figu re 4-4

112

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

ANTERIOR TRIANGLE • Submental Triangle •

• •

•

4

Borders of th e su bm en tal trian gle: • Bod y of h yoid • An terior d igastric on righ t • An terior d igastric on left Floor of th e trian gle is com p osed of th e: • Myloh yoid Roof is m ad e of th e: • Skin • Su p er cial cervical fascia with p latysm a • Deep cervical fascia Su bm en tal trian gle is u n p aired

MAJOR CONTENTS OF THE SUBMENTAL TRIANGLE Artery

Vein

Nerve

Anterior jugular

Structures Subm ental lym ph nodes

Facial artery and vein

Digastric muscle (anterior belly)

Marginal mandibular branch of facial nerve

Submandibular gland Mylohyoid muscle

Hyoid bone

Internal jugular vein Anterior jugular vein Communicating vein Great auricular nerve Thyroid cartilage Transverse cervical nerves Thyroid gland External jugular vein

Figu re 4-5

THE NECK 113

4

ANTERIOR TRIANGLE • Submandibular Triangle • •

•

•

• •

•

Often called th e digastric trian gle Borders of th e su bm an d ibu lar trian gle: • In ferior bord er of th e m an d ible (in clu d in g a lin e from th e an gle of th e m an d ible to th e m astoid p rocess) • Posterior d igastric • An terior d igastric Floor of th e trian gle is com p osed of th e: • Hyoglossu s • Myloh yoid • Mid dle con strictor Roof is m ad e of th e: • Skin • Su p er cial cervical fascia with p latysm a • Deep cervical fascia Su bm an d ibu lar trian gle is p aired Th ere are 3 clin ically sign i can t trian gles fou n d with in th e su bm an dibu lar trian gle: • Lesser’s trian gle • Pirogoff’s trian gle • Beclard’s trian gle All 3 trian gles are sm all su bd ivision of th e su bm an d ibu lar trian gle, wh ich aid s in id en tifyin g th e h yp oglossal n erve (wh ich lies su p er cial to th e h yoglossu s) an d th e lin gu al artery (wh ich lies d eep to th e h yoglossu s) wh ich m ay be im p ortan t for ligation d u rin g h em orrh age or su rgery

LESSER’S TRIANGLE

•

Bou n daries of Lesser’s trian gle: • Hyp oglossal n erve • An terior d igastric • Posterior d igastric

PIROGOV’S TRIANGLE

•

Bou n daries of Pirogov’s trian gle: • Hyp oglossal n erve • In term ed iate ten don of th e digastric • Myloh yoid (p osterior border)

BECLARD’S TRIANGLE

•

Bou n daries of Beclard ’s trian gle: • Greater corn u of th e h yoid • Posterior d igastric • Hyoglossu s (p osterior bord er)

MAJOR CONTENTS OF THE SUBMANDIBULAR TRIANGLE

114

Arteries

Veins

Nerves

Structures

Facial

Facial

Mylohyoid

Subm andibular gland

Subm ental

Subm ental

Hypoglossal

Subm andibular lym ph nodes

Lingual

Lingual

Lingual (hidden deep to deep portion of the subm andibular gland) Facial (branches of m arginal m andibular and cervical)

Inferior portion of the parotid gland

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

ANTERIOR TRIANGLE • Submandibular Triangle

4

Lateral, slightly inferior view Hyoglossus muscle Mylohyoid muscle Fibrous loop for intermediate digastric tendon Digastric muscle (anterior belly)

Mastoid process

Median raphe between mylohyoid muscles

Styloid process Digastric muscle (posterior belly) Stylohyoid muscle Greater horn Hyoid bone Lesser horn Body Thyrohyoid muscle O mohyoid muscle Sternohyoid muscle

Parotid gland

External carotid a. Retromandibular v. Anterior retromandibular v. Facial a. [a.] and v.

Posterior auricular v. Posterior retromandibular v. Facial a. Hypoglossal n. Lingual a. External jugular v.

Submental a. and v.

Common facial v.

Anterior digastric m.

Internal laryngeal n. and superior laryngeal vv.

Nerve to the mylohyoid Mylohyoid m. Nerve to the thyrohyoid Anterior jugular v.

Figu re 4-6

THE NECK 115

4

ANTERIOR TRIANGLE • Carotid Triangle • •

•

•

•

Nam ed becau se p arts of all 3 carotid arteries are located with in it Borders of th e carotid trian gle: • An terior bord er of th e stern ocleidom astoid • Posterior d igastric • Su p erior om oh yoid Floor of th e trian gle is com p osed of th e: • Hyoglossu s • Th yroh yoid • Mid dle con strictor • In ferior con strictor Roof is m ad e of th e: • Skin • Su p er cial fascia with p latysm a • Deep cervical fascia Carotid trian gle is p aired

MAJOR CONTENTS OF THE CAROTID TRIANGLE

116

Arteries

Veins

Nerves

Structures

Com m on carotid (with carotid body) • Internal carotid (with carotid sinus) • External carotid • Superior thyroid (with superior laryngeal branch) • Lingual • Facial • Ascending pharyngeal • Occipital

Internal jugular Com m on facial Lingual Superior thyroid Middle thyroid

Vagus • External laryngeal • Internal laryngeal Accessory (sm all portion) Hypoglossal Ansa cervicalis (superior lim b) Sym pathetic trunk

Larynx (sm all portion) Thyroid (sm all portion) Lym ph nodes

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

ANTERIOR TRIANGLE • Carotid Triangle

4

Posterior retromandibular v. Posterior auricular v.

Masseter m.

Cut edges of posterior digastric and stylohyoid mm.

Parotid gland Retromandibular v. Anterior retromandibular v.

O ccipital a. External jugular v.

Facial a. and v. Mylohyoid m.

Lingual a. Cut edge of internal jugular v. External carotid a. Internal carotid a. Ascending pharyngeal a. Vagus n.

Anterior digastric m. Submandibular gland Hypoglossal n. Cut edge of common facial v. Nerve to the thyrohyoid Internal laryngeal n. Superior laryngeal a. and v. O mohyoid m. Sternohyoid m.

Common carotid a. Anterior scalene m. Brachial plexus Cut edge of sternocleidomastoid

Ansa cervicalis Thyroid gland

Superficial temporal artery

Parotid fossa: right lateral dissection

Transverse facial artery Maxillary artery

Mastoid process

External carotid artery

Styloid process Facial nerve (VII) (cut) Sternocleidomastoid muscle (cut) Digastric muscle (posterior belly) (cut) O ccipital artery and sternocleidomastoid branch Accessory nerve (XI) Superior root Ansa cervicalis Inferior root

Posterior auricular artery Glossopharyngeal nerve (IX) Stylohyoid muscle Hypoglossal nerve (XII) Facial artery Lingual artery Mylohyoid muscle Hyoglossus muscle

Vagus nerve (X)

Digastric muscle (anterior belly)

Ascending pharyngeal artery Carotid branch of glossopharyngeal nerve (IX) and carotid body Internal carotid artery Internal jugular vein

Hyoid bone Branch to thyrohyoid muscle (from ansa cervicalis) Superior laryngeal artery Superior thyroid artery External carotid artery Common carotid artery

Figu re 4-7

THE NECK 117

4

ANTERIOR TRIANGLE • Muscular Triangle •

• •

•

Borders of th e m u scu lar trian gle: • An terior bord er of th e stern ocleidom astoid • Su p erior om oh yoid • Mid lin e Floor of th e trian gle is com p osed of th e: • Stern oh yoid • Stern oth yroid Roof is m ad e of th e: • Skin • Su p er cial fascia with p latysm a • Deep cervical fascia Mu scu lar trian gle is p aired

MAJOR CONTENTS OF THE MUSCULAR TRIANGLE

118

Artery

Veins

Nerve

Structures

Superior thyroid

Superior thyroid Inferior thyroid Anterior jugular

Ansa cervicalis

Strap m uscles: • Sternohyoid • Sternothyroid • Thyrohyoid Thyroid gland Parathyroid glands Larynx Trachea Esophagus Lym ph nodes

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

ANTERIOR TRIANGLE • Muscular Triangle

4

Hyoid bone Thyrohyoid membrane

Thyrohyoid muscle Thyroid cartilage O mohyoid muscle (superior belly)

Sternohyoid and omohyoid muscles (cut) Thyrohyoid muscle

Sternohyoid muscle Median cricothyroid ligament

O blique line of thyroid cartilage Cricothyroid muscle

Cricoid cartilage

Sternothyroid muscle O mohyoid muscle (superior belly) (cut) Thyroid gland Sternohyoid muscle (cut) Hyoid bone Superior laryngeal nerve Internal branch External branch Thyroid cartilage (lamina) Median cricothyroid ligament

Thyrohyoid membrane Superior root Ansa cervicalis Inferior root

Cricothyroid muscles Cricoid cartilage

Common carotid artery

Pyramidal lobe (often absent or small) Right lobe Left lobe Isthmus

Internal jugular vein Middle thyroid vein Inferior thyroid veins

Thyroid gland

Pretracheal lymph nodes

Inferior thyroid artery

Vagus nerve (X)

Thyrocervical trunk Subclavian artery and vein

1st rib (cut)

Vagus nerve (X)

Left recurrent laryngeal nerve

Right recurrent laryngeal nerve

Figu re 4-8

THE NECK 119

4

POSTERIOR TRIANGLE • General Information •

• • •

•

•

Borders of th e p osterior trian gle: • Posterior border of th e stern ocleid om astoid • Mid dle th ird of th e clavicle • An terior bord er of th e trap eziu s Located on th e lateral side of th e n eck an d sp irals arou n d th e n eck Is su bd ivid ed in to 2 trian gles by th e om oh yoid : • Om oclavicu lar (also called th e su p raclavicu lar trian gle) • Occip ital Roof of th e p osterior trian gle in clu d es: • Skin • Su p er cial fascia with p latysm a • Su p er cial (in vestin g) layer of d eep cervical fascia Floor of th e p osterior trian gle in clu des:* • Sem isp in alis cap itis (at ap ex) • Sp len iu s cap itis • Levator scap u lae • Posterior scalen e • Mid dle scalen e • An terior scalen e Posterior trian gle is p aired

*Th ese m u scles are covered by th e p revertebral layer of d eep cervical fascia.

MAJOR CONTENTS OF THE POSTERIOR TRIANGLE

120

Arteries

Veins

Nerves

Structures

3rd part of the subclavian Occipital (occasionally) Suprascapular Transverse cervical Dorsal scapular (usually)

External jugular (term inal part) Occipital (occasionally) Suprascapular Transverse cervical

Cervical plexus (sensory branches): • Lesser occipital • Transverse cervical • Great auricular • Supraclavicular Accessory Ram i and trunks of brachial plexus • Dorsal scapular • Long thoracic • Suprascapular Phrenic

Lym ph nodes

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

POSTERIOR TRIANGLE • General Information

4

Great auricular nerve Lesser occipital nerve Sternocleidomastoid muscle (cut, turned up)

Ansa cervicalis

C2 spinal nerve (ventral ramus) Accessory nerve (XI) C3 spinal nerve (ventral ramus) Levator scapulae muscle Middle scalene muscle Anterior scalene muscle C5 spinal nerve (ventral ramus) Transverse cervical artery Phrenic nerve O mohyoid muscle (inferior belly) (cut)

Superior root Inferior root

Vagus nerve (X) Vertebral artery

Brachial plexus

Thyrocervical trunk Subclavian artery and vein

Dorsal scapular artery Suprascapular artery Anterior retromandibular v. Retromandibular v.

Posterior retromandibular v. Posterior auricular v. Lesser occipital n.

Great auricular n. Facial v. External jugular v.

Common facial v. Transverse cervical nn.

Accessory n. (XI)

Supraclavicular

Figu re 4-9

THE NECK 121

4

SUBOCCIPITAL TRIANGLE • General Information •

• • •

Borders of th e su boccip ital trian gle: • Obliq u u s cap itis su p erior • Obliq u u s cap itis in ferior • Rectu s cap itis p osterior m ajor Roof of th e su boccip ital trian gle in clu d es: • Den se con n ective tissu e Floor of th e su boccip ital trian gle in clu des: • Posterior atlan to-occip ital m em bran e • Posterior arch of th e atlas Su boccip ital trian gle is p aired

VERTEBRAL ARTERIES

• • •

Th ese vessels en ter th e foram en tran sversariu m of th e 6th cervical vertebra, em ergin g above th e 1st cervical vertebra to en ter th e su boccip ital trian gle Th ey cu rve m edially to lie in a groove on th e p osterior arch of th e atlas Pass th rou gh th e p osterior atlan to-occip ital m em bran e to en ter th e vertebral can al

MAJOR CONTENTS OF THE SUBOCCIPITAL TRIANGLE Artery

Vein

Nerves

Structures

Vertebral

Vertebral (form ed by tributaries of the internal vertebral venous plexus) Suboccipital plexus

Greater occipital Suboccipital

Muscles: • Rectus capitis posterior m ajor • Rectus capitis posterior m inor • Obliquus capitis superior • Obliquus capitis inferior

Rectus capitis posterior minor muscle Rectus capitis posterior major muscle

Epicranial aponeurosis (galea aponeurotica)

Semispinalis capitis muscle (cut and reflected)

O ccipital belly (occipitalis) of occipitofrontalis muscle

Vertebral artery (atlantic part) O bliquus capitis superior muscle

Greater occipital nerve (dorsal ramus of C2 spinal nerve)

Suboccipital nerve (dorsal ramus of C1 spinal nerve)

O ccipital artery

Posterior arch of atlas (C1 vertebra) O ccipital artery

3rd (least) occipital nerve (dorsal ramus of C3 spinal nerve)

O bliquus capitis inferior muscle Greater occipital nerve (dorsal ramus of C2 spinal nerve)

Semispinalis capitis and splenius capitis muscles in posterior triangle of neck

Splenius capitis muscle (cut and reflected) 3rd (least) occipital nerve (dorsal ramus of C3 spinal nerve) Longissimus capitis muscle

Great auricular nerve (cervical plexus C2, 3) Lesser occipital nerve (cervical plexus C2) Sternocleidomastoid muscle

Splenius cervicis muscle

Trapezius muscle Posterior cutaneous branches of dorsal rami of C4, 5, 6 spinal nerves

Semispinalis cervicis muscle

Semispinalis capitis muscle (cut) Splenius capitis muscle (cut)

Figu re 4-10

122

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

VISCERAL CONTENTS • Thyroid, Parathyroid, Larynx

4

THYROID GLAND

• • • • • • • • •

High ly vascu lar organ located on th e an terior an d lateral su rfaces of th e n eck Form ed by a righ t an d a left lobe con n ected in th e m idlin e by an isth m u s Lies rou gh ly at a level between th e 5th cervical an d th e 1st th oracic vertebrae Th e isth m u s crosses at th e 2n d an d 3rd trach eal rin gs A p yram idal lobe often arises from th e isth m u s an d exten d s su p eriorly Arterial su p p ly arises from th e su p erior an d in ferior th yroid arteries, with th e m ajor p ortion from th e in ferior th yroid artery A th yroid ea im a vessel m ay su p p ly th e th yroid glan d an d arises from th e brach iocep h alic artery or as a d irect bran ch from th e aorta Ven ou s d rain age form s from a p lexu s on th e su rface of th e th yroid glan d th at d rain s in to th e su p erior, m id d le, an d in ferior th yroid vein s Microscop ically, th e th yroid is m ade of: • Th yroid follicu lar cells (wh ich secrete th yroxin e an d triiodoth yron in e) • Parafollicu lar or C cells (wh ich secrete calciton in an d develop from th e 4th p h aryn geal p ou ch )

PARATHYROID GLANDS

• • • • • •

Parath yroid glan d s n orm ally are 4 sm all en docrin e glan d s located on th e p osterior su rface of th e th yroid lobes Main role is to regu late calciu m levels in th e bod y Th e su p erior p arath yroids are su p p lied by th e su p erior th yroid artery an d th e in ferior p arath yroids are su p p lied by th e in ferior th yroid artery Microscop ically, th eir cells are organ ized in cord s Th ere are 2 m ajor cell typ es in th e p arath yroid glan d : • Ch ief cells (wh ich secrete p arath yroid h orm on e) • Oxyp h il cells Develop ed from th e 3rd (in ferior p arath yroid ) an d 4th (su p erior p arath yroid ) p h aryn geal p ou ch es, wh ich alter th eir n al p osition th rou gh m igration

LARYNX (refer to Chapte r 16 on the Larynx for m ore inform ation)

• • • • • •

Con n ection between th e p h aryn x an d th e trach ea Preven ts foreign bod ies from en terin g th e airways Design ed for th e p rod u ction of sou n d (p h on ation ) Sh orter in wom en an d ch ild ren Form ed by 9 cartilages: 3 p aired an d 3 u n p aired Located in th e m id lin e op p osite th e 3rd to 6th cervical vertebrae

THE NECK 123

4

VISCERAL CONTENTS • Thyroid, Parathyroid, Larynx

External carotid artery Internal carotid artery Superior thyroid artery and vein Superior laryngeal artery Superior root Ansa Inferior root cervicalis Common carotid artery

Pyramidal lobe (often absent or small) Right lobe Left lobe Isthmus

Internal jugular vein Middle thyroid vein Inferior thyroid veins

Inferior thyroid artery

Thyroid gland

Phrenic nerve

Transverse cervical artery

Anterior scalene muscle

Suprascapular artery Thyrocervical trunk

Vagus nerve (X)

Subclavian artery and vein

Right lateral view External carotid artery

Internal branch of superior laryngeal nerve

Superior laryngeal artery Superior thyroid artery (cut)

External branch of superior laryngeal nerve

Inferior pharyngeal constrictor muscle Common carotid artery Internal jugular vein

Superior parathyroid gland Thyroid gland (right lobe) (retracted anteriorly)

Inferior thyroid artery

Inferior parathyroid gland

Recurrent laryngeal nerve Esophagus

Figu re 4-11

124

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

ROOT OF THE NECK • General Information • •

•

4

Root of th e n eck con n ects th e stru ctu res of th e n eck with th e th oracic cavity Th e su p erior th oracic ap ertu re is bou n d ed by: • Man u briu m • 1st rib an d cartilage • 1st th oracic vertebra Th e ap ex of each lu n g exten d s in to th e root of th e n eck on th e lateral sid e of th e su p erior th oracic ap ertu re MAJOR CONTENTS OF THE ROOT OF THE NECK Arteries

Veins

Nerves

Structures

Com m on carotid Subclavian Vertebral Thyrocervical trunk • Inferior thyroid • Transverse cervical • Suprascapular • Ascending cervical

Internal jugular Subclavian Brachiocephalic Inferior thyroid Vertebral

Vagus Recurrent laryngeal Phrenic Sym pathetic trunk Brachial plexus

Trachea Esophagus Thoracic duct Right lym phatic duct Lym ph nodes

Right anterior dissection Internal jugular vein

Thyroid gland (reflected)

Common carotid artery

Middle cervical sympathetic ganglion Vagus nerve (X)

Phrenic nerve Inferior thyroid artery

Vertebral artery Common carotid artery

Transverse cervical artery Suprascapular artery

Thyrocervical trunk Subclavian artery and vein

Cricoid cartilage Common carotid artery

Pyramidal lobe (often absent or small) Right lobe

Internal jugular vein Middle thyroid vein Inferior thyroid veins

Thyroid gland

Left lobe Isthmus Pretracheal lymph nodes Phrenic nerve

Ascending cervical artery Inferior thyroid artery Transverse cervical artery Suprascapular artery

Anterior scalene muscle Vagus nerve (X)

Thyrocervical trunk Subclavian artery and vein

External jugular vein Anterior jugular vein 1st rib (cut)

Vagus nerve (X) Right recurrent laryngeal nerve

Left recurrent laryngeal nerve

Brachiocephalic trunk Brachiocephalic veins

Figu re 4-12 THE NECK 125

4

MUSCLES • Borders and Subdividers Major Borders of the Triangles Muscle

Origin

Insertion

Actions

Nerve Supply

Trapezius

External occipital protuberance Superior nuchal line Ligam entum nuchae Spinous process of C7 Spinous processes of T1 to T12

Spine of the scapula Acrom ion Lateral 1/ 3 of the clavicle

Elevate the scapula Retract the scapula Depress the scapula

Accessory n. also receives som e branches from C3 and C4, thought to be proprioceptive

Sternocleidom astoid

Manubrium Medial 1/ 3 of the clavicle

Mastoid process of the tem poral bone Superior nuchal line

Unilaterally: • Face turns to contralateral side • Head tilts to ipsilateral side Bilaterally: • Head is exed

Accessory n.

Muscles That Subdivide the Triangles Muscle

Origin

Insertion

Actions

Nerve Supply

Digastric (posterior and anterior bellies connected by a tendon attached to the hyoid)

Mastoid process

Digastric fossa of the m andible

Elevates hyoid Helps depress and retract the m andible

Facial n. (posterior belly) Trigem inal n. (anterior belly)

Om ohyoid (superior and inferior bellies connected by a tendon)

Superior border of the scapula

Body of the hyoid

Depresses the hyoid Helps depress the larynx

Ansa cervicalis

Digastric muscle (anterior belly) Mylohyoid muscle

Hyoid bone

Digastric muscle (posterior belly)

Thyrohyoid muscle

O mohyoid muscle (superior belly)

Sternohyoid and omohyoid muscles (cut)

Sternohyoid muscle

Thyrohyoid muscle

Sternothyroid muscle O mohyoid muscle (superior belly) (cut)

Trapezius muscle O mohyoid muscle (inferior belly)

Sternohyoid muscle (cut)

Figu re 4-13

126

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

MUSCLES • Suprahyoid and Infrahyoid

4

Suprahyoid Muscles Muscle

Origin

Insertion

Actions

Nerve Supply

Stylohyoid

Styloid process

Body of the hyoid

Elevates the hyoid Retracts the hyoid

Facial n.

Mylohyoid

Mylohyoid line of the m andible

Mylohyoid of opposite side at the raphe Body of the hyoid

Elevates the hyoid Elevates the oor of the oral cavity

Trigem inal n. (m andibular division)

Digastric (posterior and anterior bellies connected by a tendon attached to the hyoid)

Mastoid process

Digastric fossa of the m andible

Elevates hyoid Helps depress and retract the m andible

Facial n. (posterior belly) Trigem inal n. (anterior belly—m andibular division)

Geniohyoid

Inferior genial tubercle

Body of the hyoid

Helps m ove the hyoid and tongue anteriorly

C1 (ventral ram us, which follows the hypoglossal n.)

Infrahyoid Muscles Muscle

Origin

Insertion

Actions

Nerve Supply

Om ohyoid (superior and inferior bellies connected by a tendon)

Superior border of the scapula

Body of the hyoid

Depresses the hyoid

Ansa cervicalis

Sternohyoid

Manubrium

Body of the hyoid

Depresses the hyoid

Sternothyroid

Manubrium

Oblique line of the thyroid cartilage

Depresses the larynx

Thyrohyoid

Oblique line of the thyroid cartilage

Greater cornu (horn) of the hyoid

Depresses the hyoid

C1 (ventral ram us, which follows the hypoglossal n.)

Posterosuperior view

Mylohyoid muscle

Geniohyoid muscle Superior mental spine for origin of genioglossus muscle

Lesser horn Hyoid bone

Body

Hyoglossus muscle (cut)

Greater horn

Figu re 4-14 THE NECK 127

4

MUSCLES • Prevertebral Muscles Muscle

Origin

Insertion

Longus colli

Actions

Nerve Supply

Bilaterally: • Flexion of neck Unilaterally: • Head rotates to ipsilateral side • Head tilts to ipsilateral side

Ventral ram i of C2 to C8

Ventral ram i of C1 to C3

 Superior  oblique

Transverse processes of C3 to C5

Anterior arch of atlas

 Inferior  oblique

Vertebral bodies of T1 to T3

Transverse process of C5 to C6

 Vertical

Vertebral bodies of C5 to C7 and T1 to T3

Vertebral bodies of C2 to C4

Longus capitis

Transverse processes of C3 to C6

Rectus capitis anterior

Lateral m ass of the atlas Transverse process of the atlas

Basilar portion of the occipital bone

Bilaterally: • Flexion of head Unilaterally: • Head rotates to ipsilateral side • Head tilts to ipsilateral side

Rectus capitis lateralis

Transverse process of the atlas

Jugular portion of the occipital bone

Lateral exion of the head

Anterior scalene

Transverse processes (anterior tubercle) of C3 to C6

Scalene tubercle on the 1st rib

Elevates 1st rib Lateral exion of the neck

Ventral ram i of C4 to C6

Middle scalene

Transverse processes (posterior tubercle) of C2 to C7

1st rib

Lateral exion of the neck

Ventral ram i of C5 to C8

Posterior scalene

Transverse processes (posterior tubercle) of C5 to C7

2nd rib

Ventral ram i of C1 and C2

Ventral ram i of C6 to C8

Basilar part of occipital bone Longus capitis muscle (cut) Rectus capitis anterior muscle Rectus capitis lateralis muscle Transverse process of atlas (C1) Longus capitis muscle Posterior tubercle of transverse process of axis (C2)

Anterior Tubercles of transverse Posterior process of C3 vertebra Slips of origin of anterior scalene muscle (cut)

Longus colli muscle

Scalene muscles

Anterior Middle Posterior

Slips of origin of posterior scalene muscle Middle Scalene muscles Posterior

Phrenic nerve

Posterior tubercle of transverse process of C7 vertebra

Brachial plexus

Anterior scalene muscle (cut) 1st rib

Figu re 4-15

128

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

MUSCLES • Suboccipital Triangle Muscles Muscle

Origin

Insertion

Actions

Nerve Supply

Obliquus capitis superior

Transverse process of the atlas

Occipital bone

Bilaterally: • Extension of head Unilaterally: • Lateral exion of head to ipsilateral side

Suboccipital n. (dorsal ram i of C1)

Obliquus capitis inferior

Spinous process of the axis

Transverse process of the atlas

Rotates head to ipsilateral side

Inferior nuchal line (lateral portion) of the occipital bone

Bilaterally: • Extension of head Unilaterally: • Head rotates to ipsilateral side

Posterior arch of the atlas

Inferior nuchal line (m edial portion) of the occipital bone

Extends head

Rectus capitis posterior m ajor

Rectus capitis posterior m inor

4

Rectus capitis posterior minor muscle Rectus capitis posterior major muscle Semispinalis capitis muscle (cut and reflected) Vertebral artery (atlantic part) O bliquus capitis superior muscle Suboccipital nerve (dorsal ramus of C1 spinal nerve) Posterior arch of atlas (C1 vertebra) O ccipital artery O bliquus capitis inferior muscle

Semispinalis capitis and splenius capitis muscles in posterior triangle of neck

Greater occipital nerve (dorsal ramus of C2 spinal nerve) Splenius capitis muscle (cut and reflected) 3rd (least) occipital nerve (dorsal ramus of C3 spinal nerve) Longissimus capitis muscle Splenius cervicis muscle Semispinalis cervicis muscle

Semispinalis capitis muscle (cut)

Trapezius muscle

Splenius capitis muscle (cut)

Posterior cutaneous branches of dorsal rami of C4-6 spinal nerves

Figu re 4-16 THE NECK 129

4

VASCULAR SUPPLY OF THE NECK • Arterial Supply •

Th e m ajor arteries of th e n eck are th e com m on carotid an d th e su bclavian arteries

SUBCLAVIAN

• • • • •

Th yrocervical Costocervical Vertebral Dorsal scap u lar (u su ally) (In tern al th oracic artery is located in th e th orax)

COMMON CAROTID

• •

•

In tern al carotid Extern al carotid • Su p erior th yroid • Lin gu al • Facial • Ascen d in g p h aryn geal • Occip ital (Posterior au ricu lar, m axillary, an d su p er cial tem p oral arteries are located in th e h ead ) SUBCLAVIAN VASCULAR SUPPLY OF THE NECK

130

Artery

Source

Comments

Subclavian

Right subclavian a. is a branch of the brachiocephalic a.; left subclavian a. is a direct branch of the aorta

Both subclavian aa. travel lateral to the trachea into the root of the neck, passing between the anterior and m iddle scalene aa. Divided into 3 parts based on its relationship to the anterior scalene m .: • 1st part—extends from the beginning of the subclavian to the m edial border of the anterior scalene, and all of the branches of the subclavian a. arise from the 1st part, except the left costocervical trunk, which often is a branch of the 2nd part • 2nd part—located posterior to the anterior scalene • 3rd part—located from the lateral m argin of the anterior scalene to the lateral border of the 1st rib, where it becom es the axillary a.

Thyrocervical

A branch of the 1st part of the subclavian along the m edial aspect of the anterior scalene m .

Im m ediately divides into 3 branches: • Inferior thyroid—travels along the m edial border of the anterior scalene posterior to the carotid sheath and anterior to the vertebral a. to the thyroid gland while accom panied by the recurrent laryngeal n.; it gives rise to the inferior laryngeal a. to the larynx and the ascending cervical a., which helps supply the m uscles in the area and sends branches to the vertebral a. • Suprascapular—travels inferior to and laterally across the anterior scalene m . and phrenic n. deep to the sternocleidom astoid m . and crosses the posterior triangle of the neck to reach the scapula, where it passes superior to the transverse lig. of the scapula • Transverse cervical—travels across the posterior triangle of the neck to reach the anterior border of the trapezius m .

Costocervical

A branch of the 1st part of the right subclavian a. and the 2nd part of the left subclavian a.

Divides into 2 branches: • Deep cervical—travels superiorly along the posterior part of the neck m ainly to help supply the m uscles • Suprem e intercostal—travels to supply the 1st and 2nd intercostal spaces

Vertebral

1st part of the subclavian a.

Ascends to enter the foram en transversarium of C6 Passes around the atlas and then through the foram en m agnum to enter the skull, where it unites with the vertebral a. from the other side to form the basilar a. along the ventral surface of the pons

Dorsal  scapular

2nd or 3rd part of the subclavian a.

Arises from the subclavian a. in about 70% to 75% of people and the transverse cervical a. in the other 25% to 30% When arising from the subclavian a., it passes posteriorly between the trunks of the brachial plexus to travel across the posterior triangle of the neck to reach the anterior border of the trapezius m .

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

VASCULAR SUPPLY OF THE NECK • Arterial Supply

4

Right anterior dissection

Phrenic nerve

Vagus nerve (X)

Anterior scalene muscle

Vertebral artery

Inferior thyroid artery Common carotid artery

Transverse cervical artery

Recurrent laryngeal nerve

Suprascapular artery Dorsal scapular artery

Brachiocephalic trunk

Costocervical trunk

Internal jugular vein (cut)

Thyrocervical trunk Subclavian artery and vein

Right oblique schematic view Right external carotid artery

Vertebral artery Deep cervical artery (ascending to anastomose with descending branch of occipital artery)

Right internal carotid artery Ascending cervical artery

Superficial cervical artery

Inferior thyroid artery

Costocervical trunk

Superficial cervical artery

Supreme (superior) intercostal artery

Right common carotid artery Thyrocervical trunk

Dorsal scapular artery

Right subclavian artery (1st part medial to, 2nd part posterior to, 3rd part lateral to anterior scalene muscle)

Superior and inferior transverse scapular ligaments Acromion

Brachiocephalic trunk

Dorsal scapular artery

Suprascapular artery

Suprascapular artery Axillary artery

Aortic arch

1st and 2nd posterior intercostal arteries

Internal thoracic (mammary) artery

Thoracodorsal artery

1st, 2nd, and 3rd anterior intercostal arteries Subscapular artery

Circumflex scapular artery

Figu re 4-17

THE NECK 131

4

VASCULAR SUPPLY OF THE NECK • Arterial Supply CAROTID VASCULAR SUPPLY OF THE NECK Artery

Source

Comments

Com m on carotid

Right com m on carotid a. is a branch of the brachiocephalic a.; left com m on carotid a. is a direct branch of the aorta

Both com m on carotids ascend posterior to the sternoclavicular joint into the neck and bifurcate at the superior border of the thyroid cartilage at C3 into the: • External carotid a. • Internal carotid a. There are no branches of the com m on carotid a. in the neck Carotid  b ody: A chem oreceptor located along the com m on carotid a. Usually receives its sensory innervation from the carotid branch of the glossopharyngeal n.

Internal  carotid

The 2 branches of the com m on carotid a.; arise at the superior border of the thyroid cartilage at C3

There are no branches of the internal carotid a. in the neck Passes superiorly in the neck within the carotid sheath along with the internal jugular v. and the vagus n. anterior to the transverse processes of the upper cervical vertebrae Carotid  sinus: A baroreceptor located as a dilation at the beginning of the internal carotid a. Usually receives its sensory innervation from the carotid branch of the glossopharyngeal n.

External  carotid

Gives rise to a m ajority of the branches to the neck Located external to the carotid sheath and travels anteriorly and superiorly in the neck posterior to the m andible and deep to the posterior belly of the digastric and stylohyoid m m . to enter the parotid gland

• Superior  thyroid

The 1st branch of the external carotid a.; arises in the carotid triangle

Passes inferiorly along the inferior constrictor m . on its path to the thyroid gland The superior laryngeal a. arises from the superior thyroid a. and passes through the thyrohyoid m em brane to supply the larynx

• Lingual

External carotid a.; arises within the carotid triangle

Passes superiorly and m edially toward the greater cornu of the hyoid bone in an oblique fashion and m akes a loop by passing anteriorly and inferiorly while traveling super cial to the m iddle constrictor m . While form ing a loop, the artery is crossed super cially by the hypoglossal n. The lingual a. passes deep to the posterior belly of the digastric and stylohyoid m m . as it travels anteriorly At this region, it gives rise to a hyoid branch that travels on the superior surface of the hyoid bone supplying the m uscles in the area Passes deep to the hyoglossus m . and travels anteriorly between the hyoglossus and genioglossus m m . to supply the tongue Continued  on  next  page

132

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

VASCULAR SUPPLY OF THE NECK • Arterial Supply

4

SUBCLAVIAN VASCULAR SUPPLY OF THE NECK Continued Artery

Source

Comments

• Facial

External carotid a. in the carotid triangle of the neck

Passes superiorly im m ediately deep to the posterior belly of the digastric and stylohyoid mm. Passes along the subm andibular gland giving rise to the subm ental a., which helps supply the gland Passes superiorly over the body of the m andible at the m asseter m . in a tortuous pattern to supply the face

• Ascending  pharyngeal

Posterior portion of the external carotid a. near the bifurcation of the com m on carotid a.

The sm allest branch of the external carotid Ascends superiorly between the lateral side of the pharynx and the internal carotid a. Has a series of branches: 3 to 4 pharyngeal branches supply the superior and m iddle constrictor m m . The m ost superior branch passes through the gap superior to the superior constrictor m . Gives rise to an inferior tym panic branch, which supplies the m iddle ear cavity Gives rise to a posterior m eningeal branch, which supplies the bones of the posterior cranial fossa and dura m ater

• Occipital

External carotid a. in the carotid triangle of the neck

Branches along the inferior m argin of the posterior belly of the digastric and stylohyoid mm. The hypoglossal n. wraps around the occipital a. from the posterior part of the vessel, traveling anteriorly Passes posteriorly along the m astoid process, m aking a groove on the bone Pierces the fascia that connects the attachm ent of the trapezius with the sternocleidom astoid m. Ascends in the connective tissue layer of the scalp, dividing into m any branches Anastom oses with the posterior auricular and super cial tem poral aa. The term inal part of the artery is accom panied by the greater occipital n.

THE NECK 133

4

VASCULAR SUPPLY OF THE NECK • Arterial Supply Parotid space (bed): right lateral dissection

Maxillary artery External carotid artery Posterior auricular artery

Facial nerve (VII) (cut) Sternocleidomastoid muscle (cut) Digastric muscle (posterior belly) (cut) O ccipital artery and sternocleidomastoid branch Accessory nerve (XI)

Glossopharyngeal nerve (IX) Stylohyoid muscle Hypoglossal nerve (XII) Facial artery Lingual artery

Superior root Inferior root

Ansa cervicalis

Vagus nerve (X) Ascending pharyngeal artery Carotid branch of glossopharyngeal nerve (IX) and carotid body

Superior laryngeal artery

Internal carotid artery Superior thyroid artery

Internal jugular vein

External carotid artery Common carotid artery

Superficial temporal artery Transverse facial artery Digastric muscle (phantom )

Maxillary artery Posterior auricular artery

O ccipital artery

Facial artery

Descending branch

Lingual artery

Sternocleidomastoid branch

Ascending pharyngeal artery Internal carotid artery

Superior thyroid artery and superior laryngeal branch

External carotid artery O mohyoid muscle (phantom ) Common carotid artery

External carotid branches: schema Thyrocervical trunk

Figu re 4-18

134

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

VASCULAR SUPPLY OF THE NECK • Venous Drainage •

4

High ly variable, with in con sisten t d rain age

MAJOR VEINS OF THE NECK

•

In tern al ju gu lar • Occip ital • Com m on facial • Facial • Lin gu al • Ph aryn geal • Su p erior th yroid • Mid dle th yroid

•

•

Su bclavian • Vertebral • Extern al Ju gu lar • Tran sverse cervical • Su p rascap u lar • An terior ju gu lar Brach iocep h alic • In ferior th yroid

JUGULAR VASCULAR SUPPLY OF THE NECK Vein

Comments

Internal jugular

Continuous with the sigm oid sinus within the cranial cavity Begins at the base of the skull at a dilation called the superior bulb Lies posterior to the internal carotid a. and the glossopharyngeal, vagus, and spinal accessory nn. as it initially descends Travels lateral to the internal carotid a. within the carotid sheath with the vagus n. posterior to the vessels Unites with the subclavian v. to form the brachiocephalic v. at the root of the neck Receives a series of branches

 Occipital

Begins on the posterior portion of the scalp at the vertex Passes from super cial to deep by passing through the attachm ent of the sternocleidom astoid m . Has a m astoid em issary v. that connects it to the transverse sinus The vein’s term ination is variable, but it usually passes inferiorly to join the internal jugular v.

 Com m on  facial

In the subm andibular triangle, the facial v. joins the anterior branch of the retrom andibular to form the com m on facial v. Com m on facial v. drains into the internal jugular v.

 • Facial

 Lingual

Has no valves to allow blood to back ow Begins as the angular v. Passes inferiorly along the side of the nose, receiving the lateral nasal v. Continues in a posterior and inferior path across the angle of the m outh to the cheek, receiving the superior and inferior labial vv. While passing toward the m andible, the deep facial v. connects the facial v. to the pterygoid plexus In the subm andibular triangle, the facial v. joins the anterior branch of the retrom andibular to form the com m on facial v. Passes with the lingual a., deep to the hyoglossus m ., and ends in the internal jugular v. The vena com itans nervi hypoglossi, or accom panying v. of the hypoglossal n., begins at the apex of the tongue and either joins the lingual v. or accom panies the hypoglossal n. and enters the com m on facial v., draining into the internal jugular v. Continued  on  next  page

THE NECK 135

4

VASCULAR SUPPLY OF THE NECK • Venous Drainage JUGULAR VASCULAR SUPPLY OF THE NECK Continued

136

Vein

Comments

 Pharyngeal

Pharyngeal vv. pass from the pharyngeal plexus of vv. along the posterior portion of the pharynx Drain into the internal jugular v.

 Superior  thyroid

Form s a venous plexus on the thyroid gland with the m iddle and inferior thyroid vv. before draining into the internal jugular v.

 Middle  thyroid

Form s a venous plexus on the thyroid gland with the superior and inferior thyroid vv. before draining into the internal jugular v.

External jugular

Form ed by the com bination of the posterior branch of the retrom andibular and posterior auricular vv. in the parotid gland Lies deep to the platysm a m . but super cial to the sternocleidom astoid m . as it descends vertically Passes into the posterior triangle of the neck, where it drains into the subclavian v. im m ediately lateral to the anterior scalene m .

 Transverse  cervical

Passes from the anterior border of the trapezius m . through the posterior triangle to drain into the external jugular v.

 Suprascapular

Arises from the scapula above the transverse scapular lig. to pass through the posterior triangle of the neck to drain into the external jugular v.

 Anterior  jugular

Arises by the joining of a series of super cial veins in the subm ental region Descends anterior to the sternocleidom astoid m . and passes deep to the m uscle before draining into the external jugular or the subclavian

Brachiocephalic

The right and left brachiocephalic vv. are form ed posterior to the right and left sternoclavicular joints by the m erging of the internal jugular v. and subclavian v. from their respective sides Both brachiocephalic vv. m erge to form the superior vena cava

 Inferior  thyroid

Form s a venous plexus on the thyroid gland with the superior and m iddle thyroid vv. Typically, right and left inferior thyroid vv. form and drain into the right and left brachiocephalic vv.

Subclavian

The continuation of the axillary v. Located along the lateral border of the 1st rib until it unites with the internal jugular v. Passes anterior to the anterior scalene m .

 Vertebral

Begins as a plexus in the suboccipital triangle and descends through the foram en transversarium of all of the cervical vertebrae before draining into the subclavian v. or, m ore com m only, the brachiocephalic v.

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

VASCULAR SUPPLY OF THE NECK • Venous Drainage

Pterygoid plexus

4

Transverse facial vein (cut) Posterior auricular vein

Deep facial vein

Retromandibular vein Posterior retromandibular vein

Maxillary vein

External jugular vein (cut) Inferior alveolar vein and artery

Facial vein and artery Submental vein Anterior retromandibular vein

O ccipital vein and artery Hypoglossal nerve (XII) Common facial vein

Submandibular gland Vena comitans of hypoglossal nerve

External carotid artery Internal jugular vein

Dorsal lingual vein coursing medial to hyoglossus muscle

Common carotid artery

Lingual vein Communication to anterior jugular vein (cut) Superior laryngeal vein

Vagus nerve (X) and sympathetic trunk Middle scalene muscle Anterior scalene muscle

Superior thyroid vein

External jugular vein (cut)

Thyroid gland

Transverse cervical vein (cut)

Middle thyroid vein Inferior thyroid veins Termination of anterior jugular vein (cut) Left brachiocephalic vein

Suprascapular vein (cut) Subclavian artery Subclavian vein

Figu re 4-19

THE NECK 137

4

VASCULAR SUPPLY OF THE NECK • Venous Drainage Anterior division of retromandibular vein

Facial artery and vein

Retromandibular vein Common facial vein Internal jugular vein Superior thyroid artery and vein

Anterior jugular vein Communicating vein

Internal jugular vein

External jugular vein

Transverse cervical and suprascapular vein

Communication with internal jugular vein Pharyngeal plexus

Communication with internal jugular vein

Figu re 4-20

138

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

NERVE SUPPLY OF THE NECK • General Information •

Th e n erve su p p ly to th e n eck is exten sive; it • • Cran ial n erves • Glossop h aryn geal • Vagu s • Accessory • • Hyp oglossal • • Cervical p lexu s

4

is m ade u p of: Brach ial p lexu s • Dorsal scap u lar • Lon g th oracic • Su p rascap u lar Ph ren ic Oth er cervical ven tral ram i

Cranial Nerves of the Neck GLOSSOPHARYNGEAL NERVE • Also known as cranial nerve IX • Branches from the m edulla oblongata and passes through the jugular foram en with the vagus and spinal accessory nn. • Im m ediately after passing through the jugular foram en, it gives off the tym panic branch • As the glossopharyngeal passes through the foram en, it passes between the internal carotid a. and internal jugular v. in an inferior direction • Gives rise to the carotid branch that passes between the internal and external carotid aa. to the carotid body and carotid sinus • The m ain glossopharyngeal n. continues to pass inferiorly, giving rise to the pharyngeal branch, which is the sensory nerve to the pharyngeal plexus that perforates the m uscles of the pharynx and supplies the m ucous m em branes (m ainly oropharynx region) • Continues to pass inferiorly; travels posterior to the stylopharyngeus m . and innervates it • Passes anteriorly with the stylopharyngeus and travels between the superior and m iddle constrictor m m . to be located by the palatine tonsils • Sm all lingual branches arise from it and distribute general som atic afferent (GSA) bers to the m ucous m em brane of the posterior 1/ 3 of the tongue, in addition to the fauces, and special visceral afferent (SVA) bers to the taste buds

VAGUS NERVE • Also known as cranial nerve X • Branches from the m edulla oblongata and passes through the jugular foram en with the glossopharyngeal and spinal accessory nn. • As the vagus n. passes through the foram en, it passes between the internal carotid a. and internal jugular v. • A series of nerves branch from the vagus n. as it passes from the base of the skull through the neck: auricular, pharyngeal, superior laryngeal, recurrent laryngeal, and cardiac vagal branches

Auricular Branch • Arises from the superior ganglion, travels posterior to the internal jugular v., and passes along the tem poral bone to enter the m astoid canaliculus and give branches that innervate the skin of the back of the auricle and the posterior portion of the external acoustic m eatus

Pharyngeal Branch • Arises from the upper part of the inferior ganglion of the vagus n. and serves as the m otor com ponent to the pharyngeal plexus

Superior Laryngeal n. • Travels inferiorly posterior to the internal carotid and on the side of the pharynx, and divides into the: • Internal laryngeal n.–passes inferiorly to the larynx through the thyrohyoid m em brane along with the superior laryngeal vessels to distribute the GSA bers to the base of the tongue at the epiglottic region, and to the m ucous m em branes of the larynx as far inferiorly as the false vocal folds; and SVA bers to the taste buds in the area • External laryngeal n.–travels inferiorly along the inferior constrictor to supply the cricothyroid m uscle and the inferior portion of the inferior constrictor Continued  on  next  page

THE NECK 139

4

NERVE SUPPLY OF THE NECK • Cranial Nerves of the Neck Recurrent Laryngeal n. • Arises from the vagus n. differently, depending on the side of the body • The right recurrent laryngeal n. loops under the right subclavian, whereas the left recurrent laryngeal n. loops under the ligam entum arteriosum posterior to the aorta • Ascends on the lateral side of the trachea until reaching the pharynx where it passes deep to the inferior constrictor m . to reach the larynx, innervating the m ucous m em branes below the false vocal folds and all of the intrinsic m uscles of the larynx except the cricothyroid

Cardiac Vagal Branches • Descend to form the parasym pathetic portion of the cardiac plexus

ACCESSORY NERVE • Also known as cranial nerve XI • Classically described as being form ed from 2 parts: cranial and spinal

Cranial Part • Begins in the nucleus am biguus from the m edulla as 4 to 5 branches just inferior to the roots of the vagus n. and passes laterally to the jugular foram en, where it m erges with the bers of the spinal part of the accessory n. • While united for a short distance, it also is connected by 1 or 2 branches with the inferior ganglion of the vagus n. • Exits through the jugular foram en, separates from the spinal part, and continues over the surface of the inferior ganglion of the vagus n. to be distributed m ainly to the pharyngeal branches of the vagus to form the m otor portion of the pharyngeal plexus, which innervates the m uscles in the pharynx, soft palate, and 1 tongue m uscle

Spinal Part • Begins in the upper cervical levels of the spinal cord and after separating from the cranial part provides innervation to the sternocleidom astoid m . and passes obliquely through the posterior triangle of the neck to innervate the trapezius m .

HYPOGLOSSAL NERVE • • • • • •

Also known as cranial nerve XII Arises as a series of rootlets from the m edulla oblongata and passes through the hypoglossal canal Travels inferiorly, located between the internal carotid a. and the internal jugular v. Passes anteriorly as it wraps around the occipital a. inferior to the posterior belly of the digastric m . Passes super cial to the external carotid a. and the loop of the lingual a. in its anterior path Passes deep to the posterior belly of the digastric and stylohyoid m m . and lies super cial to the hyoglossus m . with the accom panying v. of the hypoglossal n. • Passes deep to the m ylohyoid m . and continues anterior in the genioglossus m . • Gives rise to m uscular branches that supply all the intrinsic tongue m uscles and the hyoglossus, genioglossus, and styloglossus m m .

140

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

NERVE SUPPLY OF THE NECK • Cranial Nerves of the Neck

4

Accessory nerve (XI) (cut) C1 spinal nerve (ventral ramus) (cut) C2 spinal nerve (ventral ramus) (cut) Pharyngeal plexus composed of branches from glossopharyngeal (IX), vagus (X) and cranial part of (XI) Vagus nerve (X) and superior cervical cardiac branch

Glossopharyngeal nerve (IX) and tonsillar branch Hypoglossal nerve (XII) Carotid nerve (IX) and carotid body

C4 spinal nerve (ventral ramus) (cut)

Nerve to thyrohyoid muscle (C1)

Phrenic nerve (C3, 4, 5)

Internal and external branches of superior laryngeal nerve (X) Ansa cervicalis (C1, 2, 3)

Superior root Inferior root Brachial plexus (cut)

Nerves to superior and inferior bellies of omohyoid, sternohyoid and sternothyroid muscles (ansa cervicalis)

Recurrent laryngeal nerve (X) Sympathetic trunk and middle cervical ganglion

Hypoglossal nerve (XII) (in hypoglossal canal)

Intrinsic muscles of tongue

Superior longitudinal Transverse and vertical Inferior longitudinal

Styloglossus muscle

Hypoglossal nucleus

Ventral rami of C1, 2, 3 form ansa cervicalis of cervical plexus Superior cervical sympathetic ganglion Superior root of ansa cervicalis

Genioglossus muscle Geniohyoid muscle Hyoglossus muscle

Inferior root of ansa cervicalis

Thyrohyoid muscle O mohyoid muscle (superior belly)

Ansa cervicalis

Sternothyroid muscle

Efferent fibers

Sternohyoid muscle

Afferent fibers O mohyoid muscle (inferior belly)

Figu re 4-21

THE NECK 141

4

NERVE SUPPLY OF THE NECK • Sensory Innervation of the Neck • • • •

Skin of th e n eck receives sen sory in n ervation from both d orsal an d ven tral ram i Dorsal ram u s of C1 lacks sen sory bers an d does n ot con tribu te to th e sen sory d istribu tion to th e n eck Dorsal ram i of C6 to C8 lack sen sory bers an d d o n ot con tribu te to th e sen sory d istribu tion to th e n eck Ven tral ram i p rovid e m ost of th e sen sory in n ervation to th e n eck th rou gh th e sen sory bran ch es of th e cervical p lexu s

CERVICAL PLEXUS

• • •

Form ed by C1 to C4 ven tral ram i Origin ates d eep to th e stern ocleidom astoid Sen sory bran ch es p ass alon g m id p oin t of th e p osterior bord er of th e m u scle to travel to th eir d estin ation s VENTRAL RAMI Nerve

Source

Comments

Lesser occipital

Cervical plexus by contributions from the ventral ram us of C2

Passes posterior to the m idpoint of the sternocleidom astoid m . Ascends posterior to the sternocleidom astoid along the posterior portion of the head Continues on the head posterior to the auricle supplying the skin in the region

Great auricular

Cervical plexus form ed by contributions of ventral ram i C2 and C3

Passes posterior to the m idpoint of the sternocleidom astoid m . Ascends along the sternocleidom astoid, dividing into anterior and posterior branches: • Anterior branch innervates the skin of the face over the parotid gland • Posterior branch innervates the skin over the m astoid process, the posterior portion of the auricle, and the concha and lobule

Transverse cervical

Supraclavicular

Passes posterior to the m idpoint of the sternocleidom astoid m . Crosses anteriorly along the sternocleidom astoid, dividing into ascending and descending branches Ascending and descending branches pass through the platysm a m . to supply the skin of the neck from the region between the m andible and the m anubrium Cervical plexus form ed by contributions of ventral ram i C3 and C4

Passes posterior to the m idpoint of the sternocleidom astoid m . Travels inferiorly in an oblique direction through the posterior triangle of the neck Divides  into  3  m ajor  branches: • Medial supraclavicular—supplies the skin up to the m idline • Middle supraclavicular—supplies the skin over the pectoralis m ajor and deltoid m . region • Lateral supraclavicular—supplies the skin along the deltoid and anterior trapezius m m .

DORSAL RAMI

142

Greater occipital

Dorsal ram us of C2

Ascends after em erging from the suboccipital triangle obliquely between the inferior oblique and sem ispinalis capitis m m . Passes through the trapezius m . and ascends to innervate the skin along the posterior part of the scalp to the vertex

3rd occipital

Branch of the dorsal ram us of C3 deep to the trapezius m .

Passes through the trapezius m . and ascends along in the skin of the inferior portion of the posterior surface of the head near the m idline

Dorsal ram us of C4

Dorsal ram us of C4 deep to the trapezius m .

Passes through the trapezius m . and ascends along in the skin of the inferior portion of the posterior surface of the head near the m idline

Dorsal ram us of C5

Dorsal ram us of C5 deep to the trapezius m .

Passes through the trapezius m . and ascends along in the skin of the inferior portion of the posterior surface of the head near the m idline

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

NERVE SUPPLY OF THE NECK • Sensory Innervation of the Neck

4

Auricular branch of vagus nerve (X)

Medial branches of dorsal rami of cervical spinal nerves

From ophthalmic division of trigeminal nerve (V1 )

Greater occipital nerve (C2) 3rd occipital nerve (C3) From 4th, 5th, 6th and 7th nerves in succession below

From maxillary division of trigeminal nerve (V2 )

Branches from cervical plexus Lesser occipital nerve (C2) Great auricular nerve (C2,3)

From mandibular division of trigeminal nerve (V3 )

Transverse cervical nerve (C2, 3) Supraclavicular nerves (C3, 4)

Dorsal rami of cervical spinal nerves

V1

V2

N ote: Auricular branch of vagus nerve to external acoustic meatus and small area on posteromedial surface of auricle

V3

Branches from cervical plexus

Figu re 4-22

THE NECK 143

4

NERVE SUPPLY OF THE NECK • Cervical Plexus of the Neck • •

Arises from th e ven tral ram i of C1 to C4 Divid ed in to 2 p arts: • An sa cervicalis (m otor com p on en t) • Cu tan eou s bran ch es (sen sory com p on en t): • Lesser occip ital • Tran sverse cervical • Great au ricu lar • Su p raclavicu lar ANSA CERVICALIS Source

Comments

Ventral ram i of C1 to C3

The m otor com ponent of the cervical plexus Innervates the: • Om ohyoid • Sternohyoid • Sternothyroid Divis io ns : Superior root (descendens hypoglossi) Arises from the ventral ram us of C1, which passes anteriorly and joins the hypoglossal n., and the bers travel together without m ixing As the hypoglossal n. passes anteriorly toward the tongue, som e of the bers of C1 branch inferiorly to form the superior root of the ansa cervicalis Superior root joins the inferior root along the lateral border of the carotid sheath Som e of the bers from C1 continue to follow the hypoglossal n. to innervate the geniohyoid and thyrohyoid m m . Inferior root (descendens cervicalis) Arises from the ventral ram i of C2 and C3 These branches unite to form the inferior root that unites with the superior root along the lateral border of the carotid sheath

CUTANEOUS BRANCHES Nerve

Source

Comments

Lesser occipital

Cervical plexus by contributions from the ventral ram us of C2

Passes posterior to the m idpoint of the sternocleidom astoid m . Ascends posterior to the sternocleidom astoid along the posterior portion of the head Continues on the head posterior to the auricle supplying the skin in the region

Great auricular

Cervical plexus form ed by contributions of ventral ram i C2 and C3

Passes posterior to the m idpoint of the sternocleidom astoid m . Ascends along the sternocleidom astoid, dividing into anterior and posterior branches: • Anterior branch innervates the skin of the face over the parotid gland • Posterior branch innervates the skin over the m astoid process, the posterior portion of the auricle, and the concha and lobule

Transverse cervical

Supraclavicular

144

Passes posterior to the m idpoint of the sternocleidom astoid m . Crosses anteriorly along the sternocleidom astoid dividing into ascending and descending branches Ascending and descending branches pass through the platysm a to supply the skin of the neck from the region between the m andible and the m anubrium Cervical plexus form ed by contributions of ventral ram i C3 and C4

Passes posterior to the m idpoint of the sternocleidom astoid m . Travels inferiorly in an oblique direction through the posterior triangle of the neck Divides  into  3  m ajor  branches: • Medial supraclavicular—supplies the skin up to the m idline • Middle supraclavicular—supplies the skin over the pectoralis m ajor and deltoid m . region • Lateral supraclavicular—supplies the skin along the deltoid and anterior trapezius m m .

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

NERVE SUPPLY OF THE NECK • Cervical Plexus of the Neck Sternocleidomastoid muscle (cut)

4

Great auricular nerve

Accessory nerve (XI)

Lesser occipital nerve

Hypoglossal nerve (XII)

Greater occipital nerve (from dorsal ramus of C2)

Geniohyoid muscle

C1 Nerves to anterior and lateral rectus capitis and longus capitis and colli muscles Nerves to longus capitis and colli and levator scapulae muscles Trapezius muscle Nerves to longus capitis and colli, levator scapulae and middle scalene muscles Communication to brachial plexus Phrenic nerve

C2

C3

Thyrohyoid muscle Superior root of ansa cervicalis

C4

Inferior root of ansa cervicalis C5

Transverse cervical nerve O mohyoid muscle (superior belly) Sternothyroid muscle

Sternohyoid muscle

Supraclavicular nerves (medial, intermediate and lateral)

Ansa cervicalis

Efferent fibers Afferent fibers Proprioceptive fibers

Sternocleidomastoid muscle (cut) O mohyoid muscle (inferior belly)

Cervical plexus: schema (S = gray ramus from superior cervical sympathetic ganglion)

Hypoglossal nerve (XII)

To geniohyoid muscle To thyrohyoid muscle Communication to vagus nerve

Great auricular nerve C1 S

To omohyoid muscle (superior belly)

S

Superior root Inferior root

Lesser occipital nerve C2

S

Transverse cervical nerves

Ansa cervicalis

Accessory nerve (XI)

S

To rectus capitis lateralis, longus capitis and rectus capitis anterior muscles

C3

C4

To longus capitis and longus colli muscles

To sternothyroid muscle To sternohyoid muscle To omohyoid muscle (inferior belly) Supraclavicular nerves

Phrenic nerve

To scalene and levator scapulae muscles

Figu re 4-23

THE NECK 145

4

NERVE SUPPLY OF THE NECK • Ventral Rami Nerves of the Neck Nerve

Source

Comments

Phrenic

Arises from the ventral ram i of C3 to C5

Passes inferiorly along the anterior surface of the anterior scalene m . Eventually passes through the thorax to innervate the diaphragm

Brachial plexus

Ventral ram i of C5 to C8 and T1 form the brachial plexus, which provides m otor and sensory function to the upper lim b

These ram i pass between the anterior and m iddle scalene m m . Ventral ram i of C5 and C6 unite to form the upper trunk Ventral ram us of C7 continues as the m iddle trunk Ventral ram us of C8 and T1 form the inferior trunk These trunks continue to form the divisions of the brachial plexus that enter the axilla 3 branches of the brachial plexus are contained in the posterior triangle of the neck: • Dorsal scapular—arises from C5 and passes through the m iddle scalene before passing obliquely to the levator scapulae, which it innervates (along with the rhom boid m ajor and m inor m m .) • Long thoracic—arises from the ventral ram i C5 to C7 to pass through the m iddle scalene before passing inferiorly to the serratus anterior, which it innervates • Suprascapular—arises from the upper trunk to pass through the posterior triangle of the neck to reach the supraspinatus and infraspinatus m m . by passing below the transverse scapular lig.

Great auricular nerve Lesser occipital nerve Hypoglossal nerve (XII) C2 spinal nerve (ventral ramus) Accessory nerve (XI) C3 spinal nerve (ventral ramus)

Superior root Ansa cervicalis Inferior root

C5 spinal nerve (ventral ramus)

Phrenic nerve

Vagus nerve (X)

Brachial plexus

Figu re 4-24

146

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

NERVE SUPPLY OF THE NECK • Sympathetics in the Neck • •

• • • •

4

Sym p ath etic tru n k exten ds in to th e n eck from th e th orax In th e n eck, th e sym p ath etic tru n k typ ically h as 3 gan glia: • Su p erior cervical gan glion —located at th e base of th e sku ll • Mid dle cervical gan glion —located at C6 • In ferior cervical gan glion —located im m ed iately p osterior to th e vertebral artery n ear th e vessel’s origin Often th e in ferior cervical gan glion u n ites with th e 1st th oracic gan glion to create th e stellate gan glion Sym p ath etics for th e h ead an d n eck arise in th e in term ed iolateral h orn colu m n of th e sp in al cord from T1 to T4 Th ese p regan glion ic bers ascen d th rou gh th e sym p ath etic tru n k to reach th e cervical gan glia an d syn ap se with th e p ostgan glion ic n eu ron s Postgan glion ic n eu ron s follow eith er of 2 p ath s: • May travel to th e sp in al n erves via th e gray ram u s • May follow th e arterial su p p ly to th e effector organ s of th e h ead

Glossopharyngeal nerve (IX)

C1 Vagus nerve (X) (cut) Superior cervical sympathetic ganglion C2

C3

Pharyngeal plexus Pharyngeal branch of vagus nerve External carotid artery and plexus Superior laryngeal nerve Internal carotid artery and carotid branch of glossopharyngeal nerve Carotid body Carotid sinus Superior cervical cardiac branch of vagus nerve Superior cervical sympathetic cardiac nerve

C4 Gray rami communicantes

C5 C6

Middle cervical sympathetic ganglion

C7

Middle cervical sympathetic cardiac nerve Vertebral ganglion Recurrent laryngeal nerve Cervicothoracic (stellate) ganglion Ansa subclavia Vagus nerve (X) (cut) Inferior cervical sympathetic cardiac nerve Thoracic sympathetic and vagal cardiac nerves

C8

Subclavian artery

Figu re 4-25

THE NECK 147

4

CLINICAL CORRELATES • Torticollis • • • • • •

Torticollis, also kn own as “wryn eck,” is a d isorder in wh ich th e m u scles of th e n eck are exed , exten ded, or twisted in an abn orm al p osition Th e stern ocleid om astoid is th e m ost com m on ly affected m u scle Th e n eck typ ically twists to 1 side, lead in g to abn orm al m ovem en ts an d p ostu res of th e h ead In con gen ital m u scu lar torticollis, th e ben t n eck is cau sed by a tigh t stern ocleidom astoid on 1 sid e of th e bod y Early treatm en t is im p ortan t in p reven tin g p erm an en t d eform ities Certain dru gs, su ch as n eu rolep tic agen ts, can cau se dystonia, a con d ition in wh ich in volu n tary m u scle con traction occu rs in th e n eck, back, an d tru n k

Young man with muscular torticollis. Head tilted to left with chin turned slightly to right because of contracture of left sternocleidomastoid muscle.

Untreated torticollis in middle-aged woman. Thick, fibrotic, tendon-like bands have replaced sternocleidomastoid muscle, making head appear tethered to clavicle. 2 heads of left sternocleidomastoid muscle are prominent.

Figu re 4-26

148

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

CLINICAL CORRELATES • Torticollis

4

Nonmuscular Causes of Torticollis Atlantoaxial rotatory subluxation and fixation (after Fielding and Hawkins) Transverse ligament of atlas

Inferior articular facet of atlas Superior articular facet of axis

O dontoid process

Type I

Type II

Rotatory subluxation of atlas about dens but transverse ligament intact. No anterior displacement

Type III

1 articular facet subluxated, other acts as pivot; transverse ligament defective. Anterior displacement of 3–5 mm

Type IV

Both articular facets subluxated, transverse ligament defective. Anterior displacement of 5 mm

Posterior rotatory subluxation (rare). O s odontoideum or absent or defective dens

Type I rotatory subluxation

Figu re 4-27

THE NECK 149

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CLINICAL CORRELATES • Hypothyroidism • •

• •

Con d ition in wh ich th e th yroid glan d d oes n ot p rod u ce en ou gh th yroid h orm on es Th e p itu itary glan d regu lates th e th yroid’s n orm al p rodu ction of th e h orm on es th yroxin e an d triiod oth yron in e Th e lack of h orm on es lead s to an overall slowin g of m en tal an d p h ysical activities Con gen ital h yp oth yroid ism is kn own as cretin ism

CAUSES

• •

Hash im oto’s th yroid itis—im m u n e system of th e body attacks th e glan d Irrad iation of th e glan d

• •

Su rgical rem oval of th e glan d Con gen ital defects

RISK FACTORS

• • •

Obesity Age old er th an 50 years Fem ale gen d er

CLINICAL MANIFESTATIONS

• • • • • • •

Fatigu e Weakn ess Slow p u lse Ed em a of face Cold sen sation s Dry an d coarse skin Coarse voice

Lethargy, memory impairment, slow cerebration (psychoses may occur)

Hair dry, brittle

Edema of face and eyelids Thick tongue, slow speech Deep, coarse voice

Sensation of coldness

Heart enlarged, poor heart sounds, precordial pain (occasional)

Diminished perspiration

Hypertension (frequently) Skin coarse, dry, scaling, cold (follicular keratosis), yellowish (carotenemia) Pulse slow Menorrhagia (amenorrhea may occur late in disease)

Ascites Weakness

Reflexes, prolonged recovery

Figu re 4-28

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NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

CLINICAL CORRELATES • Hyperthyroidism • •

Ch aracterized by h yp erm etabolism an d elevated levels of th yroid h orm on es Can lead to th yrotoxicosis, a toxic con d ition cau sed by excess th yroid h orm on es regard less of th e cau se

CAUSES

•

• •

Graves’ disease—m ost com m on cau se (in greater th an 80% of all cases of h yp erth yroidism ), in wh ich th e body p rodu ces an tibod ies th at stim u late th e th yroid to syn th esize excess th yroid h orm on es Ben ign growth s of th e th yroid or p itu itary glan d Th yroiditis

• •

4

In gestion of excess th yroid h orm on es or iod in e Gon ad al tu m ors

CLINICAL MANIFESTATIONS

• • • • • •

Loss of weigh t Restlessn ess Nervou sn ess In creased ap p etite Fatigu e Goiter

TREATMENT

• • •

Rad ioactive iod in e—bu t too m u ch can lead to h yp oth yroid ism Su rgery An tith yroid agen ts

Nervousness Excitability Restlessness Emotional instability Insomnia

Perspiration Facial flushing Age 12 to 50 years (usually)

Exophthalmos

Palpable lymph nodes

Goiter (may have thrill and bruit) Muscle wasting Warm, velvety skin Shortness of breath

Palpitation, tachycardia

Breast enlargement, gynecomastia in male

Increased appetite Frequent bowel movements

Loss of weight Tremor

Rapid pulse Warm, moist palms

Clubbing of fingers (in some patients with severe exophthalmos)

O ligomenorrhea or amenorrhea

Muscular weakness, fatigability

Localized myxedema

Figu re 4-29 THE NECK 151

This pa ge inte ntiona lly le ft bla nk

CHAPTER 5

SCALP AND MUSCLES OF FACIAL EXPRESSION

Overview and Topographic Anatomy

154

Overview of the Scalp

156

Vascular Supply of the Scalp

157

Nerve Supply of the Scalp

159

Overview of Muscles of Facial Expression

161

Vascular Supply of the Face

170

Nerve Supply of the Face

177

Clinical Correlates

183

5

OVERVIEW AND TOPOGRAPHIC ANATOMY • General Information SCALP

• • •

Th e area bord ered by th e foreh ead , su p erior p art of th e cran iu m , an d occip ital area im m ed iately su p erior to th e su p erior n u ch al lin e Th e lateral p ortion of th e scalp blen ds with th e tem p oral area becau se it exten ds in feriorly to th e zygom atic arch An atom y of th e scalp is im p ortan t becau se of freq u en t trau m a in th is region

FACE

• • • • • • • •

Th e area bord ered with in th e h airlin e, an terior border of th e au ricles, an d th e ch in Major con ten ts: eyes, n ose, m ou th , m u scles of facial exp ression , m u scles of m astication , p arotid glan d , trigem in al n erve, an d facial n erve Th ere is n o d eep fascia alon g th e face Th e su p er cial fascia of th e face h as varyin g am ou n ts of ad ip ose tissu e Th e su p er cial m u scu lar ap on eu rotic system (SMAS) is deep to th e su p er cial fascia an d p rovid es a su rgical p lan e for su rgery of th e face Th e skin , su p er cial fascia, an d SMAS form an an atom ic stru ctu re sim ilar to th e scalp p rop er Th e skin is attach ed to th e u n derlyin g bon e by retain in g ligam en ts, wh ich are in con stan t location s on th e face Th e release of th e retain in g ligam en ts is im p ortan t du rin g facial su rgeries to ach ieve a desired aesth etic ou tcom e

BONES

•

•

Bon es of th e facial skeleton : • Fron tal bon e • Zygom atic bon e (zygom a) • Maxilla • Palatin e bon e • Nasal bon e • Man dible Besid es th e n asal bon e, th e m ost com m on ly fractu red bon e of th e facial skeleton is th e zygom atic bon e

MUSCLES OF FACIAL EXPRESSION

• • • • •

154

Th e m u scles of facial exp ression also are called m im etic m u scles In n ervated by th e facial n erve Derivatives of th e 2n d p h aryn geal arch Origin ate from eith er bon e or fascia an d in sert on th e skin Th e SMAS p rovid es an an atom ic p lan e for th e m u scles of facial exp ression an d is m an eu vered in a rh ytid ectom y (facelift)

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

OVERVIEW AND TOPOGRAPHIC ANATOMY • General Information

Frontal bone

Infraorbital margin

Supraorbital notch

Zygomatic bone

5

Superciliary arch Glabella Nasal bone Ala of nose Philtrum

Commissure of lips

Nasolabial sulcus

Angle of jaw (mandible)

Tubercle of superior lip Mental protuberance

Frontal bone Parietal bone

Sphenoid bone Nasal bone Temporal bone Lacrimal bone Ethmoid bone

Zygomatic bone

Inferior nasal concha Vomer Maxilla

Mandible

Figu re 5-1

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OVERVIEW OF THE SCALP • General Information Layer

Description

Skin

Thickest layer of the scalp Contains the hair follicles

Connective tissue

Heavily vascularized Arteries, veins, and nerves of the scalp are located here Em issary veins connect this layer to the dural venous sinuses, providing channel for infections to spread Head wounds that pierce the skin and connective tissue layers bleed profusely Continuous with super cial fascia of the posterior part of the neck

Aponeurosis

Also called galea aponeurotica Continuous with the occipitofrontalis m .: anteriorly with the frontalis, posteriorly with the occipitalis Blends laterally with the tem poral fascia Its surgical m anipulation is im portant in cosm etic surgery Head wounds that pierce the skin, connective tissue, and aponeurosis layers bleed and gape open from the pull of the 2 bellies of the occipitofrontalis Skin, connective tissue, and aponeurosis layers are adherent and often called “scalp proper”

Loose areolar connective tissue

Thin and m obile Helps form a subaponeurotic layer that extends from the eyebrows to the superior nuchal line and external occipital protuberance Allows substances such as bacteria and blood to pass freely Separates with scalp avulsion

Pericranium

Covers the outer surface of the cranium

Skin Connective tissue Galea aponeurotica Loose areolar tissue Pericranium

Granular foveola Arachnoid granulation

Emissary vein

Calvaria

Tributary of superficial temporal vein Diploic vein Dura–skull interface (site of epidural hematoma) Dura mater Arachnoid–dura interface (site of subdural hematoma)

Bridging vein

Arachnoid Subarachnoid space Pia mater Cerebral artery Superior cerebral vein Falx cerebri

Cerebral hemisphere Superior sagittal sinus

Figu re 5-2

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VASCULAR SUPPLY OF THE SCALP • General Information • • •

5

High ly vascu larized; th e vessels an astom ose freely on th e scalp Arteries are d erived from th e extern al an d th e in tern al carotid arteries Th e n eu rovascu lar su p p ly arises from th e an terior, lateral, an d p osterior scalp region s ARTERIAL SUPPLY Artery

Source

Course

Supratrochlear

Ophthalm ic a. from the internal carotid a.

Exits the orbit at the m edial angle accom panied by supratrochlear n. Ascends up to the scalp at the frontal notch Anastom oses with the contralateral supraorbital and supratrochlear aa.

External carotid a.

Begins posterior to the neck of the m andible and travels superiorly as a continuation of the external carotid a. Joined by the auriculotem poral n. Anastom oses with a m ajority of other branches supplying the scalp

Supraorbital

Super cial tem poral

Branches from the ophthalm ic a. as the artery passes the optic n. Passes m edially to the levator palpebrae superioris and superior rectus m m . to join the supraorbital n. Passes through the supraorbital foram en (notch) and ascends superiorly along the scalp Anastom oses with the supratrochlear and super cial tem poral aa.

Posterior auricular

Arises within the parotid gland Passes superiorly between the m astoid process and the cartilage of the ear Anastom oses with the super cial tem poral and occipital aa.

Occipital

Branches along the inferior m argin of the posterior belly of the digastric and stylohyoid m m . Hypoglossal n. wraps around it from the posterior part of the vessel, traveling anteriorly Passes posteriorly along the m astoid process, m aking a groove on the bone Pierces the fascia that connects the attachm ent of the trapezius with the sternocleidom astoid m . Ascends in the connective tissue layer of the scalp, dividing into m any branches The term inal part is accom panied by the greater occipital n. Anastom oses with the posterior auricular and super cial tem poral aa.

VENOUS DRAINAGE Vein

Course

Supratrochlear

Begins on the forehead, where it com m unicates with the super cial tem poral v. Passes inferiorly along the forehead parallel with the vein of the opposite side At the m edial angle of the orbit, it joins the supraorbital and the angular v.

Supraorbital

Begins on the forehead, where it com m unicates with the super cial tem poral v. Passes inferiorly super cial to the frontalis m . and joins the supratrochlear v. at the m edial angle of the orbit and the angular v.

Super cial tem poral

Descends posterior to the zygom atic root of the tem poral bone alongside the auriculotem poral n. to enter the substance of the parotid gland Unites with the m axillary v. to form the retrom andibular v.

Posterior auricular

Begins on the side of the scalp, posterior to the auricle Passes inferiorly and joins the posterior division of the retrom andibular v. to form the external jugular v.

Occipital

Begins on the posterior portion of the scalp at the vertex Passes from super cial to deep by passing through the attachm ent of the sternocleidom astoid m . to the skull Has a m astoid em issary v. that connects it to the transverse sinus The vein’s term ination is variable, but it usually passes inferiorly to join the internal jugular v.

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VASCULAR SUPPLY OF THE SCALP • Venous Drainage

Scalp

Skin and subcutaneous tissue Epicranial aponeurosis (galea aponeurotica) (cut to reveal skull)

Parietal emissary vein

Branches of Frontal superficial temporal Parietal artery and vein

Supraorbital artery and vein Supratrochlear artery and vein

Mastoid emissary vein and meningeal branch of occipital artery (posterior meningeal artery) O ccipital artery and vein (cut) Posterior auricular artery and vein External jugular vein (cut) Retromandibular vein

Internal carotid artery External carotid artery Common carotid artery

Sources of arterial supply of face Black : from internal carotid artery (via ophthalmic artery) Red : from external carotid artery

Figu re 5-3

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NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

NERVE SUPPLY OF THE SCALP • Sensory Distribution • •

5

Sen sory su p p ly is d erived from all 3 d ivision s of th e trigem in al n erve, bran ch es of th e cervical p lexu s, an d u p p er cervical d orsal ram i Th ese n erves travel in th e scalp ’s con n ective tissu e layer SENSORY NERVES OF THE SCALP Nerve

Source

Course

Supratrochlear

Ophthalm ic division of the trigem inal n.

The frontal nerve passes anteriorly in the orbit after branching from the ophthalm ic division of the trigem inal The frontal nerve divides into supratrochlear and supraorbital nerves The supratrochlear continues to pass anteriorly toward the trochlea once the supratrochlear a. joins it within the orbit In the trochlear region, it exits the orbit at the frontal notch Ascends along the scalp, at rst deep to the m usculature in the region, before piercing them to reach the cutaneous innervation along the scalp

Supraorbital

1 of the 2 term inal branches of the frontal n. in the orbit Passes between the levator palpebrae superioris m . and periosteum of the orbit Continues anteriorly to the supraorbital foram en (notch) At the level of the supraorbital m argin, it sends nerve supply to the frontal sinus, skin, and conjunctiva of the upper eyelid Continues to ascend superiorly along the scalp Divides into m edial and lateral branches, which travel up to the vertex of the scalp

Zygom aticotem poral

Maxillary division of the trigem inal n.

Arises from the zygom atic n. in the pterygopalatine fossa, and passes through the inferior orbital ssure to enter the lateral wall of the orbit and branches into the zygom aticotem poral and zygom aticofacial branches Passes on the lateral wall of the orbit in a groove in the zygom atic bone, then through a foram en in the zygom atic bone to enter the tem poral fossa region Within the tem poral fossa, it passes superiorly between the bone and the tem poralis m . to pierce the tem poral fascia superior to the zygom atic arch Passes along the skin of the side of the scalp

Auriculotem poral

Posterior division of the m andibular division of the trigem inal n.

Norm ally arises as 2 roots, between which the m iddle m eningeal a. passes Runs posteriorly just inferior to the lateral pterygoid and continues to the m edial aspect of the neck of the m andible While passing posterior to the m andible, it provides sensory innervation to the tem porom andibular joint Turns superiorly with the super cial tem poral vessels between the auricle and the condyle of the m andible deep to the parotid gland On exiting the parotid gland, ascends over the zygom atic arch and divides into branches along the scalp

Lesser occipital

Arises from the cervical plexus from the ventral ram us of C2

Wraps around and travels superiorly along the posterior border of the sternocleidom astoid At the skull, it passes through the investing layer of deep cervical fascia and continues superiorly posterior to the auricle to supply the skin in the area

Greater occipital

Dorsal ram us of C2

Ascends between the obliquus capitis inferior and sem ispinalis capitis m m . in the suboccipital triangle Passes through the sem ispinalis capitis and trapezius m m . near their bony attachm ents Ascends on the back of the head with the occipital a. to supply the skin as far anterior as the vertex

3rd occipital

Dorsal ram us of C3

Arises deep to the trapezius m ., passes through it, and ascends in the skin of the inferior portion of the posterior surface of the head near the m idline

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NERVE SUPPLY OF THE SCALP • Sensory Distribution Epicranial aponeurosis (galea aponeurotica) O ccipital belly (occipitalis) of occipitofrontalis muscle Greater occipital nerve (dorsal ramus of C2 spinal nerve)

Suboccipital nerve (dorsal ramus of C1 spinal nerve)

O ccipital artery

Posterior arch of atlas (C1 vertebra)

3rd (least) occipital nerve (dorsal ramus of C3 spinal nerve)

O ccipital artery

Greater occipital nerve (dorsal ramus of C2 spinal nerve) Posterior auricular artery 3rd (least) occipital nerve (dorsal ramus of C3 spinal nerve)

Great auricular nerve (cervical plexus C2, 3) Lesser occipital nerve (cervical plexus C2, 3)

From ophthalmic division of trigeminal nerve (V1 ) Supraorbital nerve Supratrochlear nerve

Medial branches of dorsal rami of cervical spinal nerves Greater occipital nerve (C2) 3rd occipital nerve (C3)

From maxillary division of trigeminal nerve (V2 )

Zygomaticotemporal nerve

Branches from cervical plexus Lesser occipital nerve (C2)

From mandibular division of trigeminal nerve (V3 )

Auriculotemporal nerve

Figu re 5-4

16 0

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

OVERVIEW OF MUSCLES OF FACIAL EXPRESSION • General Information • • • • •

5

In n ervated by th e facial n erve Derivatives of th e 2n d p h aryn geal arch In sert in to th e skin to p rovid e m ovem en t Most m u scles of facial exp ression are localized arou n d th e facial ori ces Th ere is n o d eep fascia alon g th e face

Muscle Attachments of the Face: Anterior View

Temporalis muscle

Procerus muscle

O rbicularis oculi muscle

Zygomaticus minor muscle

Levator labii superioris alaeque nasi muscle Levator labii superioris muscle Masseter muscle Levator anguli oris

Zygomaticus major muscle

Nasalis muscle

Buccinator muscle

O rbicularis oris muscle

Depressor septi nasi muscle

Masseter muscle Buccinator muscle Depressor anguli oris muscle Depressor labii inferioris muscle

Mentalis muscle O rbicularis oris muscle

Platysma muscle

Figu re 5-5

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5

OVERVIEW OF MUSCLES OF FACIAL EXPRESSION • General Information Muscle Attachments of the Face: Lateral View and Inferior View Zygomaticus major muscle Zygomaticus minor muscle O rbital part O rbicularis oculi muscle Palpebral part Procerus muscle

Temporalis muscle

Lacrimal O rbicularis oculi muscle part Levator labii superioris alaeque nasi muscle

O ccipitalis muscle (occipitalis occipitofrontalis, occipital belly) Trapezius muscle Semispinalis muscle

Levator anguli oris muscle Nasalis Transverse part muscle Alar part Depressor septi nasi muscle O rbicularis oris muscle Buccinator muscle Mentalis muscle O rbicularis oris muscle Platysma muscle Depressor anguli oris muscle Depressor labii inferioris muscle

O bliquus capitis superior muscle Rectus capitis posterior minor muscle Rectus capitis posterior major muscle Longissimus capitis muscle Splenius capitis muscle Sternocleidomastoid muscle Stylopharyngeus muscle Stylohyoid muscle Styloglossus muscle (CN XII) Masseter muscle Lateral pterygoid muscle Masseter muscle Temporalis muscle

Masseter muscle Temporalis muscle Lateral pterygoid muscle Medial pterygoid muscle Tensor veli palatini muscle Longus capitis muscle Rectus capitis anterior muscle Styloglossus muscle Stylohyoid muscle Stylopharyngeus muscle Levator veli palatini muscle Longissimus capitis muscle Splenius capitis muscle Sternocleidomastoid muscle Digastric muscle (posterior belly) Rectus capitis lateralis muscle O bliquus capitis superior muscle Rectus capitis posterior major muscle Rectus capitis posterior minor muscle Semispinalis capitis muscle Trapezius muscle O ccipitalis muscle

Figu re 5-6

162

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

OVERVIEW OF MUSCLES OF FACIAL EXPRESSION • Oral Group Muscle

Origin

Insertion

Actions

Nerve

Comments

Orbicularis oris

Bone: anterior m idline of the m axilla and m andible Muscular: angle of the m outh where bers blend with levator anguli oris, depressor anguli oris, zygom aticus m ajor, and risorius mm.

Skin along the m outh

Closes lips Protrusion of lips Pursing of lips

Facial (buccal and m andibular branches)

Sphincter of the m outh Muscle bers encircle the m outh

Depressor anguli oris

Mandible along area near the external oblique line

Depresses the Facial (buccal Angle of the corners of and m outh the m outh in m andibular Som e bers an inferior branches) blend and and lateral provide origin direction for the orbicularis oris m . Fibers overlap those of the depressor labii inferioris m.

Levator anguli oris

Canine fossa of the m axilla (inferior to the infraorbital foram en)

Angle of the Elevates the m outh angle of the m outh (e.g., Som e bers in sm iling) blend and provide origin Makes nasolabial for the furrow m ore orbicularis pronounced oris m .

Zygom aticus m ajor

Zygom atic bone (anterior to the zygom aticotem poral suture)

Zygom aticus m inor

Zygom atic bone (anterior to the zygom aticus m ajor)

Lateral upper lip (just m edial to Zygom aticus m ajor attachm ent)

Facial (zygom atic and buccal branches)

5

Antagonizes levator anguli oris m.

In an infraorbital injection, the needle lies between the levator anguli oris and levator labii superioris mm.

Moves the angle of the m outh superiorly and laterally (e.g., with broad sm ile and laughing)

Dim ples typically are caused by deform ities in this m uscle (e.g., m uscle is bi d) Also called the “laughing m uscle” owing to its action

Helps elevate the upper lip

Inserts between the levator labii superioris and zygom aticus m ajor m m . Continued on next page

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5

164

OVERVIEW OF MUSCLES OF FACIAL EXPRESSION • Oral Group Muscle

Origin

Insertion

Actions

Nerve

Comments

Levator labii superioris

Maxilla (superior to the infraorbital foram en along the inferior m argin of the orbit)

Lateral upper Elevates the lip upper lip Som e bers blend and provide origin for the orbicularis oris m .

Facial (zygom atic and buccal branches)

In an infraorbital injection, the needle lies between the levator anguli oris and levator labii superioris mm.

Levator labii superioris alaeque nasi

Maxilla (near the bridge of the nose)

Alar cartilage of Elevates the the nose upper lip Lateral upper Dilates the lip (blending nostril with orbicularis oris and levator labii superioris m m .)

Also called the angular part of the levator labii superioris m.

Risorius

Fascia overlying the parotid gland

Angle of the m outh

Com m only called the “grinning m uscle”

Depressor labii inferioris

Mandible (inferior to Lower lip the m ental foram en) Fibers blend and provide origin for the orbicularis oris m .

Depresses the lower lip (e.g., in “pouting”)

Mentalis

Incisive fossa of the m andible

Skin of the chin

Elevates lower lip Protrudes lower lip (e.g., while drinking)

Buccinator

Pterygom andibular raphe Alveolar m argins of the m axilla and m andible

Som e bers Aids in blend and m astication, provide origin keeping the for the bolus between orbicularis cheek and oris teeth Som e bers Helps forcibly blend into expel air the upper and lower Helps create a lips sucking action

Moves the Facial (buccal angle of the branch) m outh laterally (e.g., with grinning, sm iling, laughing)

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

Facial (m andibular branch)

Fibers of the depressor anguli oris m . overlap the bers of the depressor labii inferioris m . Used in “pouting”

Facial (buccal branch)

Creates the fram ework of the cheek

OVERVIEW OF MUSCLES OF FACIAL EXPRESSION • Oral Group

5

Levator labii superioris alaeque nasi muscle Levator labii superioris muscle Zygomaticus minor muscle Zygomaticus major muscle Levator anguli oris muscle Buccinator muscle Risorius muscle O rbicularis oris muscle Depressor anguli oris muscle Depressor labii inferioris muscle Mentalis muscle

Levator labii superioris alaeque nasi muscle Levator labii superioris muscle

Zygomaticus minor muscle Zygomaticus major muscle Parotid duct Levator anguli oris muscle

Buccinator muscle

O rbicularis oris muscle Mentalis muscle Depressor labii inferioris muscle

Depressor anguli oris muscle

Figu re 5-7

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OVERVIEW OF MUSCLES OF FACIAL EXPRESSION • Nasal and Orbital Groups NASAL GROUP Muscle

Parts

Origin

Nasalis

Com pressor Maxilla naris (Transverse part)

Com pressor Com presses naris m . of the nostril opposite side

Dilator naris (Alar part)

Nasal cartilage

Dilates the nostril

Allows aring of the nostrils

Nasal septum

Draws nasal septum and tip of nose anteriorly

Variable and occasionally absent

Skin of the forehead between the eyes

Brings skin together producing transverse wrinkles on the bridge of the nose (e.g., in frowning)

Depressor septi

Procerus

Nasal bone (lower portion) Lateral nasal cartilage

Insertion

Actions

Nerve

Comment

Facial n.: buccal branch

Antagonist to the dilator naris

Facial n.: tem poral and zygom atic branches

Partially excised in som e facelift procedures (rhytidectom y) Also com m on area for Botox injections

ORBITAL GROUP Muscle

Parts

Actions

Nerve

Frontal process Around the orbit of m axilla Nasal portion of frontal bone Medial palpebral ligam ent

Voluntary closure of the eye (as in squinting)

Lacrim al

Lacrim al bone

Lacrim al fascia around the lacrim al canaliculi

Pulls lacrim al papilla and eyelids m edially, which aids the ow of tears

Facial n.: Fat that tem poral accum ulates and around the eye zygom atic from aging m ay branches be rem oved surgically (blepharoplasty) Because the orbicularis oculi m . m oves the skin around the eye, its attachm ent is extrem ely im portant

Palpebral

Medial palpebral ligam ent

Lateral palpebral raphe

Closure of eyelids gently (as in sleeping and blinking)

Frontal bone (m edial end of superciliary arch)

Middle of the eyebrow

Draws the Facial n.: eyebrows tem poral m edially and branch inferiorly (as in squinting)

Orbicularis Orbital oculi

Corrugator supercilii

166

Origin

Insertion

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

Comment

Fibers lie deep to the orbicularis oculi m .

OVERVIEW OF MUSCLES OF FACIAL EXPRESSION • Nasal Group

5

Procerus muscle Corrugator supercilii muscle of orbicularis O rbital part Palpebral part oculi muscle Transverse part of nasalis muscle Alar part

Depressor septi nasi muscle

O rbicularis oculi muscle

O rbital part Palpebral part

Frontal belly (frontalis) of epicranius muscle Corrugator supercilii muscle (frontalis and orbicularis oculi, partially cut aw ay)

Procerus muscle

Nasalis Transverse part muscle Alar part

Depressor septi nasi muscle

Figu re 5-8

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OVERVIEW OF MUSCLES OF FACIAL EXPRESSION • Auricular, Scalp, Neck AURICULAR GROUP Muscle

Parts

Origin

Insertion

Actions

Nerve

Comment

Auricular

Anterior

Galea aponeurosis

Helix

Draws auricle anteriorly

Facial n.: tem poral branch

Superior part of the auricle

Draws auricle superiorly

Posterior part of the auricle

Draws auricle posteriorly

These m uscles usually provide little m ovem ent and tend to not always be voluntary

Superior

Posterior

Mastoid process

Facial n.: posterior auricular branch

SCALP GROUP (OCCIPITOFRONTALIS) Muscle

Origin

Insertion

Actions

Nerve

Comment

Frontalis

Skin and super cial fascia along eyebrows and adjacent facial m uscles (corrugator supercilii, orbicularis oculi, and procerus)

Galea aponeurosis

Elevates eyebrows Wrinkles forehead

Facial n.: tem poral branch

Has no bony attachm ent Surgical m anagem ent im portant in cosm etic surgery

Occipitalis

Superior nuchal line Mastoid process

Wrinkles the back of the head

Facial n: posterior auricular branch

NECK GROUP

16 8

Muscle

Origin

Insertion

Actions

Nerve

Comment

Platysm a

Fascia of upper part of the pectoralis m ajor m . and deltoid

Inferior border of the m andible Som e bers blend with the skin of the neck and lower face

Tenses the skin of the neck (i.e. - causing the skin of the neck to wrinkle) Depresses the skin of the lower face

Facial n.: cervical branch

The external jugular lies deep to the platysm a m .

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

OVERVIEW OF MUSCLES OF FACIAL EXPRESSION • Auricular, Scalp, Neck

5

Auricularis anterior muscle Auricularis superior muscle Auricularis posterior muscle Frontal belly (frontalis) of epicranius muscle

O ccipital belly (occipitalis) of epicranius muscle

Platysma muscle

Figu re 5-9

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VASCULAR SUPPLY OF THE FACE • General Information • • • •

Most of th e arterial su p p ly to th e face arises from th e su p er cial tem p oral artery an d facial bran ch es of th e extern al carotid artery Th e m axillary bran ch of th e extern al carotid su p p lies m ost areas th at th e su p er cial tem p oral an d facial bran ch es do n ot su p p ly Th e in tern al carotid artery su p p lies th e an terior p ortion of th e foreh ead an d d orsal su rface of th e n ose via op h th alm ic artery bran ch es Th e arteries of th e face an astom ose freely

Skin and subcutaneous tissue Scalp Epicranial aponeurosis (galea aponeurotica) (cut to reveal skull) Middle temporal artery and vein

Parietal emissary vein

Frontal Branches of superficial temporal Parietal artery and vein

Zygomaticoorbital artery Transverse facial artery and vein

Anterior auricular arteries

Supraorbital artery and vein Supratrochlear artery and vein Nasofrontal vein Dorsal nasal artery and vein Zygomaticotemporal artery and vein Angular artery and vein Zygomaticofacial artery and vein

Mastoid emissary vein and meningeal branch of occipital artery (posterior meningeal artery) O ccipital artery and vein (cut)

Infraorbital artery and vein Deep facial vein (from pterygoid plexus)

Posterior auricular artery and vein

Facial artery and vein

External jugular vein (cut) Retromandibular vein Internal jugular vein Internal carotid artery External carotid artery Common carotid artery Lingual artery and vein Sources of arterial supply of face Black : from internal carotid artery (via ophthalmic artery) Red : from external carotid artery

Figu re 5-10

170

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VASCULAR SUPPLY OF THE FACE • Arterial Supply

5

EXTERNAL CAROTID ARTERY AND ITS BRANCHES IN THE FACE Artery

Source

Course

Facial

External carotid a.

Arises in the carotid triangle of the neck Passes superiorly im m ediately deep to the posterior belly of the digastric m . and the stylohyoid m m . Passes along the subm andibular gland, giving rise to the subm ental a. that helps supply the gland Passes superiorly over the body of the m andible at the m asseter m . Continues anterosuperiorly across the cheek to the angle of the m outh, giving rise to the superior and inferior labial aa. Passes superiorly along the side of the nose, giving rise to the lateral nasal a. Continues on the side of the nose as the angular a. to term inate along the m edial aspect of the eye Tortuous

Facial a.

Supplies the upper lip Gives rise to the septal branch that travels to the nasal septum

Superior labial

Inferior labial

Supplies the lower lip

Lateral nasal

Supplies the ala and nose

Angular

The facial a.’s term inal branch Passes superiorly to term inate at the m edial angle of the orbit

Super cial tem poral

Transverse facial

Maxillary

Infraorbital

External carotid a.

1 of the 2 term inal branches of the external carotid Arises posterior to the neck of the m andible and travels superiorly as a continuation of the external carotid a. Joined by the auriculotem poral n.

Super cial tem poral a.

Passes transversely before it exits the parotid gland Passes im m ediately superior to the parotid duct across the m asseter m . and face

External carotid a.

1 of the 2 term inal branches of the external carotid a. Gives rise to a series of branches; only 3 provide blood supply to the face: the infraorbital, buccal, and m ental

Maxillary a.

The continuation of the 3rd part of the m axillary a. Accom panied by the infraorbital n. and v. Passes forward in the infraorbital groove and infraorbital canal and exits the infraorbital foram en On exiting the infraorbital foram en, it lies between the levator labii superioris and levator anguli oris m m . and follows the branching pattern of the nerve: Inferior palpebral (supplies the lower eyelid) Nasal (supplies the lateral side of the nose) Superior labial (supplies the upper lip)

Buccal

A branch of the 2nd part of the m axillary A sm all artery that runs obliquely in an anterior direction between the m edial pterygoid m . and the insertion of the tem poralis m . until it reaches the outer surface of the buccinator m . to supply it and the face

Mental

A term inal branch of the inferior alveolar a., which arises from the 1st part of the m axillary a. Em erges from the m ental foram en to supply the chin region

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VASCULAR SUPPLY OF THE FACE • Arterial Supply Supratrochlear artery Supraorbital artery

From ophthalmic artery

Deep temporal arteries Dorsal nasal artery Angular artery Infraorbital artery Lateral nasal artery Buccal artery Transverse facial artery (cut)

Superior labial artery

Superficial temporal artery

Inferior labial artery

Maxillary artery Middle meningeal artery

Mental branch of inferior alveolar artery Facial artery

O phthalmic artery Supraorbital artery Supratrochlear artery Dorsal nasal artery Angular artery Infraorbital artery Buccal artery and nerve

Superficial temporal artery Maxillary artery

Mental branch of inferior alveolar artery

Submental artery Facial artery

Figu re 5-11

172

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VASCULAR SUPPLY OF THE FACE • Arterial Supply

5

OPHTHALMIC ARTERY AND ITS BRANCHES Artery

Course

Ophthalm ic

A branch of the internal carotid Enters the orbit through the optic foram en im m ediately inferior and lateral to the optic n. Crosses the optic n. to reach the m edial part of the orbit Within the orbit, besides the orbital branches, it gives rise to 5 m ajor branches that supply the face (either directly or indirectly): • Supratrochlear • Supraorbital • Lacrim al • Anterior ethm oid (from which the external nasal arises) • Dorsal nasal

Supratrochlear

Exits the orbit at the m edial angle accom panied by supratrochlear n. Ascends on the scalp, anastom osing with the supraorbital and supratrochlear aa. from the opposite side

Supraorbital

Arises as the ophthalm ic a. passes the optic n. Passes on the m edial side of the levator palpebrae superioris and superior rectus m m . to join the supraorbital n. Passes through the supraorbital foram en (notch) and ascends superiorly along the scalp Anastom oses with the supratrochlear and super cial tem poral aa.

Lacrim al

Arises near the optic foram en 1 of the largest branches of the ophthalm ic a. Follows the lacrim al n. along the superior border of the lateral rectus m . of the eye to reach and supply the lacrim al gland Gives rise to a series of term inal branches that pass to the eyelids and conjunctivae Gives rise to a zygom atic branch that divides into the zygom aticotem poral and zygom aticofacial aa., to supply those facial regions

External nasal

A term inal branch of the anterior ethm oid a. Supplies the area along the external nose at the junction of the nasal bone and the lateral nasal cartilage

Dorsal nasal

1 of the term inal branches of the ophthalm ic a. Exits the orbit along the superom edial border along with the infratrochlear n. Supplies the area along the bridge of the nose

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VASCULAR SUPPLY OF THE FACE • Arterial Supply

Supraorbital artery

Supratrochlear artery

Dorsal nasal artery

Angular artery

External nasal artery Nasalis muscle (transverse part) Infraorbital artery and nerve Lateral nasal artery Transverse facial artery

Facial artery

Supraorbital artery

Anterior view X

Supratrochlear artery X

Frontal branch of superficial temporal artery

Dorsal nasal artery Angular artery

X

Zygomaticofacial artery

X

Transverse facial artery Facial artery

Infraorbital artery (X = anastomosis of vessels from external and internal carotid arteries)

Figu re 5-12

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NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

VASCULAR SUPPLY OF THE FACE • Venous Drainage • • •

5

Facial vein s h ave sim ilar distribu tion p attern as th e arteries High ly variable 4 m ajor vein s con n ect th e su p er cial vein s of th e n ose, ch eeks, an d u p p er lip to th e d eep er vessels (p terygoid p lexu s an d cavern ou s sin u s), creatin g th e “dan ger trian gle of th e face”—it p rovid es a p ath way for in fection s to sp read to th e cavern ou s sin u s (cavern ou s sin u s th rom bosis) SUPERFICIAL VEINS Vein

Course

Facial

Begins as the angular v. Passes inferiorly along the side of the nose, receiving the lateral nasal v. Continues posteroinferiorly across the angle of the m outh to the cheek, receiving the superior and inferior labial vv. While passing toward the m andible, the deep facial v. connects it to the pterygoid plexus In the subm andibular triangle, it joins the anterior branch of the retrom andibular to form the com m on facial v. Has no valves that can allow blood to back ow

Superior labial

Drains the upper lip and joins the facial v.

Inferior labial

Drains the lower lip and joins the facial v.

Lateral nasal

Drains the ala and nose and joins the facial v.

Angular

Form s from the con uence of the supraorbital and supratrochlear vv. along the m edial part of the eye Travels along the lateral aspect of the nose to becom e the facial v.

Supraorbital

Begins on the forehead, where it com m unicates with the super cial tem poral Passes inferiorly super cial to the frontalis m . and joins the supratrochlear v. at the m edial angle of the orbit to form the angular v.

Supratrochlear

Begins on the forehead, where it com m unicates with the super cial tem poral vv. Passes inferiorly along the forehead parallel with the vein of the opposite side At the m edial angle of the orbit, it joins the supraorbital v. to form the angular v.

Super cial tem poral

Descends posterior to the zygom atic root of the tem poral bone alongside the auriculotem poral n. to enter the substance of the parotid gland Unites with the m axillary v. to form the retrom andibular v.

Transverse facial

Travels posteriorly to enter the parotid gland and join the super cial tem poral v.

Buccal

Drains the cheek and joins the pterygoid plexus

Mental

Drains the chin and joins the pterygoid plexus

Figu re 5-13 SCALP AND MUSCLES O F FACIAL EXP RESSIO N

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5

VASCULAR SUPPLY OF THE FACE • Venous Drainage COMMUNICATING VEINS Vein

Course

Superior ophthalm ic

Receives blood from the roof of the orbit and the scalp Travels posteriorly to com m unicate with the pterygoid plexus and cavernous sinus

Inferior ophthalm ic

Receives blood from the oor of the orbit Travels posteriorly with the infraorbital v., which passes through the inferior orbital ssure to com m unicate with the pterygoid plexus and the cavernous sinus

Infraorbital

Receives blood from the m idface via the lower eyelid, lateral aspect of the nose, and the upper lip Eventually com m unicates with the pterygoid plexus

Deep facial

Connects the facial v. with the pterygoid plexus

DEEP VEINS Vein

Course

Cavernous sinus

A reticulated venous structure on the lateral body of the sphenoid bone Drains posteriorly into the superior and inferior petrosal sinuses Receives blood from the superior and inferior ophthalm ic vv. The oculom otor and trochlear nn. and ophthalm ic and m axillary divisions of the trigem inal n. lie along the lateral wall of the sinus Abducens n. and internal carotid artery lie in the sinus

Pterygoid plexus

An extensive network of veins that parallels the 2nd and 3rd parts of the m axillary a. Receives branches that correspond to the m axillary a.’s branches Tributaries of the pterygoid plexus eventually converge to form a short m axillary v. Com m unicates with the cavernous sinus, pharyngeal venous plexus, facial v. via the deep facial v., and ophthalm ic vv.

Supratrochlear vein Supraorbital vein Nasofrontal vein Superior ophthalmic vein Angular vein Cavernous sinus Inferior ophthalmic vein Infraorbital vein

Pterygoid plexus

Sigmoid sinus

Superior labial vein

Superficial temporal vein

Deep facial vein Maxillary vein

Transverse facial vein (cut)

Inferior labial vein

Anterior retromandibular vein

Mental vein Facial vein and artery

Internal jugular vein Vena comitans of hypoglossal nerve

Figu re 5-14

176

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

NERVE SUPPLY OF THE FACE • General Information

Dorsal rami of cervical spinal nerves

V1

N ote: Auricular branch of vagus nerve to external acoustic meatus and small area on posteromedial surface of auricle

V2

Branches from cervical plexus

V3

Facial nerve (VII)

m

p

o

ra

l

b

ra

n

c

h

e

s

Zygom a tic bran c h e s

rv ic

al

b

ra

n

ch

Buccal branches

l in a la r g r u Ma n d ib a m nch b ra

C e

•

T

•

Man y m otor an d sen sory n erves su p p ly th e face All m otor n erves are from th e facial n erve an d su p p ly th e m u scles of facial exp ression Sen sory n erves of th e face are derived m ain ly from th e 3 d ivision s of th e trigem in al n erve (V1 , V2 , V3 ) Som e sen sory bran ch es are from th e cervical p lexu s

e

• •

5

Figu re 5-15 SCALP AND MUSCLES O F FACIAL EXP RESSIO N

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NERVE SUPPLY OF THE FACE • Sensory Innervation TRIGEMINAL NERVE: OPHTHALMIC DIVISION Nerve

Source

Course

Ophthalm ic division

Trigem inal n. in the m iddle cranial fossa

Passes anteriorly on the lateral wall of the cavernous sinus im m ediately inferior to the oculom otor and trochlear nn., but superior to the m axillary division of the trigem inal n. Im m ediately before entering the orbit, through the superior orbital ssure, it divides into 3 m ajor branches: lacrim al, frontal, and nasociliary

From the ophthalm ic division; the 2 term inal branches of the frontal n. in the orbit

1 of the 2 term inal branches of the frontal n. in the orbit Once the supratrochlear a. joins it within the orbit, it continues to pass anteriorly toward the trochlear n. In the trochlear region, it exits the orbit at the frontal notch Ascends along the scalp, at rst deep to the m usculature in the region, before piercing these m uscles to reach the cutaneous innervation along the scalp

Supratrochlear

Supraorbital

178

1 of the 2 term inal branches of the frontal n. in the orbit Passes between the levator palpebrae superioris m . and periosteum of the orbit Continues anteriorly to the supraorbital foram en (notch) At the level of the supraorbital m argin, it sends nerve supply to the frontal sinus, skin, and conjunctiva of the upper eyelid Continues to ascend superiorly along the scalp Divides into m edial and lateral branches, which travel up to the vertex of the scalp

Lacrim al

The sm allest branch of the ophthalm ic division

Sm allest of the m ajor branches of the ophthalm ic division of the trigem inal n. Passes anteriorly to enter the orbit through the superior orbital ssure In the orbit it travels superolaterally on the superior border of the lateral rectus with the lacrim al a. Before reaching the lacrim al gland, it com m unicates with the zygom atic branch of the m axillary division of the trigem inal n. to receive autonom ic nervous bers Enters the lacrim al gland and supplies it and the conjunctiva before piercing the orbital septum to supply the skin of the upper eyelid

Infratrochlear

1 of the term inal branches of the nasociliary

Passes anteriorly on the superior border of the m edial rectus m . Passes inferior to the trochlea toward the m edial angle of the eye Supplies the skin of the eyelids and bridge of the nose, the conjunctivae, and all of the lacrim al structures

External nasal

Arises from the anterior ethm oid n. (from the nasociliary n.)

Term inal branch of the anterior ethm oid n. Exits between the lateral nasal cartilage and the inferior border of the nasal bone Supplies the skin of the ala and apex of the nose around the nares

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NERVE SUPPLY OF THE FACE • Sensory Innervation

5

TRIGEMINAL NERVE: MAXILLARY DIVISION Nerve

Source

Course

Maxillary division

Trigem inal n. in the m iddle cranial fossa

Travels along the lateral wall of the cavernous sinus Before exiting the m iddle cranial fossa, it gives off a m eningeal branch that innervates the dura m ater Passes from the m iddle cranial fossa into the pterygopalatine fossa via the foram en rotundum Within the pterygopalatine fossa, it gives rise to 4 branches: posterior superior alveolar n., zygom atic n., ganglionic branches, and infraorbital n.

Zygom aticotem poral

Zygom atic branch of the m axillary division

Arises from the zygom atic n. in the pterygopalatine fossa, which passes through the inferior orbital ssure to enter the orbit, dividing into the zygom aticotem poral and zygom aticofacial Passes on the lateral wall of the orbit in a groove in the zygom atic bone, then through a foram en in the zygom atic bone to enter the tem poral fossa region Within the tem poral fossa, it passes superiorly between the bone and the tem poralis m . to pierce the tem poral fascia superior to the zygom atic arch Continues along the skin of the side of the scalp

Zygom aticofacial

Zygom atic branch of the m axillary division

Passes on the lateral wall of the orbit before em erging on the face through the zygom aticofacial foram en in the zygom atic bone Supplies the skin on the prom inence of the cheek

Infraorbital

The continuation of the m axillary division of the trigem inal n.

Passes through the inferior orbital ssure to enter the orbit, then anteriorly through the infraorbital groove, infraorbital canal, and exits onto the face via the infraorbital foram en Within the infraorbital canal, it gives rise to the anterior superior alveolar and m iddle superior alveolar nn. It exits onto the face and divides into 3 term inal branches: • Inferior palpebral (supplies the skin of the lower eyelid) • Nasal (supplies the ala of the nose) • Superior labial (supplies the skin of the upper lip)

Supratrochlear nerve Supraorbital nerve

Lacrimal nerve

Infratrochlear nerve (from nasociliary nerve) Cutaneous branch of lacrimal nerve Zygomaticotemporal nerve Zygomaticofacial nerve

O phthalmic nerve (V1 )

External nasal branch of anterior ethmoidal nerve

Trigeminal (semilunar) ganglion Trigeminal nerve (V) Foramen rotundum

Infraorbital nerve

Foramen ovale Mandibular nerve (V3 ) Maxillary nerve (V2 ) Zygomatic nerve

Figu re 5-16 SCALP AND MUSCLES O F FACIAL EXP RESSIO N

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NERVE SUPPLY OF THE FACE • Sensory Innervation TRIGEMINAL NERVE: MANDIBULAR DIVISION Nerve

Source

Course

Mandibular division

Trigem inal n. in the m iddle cranial fossa

The largest of the trigem inal n.’s 3 divisions Created by a large sensory and a sm all m otor root that unite just after passing through the foram en ovale to enter the infratem poral fossa Im m ediately gives rise to a m eningeal branch and a m edial pterygoid branch before dividing into anterior and posterior divisions: • Anterior division—sm aller and m ainly m otor, with 1 sensory branch (buccal n.) • Posterior division—larger and m ainly sensory, with 1 m otor branch (m ylohyoid n.)

Auriculotem poral

Posterior division of m andibular division of the trigem inal n.

Norm ally arises by 2 roots, between which the m iddle m eningeal a. passes Runs posteriorly just inferior to the lateral pterygoid and continues to the m edial aspect of the neck of the m andible While passing posterior to the m andible, it provides sensory innervation to the tem porom andibular joint Turns superiorly with the super cial tem poral vessels between the auricle and the condyle of the m andible deep to the parotid gland On exiting the substance of the parotid gland, it ascends over the zygom atic arch and divides into super cial tem poral branches

Buccal

Anterior division of the m andibular division of the trigem inal n.

Passes anterior between the 2 heads of the lateral pterygoid m . Descends inferiorly along the lower part of the tem poralis to em erge deep to the anterior border of the m asseter m . Supplies the skin over the buccinator m . before passing through it to supply the m ucous m em brane lining its inner surface and the gingiva along the m andibular m olars

Mental

1 of the 2 term inal branches of the inferior alveolar n.

Em erges through the m ental foram en of the m andible in the region of the 2nd m andibular prem olar Supplies the skin of the lower lip, chin, and facial gingiva as far posteriorly as the 2nd m andibular prem olar

Auriculotemporal nerve (V3 ) Middle meningeal artery Buccal nerve (V3 )

Mental nerve (V3 )

Figu re 5-17

18 0

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

NERVE SUPPLY OF THE FACE • Sensory Innervation

5

CERVICAL PLEXUS Nerve

Source

Course

Great auricular

Arises from the cervical plexus form ed by contributions of C2 and C3 ventral ram i

Passes posterior to the m idpoint of the sternocleidom astoid m . Ascends along the sternocleidom astoid dividing into anterior and posterior branches Anterior branch continues along the super cial aspect of the parotid gland’s inferior part Innervates the super cial and inferior portions of the parotid gland

Transverse cervical

Passes posterior to the m idpoint of the sternocleidom astoid m . Crosses the sternocleidom astoid to pass anteriorly toward the neck Perforates the investing layer of deep cervical fascia, dividing deep to the platysm a m . into ascending and descending branches Innervates the skin to the anterolateral region of the neck and lower face around the m andible

Sternocleidomastoid muscle (cut)

Great auricular nerve

Accessory nerve (XI)

Lesser occipital nerve

Hypoglossal nerve (XII)

Greater occipital nerve (from dorsal ramus of C2)

Geniohyoid muscle

C1

C2

Thyrohyoid muscle Superior root of ansa cervicalis Inferior root of ansa cervicalis Transverse cervical nerve O mohyoid muscle (superior belly)

C3

C4 C5

Nerves to anterior and lateral rectus capitis and longus capitis and colli muscles Nerves to longus capitis and colli and levator scapulae muscles Trapezius muscle Nerves to longus capitis and colli, levator scapulae and middle scalene muscles Communication to brachial plexus Phrenic nerve

Sternothyroid muscle

Sternohyoid muscle

Supraclavicular nerves (medial, intermediate and lateral)

Ansa cervicalis Sternocleidomastoid muscle (cut)

Efferent fibers Afferent fibers Proprioceptive fibers

O mohyoid muscle (inferior belly)

Figu re 5-18 SCALP AND MUSCLES O F FACIAL EXP RESSIO N

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5

NERVE SUPPLY OF THE FACE • Motor Innervation Nerve

Course

Facial

Exits the stylom astoid foram en and gives rise to the posterior auricular n. Enters the parotid fossa by passing between the stylohyoid m . and posterior belly of the digastric m . Sm all m uscular branches innervate the stylohyoid m ., the posterior belly of the digastric m ., and the auricularis m m . Once in the fossa, it splits the parotid gland into a super cial lobe and a deep lobe that are connected by an isthm us Within the gland, it divides into tem porofacial and cervicofacial trunks The trunks form a loop anterior to the gland super cial to the parotid duct and give rise to 5 m ajor branches before em erging from the gland: tem poral, zygom atic, buccal, m andibular, and cervical

Tem poral

Exits the superior portion of the parotid gland from the tem porofacial trunk Crosses the zygom atic arch along the tem poral fossa to innervate the forehead

Zygom atic

The zygom atic branches from the tem porofacial trunk pass across the zygom atic bone to the lateral angle of the orbit Innervates m uscles in the region

Buccal

Branches arise from both the tem porofacial and the cervicofacial trunks Innervates m uscles of the cheek

Marginal m andibular

Branches arise from the cervicofacial trunk and pass anteriorly Innervates m uscles of the lower lip and chin

Cervical

Branches arise from the cervicofacial trunk and pass anteriorly and inferiorly to innervate the platysm a m . Temporal branches

Parotid gland

Zygomatic branches

Posterior auricular nerve

Parotid duct

Main trunk of facial nerve emerging from stylomastoid foramen

Buccal branches

Nerve to posterior belly of digastric muscle and to stylohyoid muscle

Marginal mandibular branch Cervical branch Medial pterygoid muscle

Horizontal section

Ramus of mandible

Main trunk of facial nerve

Masseter muscle

Mastoid process

Parotid gland

Temporofacial division

Temporal branch

Posterior auricular nerve

Zygomatic branches

Main trunk of facial nerve Nerve to posterior belly of digastric muscle and to stylohyoid muscle

Buccal branches

Cervicofacial division

Marginal mandibular branch Cervical branch

Figu re 5-19

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CLINICAL CORRELATES • Trigeminal Neuralgia • • • • •

5

Also called tic d ou lou reu x Usu ally affects th e m axillary (V2 ) or m an d ibu lar (V3 ) division of th e trigem in al n erve; rarely affects th e op h th alm ic division (V1 ) Bilateral in volvem en t su ggests oth er factors su ch as m u ltip le sclerosis More com m on in th e 5th an d 6th d ecad es of life Cau se is u n kn own —th eories in volve n erve irritation from abn orm al vascu larity or tu m or com p ression , or a n erve in ju ry

CLINICAL MANIFESTATIONS

• • •

Period s of in ten se (lastin g 1 to 2 m in u tes), p aroxysm al p ain alon g 1 of th e d ivision s of th e trigem in al n erve Usu ally u n ilateral Pain n orm ally is in itiated by a p articu lar sen sory stim u lu s, su ch as ligh t tou ch (p u ttin g on m akeu p , wash in g th e face, sh avin g, a ligh t breeze), m astication , or bru sh in g teeth

TREATMENT

• • •

Com m on ly, trigem in al n eu ralgia is treated p h arm acologically with an ticon vu lsan ts, su ch as carbam azep in e (Tegretol) If d ru g th erap y is u n su ccessfu l, n eu rosu rgery m ay be req u ired , su ch as p ercu tan eou s rad iofreq u en cy rh izotom y of th e n erve, glycerol in jection of th e trigem in al gan glion , or n erve decom p ression Altern ative an d com p lem en tary m edicin e treatm en ts h ave in clu d ed acu p u n ctu re an d m ed itation

SCALP AND MUSCLES O F FACIAL EXP RESSIO N

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5

CLINICAL CORRELATES • Trigeminal Neuralgia

O pthalmic nerve (V1) Gasserian ganglion of trigeminal nerve (V) Posterior cerebral artery Superior cerebellar artery Trigeminal nerve (V) Basilar artery Cerebellum

Maxillary nerve (V2) Mandibular nerve (V3)

Ophthalmic n.

Maxillary n.

Zones of skin innervation of trigeminal nerve divisions

Mandibular n. Cervical plexus branches

Incision

Microvascular decompression Vessel compressing the trigeminal nerve

Trigeminal nerve

Trigeminal nerve Cerebellum

Figu re 5-20

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Vessel

Teflon pad placed between vessel and nerve relieving compression

CLINICAL CORRELATES • Cavernous Sinus Syndrome • • • •

•

5

Path ologic con d ition in volvin g th e cavern ou s sin u s th at is often cau sed by a th rom bosis, tu m or, an eu rysm , stu la, or trau m a W h en cau sed by a th rom bosis, th e syn d rom e u su ally occu rs as a sep sis from th e cen tral p ortion of th e face or p aran asal sin u ses from th eir con n ection to th e cavern ou s sin u s Before th e ad ven t of an tibiotics, death was th e u su al ou tcom e from th e sep sis It affects th e con ten ts of th e cavern ou s sin u s, in clu d in g: • In tern al carotid artery with sym p ath etics • Cran ial n erve III • Cran ial n erve IV • Cran ial n erve V1 • Cran ial n erve V2 • Cran ial n erve VI Com m on clin ical m an ifestation s in clu d e: • Op h th alm op legia with dim in ish ed p u p illary ligh t re exes • Ven ou s con gestion lead in g to p eriorbital ed em a • Exop h th alm os

Internal carotid a. Cavernous sinus Oculomotor (III) n. (divided) Trochlear (IV) n. Trigeminal (V) n. Abducens (VI) n. O culomotor (III) n. (divided) Posterior communicating a. Posterior cerebral a. Basilar a.

Cavernous sinus thrombosis Periorbital edema

Involvement of cranial nerves (III, IV, V, and VI) results in ophthalmoplegia and facial analgesia

Network of valveless veins allows migration of septic thrombi from sinus or orbit sites to cavernous sinus

Enlarged vein

Periorbital edema and ophthalmoplegia Pituitary gland O culomotor n. (III) Trochlear n. (IV) Abducens n. (VI) Trigeminal n. (V)

Cross section of cavernous sinus

Septic thrombosis in cavernous sinus

Communication between cavernous sinuses results in bilateral disease

Figu re 5-21 SCALP AND MUSCLES O F FACIAL EXP RESSIO N

185

This pa ge inte ntiona lly le ft bla nk

CHAPTER 6

PAROTID FOSSA AND GLAND

Overview and Topographic Anatomy

18 8

Recess of the Parotid Fossa

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Contents of the Parotid Fossa

19 0

Clinical Correlates

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6

OVERVIEW AND TOPOGRAPHIC ANATOMY • General Information • • • • •

Th e largest of all th e m ajor salivary glan d s, wh ich weigh s ap p roxim ately 25 g Resp on sible for 20% to 25% of saliva form ed by salivary glan ds En tirely serou s in secretion Pyram id al in sh ap e, with u p to 5 p rocesses (or exten sion s) Th e glan d ’s cap su le is extrem ely tou gh an d derived from th e deep cervical fascia (alth ou gh evid en ce su p p orts th at th e su p er cial p ortion is con tin u ou s with th e p latysm a fascia, an d it is classi ed as p art of th e su p er cial m u scu lar ap on eu rotic system [SMAS])

Anatomic Landmarks • • • • •

Ap p roxim ately 75% or m ore of th e p arotid glan d overlies th e m asseter m u scle; th e rest is retrom an d ibu lar Facial n erve en ters th e p arotid fossa by p assin g between th e styloh yoid m u scle an d th e p osterior belly of th e d igastric m u scle, wh ich sp lits th e glan d in to a “su p er cial lobe” an d a “d eep lobe” th at are con n ected by an isth m u s Deep lobe lies ad jacen t to th e lateral p h aryn geal sp ace—th u s tu m ors of th e d eep lobe are observed as swellin gs in th e orop h aryn x Tran sverse facial artery p arallels th e p arotid d u ct sligh tly su p erior to th e du ct Bu ccal an d zygom atic bran ch es of th e facial n erve form an an astom osin g loop su p er cial to th e p arotid d u ct

Temporal branches Parotid gland Zygomatic branches

Posterior auricular n.

Parotid duct

Main trunk of facial n. emerging from stylomastoid foramen

Buccal branches

Marginal mandibular branch

Nerve to posterior belly of digastric m. and to stylohyoid muscle

Cervical branch

Parotid gland: totally serous

Figu re 6-1

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RECESS OF THE PAROTID FOSSA • Borders and Structures Borders

Structures

Anterior

Masseter m . Ram us of m andible

Anterom edial

Medial pterygoid m . Stylom andibular fascia

Medial

Styloid process superom edially Transverse process of the atlas inferom edially

Posterom edial

Stylohyoid m . Posterior belly of the digastric m .

Posterior

Mastoid process of the tem poral bone Sternocleidom astoid m .

Lateral

Investing layer of deep cervical fascia helping form the capsule

Superior

External acoustic m eatus Condylar head of the m andible articulating in the glenoid fossa

Inferior

Angular tract of Eisler between the angle of the m andible and the sternocleidom astoid m .

6

Condylar process of mandible

Mastoid process External acoustic meatus

Ramus Mandible Angle

Atlas (C1) Styloid process Horizontal section below lingula of mandible (superior view) demonstrating bed of parotid gland Digastric muscle (posterior belly) Axis (C2)

Sternocleidomastoid muscle Superficial layer of investing fascia Deep layer of investing fascia Parotid gland Facial nerve Masseter muscle Ramus of mandible Medial pterygoid muscle Stylohyoid muscle

Figu re 6-2 PAROTID FO SSA AND GLAND

189

6

19 0

CONTENTS OF THE PAROTID FOSSA • Major Structures Structure

Features

Parotid gland

The largest of all of the m ajor salivary glands, entirely serous in secretion Pyram idal in shape, with up to 5 processes (or extensions) The gland’s capsule is from the deep cervical fascia About 75% or m ore of the parotid gland overlies the m asseter m .; the rest is retrom andibular

Facial nerve

Facial n. exits the stylom astoid foram en and gives rise to the posterior auricular n. Enters the parotid fossa by passing between the stylohyoid m . and the posterior belly of the digastric m . Sm all m uscular branches innervate the stylohyoid m ., the posterior belly of the digastric m ., and the auricularis m m . Once in the fossa, it splits the parotid gland into a super cial lobe and a deep lobe that are connected by an isthm us Parotid gland’s deep lobe lies adjacent to the lateral pharyngeal space Within the gland, the facial n. divides into tem porofacial and cervicofacial trunks The trunks form a loop anterior to the gland super cial to the parotid duct and give rise to 5 m ajor branches before em erging from the gland: • Tem poral • Zygom atic • Buccal • Marginal m andibular • Cervical Although it passes through the parotid gland, the facial n. does not provide any innervation to it Buccal and zygom atic branches of the facial n. form an anastom osing loop super cial to the parotid duct

Parotid duct

Also known as Stensen’s duct The duct typically is 5 cm in length Form s within the deep lobe and passes from the anterior border of the gland across the m asseter super cially, through the buccinator into the oral cavity opposite the 2nd m axillary m olar Accessory parotid tissue often follows the parotid duct

External carotid artery

The external carotid a. travels through the parotid gland and gives off branches within the gland: • Posterior auricular a. • Maxillary a. • Super cial tem poral a. • Transverse facial a.

Retrom andibular vein

The retrom andibular vein is located super cial to the external carotid artery within the parotid gland The retrom andibular vein is form ed by the union of: • Super cial tem poral v. (a sm all transverse facial v. drains into this vein) • Maxillary v. Typically, the retrom andibular v. exits the inferior portion of the parotid gland and divides into: • Anterior division of the retrom andibular (which joins the facial v. to form the com m on facial v.) • Posterior division of the retrom andibular (which joins the posterior auricular v. to form the external jugular v.)

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

CONTENTS OF THE PAROTID FOSSA • Major Structures

6

Temporal branches Parotid gland

Zygomatic branches

Posterior auricular nerve Main trunk of facial nerve emerging from stylomastoid foramen

Parotid duct Buccal branches

Nerve to posterior belly of digastric muscle and to stylohyoid muscle

Marginal mandibular branch Cervical branch

Horizontal section

Medial pterygoid muscle Ramus of mandible

Main trunk of facial nerve

Masseter muscle

Mastoid process Parotid gland

Posterior auricular nerve

Temporofacial division

Temporal branch Zygomatic branches

Main trunk of facial nerve Nerve to posterior belly of digastric muscle and to stylohyoid muscle

Buccal branches

Cervicofacial division

Cervical branch

Marginal mandibular branch

Figu re 6-3 PAROTID FO SSA AND GLAND

191

6

CONTENTS OF THE PAROTID FOSSA • Vascular Supply ARTERIAL SUPPLY Artery

Source

Course

External carotid

The bifurcation of the com m on carotid a. (m ost com m only located at vertebral level C3)

Ascends superiorly posterior to the m andible and deep to the posterior belly of the digastric m . and the stylohyoid m . to enter the parotid gland Within the parotid gland, it gives branches to the gland and the posterior auricular a. Then branches into the super cial tem poral and m axillary aa. within the gland The transverse facial a. arises from the super cial tem poral a. within the gland

Posterior auricular

External carotid a. within the parotid gland

Passes superiorly between the m astoid process and cartilage of the ear

Maxillary

The 2 term inal branches of the external carotid a. within the parotid gland

Begins posterior to the neck of the m andible and travels anterom edially between the sphenom andibular lig. and the ram us of the m andible On exiting the parotid gland, passes either super cial or deep to the lateral pterygoid m uscle

Super cial tem poral

• Transverse facial

Begins posterior to the neck of the m andible and travels superiorly as a continuation of the external carotid Joined by the auriculotem poral n. Super cial tem poral a. before it exits the parotid gland

Passes transversely to exit the gland Passes im m ediately superior to the parotid duct across the m asseter m . and face

Transverse facial artery (cut) Superficial temporal artery Maxillary artery Posterior auricular artery Ascending pharyngeal artery

External carotid artery

Figu re 6-4

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CONTENTS OF THE PAROTID FOSSA • Vascular Supply

6

VENOUS DRAINAGE Vein

Course

Super cial tem poral

Descends posterior to the zygom atic root of the tem poral bone alongside the auriculotem poral n. to enter the parotid gland Unites with the m axillary v. to form the retrom andibular v.

Transverse facial

Travels posteriorly to enter the parotid gland and join the super cial tem poral v.

Maxillary

A short, som etim es paired vein, form ed by the convergence of the tributaries of the pterygoid plexus Enters the parotid gland traveling posteriorly between the sphenom andibular lig. and the neck of the m andible Unites with the super cial tem poral v. to form the retrom andibular v.

Retrom andibular

Arises from the joining of the super cial tem poral and m axillary vv. within the parotid gland Descends super cial to the external carotid a. in the gland, where it branches into: • Anterior division of the retrom andibular (which joins the facial v. to form the com m on facial v.) • Posterior division of the retrom andibular (which joins the posterior auricular to form the external jugular v.)

Anterior division of the retrom andibular

1 of the term inal divisions of the retrom andibular vein Typically branches once the retrom andibular vein has exited the parotid gland inferiorly Joins the facial v to form the com m on facial v., which drains into the internal jugular v.

Posterior division of the retrom andibular

1 of the term inal divisions of the retrom andibular vein Typically branches once the retrom andibular vein has exited the parotid gland inferiorly Joins the posterior auricular v. (which arises as a plexus of veins created by the occipital and super cial tem poral vv.) to form the external jugular v., which drains into subclavian v.

PAROTID FO SSA AND GLAND

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6

CONTENTS OF THE PAROTID FOSSA • Vascular Supply Maxillary veins

Superficial temporal vein and artery

Transverse facial vein (cut) Posterior auricular vein Retromandibular vein

External carotid artery

Transverse facial artery and vein

Branches of superficial temporal artery and vein Frontal

Parietal

Posterior auricular artery and vein Posterior division of the retromandibular vein Retromandibular vein

External jugular vein Anterior division of the retromandibular vein External carotid artery

Figu re 6-5

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CONTENTS OF THE PAROTID FOSSA • Nerve Supply

6

SENSORY NERVES OF THE PAROTID Nerve

Source

Course

Auriculotem poral

Mandibular division of the trigem inal n.

Often arises as 2 roots surrounding the m iddle m eningeal a. that unite Passes inferior to the lateral pterygoid toward the neck of the m andible Passes posterior to the neck of the m andible to ascend with the super cial tem poral a. Provides sensory bers to the parotid gland

Great auricular

The cervical plexus form ed by contributions of C2 and C3 ventral ram i

After passing posterior to the m idpoint of the sternocleidom astoid, it ascends along the sternocleidom astoid m ., dividing into anterior and posterior branches The anterior branch continues along the super cial aspect of the inferior part of the parotid gland Helps supply parotid capsule

Auricular branch of vagus nerve (X)

From ophthalmic division of trigeminal nerve (V1 ) Supraorbital nerve Supratrochlear nerve

Medial branches of dorsal rami of cervical spinal nerves Greater occipital nerve (C2)

Palpebral branch of lacrimal nerve Infratrochlear nerve External nasal branch of anterior ethmoidal nerve

3rd occipital nerve (C3) From 4th, 5th, and 7th nerves in succession below

From maxillary division of trigeminal nerve (V2 ) Infraorbital nerve Zygomaticofacial nerve Zygomaticotemporal nerve

Branches from cervical plexus Lesser occipital nerve (C2) Great auricular nerve (C2, 3) Transverse cervical nerve (C2, 3) Supraclavicular nerves (C3, 4)

From mandibular division of trigeminal nerve (V3 ) Mental nerve Buccal nerve Auriculotemporal nerve

Figu re 6-6

PAROTID FO SSA AND GLAND

195

6

CONTENTS OF THE PAROTID FOSSA • Nerve Supply

Sternocleidomastoid muscle (cut)

Great auricular nerve

Accessory nerve (XI)

Lesser occipital nerve

Hypoglossal nerve (XII)

Greater occipital nerve (from dorsal ramus of C2)

Geniohyoid muscle

C1 Nerves to anterior and lateral rectus capitis and longus capitis and colli muscles

C2

Thyrohyoid muscle Superior root of ansa cervicalis

Nerves to longus capitis and colli and levator scapulae muscles Trapezius muscle

C3

Nerves to longus capitis and colli, levator scapulae and middle scalene muscles

C4

Inferior root of ansa cervicalis Transverse cervical nerve

Communication to brachial plexus Phrenic nerve

C5

O mohyoid muscle (superior belly) Sternothyroid muscle

Supraclavicular nerves (medial, intermediate and lateral)

Sternohyoid muscle Ansa cervicalis Sternocleidomastoid muscle (cut)

Efferent fibers

O mohyoid muscle (inferior belly)

Afferent fibers Proprioceptive fibers

Figu re 6-7

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CONTENTS OF THE PAROTID FOSSA • Nerve Supply

6

ANATOMIC PATHWAY FOR PARASYMPATHETICS OF THE PAROTID GLAND Characteristics of Cell Body

Type of Neuron

Name of Cell Body

Course of the Neuron

Preganglionic neuron

Inferior salivatory nucleus

A collection of nerve cell bodies located in the m edulla

Preganglionic parasym pathetic bers arise from the inferior salivatory nucleus in the m edulla These bers travel through the glossopharyngeal n. (IX) and exit the jugular foram en Gives rise to the tym panic branch of IX, which reenters the skull via the tym panic canaliculus Tym panic branch of IX form s the tym panic plexus along the prom ontory of the ear The plexus re-form s as the lesser petrosal n., typically exiting the foram en ovale to enter the infratem poral fossa Lesser petrosal n. joins the otic ganglion

Postganglionic neuron

Otic ganglion

A collection of nerve cell bodies located inferior to the foram en ovale m edial to the m andibular division of the trigem inal n.

Postganglionic parasym pathetic bers arise in the otic ganglion These bers travel to the auriculotem poral branch of the trigem inal n. Auriculotem poral n. travels to the parotid gland Postganglionic parasym pathetic bers innervate the parotid gland

ANATOMIC PATHWAY FOR SYMPATHETICS OF THE PAROTID GLAND Characteristics of Cell Body

Type of Neuron

Name of Cell Body

Course of the Neuron

Preganglionic neuron

Interm ediolateral horn nucleus

Collection of nerve cell bodies located in the lateral horn nucleus of the spinal cord between spinal segm ents T1 and T3 (and possibly T4)

Arise from the interm ediolateral horn nuclei from T1 and T3(4) Travel through the ventral root of the spinal cord to the spinal nerve Enter the sym pathetic chain via white ram i com m unicantes Once in the sym pathetic chain, the preganglionic bers for the eye will ascend and synapse with postganglionic bers in the superior cervical ganglion

Postganglionic neuron

Superior cervical ganglion

Collection of nerve cell bodies located in the superior cervical ganglion, which is located at the base of the skull

Arise in the superior cervical ganglion Postganglionic bers will follow the external carotid a. Branches from the external carotid follow the arteries that supply the parotid gland

PAROTID FO SSA AND GLAND

197

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CONTENTS OF THE PAROTID FOSSA • Nerve Supply

Mandibular nerve (V3 ) O tic ganglion O phthalmic nerve (V1 ) Maxillary nerve (V2 ) Auriculotemporal nerve

Trigeminal ganglion Lesser petrosal nerve Chorda tympani nerve Trigeminal nerve (V) Facial nerve (VII) Glossopharyngeal nerve (IX) Inferior salivatory nucleus

Superficial temporal artery

Pons

Parotid gland Medulla oblongata

Maxillary artery

Tympanic plexus Tympanic nerve (of Jacobson)

Inferior alveolar nerve

Inferior ganglion (IX) Superior cervical sympathetic ganglion Sympathetic trunk T1 and T2 spinal nerves Thoracic spinal cord

Lingual nerve External carotid artery

Dorsal root

Internal carotid artery Common carotid artery Sympathetic preganglionic fibers Sympathetic postganglionic fibers Parasympathetic preganglionic fibers Parasympathetic postganglionic fibers

White Gray Rami communicantes

Sympathetic preganglionic cell bodies in intermediolateral nucleus (lateral horn) of gray matter Ventral root

Lateral view Foramen ovale Foramen spinosum Middle meningeal a.

Auriculotemporal n. Facial nerve (VII) Chorda tympani nerve Lingual nerve Inferior alveolar nerve (cut) Nerve to mylohyoid

Inferior alveolar nerve (cut) Digastric muscle (anterior belly)

Figu re 6-8

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CLINICAL CORRELATES • Bell’s Palsy •

6

Un ilateral facial p aralysis from facial n erve (cran ial n erve VII) d am age

CAUSES

• •

• •

Ap p roxim ately 80% of cases h ave u n clear etiology Eviden ce su ggests h erp es sim p lex viru s (HSV-1) in fection as a cau se • Proposed m echanism : W h en th e viru s becom es active at th e facial n erve, if th e in am m ation is in th e bon y facial can al, lim ited room for exp an sion resu lts in n erve com p ression Bacterial in fection s also h ave been im p licated • In som e cases of otitis m ed ia, bacteria m ay en ter th e facial can al, an d an y resu ltin g in am m atory resp on se cou ld com p ress th e facial n erve Tem p orary Bell’s p alsy can resu lt from den tal p rocedu res if in ferior alveolar n erve block an esth etic is im p rop erly ad m in istered in th e p arotid fossa; sign s an d sym p tom s d isap p ear wh en th e an esth etic effects wear off

PROGNOSIS

• • •

Mild cases p rod u ce a facial n erve n eu rap raxia; th e p rogn osis for com p lete recovery is very good , u su ally with in 2 to 3 weeks In m ore m od erate cases, an axon otm esis m ay occu r, p rod u cin g wallerian d egen eration ; fu ll recovery m ay take 2 to 3 m on th s In a sm all p ercen tage of cases, fu n ction is n ever com p letely recovered

Temporal branches Parotid gland Posterior auricular nerve Main trunk of facial nerve emerging from stylomastoid foramen Nerve to posterior belly of digastric muscle and to stylohyoid muscle

Zygomatic branches

Parotid duct Buccal branches Marginal mandibular branch Cervical branch

Horizontal section

PAROTID FO SSA AND GLAND

199

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CLINICAL CORRELATES • Bell’s Palsy

Course and distribution of facial (VII) nerve O ccipitofrontal m.

O rbicularis oculi m.

Corrugator supercilii m.

Pterygopalatine ganglion

Facial (VII) n.

Lacrimal gland

Acoustic (VIII) n.

Pons Geniculate ganglion

Greater petrosal n.

Temporal branch

2

Stapedius m. Tympanum Lingual n.

1

3

Stylomastoid foramen Posterior auricular n. Chorda

To n gu e

4

Parotid gland Buccal branch Marginal mandibular branch Cervical branch

O rbicularis oris m. Levator anguli oris m.

Zygomatic branch Sublingual gland

Risorius m. Depressor anguli oris m.

Platysma m. Submandibular ganglion Submandibular gland

Sites of lesions and their manifestations 1. Intracranial and/or internal auditory meatus. All symptoms of 2, 3, and 4, plus deafness due to involvement of 8th cranial nerve. 2. Geniculate ganglion. All symptoms of 3 and 4, plus pain behind ear. Herpes of tympanum and of external auditory meatus may occur. 3. Facial canal. All symptoms of 4, plus loss of taste in anterior tongue and decreased salivation on affected side due to chorda tympani involvement. Hyperacusia due to effect on nerve branch to stapedius muscle. 4. Below stylomastoid foramen (parotid gland tumor, trauma) Facial paralysis (mouth draws to opposite side; on affected side, patient unable to close eye or wrinkle forehead; food collects between teeth and cheek due to paralysis of buccinator muscle).

Buccinator m. Hyperacusis

Left Peripheral VII Facial Weakness Attempt to close eye results in eyeball rolling superiorly, exposing sclera (Bell phenomenon) but no closure of the lid per se.

Patient unable to wrinkle forehead; eyelid droops very slightly; cannot show teeth at all on affected side in attempt to smile; and lower lip droops slightly.

This may be early or initial symptom of a peripheral VII nerve palsy: patient holds phone away from ear because of painful sensitivity to sound. Loss of taste also may occur on affected side.

Figu re 6-9

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CLINICAL CORRELATES • Frey’s Syndrome • • • •

6

Cau sed by regen eration of th e au ricu lotem p oral au ton om ic bers in an abn orm al fash ion , in n ervatin g th e sweat glan d s n ear th e p arotid glan d after a p arotid ectom y Sym p tom s in clu de sweatin g an d red n ess in th e d istribu tion of th e au ricu lotem p oral n erve d u rin g eatin g Diagn osis is via Min or’s starch iod in e test—creates a d ark sp ot over th e gu statory sweatin g area Treatm en ts in clu d e tym p an ic n eu rectom y (severin g th e p arasym p ath etic com p on en t) an d th e top ical an tich olin ergic glycop yrrolate (Robin u l)

Frey’s Syndrome

Figu re 6-10

PAROTID FO SSA AND GLAND

201

6

CLINICAL CORRELATES • Tumors of the Parotid Gland • • • • •

80% of p arotid tu m ors are ben ign Th e m ost com m on ben ign tu m or is a p leom orp h ic ad en om a, wh ich , if p resen t for m an y years, can con vert to a h igh ly m align an t carcin om a W h en p leom orp h ic ad en om as exten d th rou gh th e cap su le, th ey m u st be rem oved to red u ce recu rren ce Becau se of th e p roxim ity, th ese tu m ors can exten d in to th e lateral p h aryn geal sp ace Rem oval of th e tu m or with its su rrou n d in g cap su le an d tissu e is im p ortan t to obtain a low recu rren ce rate • Histologically, p leom orp h ic ad en om as h ave exten sion s th rou gh th e tu m or cap su le in to ad jacen t tissu e, so sim p le en u cleation wou ld allow recu rren ce from tu m or cells left beh in d

Mixed tumor

Lymphosarcoma

Adenocarcinoma of parotid gland

3 2 1 4

Local spread of carcinoma of parotid 1. Mandible 2. Pharynx 3. Base of skull and middle ear 4. Cervical lymph nodes

Exposure and resection of tumor sparing facial nerve branches

Figu re 6-11

202

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CLINICAL CORRELATES • Parotitis/Mumps • • •

6

An in am m ation of th e p arotid glan d s th at typ ically is cau sed by a bacterial or viral in fection Can also be cau sed by oth er d iseases, su ch as Sjögren ’s syn d rom e, tu bercu losis, an d h u m an im m u n od e cien cy viru s (HIV) in fection Pain on m an d ibu lar m ovem en t is th e resu lt of th e com p ression of th e d eep lobe of th e glan d by th e m an d ibu lar ram u s

BACTERIAL PAROTITIS

• • •

Less com m on sin ce th e in trodu ction of an tibiotics, p rop er h yd ration , an d better oral h ygien e Mortality rate in th e early 19th cen tu ry was as h igh as 70% to 80% Most cases n ow seen in p atien ts on an tich olin ergic m ed ication , esp ecially th e eld erly, becau se it in h ibits th e salivary ow, wh ich m akes it easier for th e bacteria to be tran sp orted in retrograd e fash ion alon g th e p arotid d u ct in to th e glan d , wh ere th ey m ay settle to cau se an in fection

VIRAL PAROTITIS

• • • • •

Kn own as m u m p s Cau sative viru s is a p aram yxoviru s th at in fects d ifferen t bod y p arts, n otably th e p arotid glan d s Usu ally is sp read th rou gh saliva, cou gh in g, an d sn eezin g Parotid glan d s typ ically swell an d becom e very p ain fu l With th e in trod u ction of m u m p s vaccin ation in th e 1970s, n ow rare in m ost d evelop ed n ation s

Pouting of orifice of Stensen’s duct

Parotitis (obstruction or ascending infection)

Figu re 6-12

PAROTID FO SSA AND GLAND

203

6

CLINICAL CORRELATES • Xerostomia • • • • •

X erostom ia: “d ry m ou th ” Dry m ou th is a sym p tom th at in creases th e affected p erson ’s su scep tibility to d en tal caries Can be cau sed by an y m ed ication th at redu ces salivary ou t ow, com m on ly m an y an tih istam in es, an tidep ressan ts, ch em oth erap y agen ts, an tih yp erten sives, an d an algesics, as well as by th erap eu tic irrad iation Occu rs in d isease p rocesses su ch as d ep ression , stress, en d ocrin e d isord ers, Sjögren ’s syn drom e, an d im p rop er n u trition Can lead to th e form ation of sialolith s, calcu li th at form in th e d u ct or glan d, alth ou gh th ey are m ore com m on ly associated with in fection s of th e su bm an dibu lar glan d th an of th e p arotid glan d an d d u ct

Calculus in Wharton’s duct: probe inserted and drop of pus exuding

Xerostomia and glossitis

Figu re 6-13

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CLINICAL CORRELATES • Fistulas and Sialoceles •

6

Parotid f stula: a com m u n ication between th e skin an d th e p arotid glan d or d u ct th at m ay lead to th e form ation of a sialocele, a cyst lled with a collection of m u coid saliva in th e tissu es su rrou n d in g th e glan d

CAUSES

• •

Both p arotid stu las an d sialoceles often occu r as th e resu lt of trau m a d u rin g su rgery May also be cau sed by: • Section or in ju ry of th e d u ct or 1 of its bran ch es d u rin g op eration for can cer of th e ch eek or face • Rem oval of p arotid tu m ors, esp ecially th ose of th e accessory lobe • Prim ary or secon d ary m align an t tu m ors th at u lcerate th e skin • In cision an d d rain age for acu te bacterial p arotitis • Ulceration an d in fection associated with large salivary calcu li • Fistu la m ay develop after a m astoid or fen estration op eration • Con gen ital • In fection (actin om ycosis, tu bercu losis, syp h ilis, can cru m oris)

TREATMENT

• • • • •

Fistu las th at lead directly in to th e oral cavity n eed n o treatm en t Fistu las on th e skin m ay or m ay n ot n eed su rgical in terven tion An tich olin ergics are u sefu l agen ts to d im in ish th e salivation du rin g treatm en t Sialoceles often resolve with asp iration or com p ression an d n orm ally do n ot req u ire d rain p lacem en t In ju ry to th e p arotid glan d or du ct sh ou ld be rep aired to p reven t form ation of stu las an d sialoceles

COMMON REPAIRS

• • •

Rep air of th e du ct u sin g a sten t Ligation of th e du ct Creatin g a stu la from th e d u ct in to th e oral cavity Parotid gland 3-layer closure used in repair of parotid gland to prevent formation of fistula or sialocele

Parotid gland

Parotid capsule closed with 4–0 chromic gut

Parotid duct

Subcutaneous space closed with subcuticular sutures Skin closed with interrupted sutures

Figu re 6-14

PAROTID FO SSA AND GLAND

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This pa ge inte ntiona lly le ft bla nk

CHAPTER 7

TEMPORAL AND INFRATEMPORAL FOSSAE

Overview and Topographic Anatomy

20 8

Borders of the Temporal Fossa

209

Contents of the Temporal Fossa

210

Borders of the Infratemporal Fossa

214

Contents of the Infratemporal Fossa

216

7

OVERVIEW AND TOPOGRAPHIC ANATOMY • General Information •

Th e en tire tem p oral area con sists o 2 ossae divid ed by th e zygom atic arch

TEMPORAL FOSSA

• •

Related to th e tem p le o th e h ead Com m u n icates with th e in ratem p oral ossa ben eath th e zygom atic arch

INFRATEMPORAL FOSSA

• •

An irregu larly sh ap ed ossa in erior an d m ed ial to th e zygom atic arch Com m u n icates with th e p terygop alatin e ossa at th e p terygom axillary f ssu re

Temporal bone Sphenoid bone Temporal fossa Condylar process of mandible Zygomatic arch Mandibular notch Coronoid process of mandible Lateral pterygoid plate (broken line) Hamulus of medial pterygoid plate (broken line) Pterygomandibular raphe (broken line)

Mandible

Mastoid process External acoustic meatus Atlas (C1) Styloid process

Ramus Angle Body

Axis (C2)

Stylohyoid ligament Hyoid bone

Stylomandibular ligament

Body Lesser horn Greater horn

C3 vertebra

Epiglottis Spine of sphenoid bone Foramen spinosum Foramen ovale

Infratemporal fossa Sphenopalatine foramen Pterygopalatine fossa Choanae (posterior nares) Lateral plate Medial plate of pterygoid process Hamulus

Tuberosity of maxilla Alveolar process of maxilla

Pyramidal process of palatine bone

Figu re 7-1

20 8 NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

BORDERS OF THE TEMPORAL FOSSA • Overview Border

Structures

Superior

Superior tem poral line Inferior tem poral line

Inferior

Zygom atic arch (laterally) Infratem poral crest of greater wing of sphenoid (m edially)

Anterior

Frontal process of the zygom a Zygom atic process of the frontal bone

Posterior

Supram astoid crest Posterior portion of superior tem poral line (which arches inferiorly to the supram astoid crest)

Medial

Frontal Greater wing of the sphenoid Squam ous part of the tem poral Parietal

Lateral

Tem poral fascia

7

Parietal bone Temporal fossa

Sphenoid bone Greater wing Frontal bone Zygomatic process

Superior temporal line Inferior temporal line Coronal suture

Temporal bone

Pterion

Squamous part

Zygomatic bone Frontal process Zygomatic arch

Figu re 7-2

TEMPO RAL AND INFRATEMPO RAL FO SSAE 209

7

CONTENTS OF THE TEMPORAL FOSSA • Vascular Supply ARTERIAL SUPPLY Artery

Source

Course

Super cial tem poral

A term inal branch of the external carotid a. that arises within the parotid gland

Within the substance of the parotid gland, it gives off a transverse facial a. Em erges from the superior part of the parotid gland im m ediately posterior to the tem porom andibular joint and anterior to the external auditory m eatus Passes super cial to the root of the zygom atic arch just anterior to the auriculotem poral n. and the auricle Im m ediately superior to the root of the zygom atic arch, it gives rise to the m iddle tem poral a. that pierces deep into the tem poralis fascia and m uscle As it continues to pass superiorly, it divides into anterior and posterior branches

Middle tem poral

Super cial tem poral a. after it passes superior to the root of the zygom atic arch

Passes deep into the tem poralis fascia and tem poralis m ., where it anastom oses with the anterior and posterior deep tem poral vessels

Anterior and posterior deep tem poral

Branches of the 2nd part of the m axillary a.

Pass between the skull and the tem poralis m . Supply the tem poralis throughout their course While ascending, they anastom ose with the m iddle tem poral a.

Anterior Posterior Deep temporal arteries and nerves

Superficial temporal artery

Anterior and posterior deep temporal arteries Middle temporal arteries

Superficial temporal artery

Figu re 7-3

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CONTENTS OF THE TEMPORAL FOSSA • Vascular Supply

7

VENOUS DRAINAGE Vein

Course

Super cial tem poral

Begins at the vertex and lateral aspect of the skull Form s a venous plexus along the scalp by com m unicating with the supraorbital, posterior auricular, occipital vv. and corresponding veins from the opposite side Form s an anterior and a posterior branch of the super cial tem poral v. that pass inferiorly im m ediately anterior to the artery A m iddle tem poral v. joins the super cial tem poral before the vessel passes inferior to the root of the zygom atic arch Enters the parotid gland, where it receives the transverse facial v. Joins the m axillary v. to form the retrom andibular v.

Middle tem poral

Arises deep within the tem poralis m . and fascia Within the tem poralis m . and fascia, it anastom oses with the anterior and posterior deep tem poral vessels Joins the super cial tem poral a. im m ediately before it passes inferior to the root of the zygom atic arch

Anterior and posterior deep tem poral

Drain into the pterygoid plexus of veins Also com m unicate with the m iddle tem poral v.

Middle temporal vein

Superficial temporal vein Maxillary vein

Figu re 7-4

TEMPO RAL AND INFRATEMPO RAL FO SSAE 211

7

CONTENTS OF THE TEMPORAL FOSSA • Nerve Supply Nerve

Source

Course

Mandibular division of the trigem inal

The largest of the 3 divisions of the trigem inal n. Created by a large sensory and sm all m otor root that unite just after passing through the foram en ovale to enter the infratem poral fossa

Im m ediately gives rise to a m eningeal branch and m edial pterygoid branch before it divides into anterior and posterior divisions The anterior division is sm aller and m ainly m otor, with 1 sensory branch (buccal n.) The posterior division is larger and m ainly sensory, with 1 m otor branch (m ylohyoid n.)

Anterior and posterior deep tem poral

Arise from the anterior division of the m andibular division of the trigem inal n.

Pass superior to the lateral pterygoid m . between the skull and the tem poralis m . while passing deep to the m uscle to innervate it

Auriculotem poral

Arises from the posterior division of the m andibular division of the trigem inal n.

Norm ally arises from 2 roots, between which the m iddle m eningeal a. passes Runs posteriorly just inferior to the lateral pterygoid and continues to the m edial side of the neck of the m andible While passing posterior to the m andible, it provides sensory innervation to the tem porom andibular joint Turns superiorly with the super cial tem poral vessels between the auricle and the condyle of the m andible deep to the parotid gland On exiting the substance of the parotid gland, it ascends over the zygom atic arch and divides into super cial tem poral branches

Motor branches that arise in the substance of the parotid gland

Cross the zygom atic arch to the tem poral region Supply the m uscles in the area, including the frontalis, anterior auricular, superior auricular, orbicularis oculi, procerus, and corrugator supercilii m m .

Tem poral branches of the facial

Temporal branches Parotid gland Zygomatic branches Posterior auricular nerve

Parotid duct

Main trunk of facial nerve emerging from stylomastoid foramen

Buccal branches

Nerve to posterior belly of digastric muscle and to stylohyoid muscle

Marginal mandibular branch

Cervical branch

Figu re 7-5

212

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CONTENTS OF THE TEMPORAL FOSSA • Nerve Supply

Anterior division Lateral view

Temporal fascia and temporalis muscle

Posterior division

Posterior Anterior

7

Deep temporal nerves

Foramen ovale

Auriculotemporal nerve

Medial view Trigeminal (semilunar) ganglion

Motor root Sensory root

O phthalmic nerve (V1 ) Maxillary nerve (V2 ) Mandibular nerve (V3 ) Anterior division

Auriculotemporal nerve

Figu re 7-6

TEMPO RAL AND INFRATEMPO RAL FO SSAE 213

7

BORDERS OF THE INFRATEMPORAL FOSSA • Overview Border

Structure(s)

Superior

Infratem poral surface of the greater wing of the sphenoid (with the foram en ovale and foram en spinosum ) Infratem poral surface of the tem poral bone

Inferior

No anatom ic oor—the boundary of the fossa ends where the m edial pterygoid attaches to the m andible

Lateral

Ram us of the m andible (m edial surface)

Medial

Lateral pterygoid plate of the sphenoid (lateral surface) Pyram idal process of the palatine bone

Anterior

Posterior portion of the m axilla

Posterior

Styloid process Condylar process of the m andible

MUSCLES

• • •

Tem p oralis Lateral p terygoid Med ial p terygoid

ARTERIES

•

Maxillary an d its bran ch es

VEINS

•

Pterygoid p lexu s of vein s an d tribu taries

NERVES

• • • • •

Man dibu lar d ivision of th e trigem in al n . an d bran ch es Posterior su p erior alveolar (bran ch of m axillary d ivision of trigem in al) Ch ord a tym p an i (bran ch of th e facial n .) Otic gan glion Lesser p etrosal

Infratemporal fossa exposed by removal of zygomatic arch and mandible*

Sphenoid bone Greater wing

Lateral plate of pterygoid process

Maxilla Infratemporal surface of maxilla

Temporal bone Styloid process

*Superficially, mastoid process forms posterior boundary

Figu re 7-7

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BORDERS OF THE INFRATEMPORAL FOSSA • Overview

7

Maxilla

Transverse palatine suture

Sphenoid bone

Palatine bone

Lateral plate

Pyramidal process

Greater wing Foramen ovale Foramen spinosum

Temporal bone Styloid process

Articular disc of temporomandibular joint Articular tubercle Lateral pterygoid muscle Sphenomandibular ligament Medial pterygoid muscle Parotid duct Buccinator muscle Pterygomandibular raphe Superior pharyngeal constrictor muscle

Lateral view

Figu re 7-8

TEMPO RAL AND INFRATEMPO RAL FO SSAE 215

7

CONTENTS OF THE INFRATEMPORAL FOSSA • Vascular Supply MAXILLARY ARTERY • The larger of the 2 term inal branches of the external carotid a. (super cial tem poral a.) • Arises posterior to the condylar neck of the m andible within the parotid gland • Exits the parotid gland and passes anteriorly between the ram us of the m andible and the sphenom andibular lig. within the infratem poral fossa • Takes a course that is either super cial or deep to the lateral pterygoid until reaching the pterygopalatine fossa via the pterygom axillary ssure • Supplies the deep structures of the face and m ay be divided into 3 parts as it passes m edially through the infratem poral fossa: • 1st part—m andibular part • 2nd part—pterygoid part • 3rd part—pterygopalatine part

Maxillary Artery: 1st Part (Mandibular Part) Artery

Course

1st part (m andibular part)

Passes between the ram us of the m andible and the sphenom andibular lig. Lies parallel to and inferior to the auriculotem poral n. Crosses the inferior alveolar n. and passes on the inferior border of the lateral pterygoid Gives rise to 5 branches: anterior tym panic, deep auricular, m iddle m eningeal, accessory m eningeal, and the inferior alveolar

Deep auricular

Given off in the sam e area as the anterior tym panic Lies in the parotid gland, posterior to the tem porom andibular joint, where it gives branches to supply the tem porom andibular joint and continues along the osseous and cartilaginous portions of the auditory tube, supplying them as well as a sm all part of the tym panic m em brane

Anterior tym panic

Given off in the sam e area as for the the deep auricular a. Passes superiorly im m ediately posterior to the tem porom andibular joint, where it gives branches to supply the tem porom andibular joint Enters the tym panic cavity through the petrotym panic ssure and aids in supplying the tym panic m em brane, along with branches of the posterior auricular a., artery of the pterygoid canal, deep auricular a., and caroticotym panic branch from the internal carotid a.

Middle m eningeal

Passes superiorly between the sphenom andibular lig. and the lateral pterygoid between the 2 roots of the auriculotem poral n. to the foram en spinosum of the sphenoid bone In the m iddle cranial fossa, passes anteriorly in a groove on the greater wing of the sphenoid, dividing into an anterior and a posterior branch

Accessory m eningeal

Arises from the m axillary or m iddle m eningeal a. Enters the skull through the foram en ovale to supply the trigem inal ganglion and dura m ater

Inferior alveolar

Descends inferiorly following the inferior alveolar n. to enter the m andibular foram en

Maxillary Artery: 2nd Part (Pterygoid Part)

216

Artery

Course

2nd part (pterygoid part)

Passes obliquely and anterosuperiorly between the ram us of the m andible and insertion of the tem poralis m . Then passes on the super cial surface of the lateral pterygoid to travel between the m uscle’s 2 heads Has 5 branches: anterior and posterior deep tem poral, m asseteric, pterygoid, and buccal

Anterior and posterior deep tem poral

Pass between the skull and the tem poralis m . Supply the tem poralis throughout their course While ascending, these arteries anastom ose with the m iddle tem poral a. from the super cial tem poral a.

Masseteric

Sm all; passes laterally through the m andibular notch to supply the deep surface of the m asseter m .

Pterygoid

An irregular num ber of arteries supplying the pterygoid m m .

Buccal

A sm all artery that runs obliquely in an anterior direction between the m edial pterygoid m . and the insertion of the tem poralis m . until it reaches the outer surface of the buccinator m . to supply it, anastom osing with the facial and infraorbital branches

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

CONTENTS OF THE INFRATEMPORAL FOSSA • Vascular Supply

7

MAXILLARY ARTERY Maxillary Artery: 3rd Part (Pterygopalatine Part) Artery

Course

3rd part (pterygopalatine part)

Passes from the infratem poral fossa into the pterygopalatine fossa via the pterygom axillary ssure Before passing through the pterygom axillary ssure, it gives off the posterior superior alveolar a. (the only artery off the 3rd part of the m axillary a. that does not norm ally branch off within the pterygopalatine fossa)

Posterior superior alveolar

Arises in the infratem poral fossa Descends on the m axillary tuberosity to enter the posterior surface of the m axilla to supply the m olars and prem olars, lining of the m axillary sinus, and the gum s

Anterior Deep temporal arteries Posterior and nerves Accessory meningeal artery Middle meningeal artery Anterior tympanic artery Deep auricular artery

Posterior superior alveolar artery

Buccal artery

Pterygoid arteries Masseteric artery Inferior alveolar artery

Anterior Posterior

Lateral pterygoid artery and muscle

Deep temporal arteries and nerves Masseteric artery and nerve

Middle meningeal artery Maxillary artery Posterior superior alveolar arteries Inferior alveolar artery and nerve

Buccal artery and nerve Medial pterygoid artery and muscle Pterygomandibular raphe

Figu re 7-9

TEMPO RAL AND INFRATEMPO RAL FO SSAE 217

7

CONTENTS OF THE INFRATEMPORAL FOSSA • Vascular Supply

Transverse facial artery

Deep temporal artery

Masseteric artery

Zygomatic process

Middle meningeal artery

Joint capsule

Anterior tympanic artery

Maxillary artery

Superficial temporal artery Deep auricular artery Lateral pterygoid muscle (cut) Sphenomandibular ligament Inferior alveolar artery External carotid artery

Lingual artery

Facial artery

Figu re 7-10

218

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CONTENTS OF THE INFRATEMPORAL FOSSA • Vascular Supply

7

VENOUS DRAINAGE Vein

Course

Pterygoid plexus

An extensive network of veins that parallel the 2nd and 3rd parts of the m axillary a. Receives branches that correspond with the sam e branches of the m axillary a. The tributaries of the pterygoid plexus eventually converge to form a short m axillary v. Com m unicates with the cavernous sinus, pharyngeal venous plexus, facial v. via the deep facial v., and ophthalm ic vv.

Deep facial

Connects the facial v. with the pterygoid plexus

Maxillary

A short, som etim es paired vein, form ed by the convergence of the tributaries of the pterygoid plexus Enters the parotid gland traveling posteriorly between the sphenom andibular lig. and the neck of the m andible Unites with the super cial tem poral v. to form the retrom andibular v. Lateral view

Supratrochlear vein Supraorbital vein Angular vein

Superior ophthalmic vein Cavernous sinus

Facial vein Inferior ophthalmic vein Pterygoid plexus Maxillary vein Retromandibular vein

Deep facial vein

Infraorbital and posterior superior alveolar arteries and nerves Inferior head of the lateral pterygoid muscle Buccal nerve Maxillary artery Pterygoid (venous) plexus Superior head of lateral pterygoid muscle (cut) Mandibular nerve (V3 ) Anterior deep temporal nerve and artery (cut and reflected anterolaterally) Coronoid process Maxillary nerve (V2 ) Roots of auriculotemporal nerve O phthalmic nerve (V1 ) Nerves to tensor veli palatini and medial pterygoid muscles

Posterior deep temporal nerve and artery Masseteric artery and nerve Masseter muscle

Internal carotid artery

Temporomandibular joint capsule Articular disc

O tic ganglion and lesser petrosal nerve

Temporalis muscle

Foramen ovale O culomotor nerve (III)

Superficial temporal artery and vein

Abducent nerve (VI) Trochlear nerve (IV)

Parotid gland

Trigeminal nerve (V)

External carotid artery

Accessory meningeal artery Inferior alveolar nerve Middle meningeal artery and nervus spinosus Vestibulocochlear nerve (VIII) and motor root of facial nerve (VII) Sphenomandibular ligament Lesser petrosal nerve and superior tympanic artery Greater petrosal nerve

Auriculotemporal nerve Facial nerve Posterior auricular artery Maxillary artery Malleus (head) and incus Chorda tympani (reflected medially) and anterior tympanic artery Geniculate ganglion Stylomandibular ligament

Figu re 7-11 TEMPO RAL AND INFRATEMPO RAL FO SSAE 219

7

CONTENTS OF THE INFRATEMPORAL FOSSA • Nervous Structures MANDIBULAR DIVISION • Mandibular division (V3 ) is the largest of the 3 divisions of the trigem inal n. • Has m otor and sensory functions • Created by a large sensory and a sm all m otor root that unite just after passing through the foram en ovale to enter the infratem poral fossa • Im m ediately gives rise to a m eningeal branch and a m edial pterygoid branch before dividing into anterior and posterior divisions

Branches From the Undivided Trunk Branch

Course

Meningeal (nervus spinosum )

After passing through the foram en ovale, the undivided trigem inal trunk is located between the tensor veli palatini and the lateral pterygoid The undivided trunk then gives rise to a lateral branch called the m eningeal nerve The branch travels through the foram en spinosum to enter the m iddle cranial fossa and innervate the dura m ater

Medial pterygoid

After passing through the foram en ovale, the undivided trigem inal trunk is located between the tensor veli palatini and the lateral pterygoid The undivided trunk then gives rise to a m edial branch to the m edial pterygoid This branch continues to supply the tensor veli palatini and the tensor tym pani

Anterior Division • Sm aller; m ainly m otor with 1 sensory branch (buccal): • Masseteric • Anterior and posterior deep tem poral • Medial pterygoid • Lateral pterygoid • Buccal Posterior Division • Larger, m ainly sensory with 1 m otor branch (m ylohyoid n.): • Auriculotem poral • Lingual • Inferior alveolar • Mylohyoid n.

Anterior Division of the Mandibular Division

220

Branch

Course

Masseteric

Passes laterally superior to the lateral pterygoid Lies anterior to the tem porom andibular joint and posterior to the tendon of the tem poralis m . Crosses the m andibular notch with the m asseteric a. to innervate the m asseter m . Also provides a sm all branch to the tem porom andibular joint

Anterior and posterior deep tem poral

Pass superior to the lateral pterygoid m . between the skull and the tem poralis m . while passing deep to the m uscle to innervate it Provides a sm all branch to the tem porom andibular joint

Lateral pterygoid

Passes into the deep surface of the m uscle Often arises from the buccal n.

Buccal

Passes anteriorly between the 2 heads of the lateral pterygoid m . Descends inferiorly along the lower part of the tem poralis m . to appear from deep to the anterior border of the m asseter m . Supplies the skin over the buccinator m . before passing through it to supply the m ucous m em brane lining its inner surface and the gingiva along the m andibular m olars

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

CONTENTS OF THE INFRATEMPORAL FOSSA • Nervous Structures

7

MANDIBULAR DIVISION Posterior Division of the Mandibular Division Branch

Course

Auriculotem poral

Norm ally arises from 2 roots, between which the m iddle m eningeal a. passes Runs posteriorly just inferior to the lateral pterygoid and continues to the m edial aspect of the neck of the m andible While passing posterior to the m andible, it provides sensory innervation to the tem porom andibular joint Then it turns superiorly with the super cial tem poral vessels between the auricle and condyle of the m andible deep to the parotid gland On exiting the parotid gland, it ascends over the zygom atic arch and divides into super cial tem poral branches

Lingual

Lies inferior to the lateral pterygoid and m edial and anterior to the inferior alveolar n. The chorda tym pani n. also joins the posterior part The lingual n. passes between the m edial pterygoid and the ram us of the m andible to pass obliquely to enter the oral cavity bounded by the superior pharyngeal constrictor m ., m edial pterygoid m ., and the m andible Supplies the m ucous m em brane of the anterior 2/ 3 of the tongue and gingiva on the lingual aspect of the m andibular teeth

Inferior alveolar

The largest branch of the m andibular division Descends following the inferior alveolar a. inferior to the lateral pterygoid and, nally, between the sphenom andibular lig. and the ram us of the m andible until it enters the m andibular foram en Innervates all m andibular teeth and the gingiva from the prem olars anteriorly to the m idline via the m ental branch

Mylohyoid

Branches from the inferior alveolar n. im m ediately before it enters the m andibular foram en Descends in a groove on the deep side of the ram us of the m andible until it reaches the super cial surface of the m ylohyoid m . Supplies the m ylohyoid m . and the anterior belly of the digastric m .

MAXILLARY NERVE Branch

Course

Posterior superior alveolar

Passes through the pterygom axillary ssure to enter the infratem poral fossa In the infratem poral fossa, it passes on the posterior surface of the m axilla along the region of the m axillary tuberosity Gives rise to a gingival branch that innervates the buccal gingiva alongside the m axillary m olars Enters the posterior surface of the m axilla and supplies the m axillary sinus and the m axillary m olars, with the possible exception of the m esiobuccal root of the 1st m axillary m olar

TEMPO RAL AND INFRATEMPO RAL FO SSAE 221

7

CONTENTS OF THE INFRATEMPORAL FOSSA • Nervous Structures

Efferent fibers Afferent fibers Proprioceptive fibers Parasympathetic fibers Sympathetic fibers

Ophthalmic nerve (V1 )

Trigeminal nerve (V) ganglion and nuclei

Maxillary nerve (V2 )

Deep temporal nerves (to temporalis muscle) Lateral pterygoid and masseteric nerves Medial pterygoid nerves Buccal nerve Lingual nerve

Auriculotemporal nerve Inferior alveolar nerve Parotid branches Mylohyoid nerve Mandibular nerve (V3 )

Posterior Anterior

Lateral view

Deep temporal nerves Masseteric nerve Lateral pterygoid nerve and muscle Posterior superior alveolar nerve

Auriculotemporal nerve

Lingual nerve Inferior alveolar nerve (cut) Nerve to mylohyoid Medial pterygoid muscle (cut)

Inferior alveolar nerve (cut)

Figu re 7-12

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CONTENTS OF THE INFRATEMPORAL FOSSA • Nervous Structures

Infraorbital and posterior superior alveolar arteries and nerves

7

Inferior head of the lateral pterygoid muscle

Buccal nerve

Maxillary artery

Pterygoid (venous) plexus

Superior head of lateral pterygoid muscle (cut)

Mandibular nerve (V3 ) (cut and reflected anterolaterally)

Anterior deep temporal nerve and artery Coronoid process

Maxillary nerve (V2 )

Roots of auriculotemporal nerve Posterior deep temporal nerve and artery

O phthalmic nerve (V1 ) Nerves to tensor veli palatini and medial pterygoid muscles

Masseteric artery and nerve

Internal carotid artery

Masseter muscle Temporomandibular joint capsule

O tic ganglion and lesser petrosal nerve

Articular disc

Foramen ovale

Temporalis muscle

O culomotor nerve (III)

Superficial temporal artery and vein

Abducent nerve (VI)

Parotid gland

Trochlear nerve (IV)

External carotid artery

Trigeminal nerve (V) Accessory meningeal artery Inferior alveolar nerve Middle meningeal artery and nervus spinosus Vestibulocochlear nerve (VIII) and motor root of facial nerve (VII)

Auriculotemporal nerve Facial nerve Posterior auricular artery Maxillary artery Malleus (head) and incus Chorda tympani (reflected medially) and anterior tympanic artery

Sphenomandibular ligament Lesser petrosal nerve and superior tympanic artery

Geniculate ganglion Stylomandibular ligament

Greater petrosal nerve

Figu re 7-13

TEMPO RAL AND INFRATEMPO RAL FO SSAE 223

7

CONTENTS OF THE INFRATEMPORAL FOSSA • Nervous Structures CHORDA TYMPANI, LESSER PETROSAL NERVE, AND OTIC GANGLION Nerve

Source

Course

Chorda tym pani

Branch from the facial n. in the tym panic cavity

Carries the preganglionic parasym pathetic bers to the subm andibular ganglion and taste bers to the anterior 2/ 3 of the tongue Passes anteriorly to enter the tym panic cavity and lies along the tym panic m em brane and m alleus until exiting the petrotym panic ssure Once it exits the petrotym panic ssure, it joins the posterior border of the lingual n. in the infratem poral fossa The lingual n. is distributed to the anterior 2/ 3 of the tongue, and the SVA* bers from the chorda tym pani travel to the taste buds in this region

Lesser petrosal

Tym panic plexus along the prom ontory of the ear re-form s as the lesser petrosal n.

Form s in the m iddle ear cavity Carries the preganglionic parasym pathetic (from the tym panic branch of glossopharyngeal n. [IX]) and postganglionic sym pathetic (from the caroticotym panic branch of the internal carotid a. plexus) that are traveling to the parotid gland The nerve passes along the groove for the lesser petrosal n. on the petrous portion of the tem poral bone toward the foram en ovale Norm ally enters the infratem poral fossa by passing through the foram en ovale Joins the otic ganglion

Nerve Cell Body

Characteristics of Cell Body

Course

Otic ganglion

A collection of nerve cell bodies located in the infratem poral fossa This very sm all stellateshaped ganglion is inferior to the foram en ovale and m edial to the m andibular division of the trigem inal n.

Postganglionic parasym pathetic bers arise in the otic ganglion and travel to the auriculotem poral branch of the trigem inal n. Auriculotem poral n. travels to the parotid gland These postganglionic parasym pathetic bers innervate the: • Parotid gland—secretion of saliva

*SVA, special visceral afferent. See Chapter 3 for a discussion of the SVA and other functional columns.

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CONTENTS OF THE INFRATEMPORAL FOSSA • Nervous Structures

Trigeminal nerve (V)

7

Sensory root Motor root Ganglion

Internal carotid artery and plexus

Facial nerve (VII)

O tic ganglion

Chorda tympani nerve

Superior cervical sympathetic ganglion

Lingual nerve

Internal carotid artery and plexus Submandibular ganglion

Figu re 7-14

TEMPO RAL AND INFRATEMPO RAL FO SSAE 225

7

CONTENTS OF THE INFRATEMPORAL FOSSA • Nervous Structures Medial view Trigeminal (semilunar) ganglion

Motor root Sensory root

Geniculum

O phthalmic nerve (V1 )

Tympanic cavity

Maxillary nerve (V2 )

Chorda tympani nerve

Mandibular nerve (V3 )

Facial nerve (VII)

Anterior division Tensor veli palatini nerve and muscle

Tensor tympani muscle and nerve Lesser petrosal nerve

O tic ganglion

Auriculotemporal nerve

Chorda tympani nerve Medial pterygoid nerve and muscle (cut)

Maxillary artery Mylohyoid nerve

Pterygoid hamulus

Inferior alveolar nerve entering mandibular foramen

Lingual nerve

Figu re 7-15

ANATOMIC PATHWAY FOR PARASYMPATHETICS OF THE PAROTID GLAND

226

Characteristics of Cell Body

Type of Neuron

Name of Cell Body

Course of the Neuron

Preganglionic neuron

Inferior salivatory nucleus

A collection of nerve cell bodies located in the m edulla

Preganglionic parasym pathetic bers arise from the inferior salivatory nucleus in the m edulla Travel through the glossopharyngeal n. (IX) and exit the jugular foram en The glossopharyngeal n. gives rise to the tym panic branch of IX, which reenters the skull via the tym panic canaliculus Tym panic branch of IX form s the tym panic plexus along the prom ontory of the ear The plexus re-form s as the lesser petrosal n., which typically exits the foram en ovale to enter the infratem poral fossa Lesser petrosal n. joins the otic ganglion

Postganglionic neuron

Otic ganglion

A collection of nerve cell bodies This very sm all stellateshaped ganglion is located inferior to the foram en ovale, m edial to the m andibular division of the trigem inal n.

Postganglionic parasym pathetic bers arise in the otic ganglion These bers travel to the auriculotem poral branch of the trigem inal n. Auriculotem poral n. travels to the parotid gland These postganglionic parasym pathetic bers innervate the: • Parotid gland—secretion of saliva

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

CONTENTS OF THE INFRATEMPORAL FOSSA • Nervous Structures

7

Trigeminal ganglion

Mandibular nerve (V3 )

Lesser petrosal nerve

O tic ganglion

Chorda tympani nerve O phthalmic nerve (V1 )

Trigeminal nerve (V)

Maxillary nerve (V2 )

Facial nerve (VII) Glossopharyngeal nerve (IX)

Auriculotemporal nerve

Inferior salivatory nucleus

Superficial temporal artery

Pons

Parotid gland Maxillary artery Medulla oblongata Tympanic plexus Inferior alveolar nerve

Tympanic nerve (Jacobson) Inferior ganglion (IX)

Lingual nerve

Superior cervical sympathetic ganglion Sympathetic trunk T1 and T2 spinal nerves Thoracic spinal cord

External carotid artery

Dorsal root Internal carotid artery

Common carotid artery White

Gray

Rami communicantes Sympathetic presynaptic fibers Sympathetic postsynaptic fibers Parasympathetic presynaptic fibers Parasympathetic postsynaptic fibers

Ventral root

Sympathetic presynaptic cell bodies in intermediolateral nucleus (lateral horn) of gray matter

Figu re 7-16

TEMPO RAL AND INFRATEMPO RAL FO SSAE 227

This pa ge inte ntiona lly le ft bla nk

CHAPTER 8

MUSCLES OF MASTICATION

Overview and Topographic Anatomy

230

Muscles of Mastication

231

Vascular Supply

234

Nerve Supply

237

Clinical Correlates

239

8

OVERVIEW AND TOPOGRAPHIC ANATOMY • General Information • • • • •

Mastication is th e p rocess o ch ewin g ood in p rep aration or d eglu tition (swallowin g) an d d igestion All m u scles o m astication origin ate on th e sku ll an d in sert on th e m an d ible All m u scles o m astication are in n ervated by th e m an d ibu lar d ivision o th e trigem in al n erve All m u scles o m astication are d erivatives o th e 1st p h aryn geal arch Movem en ts o th e m an d ible are classif ed as: • Elevation • Dep ression • Protru sion • Retru sion • Sid e-to-side (lateral) excu rsion

Spine of sphenoid bone Foramen ovale

Infratemporal fossa Sphenopalatine foramen Pterygopalatine fossa Tuberosity of maxilla

Foramen spinosum Choanae (posterior nares)

Alveolar process of maxilla Pyramidal process of palatine bone

Lateral plate of pterygoid Medial plate process Hamulus

Temporalis m.

(Posterior temporalis m. fibers retract jaw) Lateral pterygoid m. Medial pterygoid m. Masseter m. Buccinator m. Tongue m. O rbicularis oris m.

Assist in moving food into position

Geniohyoid m. (deep to other mm.) Mylohyoid m. Digastric m. (anterior belly)

Figu re 8-1

230

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

Depress jaw

MUSCLES OF MASTICATION • Overview

8

MASSETER Parts

Origin

Insertion

Supe r cial he ad (larger part)

Inferior border Angle of m andible of the anterior Inferior and late ral 2/ 3 of the parts of the zygom atic m andibular ram us arch Maxillary process of the zygom atic bone

De ep head (sm aller part)

Medial border of Supe rior and lateral the zygom atic m andibular ram us arch Coronoid process Inferior border of the posterior 1/ 3 of the zygom atic arch

Main Actions

Nerve Supply

Comments

Elevates m andible Protrudes m andible (super cial head) Aids in late ral excursion of the m andible

Masseteric branch Supe r cial head’s bers run from the anterior division of the posteroinferiorly m andibular The parotid duct, division of the transverse facial a., trigem inal n. and branches of the facial n. pass super cial to the m asseter m . Som e evidence suggests the presence of m iddle bers, which corresponds to part of the traditionally de scribed deep he ad of the m asseter

TEMPORALIS Entire tem poral fossa: along the inferior tem poral line including the tem poral fascia

Coronoid process: Elevates m andible along the apex, Retrudes m andible anterior and (posterior bers) posterior borders, Aids in late ral m edial surface excursion of the extending infe riorly m andible on the anterior border of the m andibular ram us (tem poral cre st) to the 3rd m olar tooth

Anterior and poste rior deep tem poral branches from the anterior division of the m andibular division of the trigem inal n. (Anterior deep tem poral m ay branch from the buccal n., and the posterior deep tem poral m ay branch from the m asse teric n.)

The m ain postural m uscle—m aintains the m andible in re st position

MEDIAL PTERYGOID De ep head

Super cial head

Medial surface of lateral pterygoid plate

Medial surface of Elevates m andible Medial pterygoid The deepest m uscle ram us and angle of Protrudes m andible branch from the of m astication the m andible m andibular Form s the Lateral excursion of (pterygoid division of the pterygom asseteric the m andible tubercles) trigem inal n. sling with the (side -to-side (m ain trunk Maxillary m asseter m ovem ents) (Acting be fore it divides tuberosity unilaterally, it causes into anterior and If ane sthe tic is Pyram idal injected into the the m andible to posterior process of the m edial pterygoid de viate to the divisions) palatine m . during an contralate ral side, rotating around axis infe rior alveolar created by nerve block, contralate ral trism us will result condyle, which is im portant in grinding on ipsilateral side)

LATERAL PTERYGOID Upper head Infratem poral crest of the greater wing of the sphenoid

Lower head Lateral surface of the lateral pterygoid plate

Maxillary a. runs Anterior and m edial Protrudes m andible Lateral pterygoid either super cial or branches (for portions of the Depre sses m andible de ep to it each head) from articular disc (as result of the anterior Surrounded by the Capsule of the protrusion) division of the pterygoid venous tem porom andibular Lateral excursion of m andibular ple xus joint the m andible division of the Buccal branch of the Pterygoid fovea (side -to-side trigem inal n., trigem inal n. (upper portion) m ovem ents) (Acting which e xits the passes between unilaterally, it causes foram en ovale, the 2 heads the m andible to Pterygoid fovea on lying m e dial to deviate to the the neck of the the lateral contralateral side, condyle of the pterygoid (often rotating around axis m andible this innervation cre ated by is observed to contralateral be a branch condyle, which is from the buccal im portant in branch of the grinding on trigem inal n.) ipsilateral side)

MUSCLES O F MASTICATIO N

231

8

MUSCLES OF MASTICATION • Overview

Temporalis muscle Temporal fascia Superficial layer Deep layer

Articular disc of temporomandibular joint Deep part Superficial part

Masseter muscle

Parotid duct Buccinator muscle

Temporalis muscle Insertion of temporalis muscle to coronoid process of mandible Parotid duct Buccinator muscle Lateral pterygoid muscle

O rbicularis oris muscle

Masseteric nerve and artery Maxillary artery Insertion of masseter muscle

Figu re 8-2

232

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

MUSCLES OF MASTICATION • Overview

8

Lateral pterygoid muscle Sphenomandibular ligament Medial pterygoid muscle

Parotid duct Buccinator muscle

Pterygomandibular raphe Superior pharyngeal constrictor muscle

Lateral view

Sphenomandibular ligament

Cartilaginous part of pharyngotympanic (auditory) tube

Masseteric nerve Lateral pterygoid plate

Middle meningeal artery

Auriculotemporal nerve

Lateral pterygoid muscle

Maxillary artery

Medial pterygoid muscle

Inferior alveolar nerve Lingual nerve Medial pterygoid muscle

Tensor veli palatini muscle Levator veli palatini muscle

Nerve to mylohyoid Posterior view

Figu re 8-3

MUSCLES O F MASTICATIO N

233

8

VASCULAR SUPPLY • Arterial Supply Artery

Source

Course

Maxillary

Larger of the 2 term inal branches of the external carotid a. (super cial tem poral a. is the other term inal branch)

Arises posterior to the condylar neck of the m andible within the parotid gland Exits the parotid gland and passes anteriorly between the condylar neck of the m andible and the sphenom andibular ligam ent within the infratem poral fossa Takes a course that is either super cial or deep to the lateral pterygoid until reaching the pterygopalatine fossa via the pterygom axillary ssure Supplies the deep structures of the face and is divided into 3 parts as it passes m edially through the infratem poral fossa: • 1st part: m andibular • 2nd part: pterygoid • 3rd part: pterygopalatine 1st and 3rd parts do not supply the m uscles of m astication 2nd part also feeds the buccinator m ., which is not a m uscle of m astication

2nd part: (pterygoid part)

External carotid a.

Passes obliquely in an anterior and superior direction between the ram us of the m andible and insertion of the tem poralis m . Courses on the super cial surface of the lateral pterygoid m . to travel between the 2 heads of the m uscle Provides the m uscular branches to the m uscles of m astication and the buccinator m . Gives rise to 5 branches: anterior and posterior deep tem poral, m asseteric, pterygoid branches, and buccal

Pterygoid (2nd part of the m axillary a.)

Pass between the skull and the tem poralis m . Supply the tem poralis throughout their course While ascending, they anastom ose with the m iddle tem poral a. from the super cial tem poral a.

Anterior and posterior deep tem poral

234

Masseteric

Typically arises between the condylar neck of the m andible and the sphenom andibular lig. Passes laterally through the m andibular notch with the nerve Supplies the deep surface of the m asseter

Pterygoid

An irregular num ber of branches supply the m edial and lateral pterygoids

Buccal

A sm all artery that runs obliquely in an anterior direction between the m edial pterygoid and the insertion of the tem poralis m . until it reaches the outer surface of the buccinator, which it supplies Occasionally a sm all lingual branch is observed, which accom panies the lingual nerve into the oral cavity

Middle tem poral

Super cial tem poral a. after it passes superior to the root of the zygom atic arch

Passes deep into the tem poralis fascia and tem poralis m . Anastom oses with the anterior and posterior deep tem poral vessels

Transverse facial

Super cial tem poral a. before it exits the parotid gland

Passes transversely to exit the gland Passes im m ediately superior to the parotid duct across the m asseter m . and face, providing vascular supply along the way

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

VASCULAR SUPPLY • Arterial Supply

8

Anterior Posterior Deep temporal arteries and nerves Masseteric artery and nerve

Lateral pterygoid artery and muscle

Buccal artery and nerve Superficial temporal artery

Medial pterygoid artery and muscle

Maxillary artery

Anterior Deep temporal arteries Posterior and nerves

Buccal artery

Superficial temporal artery Pterygoid arteries

Masseteric artery

Middle temporal artery and vein

Transverse facial artery and vein

Facial artery and vein

Figu re 8-4

MUSCLES O F MASTICATIO N

235

8

VASCULAR SUPPLY • Venous Drainage Vein

Course

Pterygoid plexus

An extensive network of veins that parallel the 2nd and 3rd parts of the m axillary a. Receives branches that correspond with the sam e branches of the m axillary a. Tributaries of the pterygoid plexus eventually converge to form a short m axillary v. Com m unicates with the cavernous sinus, pharyngeal venous plexus, facial v. via the deep facial v., and ophthalm ic vv.

Maxillary

Form ed by the convergence of the pterygoid plexus of veins Is a short vein that parallels the 1st part of the m axillary a. Passes posteriorly between the condylar neck and the sphenom andibular ligam ent into the parotid gland In the parotid gland, it joins the super cial tem poral v. to form the retrom andibular v.

Middle tem poral

Arises from deep within the tem poralis m . and fascia, where it anastom oses with the anterior and posterior deep tem poral vessels Joins the super cial tem poral v. im m ediately before it passes inferior to the root of the zygom atic arch

Transverse facial

Travels posteriorly to enter the parotid gland and join the super cial tem poral v.

Anterior and posterior deep tem poral

Join the pterygoid plexus of veins Also com m unicate with the m iddle tem poral v.

Masseteric

Join the pterygoid plexus of veins

Pterygoid Buccal

Middle temporal vein

Superficial temporal vein and artery Transverse facial vein (cut)

Pterygoid plexus

Figu re 8-5

236

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

NERVE SUPPLY • Motor Innervation of Muscles of Mastication

8

MANDIBULAR DIVISION OF THE TRIGEMINAL • Largest of the 3 divisions of the trigem inal n. • Created by a large sensory and a sm all m otor root that unite just after passing through the foram en ovale to enter the infratem poral fossa • Upon passing through the foram en ovale, the m andibular division of the trigem inal is located between the lateral pterygoid m . (lateral to the nerve) and the tensor veli palatine m . (m edial to the nerve) • Im m ediately gives rise to 2 branches: • m eningeal (sensory to the dura m ater) • m edial pterygoid (which provides branches to the): • tensor veli palatini • tensor tym pani • The m andibular division divides into anterior and posterior divisions • Anterior division (sm aller)—m ainly m otor with 1 sensory branch (buccal n.) • Posterior division (larger)—m ainly sensory with 1 m otor branch (m ylohyoid n.) • The anterior division provides m otor innervation to m ost of the m uscles of m astication

MOTOR BRANCH FROM THE UNDIVIDED TRUNK Branch

Course

Medial pterygoid

Passes through the otic ganglion to provide m otor and proprioceptive innervation to the m edial pterygoid m . Passes anteriorly and inferiorly to enter the m edial pterygoid This branch continues to supply the tensor veli palatini and the tensor tym pani

ANTERIOR DIVISION OF THE MANDIBULAR DIVISION Branch

Course

Anterior and posterior deep tem poral

Arises from the anterior part of the m andibular division of the trigem inal n. The anterior deep tem poral n. som etim es arises from the buccal n. Pass superior to the lateral pterygoid m . between the skull and the tem poralis m . while passing deep to the tem poralis to innervate it Innervates the tem poralis Posterior deep tem poral n. also provides slight innervation to the tem porom andibular joint

Masseteric

Arises from the anterior part of the m andibular division of the trigem inal n., but occasionally arises from a com m on branch with the posterior deep tem poral n. Runs superior to the lateral pterygoid m . and continues on the lateral aspect of the m uscle as it approaches the m andible Lies anterior to the tem porom andibular joint and posterior to the tendon of the tem poralis m . Passes though the m asseteric notch with the m asseteric vessels Enters the m asseter m .’s deep surface to innervate it Also provides innervation to the tem porom andibular joint

Lateral pterygoid

Arises from the anterior part of the m andibular division of the trigem inal n., but som etim es arises as a branch from the buccal n. These branches, 1 for each m uscular head, enter the deep surface of the lateral pterygoid m . to innervate it Occasionally receives innervation from a branch from the buccal n.

MUSCLES O F MASTICATIO N

237

8

NERVE SUPPLY • Motor Innervation of Muscles of Mastication

Medial view Motor root Sensory root

Trigeminal (semilunar) ganglion O phthalmic nerve (V1 ) Maxillary nerve (V2 )

Chorda tympani nerve

Mandibular nerve (V3 )

Facial nerve (VII)

Anterior division

Tensor tympani muscle and nerve Lesser petrosal nerve

Tensor veli palatini nerve and muscle O tic ganglion

Auriculotemporal nerve

Chorda tympani nerve Medial pterygoid nerve and muscle (cut)

Mylohyoid nerve Inferior alveolar nerve entering mandibular foramen

Lingual nerve

Anterior division Lateral view

Posterior Anterior

Posterior division Foramen ovale

Deep temporal nerves Masseteric nerve Lateral pterygoid nerve and muscle

Middle meningeal artery Auriculotemporal nerve

Facial nerve (VII) Chorda tympani nerve

Buccal nerve and buccinator muscle (cut)

Lingual nerve

Submandibular ganglion

Inferior alveolar nerve (cut) Nerve to mylohyoid

Sublingual gland

Medial pterygoid muscle (cut) Digastric muscle (posterior belly)

Mylohyoid muscle (cut)

Stylohyoid muscle

Mental nerve

Hypoglossal nerve Submandibular gland

Inferior alveolar nerve (cut) Digastric muscle (anterior belly)

Figu re 8-6

238

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

CLINICAL CORRELATES • Mastication • •

8

Mastication p rep ares food by ch ewin g for deglu tition an d d igestion It is th e 1st step in th e breakd own of food by: • Makin g sm aller p ieces from larger p ieces (th u s in creasin g th e su rface area for d igestive breakd own ) • Help in g soften an d lu bricate th e food with saliva

BONES INVOLVED

• •

Base of th e sku ll an d th e m an d ible Th ey articu late at th e tem p orom an d ibu lar join t (between th e sq u am ou s p ortion of th e tem p oral bon e [sku ll] an d th e con d yle of th e m an d ible)

MUSCLES INVOLVED

•

• •

•

4 m u scles of m astication : • Masseter • Tem p oralis • Med ial p terygoid • Lateral p terygoid All m u scles of m astication are in n ervated by th e m an d ibu lar d ivision of th e trigem in al n erve (n erve of th e 1st p h aryn geal arch ) Mastication in volves u sin g th e 4 m u scles in d ifferen t com bin ation s to m ove th e m an d ible in 1 of 3 p lan es in an an tagon istic fash ion : • Elevation / dep ression • Protru sion / retru sion • Sid e-to-side excu rsion Alth ou gh th e bu ccin ator is n ot a m u scle of m astication , it aids in keep in g th e bolu s of food again st th e teeth to h elp in m astication

MUSCLES O F MASTICATIO N

239

8

CLINICAL CORRELATES • Mastication

O

}

Incisor teeth (cutting action) Bicuspid and molar teeth (grinding action)

a lf

c

to

ry

fe r

af

Aromatic substances released from food

en

ts

Mesencephalic nucleus V Sensory nucleus V From teeth and palate Saliva entering mouth

d Parotid an gland th te e Fro m

Sublingual gland

Submandibular gland

V IX

X

From back of tongue Afferents “report” on character of food and progress of mastication Proprioceptive bers “report” on pressure Bolus of food, particulated, mixed with and lubricated by saliva, passing down esophagus

Dorsal nucleus of vagus Nucleus of solitary tract

Vagus nerve carries secretory and motor impulses to stomach

Sordes and parched lips

Difficulty in swallowing “dry” bolus

Bolus Pathologically diminished salivary secretion (as in entering fever, dehydration, drug action, Sjögren’s syndrome) stomach Gastric emptying facilitated by smaller size of particles Key Afferents (other than) Proprioception Parasympathetic efferents Somatic efferents Indefinite paths

Gastric secretion stimulated

Digestion of starch by salivary amylase (ptyalin) continues in stomach until arrested by gastric acidity. Bolus temporarily protected from gastric acid by previously ingested food

Figu re 8-7

240

ue

To muscles of mastication

Food particles progressively reduced in size and mixed with saliva. Tongue aids in mixing process

Increased thirst

t

g on

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

CHAPTER 9

TEMPOROMANDIBULAR JOINT

Overview and Topographic Anatomy

242

Anatomy

243

Vascular Supply

248

Nerve Supply

250

Clinical Correlates

251

9

OVERVIEW AND TOPOGRAPHIC ANATOMY • General Information • •

Th e tem porom andibular joint (TMJ) is th e articu lation between th e sq u am ou s p ortion of th e tem p oral bon e an d th e con dyle of th e m an dible It is a gin glym oarth rod ial join t becau se it h as both a h in ge an d a glidin g action

STRUCTURAL COMPONENTS

•

Th e TMJ com p rises 2 typ es of syn ovial join ts—hinge an d sliding—an d con sists of th e followin g: • Sq u am ou s p ortion of th e tem p oral bon e • Articu lar d isc (con tain ed with in th e TMJ) • Con d yle of th e m an d ible • Ligam en ts (also serve as bou n d aries)

TMJ DYSFUNCTION

• • •

Affects 33% of th e p op u lation an d m ay be severe Cau ses in clu de arth ritis, trau m a, in fection , bru xism , an d disc d isp lacem en t More com m on in fem ales

Anterolateral view Temporalis muscle (cut)

Articular disc (cut) Floor of middle cranial fossa

External acoustic meatus Superior head of lateral pterygoid muscle (cut)

Upper joint space Lower joint space Head of condylar process

Inferior head of lateral pterygoid muscle

Condylar process

Coronoid process of mandible Lateral ligament and joint capsule (cut) Inferior (oblique) view Superior (oblique) view

Superior head of lateral pterygoid muscle

Articular disc

Inferior head of lateral pterygoid muscle

Coronoid process

Superior head of lateral pterygoid muscle Retrodiscal tissue Articular capsule (cut)

Articular disc

Articular capsule

Pars anterior Pars intermedia pars posterior Retrodiscal tissue

Figu re 9-1

242

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ANATOMY • Anatomic Features

9

OSSEOUS STRUCTURES Squamous Portion of the Temporal Bone • The TMJ articulation is located on the squam ous portion o the tem poral bone • Has an avascular articular sur ace com posed prim arily o f brous connective tissue and som e f brocartilage instead o hyaline cartilage • The m ain load-bearing areas are on the lateral aspect o the squam ous portion, condyle, and articular disc • The dense f brous connective tissue is thickest in the load-bearing areas • Relations o the squam ous portion o the tem poral bone: • Anterior—articular em inence • Interm ediate—glenoid ossa • Posterior—tym panic plate tapering to the postglenoid tubercle

Structure

Comments

Articular em inence

The strong bony prom inence on the base o the zygom atic process

Articular tubercle

The lateral part o the articular em inence is re erred to as the articular tubercle and provides attachm ent or the capsule and lateral tem porom andibular ligam ent

Glenoid ossa

The depression into which the condyle is located Superior to this thin plate o bone is the m iddle cranial ossa The anterior boundary o the glenoid ossa is the articular em inence The posterior boundary o the glenoid ossa is the tym panic plate The glenoid ossa can be divided into 2 parts by the squam otym panic f ssure (lateral) and the petrotym panic f ssure (m edial): • Anterior articular area—squam osal part o the tem poral bone (this is where the articulation occurs) • Posterior nonarticular area—tym panic portion (parotid gland m ay extend into this area)

Tym panic plate

The vertical plate located anterior to the external auditory m eatus

Postglenoid tubercle

An in erior extension o the squam ous portion o the tem poral bone Makes the posterior aspect o the glenoid ossa Provides attachm ent or the capsule and retrodiscal pad

Mandibular Condyles • Articulate with the articular disc • Ovoid in shape: • Mediolateral—20 m m • Anteroposterior—10 m m • Articular sur ace is avascular f brous connective tissue instead o hyaline cartilage • The m ain load-bearing areas are on the lateral aspect

TEMPO RO MANDIBULAR JO INT 243

9

ANATOMY • Anatomic Features

Incisive fossa

Greater palatine foramen

Lesser palatine foramen

Foramen lacerum

Foramen ovale Articular eminence Foramen spinosum Articular tubercle Carotid canal Petrotympanic fissure Postglenoid tubercle Tympanic canaliculus

Mastoid canaliculus

Stylomastoid foramen

Jugular fossa

Hypoglossal canal

Mastoid foramen

Condylar canal

Foramen magnum

Figu re 9-2

244

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ANATOMY • Anatomic Features

9

ARTICULAR DISC • Com posed o dense f brous connective tissue • Located between the squam ous portion o the tem poral bone and the condyle • Is avascular and aneural in its central part but is vascular and innervated in the peripheral areas, where load-bearing is m inim al • The m ain load-bearing areas are located on the lateral aspect; this is an area o potential per oration • Merges around its periphery, attaching to the capsule • Divided into 3 bands: • Anterior—this thick band lies just anterior to the condyle with the m outh closed • Interm ediate—this band, the thinnest part, is located along the articular em inence with the m outh closed • Posterior—this thick band is located superior to the disc with the m outh closed • Additional attachm ents: • Medial/ lateral—strong m edial and lateral collateral ligam ents anchor the disc to the condyle • Anterior—the disc is attached to the capsule and the superior head o the lateral pterygoid, but not the condyle, allowing the disc to rotate over the condyle in an anteroposterior direction • Posterior—the disc is contiguous with the bilam inar zone that blends with the capsule

BILAMINAR ZONE (Posterior Attachment Complex) • A bilam inar structure located posterior to the articular disc • Highly distortable, especially on opening the m outh • Com posed o : • Superior lam ina (stratum )—contains elastic f bers and anchors the superior aspect o the posterior portion o the disc to the capsule and bone at the postglenoid tubercle and tym panic plate • Retrodiscal pad—the highly vascular and neural portion o the TMJ, m ade o collagen, elastic f bers, at, nerves, and blood vessels (a large venous plexus f lls with blood when the condyle m oves anteriorly) • In erior lam ina (stratum )—contains m ainly collagen f bers and anchors the in erior aspect o the posterior portion o the disc to the condyle

Pars anterior Pars intermedia Pars posterior

Superior view Anterior border

Inferior view Fibers of superior head of lateral pterygoid muscle

Lateral view Pars posterior Pars intermedia Pars anterior

Retrodiscal tissue (bilaminar zone)

Medial border

Anterior border Lateral border

Retrodiscal tissue (bilaminar zone)

Posterior border

Posterior border

Anterior view

Inferior stratum of bilaminar zone

Posterior view

Lateral border

Medial view Fibers of superior head of lateral pterygoid muscle

Medial border Lateral border

Retrodiscal tissue (bilaminar zone)

Posterior border Fibers of superior head of lateral pterygoid muscle

Retrodiscal tissue (bilaminar zone)

Inferior stratum of bilaminar zone

Medial border

Figu re 9-3 TEMPO RO MANDIBULAR JO INT 245

9

ANATOMY • Anatomic Features TMJ COMPARTMENTS • The articular disc divides the TMJ into superior and in erior com partm ents • The internal sur ace o both com partm ents contains specialized endothelial cells that orm a synovial lining that produces synovial uid, m aking the TMJ a synovial joint • Synovial uid acts as: • A lubricant • A m edium or providing the m etabolic requirem ents to the articular sur aces o the TMJ Superior com partm ent

Between the squam ous portion o the tem poral bone and the articular disc Volum e = 1.2 m L Provides or the translational m ovem ent o the TMJ

In erior com partm ent

Between the articular disc and the condyle Volum e = 0.9 m L Provides or the rotational m ovem ent o the TMJ

CAPSULE AND LIGAMENTS Capsule • • • • • •

Com pletely encloses the articular sur ace o the tem poral bone and the condyle Com posed o f brous connective tissue Toughened along the m edial and lateral aspects by ligam ents Lined by a highly vascular synovial m em brane Has various sensory receptors including nociceptors Attachm ents: • Superior—along the rim o the tem poral articular sur aces • In erior—along the condylar neck • Medial—blends along the m edial collateral ligam ent • Lateral—blends along the lateral collateral ligam ent • Anterior—blends with the superior head o the lateral pterygoid m . • Posterior—along the retrodiscal pad

Ligaments

246

Collateral ligam ents

• Com posed o 2 ligam ents: Medial collateral ligam ent—connects the m edial aspect o the articular disc to the m edial pole o the condyle Lateral collateral ligam ent—connects the lateral aspect o the articular disc to the lateral pole o the condyle • Frequently called the discal ligam ents • Com posed o collagenous connective tissue; thus, they are not designed to stretch

Tem porom andibular (lateral) ligam ent

The thickened ligam ent on the lateral aspect o the capsule Prevents posterior displacem ent o the condyle Com posed o 2 separate bands: Outer oblique part—largest portion; attached to the articular tubercle; travels posteroin eriorly to attach im m ediately in erior to the condyle; this lim its the opening o the m andible Inner horizontal part—sm aller band attached to the articular tubercle running horizontally to attach to the lateral part o the condyle and disc; this lim its posterior m ovem ent o the articular disc and the condyle

Stylom andibular ligam ent

Com posed o a thickening o deep cervical ascia Extends rom the styloid process to the posterior m argin o the angle and the ram us o the m andible Helps lim it anterior protrusion o the m andible

Sphenom andibular ligam ent

Rem nant o Meckel’s cartilage Extends rom the spine o the sphenoid to the lingula o the m andible Som e authors suggest it m ay help act as a pivot on the m andible by m aintaining the sam e am ount o tension during both opening and closing o the m outh Som e authors suggest it m ay help lim it anterior protrusion o the m andible Is the ligam ent m ost requently dam aged in an in erior alveolar nerve block

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

ANATOMY • Anatomic Features

9

Lateral view

Joint capsule Lateral (temporomandibular) ligament Sphenomandibular ligament

Sphenomandibular ligament (phantom ) Styloid process Stylomandibular ligament

Joint capsule

Sphenomandibular ligament Stylomandibular ligament

Coronal view

Medial view

Superior compartment Temporomandibular disc Lateral collateral ligament blending with capsule

Cut edges of lateral pterygoid m., superior and inferior head

Inferior compartment Masseter m.

Medial collateral ligament blending with capsule

Figu re 9-4

TEMPO RO MANDIBULAR JO INT 247

9

VASCULAR SUPPLY • Arterial Supply Artery

Source

Course

Superf cial tem poral

Term inal branch o the external carotid a.

Begins in the parotid gland and initially is located posterior to the m andible, where it provides sm all branches to the TMJ

Deep auricular

Maxillary a.

Arising in the sam e area as that o the anterior tym panic a. Lies in the parotid gland, posterior to the TMJ, where it gives branches to the TMJ

Anterior tym panic

Arising in the sam e area as that o the deep auricular a. Passes superiorly behind the TMJ to enter the tym panic cavity through the petrotym panic f ssure, where it gives branches to the TMJ

Deep temporal arteries

Zygomatic process Joint capsule and lateral ligament

Superficial temporal artery

Transverse facial artery

External carotid artery

Maxillary artery Facial Artery Lingual artery

Masseteric artery

Joint capsule

Middle meningeal artery

Zygomatic process Deep temporal artery Anterior tympanic artery

Transverse facial artery Maxillary artery Masseteric artery Lateral pterygoid muscle (cut) Sphenomandibular ligament

Superficial temporal artery Deep auricular artery

Facial artery

Inferior alveolar artery External carotid artery

Lingual artery

Figu re 9-5

248

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

VASCULAR SUPPLY • Venous Drainage Vein

Course

Superf cial tem poral

Receives som e branches rom the TMJ Then joins the m axillary v. to orm the retrom andibular v.

Maxillary

Receives som e branches rom the TMJ Joins the superf cial tem poral v. to orm the retrom andibular v.

Mandibular nerve (V3 ) (cut and reflected anterolaterally)

9

Pterygoid (venous) plexus Inferior head of the lateral pterygoid muscle Maxillary artery Anterior deep temporal nerve, artery, and vein Superior head of lateral pterygoid muscle (cut) Posterior deep temporal nerve, artery, and vein Masseteric artery, nerve, and vein Masseter muscle Temporomandibular joint capsule Temporalis muscle Articular disc Superficial temporal artery and vein Parotid gland External carotid artery Auriculotemporal nerve

Sphenomandibular ligament

Maxillary artery

Figu re 9-6

TEMPO RO MANDIBULAR JO INT 249

9

NERVE SUPPLY • Sensory Innervation Nerve

Source

Comment

Auriculotem poral

Posterior division of the m andibular division of the trigem inal n.

From the posterior division of the m andibular division of the trigem inal n. Splits around the m iddle m eningeal a. and passes between the sphenom andibular ligam ent and the condylar neck Supplies sensory branches all along the capsule Sensory but carries autonom ic function to the parotid gland

Masseteric

Anterior division of the m andibular division of the trigem inal n.

Lies anterior to the TMJ and provides branches to the joint before passing over the m asseteric notch to reach the m asseter m . Sensory branches aid the auriculotem poral n.

Posterior deep tem poral

Lies anterior to the TMJ and provides branches to the joint before innervating the tem poralis m . Sensory branches aid the auriculotem poral n. in supplying the anterior part of the TMJ Mainly m otor, but carries additional sensory function to the TMJ

Temporalis muscle

Auriculotemporal nerve

Posterior deep temporal nerve Mandibular division of trigeminal nerve (V3 ) Auriculotemporal nerve

Masseteric nerve Deep head of masseter muscle Superficial head of masseter muscle

Figu re 9-7

250

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

CLINICAL CORRELATES • Perforations of the Articular Disc • • • •

• • •

9

Up to 33% of ad u lts h ave a TMJ-related p roblem Perforation s of th e articu lar d isc typ ically occu r in th e later stages of TMJ d ysfu n ction Wom en h ave a h igh er p revalen ce of disc p erforation s th an m en Man y factors m ay con tribu te to ch an ges in th e d isc: • Bru xism • Trau m a • Lateral p terygoid m u scle abn orm al activity • Overload in g Most d isc p erforation s occu r in th e lateral or p osterior p ortion s of th e d isc an d vary in size Crep itu s an d clickin g sou n d s on op en in g th e m ou th are com m on clin ical m an ifestation s An terior d isc d isp lacem en t also is com m on

Anterosuperior view of condylar process and articular discs Coronal cut of normal articular disc

Right disc

Perforation

Right disc

Perforated discs

Perforation

Left disc

Figu re 9-8

TEMPO RO MANDIBULAR JO INT 251

9

CLINICAL CORRELATES • Mandibular Dislocation •

• • •

Mandibular dislocation (or su blu xation of th e TMJ) occu rs wh en th e con d yle m oves an terior to th e articu lar em in en ce • With d islocation , th e m ou th ap p ears “wide op en ” • Becau se th e con dyle is d isp laced an terior to th e articu lar em in en ce, a d ep ression can be p alp ated p osterior to th e con d yle Sp on tan eou s d islocation s can occu r from a variety of action s ran gin g from a sim p le yawn to an exten ded den tal treatm en t Becau se th e m an d ible is dislocated, th e p atien t h as a great deal of d if cu lty verbalizin g h is or h er p red icam en t Relocation in volves rep osition in g th e con d yle p osterior to th e articu lar em in en ce

Closed position

Open position

Figu re 9-9

252

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

Anterior dislocation

CLINICAL CORRELATES • Opening the Mandible • •

•

9

Op en in g th e m an d ible in volves a com p lex series of m ovem en ts In itial m ovem en t is rotational, wh ich occu rs in th e lower TMJ com p artm en t: • Lateral p terygoid (in ferior h ead) in itiates th e op en in g of th e jaw (th e su p erior h ead of th e lateral p terygoid is described as bein g active du rin g elevation of th e m an d ible in a “p ower stroke”) • As th e m an d ible is d ep ressed , th e m ed ial an d collateral ligam en ts tigh tly attach th e con d yle to th e articu lar d isc, th ereby allowin g for on ly rotation al m ovem en t • On ce th e TMJ becom es tau t, n o fu rth er rotation of th e con dyle can occu r • Norm ally, rotation al m ovem en t con tin u es u n til th e u p p er an d th e lower teeth are abou t 20 m m away from each oth er For ad dition al/ fu rth er op en in g of th e m an dible, translational m ovem en t m u st occu r: • A tran slation al m ovem en t occu rs in th e u p p er TMJ com p artm en t an d p rovid es for m ost of th e m an d ible’s ability to op en • In th is m ovem en t, th e articu lar d isc an d th e con d yle com p lex slid e in feriorly on th e articu lar em in en ces, allowin g for m axim u m d ep ression of th e m an d ible Mandibular fossa Articular disc Articular tubercle

Joint capsule Jaws slightly opened (hinge action predominates)

Jaws closed

Jaws widely opened (hinge and gliding action combined)

Mouth closed

Initial rotation beginning in lower compartment

Rotation continuing in lower compartment

Translation occurring in upper compartment

Figu re 9-10

TEMPO RO MANDIBULAR JO INT 253

9

CLINICAL CORRELATES • Opening the Mandible

Opening the mouth Retrodiscal tissue (bilaminar zone)

Articular disc (cut sagittally) Floor of middle cranial fossa

External acoustic meatus Head of condyle process

Superior head (cut)

Joint capsule (cut)

Inferior head

Lateral (temporomandibular) ligament (cut)

Lateral pterygoid muscle

Styloid process Mastoid process Mandibular notch

Mandibular ramus

Upper layer of bilaminar zone Articular disc (cut sagittally) Joint capsule

Retrodiscal tissue (bilaminar zone) expanded

Inferior layer of bilaminar zone

Direction of force vector generated by the contraction of lateral pterygoid muscles

Translation of condyle and ramus of mandible during opening of the mouth

Figu re 9-11

254

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

CLINICAL CORRELATES • Arthritis and Ankylosis

9

ARTHRITIS

• • • • •

Arthritis is th e m ost com m on cau se of p ath ologic ch an ges in th e TMJ W h en rh eu m atoid arth ritis occu rs, u su ally both TMJs are affected , an d oth er join ts ten d to be affected before th e TMJ Rad iologic im ages in th e initial d isease stages sh ow d ecreased join t sp ace with ou t osseou s ch an ges Rad iologic im ages in th e late d isease stages sh ow d ecreased join t sp ace with osseou s ch an ges, p ossibly in clu d in g an kylosis In osteoarth ritis, cau ses in clu d e n orm al wear, trau m a, an d bru xism , an d clin ical m an ifestation s m ay ran ge from m ild to severe

ANKLYOSIS

• • •

Ankylosis is an obliteration of th e TMJ sp ace with abn orm al osseou s m orp h ologic featu res, wh ich often occu rs as a resu lt of trau m a or in fection Classi ed as eith er true (in tracap su lar) or false (extracap su lar, u su ally associated with an abn orm ally large coron oid p rocess or zygom atic arch ) an kylosis Treatm en t varies in accord an ce with th e cau se bu t m ay in clu d e a p rosth etic rep lacem en t or con d ylectom y

Unilateral ankylosis

Ankylosis

Ankylosis of TMJ

Osteoarthritis

Figu re 9-12

TEMPO RO MANDIBULAR JO INT 255

This pa ge inte ntiona lly le ft bla nk

CHAPTER 10

PTERYGOPALATINE FOSSA

Overview and Topographic Anatomy

258

Borders and Openings

259

Contents of the Pterygopalatine Fossa

262

Imaging

273

10

OVERVIEW AND TOPOGRAPHIC ANATOMY • General Information • • • • • •

•

•

Th e pterygopalatine fossa is a p yram id -sh ap ed fossa on th e lateral asp ect of th e sku ll between th e m axilla’s in fratem p oral su rface an d th e p terygoid p rocess of th e sp h en oid Is located in ferior to th e ap ex of th e orbit Is located between th e in fratem p oral fossa an d th e n asal cavity Is a m ajor p ath way for th e sp read of in fection s an d tu m ors from th e h ead an d n eck in to th e sku ll base Allows th e in fratem p oral fossa, m idd le cran ial fossa, n asop h aryn x, n asal cavity, orbit, an d oral cavity to com m u n icate Con tain s m ajor n erves an d vessels: • Maxillary d ivision of th e trigem in al n erve an d bran ch es • Pterygop alatin e (sp h en op alatin e, Meckel’s) gan glion • 3rd p art of th e m axillary artery an d bran ch es (with corresp on d in g vein s) Clin ically, th e p terygop alatin e fossa is often d escribed as bein g d ivid ed in to: • An terior (Vascu lar) Com p artm en t–location of 3rd p art of m axillary a. an d its bran ch es • Posterior (Neu ral) Com p artm en t–location of m axillary d ivision of th e trigem in al n ., p terygop alatin e gan glion , an d n . of th e p terygoid can al 7 op en in gs (foram in a/ ssu res/ can als) allow p assage of n erves an d vessels Spine of sphenoid bone Foramen spinosum Foramen ovale

Sphenopalatine foramen Pterygopalatine fossa Choanae (posterior nares) Lateral plate Medial plate Tuberosity of maxilla

of pterygoid process

Hamulus

Infratemporal fossa Pyramidal process of palatine bone

Alveolar process of maxilla

Figu re 10-1

258

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

BORDERS AND OPENINGS • Borders Border

Structure(s)

Anterior

In ratem poral sur ace o the posterior m axilla

Posterior

Pterygoid process o the sphenoid

Foram en rotundum Pterygoid (vidian) canal Palatovaginal (pharyngeal) canal

Medial

Perpendicular plate o the palatine

Sphenopalatine oram en

Lateral

Pterygom axillary f ssure

Pterygom axillary f ssure

Superior

In erior sur ace o the sphenoid and the orbital plate o the palatine bone

In erior orbital f ssure

In erior

Pyram idal process o the palatine

Greater palatine canal

10

Opening(s)

Openings Opening

Location

Communicates With

Pterygom axillary f ssure

Lateral part o the pterygopalatine ossa

In ratem poral ossa

Posterior superior alveolar n. rom the pterygopalatine ossa into the in ratem poral ossa 3rd part o the m axillary a. rom the in ratem poral ossa into the pterygopalatine ossa A variable network o veins, such as the sphenopalatine, into the pterygoid plexus o vv.

Sphenopalatine oram en

Medial wall o the pterygopalatine ossa O ten located posterior to the m iddle nasal concha

Nasal cavity

Nasopalatine n. Posterior superior nasal n. (m edial and lateral branches) Sphenopalatine a. and v.

In erior orbital f ssure

Superior part o the pterygopalatine ossa Continues posteriorly with the superior part o the pterygom axillary f ssure

Orbit

In raorbital n. rom the m axillary division o the trigem inal n. Zygom atic n. rom the m axillary division o the trigem inal In raorbital a. and v. Orbital branches rom the m axillary division o the trigem inal In erior ophthalm ic v. that connects with the pterygoid plexus o veins

Greater palatine canal

In erior part o the pterygopalatine ossa Eventually term inates into the greater and lesser palatine oram ina

Oral cavity

Greater palatine n. and vessels (through the greater palatine oram en) onto the hard palate Lesser palatine n. and vessels (through the lesser palatine oram en) onto the so t palate

Foram en rotundum

Posterolateral part o the pterygopalatine ossa

Middle cranial ossa

Maxillary division o the trigem inal n.

Pterygoid (vidian) canal

Posterior part o the pterygopalatine ossa Between the pterygopalatine ossa and the oram en lacerum In erior and m edial to the oram en rotundum

Middle cranial ossa

Nerve o the pterygoid canal (vidian n.) Artery (and vein) o the pterygoid canal

Palatovaginal (pharyngeal) canal

Posterom edial part o the pterygopalatine ossa Medial to the pterygoid canal

Nasopharynx

Pharyngeal n. Pharyngeal a. and v.

Transmitted Structures

PTERYGO PALATINE FO SSA 259

10

BORDERS AND OPENINGS • Openings

Infratemporal fossa exposed by removal of zygomatic arch and mandible*

Inferior orbital fissure

Pterygopalatine fossa Sphenopalatine foramen *Superficially, mastoid process forms posterior boundary

Superior orbital fissure O ptic foramen

Sphenoidal sinus

Cut edge of zygoma to view into the pterygopalatine fossa

Pterygoid canal Pharyngeal (palatovaginal) canal

Foramen rotundum Nasal cavity

Cut edge of zygomatic arch

Sphenopalatine foramen

Styloid process Maxillary sinus (posterior portion)

Figu re 10-2

26 0 NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

BORDERS AND OPENINGS • Openings

10

Posterior – Red border Superior

Pterygoid canal

Inferior orbital fissure Foramen rotundum communicating with the middle cranial fossa

Medial

Sphenopalatine foramen communicating with the nasal cavity

Lateral

Pharyngeal (palatovaginal) canal communicating with the nasopharynx

Pterygomaxillary fissure communicating with the infratemporal fossa

Greater palatine canal communicating with the oral cavity Inferior

Infraorbital artery Maxillary division

Pterygopalatine ganglion Infraorbital nerve

Posterior superior alveolar nerve Zygomatic nerve Posterior superior nasal nerve Sphenopalatine artery and nasopalatine nerve

Maxillary artery

Pharyngeal artery and nerve

Nerve and artery of the pterygoid canal

Greater palatine nerve

Descending palatine artery Greater palatine artery Lesser palatine artery

Lesser palatine nerve

Figu re 10-3

PTERYGO PALATINE FO SSA 261

10

CONTENTS OF THE PTERYGOPALATINE FOSSA • Vascular Supply ARTERIAL SUPPLY

262

Artery

Source

Course

Maxillary (3rd part)

External carotid a.

Passes rom the in ratem poral ossa into the pterygopalatine ossa via the pterygom axillary f ssure Prior to passing through the pterygom axillary f ssure, it gives o the posterior superior alveolar a. (the only artery rom the 3rd part o the m axillary a. that does not norm ally branch o within the pterygopalatine ossa)

Infraorbital

The continuation o the 3rd part o the m axillary a.

Accom panied by the in raorbital n. and v. The artery passes orward in the in raorbital groove, in raorbital canal, and exits the in raorbital oram en In the in raorbital canal, it gives rise to various orbital branches that aid in supplying the lacrim al gland and extraocular m uscles In the in raorbital canal, it also gives rise to the anterior and m iddle (i present) superior alveolar aa. that supply the m axillary teeth rom the central incisors to the prem olars (where they anastom ose with the posterior superior alveolar a.) and the m ucous m em brane o the m axillary sinus On exiting the in raorbital oram en, the artery is located between the levator labii superioris and levator anguli oris m m . and ollows the branching pattern o the nerve: • In erior palpebral branch (supplies the lower eyelid) • Nasal branch (supplies the lateral side o the nose) • Superior labial branch (supplies the upper lip)

Descending palatine

3rd part o the m axillary a.

Descends into the greater palatine canal Within the canal, the artery splits into the greater and lesser palatine aa. Greater palatine a. exits the greater palatine oram en and passes anteriorly toward the incisive oram en and supplies the hard palate gingiva, m ucosa, and palatal glands and anastom oses with the term inal branch o the sphenopalatine a. that exits the incisive oram en Lesser palatine a. supplies the so t palate and palatine tonsil

Artery of the pterygoid canal

Passes posteriorly into the pterygoid canal, accom panying the nerve o the pterygoid canal (vidian n.) Helps supply the auditory tube and sphenoid sinus

Pharyngeal

Passes posterom edially into the palatovaginal canal Helps supply the auditory tube and nasopharynx

Sphenopalatine

Passes m edially into the sphenopalatine oram en to enter the nasal cavity It then gives rise to the posterior lateral nasal branches and posterior septal branches, which supply the nasal concha, m ucous m em branes, and nasal septum The sphenopalatine a. continues along the nasal septum to enter the hard palate via the incisive canal

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

CONTENTS OF THE PTERYGOPALATINE FOSSA • Vascular Supply Pterygoid canal (behind ganglionic branches connecting maxillary nerve and pterygopalatine ganglion) Maxillary nerve

Posterior superior Nasopalatine nerve and inferior lateral (septal branch) nasal branches of maxillary nerves

10

Posterior lateral nasal branches of sphenopalatine artery Pharyngeal artery

Pterygopalatine ganglion

Artery of pterygoid canal

Lacrimal nerve

Sphenopalatine artery

Zygomatic nerve Zygomaticotemporal nerve

Infraorbital artery Posterior superior alveolar artery Descending palatine artery

Zygomaticofacial nerve Infraorbital nerve Middle superior alveolar nerve

Maxillary artery

Posterior wall of right maxillary sinus (cut)

Superficial temporal artery

Posterior superior alveolar nerve

External carotid artery

Greater and lesser palatine nerves

Anterior and middle superior alveolar arteries

Dental and gingival branches (of superior alveolar nerves) Communication between greater palatine and nasopalatine nerves, and anastomosis between posterior septal branch of sphenopalatine artery and greater palatine artery in incisive canal

Dental branches of superior alveolar artery Lesser and greater palatine arteries

Anterior perspective of fossa with lower facial skeleton removed

Sphenopalatine artery Infraorbital artery

Sphenopalatine foramen Artery of pterygoid canal

Sphenopalatine artery Descending palatine artery in pterygopalatine fossa

External carotid artery

Figu re 10-4

PTERYGO PALATINE FO SSA 263

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CONTENTS OF THE PTERYGOPALATINE FOSSA • Vascular Supply VENOUS DRAINAGE Vein

Course

Posterior superior alveolar

Receives blood rom the posterior teeth and so t tissue

Pharyngeal

Receives blood rom the nasopharynx

Descending palatine

Receives blood rom the hard and so t palate

In raorbital

Receives blood rom the m id ace via the lower eyelid, lateral side o the nose, and the upper lip

Sphenopalatine

Receives blood rom the nasal cavity and the nasal septum

Vein o the pterygoid canal

Receives blood rom the oram en lacerum region and the sphenoid sinus

In erior ophthalm ic

Receives blood rom the oor o the orbit Branches into 2 parts The 1st branch travels posteriorly with the in raorbital v. that passes through the in erior orbital f ssure to com m unicate with the pterygoid plexus and the cavernous sinus The m ain branch travels posteriorly to com m unicate with the superior ophthalm ic vein in the superior orbital f ssure or travels posteriorly in the f ssure to join the cavernous sinus

Pterygoid plexus

An extensive network o veins that parallels the 2nd and 3rd parts o the m axillary a. The tributaries o the pterygoid plexus eventually converge to orm a short m axillary v.

Eventually com m unicate with the pterygoid plexus o veins

Supratrochlear vein Supraorbital vein Superior ophthalmic vein

Nasofrontal vein Angular vein

Cavernous sinus

Vorticose veins Facial vein

Inferior ophthalmic vein Pterygoid plexus Maxillary vein Deep facial vein

Retromandibular vein

Figu re 10-5

264

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CONTENTS OF THE PTERYGOPALATINE FOSSA • Nerve Supply

10

MAXILLARY NERVE Nerve

Source

Course

Maxillary division o the trigem inal n.

Trigem inal n.

Sensory in unction Travels along the lateral wall o the cavernous sinus Be ore exiting the m iddle cranial ossa, it gives o a m eningeal branch that innervates the dura m ater Passes rom the m iddle cranial ossa into the pterygopalatine ossa via the oram en rotundum Within the pterygopalatine ossa, gives rise to 4 branches: • Posterior superior alveolar n. • Zygom atic n. • Ganglionic branches • In raorbital n.

Posterior superior alveolar

Maxillary division o the trigem inal n. in pterygopalatine ossa

Passes through the pterygom axillary f ssure to enter the in ratem poral ossa In the in ratem poral ossa, it passes on the posterior sur ace o the m axilla along the region o the m axillary tuberosity Gives rise to a gingival branch that innervates the buccal gingiva and adjacent m ucosa alongside the m axillary m olars Enters the posterior sur ace o the m axilla and supplies the m axillary sinus and the m axillary m olars, with the possible exception o the m esiobuccal root o the 1st m axillary m olar

Zygom atic

Passes through the in erior orbital f ssure to enter the orbit Passes on the lateral wall o the orbit and branches into the zygom aticotem poral and zygom atico acial branches A com m unicating branch rom it joins the lacrim al n. rom the ophthalm ic division o the trigem inal to carry autonom ics to the lacrim al gland

Ganglionic branches

Usually 1 or 2 ganglionic branches that connect the m axillary division o the trigem inal to the pterygopalatine ganglion Contain sensory f bers that pass through the pterygopalatine ganglion (without synapsing) to be distributed with the nerves that arise rom the pterygopalatine ganglion Also contain postganglionic autonom ic f bers to the lacrim al gland that pass through the pterygopalatine ganglion (parasym pathetic f bers orm a synapse here, between the preganglionic f bers rom the vidian n. and the postganglionic f bers)

In raorbital

Considered the continuation o the m axillary division o the trigem inal n.

Passes through the in erior orbital f ssure to enter the orbit Passes anteriorly through the in raorbital groove, in raorbital canal, and exits onto the ace via the in raorbital oram en Within the in raorbital canal, it gives rise to: • Anterior superior alveolar (supplies the m axillary sinus; m axillary central incisor, lateral incisor, and canine; gingiva and m ucosa alongside the sam e teeth) • A sm all branch o the anterior superior alveolar (supplies the nasal cavity) • Middle superior alveolar (present about 30% o the tim e; supplies the m axillary sinus, m axillary prem olars and o ten the m esiobuccal root o the 1st m axillary m olar, and gingiva and m ucosa alongside the sam e teeth)

PTERYGO PALATINE FO SSA 265

10

CONTENTS OF THE PTERYGOPALATINE FOSSA • Nerve Supply

O phthalmic nerve (V1 ) Trigeminal (semilunar) ganglion Trigeminal nerve (V1 )

Infraorbital nerve

Mandibular nerve (V3 ) Maxillary nerve (V2 ) Zygomatic nerve Nerve (vidian) of pterygoid canal Pterygopalatine ganglion Infraorbital nerve entering infraorbital canal

Greater and lesser palatine nerves Ganglionic branches to pterygopalatine ganglion

Posterior superior alveolar nerve

Figu re 10-6

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CONTENTS OF THE PTERYGOPALATINE FOSSA • Nerve Supply

10

BRANCHES OF THE MAXILLARY DIVISION OF THE TRIGEMINAL NERVE ASSOCIATED WITH THE PTERYGOPALATINE GANGLION • A parasym pathetic ganglion nam ed because it is a collection o cell bodies in the peripheral nervous system (postganglionic cell bodies) • The ganglionic branches are o the m axillary division o the trigem inal n. that pass through the pterygopalatine ganglion • The vidian n. connects to the pterygopalatine ganglion • 3 sets o nerve f bers travel through the pterygopalatine ganglion: • General sensory f bers rom the trigem inal n. (without synapsing) • Postganglionic sym pathetic f bers (carried to the pterygopalatine ganglion via the vidian n, without synapsing) • Preganglionic parasym pathetic f bers (carried to the pterygopalatine ganglion via the vidian n. and orm ed by synapsing in the pterygopalatine ganglion with the postganglionic parasym pathetic f bers) • All branches arising rom the pterygopalatine ganglion carry these 3 sets o f bers to the areas where they term inate • These nerves o the m axillary division travel through the pterygopalatine ganglion: • Nasopalatine n. • Posterior superior nasal n. • Greater palatine n. • Lesser palatine n. • Pharyngeal n. • Orbital branches

Branch(es)

Source

Course

Vidian (nerve o the pterygoid canal)

Form ed by the greater and deep petrosal nn.

An autonom ic nerve: • Greater petrosal n. carries the preganglionic parasym pathetic f bers • Deep petrosal n. carries the postganglionic sym pathetic f bers Com m unicates with the pterygopalatine ganglion, which allows the autonom ics to be distributed along any nerve connected to the ganglion

Nasopalatine

A nerve o the m axillary division o the trigem inal n., which branches o the pterygopalatine ganglion in the pterygopalatine ossa

Passes through the sphenopalatine oram en to enter the nasal cavity Passes along the superior portion o the nasal cavity to the nasal septum ; then travels anteroin eriorly to the incisive canal Exits the incisive oram en on the hard palate and supplies the palatal gingiva and m ucosa rom the region o the central incisors to the canines

Posterior superior nasal

Passes through the sphenopalatine oram en to enter the nasal cavity, where it divides into 2 nerves: • Lateral posterior superior (supplies the lateral wall o the nasal cavity) • Medial posterior superior nasal (supplies the posterosuperior portion o the nasal septum )

Greater palatine

Passes through the greater palatine canal to enter the hard palate via the greater palatine oram en Supplies the palatal gingiva and m ucosa rom the area in the prem olar region to the posterior border o the hard palate to the m idline

Lesser palatine

Passes through the greater palatine canal to enter and supply the so t palate via the lesser palatine oram en

Pharyngeal

Passes through the palatovaginal (pharyngeal) canal to enter and supply the nasopharynx

Orbital

Several branches arising rom the m axillary division o the trigem inal n., which branch o o the pterygopalatine ganglion in the pterygopalatine ossa

Pass through the in erior orbital f ssure to enter the orbit (supplying orbital periosteum ) and som e f bers continue through the posterior ethm oid oram en supplying the sphenoid and posterior ethm oid sinuses

PTERYGO PALATINE FO SSA 267

10

CONTENTS OF THE PTERYGOPALATINE FOSSA • Nerve Supply

Medial wall of nasal cavity (nasal septum) Sphenopalatine foramen (dissected aw ay)

Nasopalatine nerve (V2 )

Pterygopalatine ganglion Nerve (vidian) of pterygoid canal

Greater and lesser palatine nerves (V2 ) Lesser palatine nerves (V2 ) Greater palatine nerve (V4 )

Lateral wall of nasal cavity

Maxillary n. Pterygopalatine ganglion and branches Lateral wall

Nerve of pterygoid canal Greater petrosal n. Deep petrosal n. Pharyngeal branch Nasopalatine n. (passing to septum)

Lesser (minor) palatine nn. Greater (major) palatine n. and branches

Nasopalatine n.

Nasal septum

Figu re 10-7

26 8 NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

CONTENTS OF THE PTERYGOPALATINE FOSSA • Nerve Supply

10

AUTONOMICS TRAVERSING THE PTERYGOPALATINE FOSSA Type of Neuron

Name of Cell Body

Characteristics of Cell Body

Course of the Neuron

Anatomic Pathway for Parasympathetics Associated With the Maxillary Division of the Trigeminal Nerve Preganglionic neuron

Superior salivatory nucleus

A collection o nerve cell bodies located in the pons Travel through the nervus interm edius o the acial n. into the internal acoustic m eatus In the acial canal, the acial n. gives rise to 2 parasym pathetic branches: • Greater petrosal n. • Chorda tym pani n.

Gre ate r Pe tro s al Ne rve Greater petrosal n. exits along the hiatus or the greater petrosal n. toward the oram en lacerum , where it joins the deep petrosal n. (sym pathetics) to orm the nerve o the pterygoid canal (vidian n.) Vidian n. passes through the pterygoid canal and enters the pterygopalatine ossa, where it joins with the pterygopalatine ganglion

Postganglionic neuron

Pterygopalatine ganglion

Pterygopalatine ganglion is a collection o nerve cell bodies located in the pterygopalatine ossa Postganglionic parasym pathetic f bers that arise in the pterygopalatine ganglion are distributed to the ophthalm ic and m axillary divisions o the trigem inal n. to the: • Lacrim al gland • Nasal glands (in respiratory epithelium ) • Paranasal sinus glands (in respiratory epithelium ) • Palatine glands • Pharyngeal glands

Ophthalmic Divis ion Dis tribution Postganglionic f bers travel along the zygom atic branch o the m axillary division or a short distance to enter the orbit A short com m unicating branch joins the lacrim al n. o the ophthalm ic division o the trigem inal n. These f bers innervate the lacrim al gland to cause the secretion o tears Maxillary Divis io n Dis tributio n Postganglionic f bers travel along the m axillary division o the trigem inal n. to be distributed along its branches that are located in the nasal cavity, paranasal sinuses, oral cavity, and pharynx (e.g., nasopalatine, greater palatine) These f bers innervate: • Nasal glands • Paranasal glands • Palatine glands • Pharyngeal glands

PTERYGO PALATINE FO SSA 269

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CONTENTS OF THE PTERYGOPALATINE FOSSA • Nerve Supply

Trigeminal ganglion Deep petrosal nerve Greater petrosal nerve Chorda tympani nerve Trigeminal nerve (V) Facial nerve (VII) (intermediate nerve) Superior salivatory nucleus

O phthalmic nerve (V1 ) Mandibular nerve (V3 ) O tic ganglion Lingual nerve Maxillary nerve (V2 ) Nerve (vidian) of pterygoid canal Pterygopalatine ganglion Lacrimal gland

Descending palatine nerves Posterior nasal nerves

Pharyngeal nerve Maxillary artery Internal carotid nerve

Palatine nerves

Glossopharyngeal nerve (IX) Superior cervical sympathetic ganglion Sympathetic trunk

Greater Lesser

T1 and T2 spinal nerves Thoracic spinal cord

Submandibular ganglion

Dorsal root Sublingual gland White

Submandibular gland Facial artery

Gray

Rami communicantes

Lingual artery

Internal carotid artery

External carotid artery and plexus Common carotid artery

Ventral root

Sympathetic presynaptic cell bodies in intermediolateral nucleus (lateral horn) of gray matter

Sympathetic presynaptic fibers Sympathetic postsynaptic fibers Parasympathetic presynaptic fibers Parasympathetic postsynaptic fibers

Figu re 10-8

270

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CONTENTS OF THE PTERYGOPALATINE FOSSA • Nerve Supply

10

AUTONOMICS TRAVERSING THE PTERYGOPALATINE FOSSA Type of Neuron

Name of Cell Body

Characteristics of Cell Body

Course of the Neuron

Anatomic Pathway for Sympathetics Associated With the Maxillary Division of the Trigeminal Nerve Preganglionic neuron

Interm ediolateral horn nucleus

Collection o nerve cell bodies located in the lateral horn nucleus o the spinal cord between spinal segm ents T1 and T3 (and possibly T4)

Arise rom the interm ediolateral horn nuclei rom T1 to T3 (or T4) Travel through the ventral root o the spinal cord to the spinal n. Enter the sym pathetic chain via a white ram us com m unicans Once in the sym pathetic chain, the preganglionic f bers or the eye will ascend and synapse with postganglionic f bers in the superior cervical ganglion

Postganglionic neuron

Superior cervical ganglion

Collection o nerve cell bodies located in the superior cervical ganglion, which is located at the base o the skull Postganglionic sym pathetic f bers ollow the internal carotid or external carotid a. to pass near their respective e ector organs: • Nasal cavity • Paranasal sinuses • Palate • Lacrim al gland

Nas al Cavity, Paranas al Sinus e s , and Palate • Postganglionic sym pathetic f bers ollow both the internal and external carotid aa. • Postganglionic f bers that will ollow the internal carotid a. will orm the internal carotid n., which travels along the internal carotid a., orm ing the internal carotid plexus • Postganglionic sym pathetic f bers rom the internal carotid plexus branch in the region o the oram en lacerum to orm the deep petrosal n. • The deep petrosal n. joins the greater petrosal n. (parasym pathetics) to orm the nerve o the pterygoid canal (vidian n.) • Postganglionic sym pathetic f bers travel along the branches o the m axillary division o the trigem inal n. associated with the pterygopalatine ganglion to be distributed along its branches in the nasal cavity, paranasal sinuses, and palate • Postganglionic sym pathetic f bers that will ollow the external carotid travel to the external carotid a. and branch and ollow the m axillary a. • These f bers travel along the branches o the m axillary a. to be distributed along the nasal cavity, paranasal sinuses, and palate Lacrimal Gland • Postganglionic sym pathetic f bers ollow the internal carotid a. • Postganglionic f bers that will ollow the internal carotid a. will orm the internal carotid n., which travels along the internal carotid a., orm ing the internal carotid plexus • Postganglionic sym pathetic f bers rom the internal carotid plexus branch o in the region o the oram en lacerum to orm the deep petrosal n. • The deep petrosal n. joins the greater petrosal n. (parasym pathetics) to orm the nerve o the pterygoid canal (vidian n.) • Postganglionic f bers travel along the zygom atic branch o the m axillary division or a short distance to enter the orbit • A short com m unicating branch joins the lacrim al n. o the ophthalm ic division o the trigem inal n. • These f bers are distributed to the lacrim al gland

PTERYGO PALATINE FO SSA 271

10

CONTENTS OF THE PTERYGOPALATINE FOSSA • Nerve Supply

Superior salivatory nucleus (parasympathetic) Facial nerve (VII) Geniculum Greater petrosal nerve (parasympathetic) Deep petrosal nerve (sympathetic) Nerve (vidian) of pterygoid canal Maxillary nerve (V2 ) entering foramen rotundum Pterygopalatine ganglion in pterygopalatine fossa Lateral and medial posterior superior nasal branches in pterygopalatine fossa Infraorbital nerve Posterior superior and inferior lateral nasal nerves (cut ends)

Medulla oblongata Spinal cord Sympathetic trunk

Tympanic cavity Internal carotid nerve Internal Greater carotid and lesser palatine artery Superior nerves cervical ganglion

Posterior superior alveolar nerves

Maxillary sinus

Postsynaptic fibers to vessels (sympathetic) and glands (parasympathetic) of nasal cavity, maxillary sinus and palate

T1 T2 T3 Presynaptic sympathetic cell bodies in intermediolateral nucleus (lateral horn) of gray matter

Presynaptic parasympathetic fibers Postsynaptic parasympathetic fibers Presynaptic sympathetic fibers Postsynaptic sympathetic fibers

Figu re 10-9

272

Nasopalatine nerve

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

IMAGING Pterygoid canal

Sphenopalatine foramen

Pterygopalatine fossa

Foramen rotundum

(Beginning of) infraorbital fissure Foramen rotundum

10

Pterygopalatine fossa

Pterygopalatine fossa

Pterygoid canal

Greater palatine canal

Sphenopalatine foramen Pterygopalatine fossa

Infraorbital fissure

Foramen rotundum Pterygoid canal

Figu re 10-10

PTERYGO PALATINE FO SSA 273

10

IMAGING

Pterygoid canal

Infraorbital fissure

Foramen rotundum

Pterygopalatine fossa

Greater palatine canal

Pterygopalatine fossa leading to Sphenopalatine foramen

Figu re 10-11

274

Pterygopalatine fossa

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CHAPTER 11

NOSE AND NASAL CAVITY

Overview and Topographic Anatomy

276

Nose

278

Nasal Cavity

28 6

Clinical Correlates

304

Imaging

30 8

11

OVERVIEW AND TOPOGRAPHIC ANATOMY • General Information NOSE

• •

Th e p rom in en t an atom ic stru ctu re located in erior an d m ed ial to th e eyes Help s in breath in g an d ol action

NASAL CAVITY

•

Th e com p lex ch am ber located p osterior to th e vestibu le an d atriu m o th e n ose

RESPIRATORY EPITHELIUM

• • •

Pseu dostrati ed colu m n ar ep ith eliu m with cilia High ly vascu lar an d easily con gested W h en th is tissu e is irritated , its blood vessels ref exively d ilate an d th e glan d s secrete, n orm ally lead in g to sn eezin g

Sagittal section Ethmoidal cells Frontal sinus

O pening of sphenoidal sinus

O pening of frontonasal duct Sphenoidal sinus

Semilunar hiatus

Middle nasal concha (cut aw ay)

Uncinate process O pening of maxillary sinus Inferior nasal concha

Frontal sinus O pening into middle nasal meatus

O rbit

Pterygopalatine fossa

Maxillary sinus

Lateral dissection Roots of teeth

Figu re 11-1

276

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OVERVIEW AND TOPOGRAPHIC ANATOMY • General Information

11

Coronal section O lfactory bulbs

Cerebral falx Brain

Frontal sinus

Nasal cavities

O rbital fat

Nasal septum

Ethmoidal cells

Middle nasal concha

O pening of maxillary sinus

Middle nasal meatus

Infraorbital Zygomatic Alveolar

Maxillary sinus Inferior nasal meatus

Recesses of maxillary sinus

Buccinator muscle Alveolar process of maxilla

Inferior nasal concha

Body of tongue

Hard palate

Sublingual gland O ral cavity Mandible (body)

Nasal cavities Eyeball Nasal septum Ethmoidal cells Medial wall of orbit

O rbital fat and muscles

O ptic nerve (II) Sphenoidal sinuses Brain O ptic chiasm Horizontal section

Figu re 11-2

NO SE AND NASAL CAVITY 277

11

NOSE • Anatomy of the Nose • • • •

• •

• • • • • • • •

Th e n ose is p yram idal in orm Fractu res o th e n asal bon es are com m on —th ese are th e m ost req u en tly broken bon es in th e ace Th e op en in g in th e sku ll is th e p iri orm ap ertu re an d is bou n ded by 2 bon es: • Nasal • Maxilla 3 p airs o bones orm th e root o th e n ose: • Fron tal (n asal p rocess) • Maxilla ( ron tal p rocess) • Nasal Becau se th e root o th e n ose is m ad e o bon e, it is f xed 3 di eren t m ajor cartilages orm th e d orsu m an d ap ex o th e n ose: • Sep tal • Lateral n asal (u p p er n asal) • Major alar (lower n asal) Min or cartilages th at com p lete th e n ose are th e: • Lesser alar (3 to 4 cartilages) • Vom eron asal Becau se th e dorsu m an d ap ex are cartilagin ou s, th e n ose is q u ite m obile Th e cavity o th e n ose op p osite th e alar cartilage is called th e vestibu le an d is lin ed by m an y coarse h airs called vibrissae Th e skin over th e n ose is keratin ized stratif ed sq u am ou s ep ith eliu m Th e cavity p osterior to th e vestibu le is th e atriu m At th e ap ex are ou n d th e 2 n ostrils, or an terior n ares, wh ich are sep arated by th e sep tu m con n ectin g th e ap ex to th e p h iltru m o th e u p p er lip Fibrou s tissu e h elp s con n ect th e cartilages togeth er an d p osteriorly to th e m axilla Th e p rim ary lym p h atic d rain age o th e n ose is in to th e su bm an d ibu lar lym p h n od es

Superciliary arch Glabella Nasal bone Ala of nose Anterior nares (nostril) Commissure of lips

Philtrum Nasolabial sulcus Tubercle of superior lip

Figu re 11-3

278

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NOSE • Anatomy of the Nose Anterolateral view

11

Inferior view Major alar cartilage

Frontal bone Nasal bones

Lateral crus

Frontal process of maxilla Lateral process of septal nasal cartilages

Medial crus

Septal cartilage Minor alar cartilage Accessory nasal cartilage

Major alar cartilage

Lateral crus Medial crus

Alar fibrofatty tissue Septal nasal cartilage

Septal nasal cartilage Anterior nasal spine of maxilla Alar fibrofatty tissue Infraorbital foramen

Anterior nasal spine of maxilla Intermaxillary suture

Figu re 11-4

Vascular Supply of the Nose •

• • •

Th e blood su p p ly to th e n ose arises from 3 m ajor arteries: • Op h th alm ic • Maxillary • Facial Th ese vessels are derived from th e extern al an d in tern al carotid arteries Th ese arteries an astom ose alon g th e n ose Man y n osebleed s are d u e to trau m a to th e sep tal bran ch of th e su p erior labial artery from th e facial artery

Sources of arterial supply of face Black : from internal carotid artery (via ophthalmic artery) Red : from external carotid artery

Figu re 11-5

NO SE AND NASAL CAVITY 279

11

NOSE • Vascular Supply of the Nose ARTERIAL SUPPLY Artery

Source

Course

Ophthalm ic

Internal carotid a.

Enters the orbit through the optic foram en im m ediately inferior and lateral to the optic n. Crosses the optic n. to reach the m edial part of the orbit While in the orbit, besides other branches including the orbital vessels, it gives rise to 2 m ajor branches that supply the nose: • Dorsal nasal • External nasal from the anterior ethm oidal a.

Dorsal nasal

Ophthalm ic a.

1 of 2 term inal branches of the ophthalm ic a. Exits the orbit along the superom edial border along with the infratrochlear n. Supplies the area along the bridge of the nose

External nasal

Anterior ethm oid a.

A term inal branch of the anterior ethm oid a. Supplies the area along the external nose at the junction between the nasal bone and the lateral nasal cartilage

External carotid a.

Gives rise to a series of branches; only 1 provides blood supply to the nose: nasal branch of the infraorbital a.

Maxillary a.

Infraorbital is the continuation of the m axillary a. Arises with the inferior palpebral branch and the superior labial branch Supplies the lateral aspect of the nose

External carotid a.

Passes superiorly im m ediately deep to the posterior belly of the digastric m . and the stylohyoid m . Passes along the subm andibular gland, giving rise to the subm ental a., which helps supply the gland Passes superiorly over the body of the m andible at the m asseter, giving rise to the: • Prem asseteric a. Continues anterosuperiorly across the cheek to the angle of the m outh, giving rise to the: • Superior labial a. • Inferior labial a. Passes superiorly along the side of the nose, giving rise to the: • Lateral nasal a. Following the last branch, it continues on the side of the nose as the angular a. that term inates along the m edial side of the eye Tortuous

(Nasal) septal

Superior labial a.

Supplies the septum

Alar

Superior labial a.

Supplies the ala of the nose

Lateral nasal

Facial a.

Supplies the ala and dorsal surface of nose

Maxillary Nasal branch of the infraorbital

Facial

28 0 NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

NOSE • Vascular Supply of the Nose

11

Frontalis muscle Supraorbital artery and nerve Supratrochlear artery and nerve Procerus muscle Corrugator supercilii muscle Dorsal nasal artery Infratrochlear nerve Angular artery External nasal artery and nerve Nasalis muscle (transverse part) Infraorbital artery and nerve Lateral nasal artery Transverse facial artery Nasalis muscle (alar part) Depressor septi nasi muscle O rbicularis oris muscle Facial artery

Anterior lateral nasal branch External nasal branch of anterior ethmoidal artery Alar branches of lateral nasal branch (of facial artery)

Posterior lateral nasal branches of sphenopalatine artery Sphenopalatine artery

Anterior septal branch

Posterior septal branch of sphenopalatine artery

Maxillary artery External carotid artery Lesser palatine foramen and artery

Nasal septal branch of superior labial branch (of facial artery)

Greater palatine foramen and artery Lateral wall of nasal cavity

Figu re 11-6

NO SE AND NASAL CAVITY 281

11

NOSE • Vascular Supply of the Nose VENOUS DRAINAGE Vein

Course

Facial

Begins as the angular v. Passes inferiorly along the side of the nose, receiving the lateral nasal v. Continues in a posteroinferior path across the angle of the m outh to the cheek, receiving the superior and inferior labial vv. While passing toward the m andible, the deep facial v. connects the facial vein to the pterygoid plexus In the subm andibular triangle, the facial v. joins the anterior branch of the retrom andibular to form the com m on facial v. Has no valves that can allow blood to back ow

Angular

From the con uence of the supraorbital and supratrochlear vv. along the m edial part of the eye Travels along the lateral side of the nose to becom e the facial v.

Superior ophthalm ic

Receives blood from the roof of the orbit and the scalp Anastom oses with the angular v. Travels posteriorly to com m unicate with the pterygoid plexus

Inferior ophthalm ic

Receives blood from the oor of the orbit Anastom oses with the angular v. Travels posteriorly with the infraorbital v. that passes through the inferior orbital ssure to com m unicate with the pterygoid plexus

Supratrochlear vein Supraorbital vein Superior ophthalmic vein Angular vein

Pterygoid plexus

Superficial temporal vein and artery

Superior labial vein

Posterior auricular vein Deep facial vein Maxillary vein External jugular vein (cut)

Inferior labial vein Facial vein and artery

Common facial vein Submental vein Submandibular gland

Figu re 11-7

282

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NOSE • Nerve Supply of the Nose •

11

Th e sen sory su p p ly to th e n ose arises from bran ch es of th e op h th alm ic an d m axillary d ivision s of th e trigem in al n erve OPHTHALMIC DIVISION OF THE TRIGEMINAL Arises from the trigem inal in the m iddle cranial fossa Passes anterior on the lateral wall of the cavernous sinus im m ediately inferior to the oculom otor and trochlear nn., but superior to the m axillary division of the trigem inal n. Im m ediately prior to entering the orbit, through the superior orbital ssure, the ophthalm ic division divides into 3 m ajor branches: • Lacrim al • Frontal • Nasociliary The nasociliary branch term inates as the: • Anterior ethm oid n. • Infratrochlear n.

Nerve

Source

Course

External nasal

Anterior ethm oid n.

Exits between the lateral nasal cartilage and the inferior border of the nasal bone Supplies the skin of the ala and apex of the nose around the nares

Internal nasal

Infratrochlear

Supplies the skin on the internal surface of the vestibule as the: • Medial internal nasal n. • Lateral internal nasal n. Nasociliary n.

Passes anteriorly on the superior border of the m edial rectus m. Passes inferior to the trochlea toward the m edial angle of the eye Supplies the skin of the bridge of the nose Also supplies the eyelids, the conjunctiva, and all lacrim al structures

MAXILLARY DIVISION OF THE TRIGEMINAL Travels along the lateral wall of the cavernous sinus Passes from the m iddle cranial fossa into the pterygopalatine fossa via the foram en rotundum 4 branches: • Infraorbital—this is the continuation of the m axillary division • Posterior superior alveolar • Zygom atic • Ganglionic Infraorbital

Continuation of m axillary division of the trigem inal n.

Passes through the inferior orbital ssure to enter the orbit Passes anteriorly through the infraorbital groove and infraorbital canal and exits onto the face via the infraorbital foram en Once it exits onto the face, it divides into 3 term inal branches: • Nasal (supplies the ala of the nose) • Inferior palpebral (supplies the skin of the lower eyelid) • Superior labial (supplies the skin of the upper lip)

Nasal branch of the infraorbital

Infraorbital n.

Supplies the ala of the nose

NO SE AND NASAL CAVITY 283

11

NOSE • Nerve Supply of the Nose

Lacrimal gland

Infratrochlear nerve (from nasociliary nerve)

Anterior ethmoidal nerve

O phthalmic nerve (V1 )

External nasal branch of anterior ethmoidal nerve

Trigeminal (semilunar) ganglion Trigeminal nerve (V)

Nasal branch of infraorbital n.

Infraorbital nerve Mandibular nerve (V3 ) Maxillary nerve (V2 ) Efferent fibers Afferent fibers Proprioceptive fibers Parasympathetic fibers Sympathetic fibers

Ophthalmic nerve (V1 )

Trigeminal nerve (V) ganglion and nuclei

Anterior ethmoidal nerve Infratrochlear nerve Internal nasal branches and External nasal branches of anterior ethmoidal nerve

Maxillary nerve (V2 )

Mandibular nerve (V3 )

Figu re 11-8

284

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NOSE • Nerve Supply of the Nose

11

O lfactory nerves (I) O lfactory nerves (I)

Lateral internal nasal External nasal branches of anterior ethmoidal nerve (V1 ) Internal nasal branches of infraorbital nerve (V2 )

Nasopalatine nerve (V2 )

Medial internal nasal branches of anterior ethmoidal nerve (V1 )

Pterygopalatine ganglion

Posterior superior lateral nasal branch of maxillary nerve (V2 ) Posterior inferior lateral nasal branch of greater palatine nerve (V2 ) Lesser palatine nerves (V2 ) Greater palatine nerve (V2 ) Lateral wall of nasal cavity

Figu re 11-9

NO SE AND NASAL CAVITY 285

11

NASAL CAVITY • Anatomy • • •

Lin ed by p seu d ostratif ed colu m n ar ep ith eliu m with cilia In erior p ortion is larger th an su p erior p ortion Ol actory ep ith eliu m is located at th e su p erior p art o th e n asal cavity arou n d th e cribri orm p late

PIRIFORM APERTURE

•

An terior op en in g bou n ded by th e n asal bon es an d m axilla

NASAL SEPTUM

•

Freq u en tly d eviates to 1 side, givin g rise to u n eq u al ch am bers

LATERAL WALLS

• • • •

Com p osed o large ven ou s p lexu ses th at h ave th e ap p earan ce o erectile tissu e 3 large elevation s, kn own as con ch ae, p rotru de rom th e lateral wall All o th e p aran asal sin u ses an d th e n asolacrim al d u ct drain in to th e lateral walls o th e n asal cavity Th e sp h en op alatin e oram en , located in th e p osterior p ortion o th e lateral walls, con n ects th e n asal cavity to th e p terygop alatin e ossa

CHOANAE

•

Also kn own as th e p osterior n asal ap ertu res, th ese op en in gs con n ect th e n asal cavity to th e n asop h aryn x

Sphenoid bone Frontal bone

Lesser wing

Nasal bone

Greater wing

Lacrimal bone

Ethmoid bone O rbital plate

Zygomatic bone

Perpendicular plate Middle nasal concha Inferior nasal concha Vomer Mandible

Maxilla

Ramus

Anterior nasal spine

Body Sphenoethmoidal recess Hypophysis (pituitary gland) in sella turcica

Frontal sinus Superior nasal concha Superior nasal meatus Middle nasal concha

Sphenoidal sinus Pharyngeal tonsil (adenoid if enlarged) Basilar part of occipital bone

Middle nasal meatus Inferior nasal concha (turbinate)

Choana

Nasal vestibule

Torus tubarius O pening of pharyngotympanic (auditory) tube

Inferior nasal meatus Palatine process of maxilla

Pharyngeal recess Horizontal plate of palatine bone

Incisive canal

Figu re 11-10

28 6 NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

NASAL CAVITY • Boundaries and Relations of the Nasal Cavity

11

BOUNDARIES Border

Structure(s)

Superior

Nasal, frontal, cribriform plate of the ethm oid, body of the sphenoid

Inferior

Palatine process of the m axilla, horizontal plate of the palatine

Anterior

External nose

Posterior

Choanae (posterior nasal aperture)

Medial

Ethm oid (perpendicular plate), vom er, septal cartilage

Lateral

Maxilla, ethm oid, palatine, sphenoid (m edial pterygoid plate), and inferior nasal concha, lacrim al

RELATIONS Border

Structure(s)

Superior

Frontal sinus, sphenoid sinus, anterior cranial fossa with frontal lobe of the brain

Inferior

Palate, oral cavity

Medial

Other half of nasal cavity

Lateral

Maxillary sinus, ethm oid sinuses, orbit, and pterygopalatine fossa

Falx cerebri Cribriform plate of ethmoid bone Dura mater Sella turcica

Frontal sinus Sphenoidal sinus Nasal septum Choanae

Nasal vestibule Anterior nasal spine Incisive canal O ral cavity Tongue Soft palate

Sinus of frontal bone Nasal bone Vomer

Septal cartilage

Crista galli Cribriform plate Ethmoid bone Perpendicular plate Body Sphenoidal sinus Medial and Sphenoid Lateral bone plates of pterygoid process Basilar part of occipital bone Perpendicular plate

Anterior nasal spine

Posterior nasal spine Horizontal plate

Palatine bone

Incisive canal Palatine process

Figu re 11-11 NO SE AND NASAL CAVITY 287

11

NASAL CAVITY • Boundaries and Relations of the Nasal Cavity

Lacrimal bone Middle nasal concha Uncinate process

Sinus of frontal bone

Ethmoid bone

Cribriform plate Superior nasal concha Highest nasal concha Sphenoethmoidal recess

Nasal bone

Sphenopalatine foramen

Lateral process of septal nasal cartilage Major alar cartilage Alar fibrofatty tissue

Sphenoidal sinus Medial and Lateral plates of pterygoid process

Frontal process Anterior nasal spine Maxilla

Incisive canal

Pterygoid hamulus

Palatine process Alveolar process

Sphenoid bone

Perpendicular plate Horizontal plate

Inferior nasal concha

Palatine bone

Ethmoidal bulla Frontal sinus

O pening of middle ethmoidal cells Superior nasal concha (cut aw ay) O penings of posterior ethmoidal cells

Middle nasal concha (cut aw ay)

O pening of sphenoidal sinus

Infundibulum leading to frontonasal canal

O penings into maxillary sinus

Semilunar hiatus with openings of anterior ethmoidal cells

Sphenopalatine foramen

Uncinate process Ethmoidal process of inferior nasal concha

Inferior nasal concha (cut aw ay)

Lesser palatine foramen

O pening of nasolacrimal canal

Greater palatine foramen

Figu re 11-12

28 8 NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

NASAL CAVITY • Conchae of the Nasal Cavity Concha

Regions Drained

Location

Structures Drained

Superior

Sphenoethm oidal recess

Superior to the superior m eatus

Sphenoidal sinus

Superior m eatus

Inferior to the superior m eatus

Posterior ethm oid sinus

Middle

Middle m eatus

Inferior to the m iddle m eatus

Anterior ethm oidal sinus Middle ethm oidal sinus Maxillary sinus Frontal sinus

Inferior

Inferior m eatus

Inferior to the inferior m eatus

Nasolacrim al duct

11

Sphenoethmoidal recess O pening of sphenoidal sinus

Frontal sinus Superior nasal concha Superior nasal meatus Middle nasal concha

Sphenoidal sinus Middle nasal meatus Inferior nasal concha (turbinate)

Inferior nasal meatus

Frontal sinus Probe passing from semilunar hiatus into frontal sinus via frontonasal duct

Probe in opening of sphenoidal sinus Sphenoidal sinus Superior nasal meatus with opening of posterior ethmoidal cells

Middle nasal concha (cut surface) Ethmoidal bulla O penings of middle ethmoidal cells Semilunar hiatus with opening of anterior ethmoidal cells Inferior nasal concha (cut surface) O pening of nasolacrimal duct Inferior nasal meatus

O pening of maxillary sinus

Figu re 11-13

NO SE AND NASAL CAVITY 289

11

NASAL CAVITY • Conchae of the Nasal Cavity

O rbital part of lacrimal gland

Palpebral part of lacrimal gland

Lacrimal sac

Nasolacrimal duct

O pening of nasolacrimal duct

Lacrimal canaliculi

O rbital part of lacrimal gland

Lacrimal sac Palpebral part of lacrimal gland Nasolacrimal duct

Middle nasal concha

Nasal cavity Lacrimal caruncle Inferior nasal concha (cut)

O pening of nasolacrimal duct

Inferior nasal meatus

Figu re 11-14

29 0 NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

NASAL CAVITY • Vascular Supply of the Nasal Cavity •

• •

•

11

Th e blood su p p ly to th e n asal cavity arises from 3 m ajor arteries: • Op h th alm ic • Maxillary • Facial Th ese 3 vessels are derived from th e extern al an d in tern al carotid arteries an d gen erally follow th e p ath s of th e n erves Kiesselbach ’s p lexu s is th e an astom osis alon g th e n asal sep tu m form ed by: • An terior eth m oid a. • Sp h en op alatin e a. • Greater p alatin e a. • Sep tal bran ch from th e su p erior labial a. Th e veins gen erally corresp on d to th e arteries ARTERIAL SUPPLY Artery

Source

Course

Ophthalm ic

Internal carotid a.

Enters the orbit through the optic foram en im m ediately inferior and lateral to the optic n. Crosses the optic n. to reach the m edial part of the orbit While in the orbit, besides the orbital branches, it gives rise to 2 m ajor branches that supply the nasal cavity: • Anterior ethm oid • Posterior ethm oid

Anterior ethm oid

Ophthalm ic a.

Travels with the nasociliary n. through the anterior ethm oidal foram en Enters the anterior cranial fossa, where it gives rise to a m eningeal branch Continues its path to give rise to nasal branches that descend into the nasal cavity: • Lateral branch • Septal branch Supplies branches to the lateral wall and septum of the nose before giving rise to the external nasal a., which supplies the external nose

Posterior ethm oid

Ophthalm ic a.

Travels through the posterior ethm oidal foram en Enters the anterior cranial fossa, where it gives rise to a m eningeal branch Continues its path to give rise to nasal branches that descend into the nasal cavity through the cribriform plate: • Lateral branch • Septal branch Supplies part of the lateral wall near the superior nasal concha and the posterosuperior portion of the nasal septum

External carotid a.

Gives rise to a series of branches; 2 provide blood supply to the nasal cavity: • Sphenopalatine • Greater palatine

3rd part of the m axillary a.

After passing through the sphenopalatine foram en, enters the nasal cavity, where it gives rise to the posterior nasal branches: • The posterior lateral nasal branch supplies the nasal concha, m ucous m em branes, and lateral wall • The posterior septal branch continues along the nasal septum to enter the hard palate via the incisive canal

Maxillary

Sphenopalatine

Continued on next page

NO SE AND NASAL CAVITY 291

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NASAL CAVITY • Vascular Supply of the Nasal Cavity ARTERIAL SUPPLY Continued Artery Greater palatine

Facial

Superior labial

Source

Course

Descending palatine from the m axillary a.

Travels in the palatine canal, where it splits into the lesser palatine a. (supplies the soft palate and palatine tonsil), and greater palatine a., which exits the greater palatine foram en and passes anteriorly toward the incisive foram en (supplies the hard palate gingiva, m ucosa, and palatal glands) and anastom oses with the term inal branch of the sphenopalatine a. that exits the incisive foram en Also provides branches that supply the area of the inferior m eatus

External carotid a.

Tortuous Passes superiorly im m ediately deep to the posterior belly of the digastric and the stylohyoid m m . Passes along the subm andibular gland, giving rise to the subm ental a. that helps supply the gland Passes superiorly over the body of the m andible at the m asseter m . Continues anterosuperiorly across the cheek to the angle of the m outh, giving rise to the superior and inferior labial aa. Passes superiorly along the side of the nose, giving rise to the lateral nasal a. Continues on the side of the nose as the angular a. that term inates along the m edial aspect of the eye

Facial

Supplies the upper lip Gives rise to the septal branch that travels to the nasal septum The m ajor blood supply to the anterior part of the nasal septum

Superior view Supratrochlear artery Dorsal nasal artery Supraorbital artery Anterior meningeal artery Anterior ethmoidal artery

Posterior ciliary arteries

Posterior ethmoidal artery Lacrimal artery Central retinal artery O phthalmic artery Internal carotid artery

Figu re 11-15

292

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NASAL CAVITY • Vascular Supply of the Nasal Cavity

Anterior lateral nasal branch External nasal branch of anterior ethmoidal artery

Posterior lateral nasal branches of sphenopalatine artery Sphenopalatine artery

11

Anterior septal branch

Posterior septal branch of sphenopalatine artery

Alar branches of lateral nasal branch (of facial artery)

Lateral wall of nasal cavity

Maxillary artery External carotid artery Lesser palatine foramen and artery

Nasal septal branch of superior labial branch (of facial artery)

Greater palatine foramen and artery

Figu re 11-16

NO SE AND NASAL CAVITY 293

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NASAL CAVITY • Vascular Supply of the Nasal Cavity VENOUS DRAINAGE Vein

Course

• A well-developed cavernous plexus lies deep to the m ucous m em brane • The plexus drains into the following series of veins: Em issary

Vein from the cavernous plexus in the nasal cavity passes through the foram en cecum to drain into the superior sagittal sinus

Sphenopalatine

Blood from the venous plexus along the posterior portion of the nasal cavity drains to the sphenopalatine v. Travels through the sphenopalatine foram en to enter the pterygoid plexus

Anterior ethm oid

Blood from the venous plexus in the anterior portion of the nasal cavity drains into the anterior ethm oid, which term inates in the ophthalm ic v. and/ or facial v.

Posterior ethm oid

Blood from the venous plexus in the posterior portion of the nasal cavity drains into posterior ethm oid, which term inates in the ophthalm ic v. and/ or facial v.

Septal branch of the superior labial

Blood from the anterior portion drains into the septal branch of the superior labial, which drains into the facial v.

Anterior ethmoidal vein connecting to septum and plexus

Posterior ethmoidal veins connecting to septum and plexus Sphenopalatine vein

Pterygoid plexus Retromandibular vein Epithelium removed to visualize the nasal venous plexus over concha resembling erectile tissue

Figu re 11-17

294

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NASAL CAVITY • Nerve Supply of the Nasal Cavity •

11

2 m ajor typ es of sen sory in n ervation to th e n asal cavity: • Olfaction (sp ecial visceral afferen t) via th e olfactory n erve • Gen eral sen sation (gen eral som atic afferen t) via op h th alm ic an d m axillary d ivision s of th e trigem in al n erve

Efferent fibers Afferent fibers Proprioceptive fibers Parasympathetic fibers Sympathetic fibers

Ophthalmic nerve (V1 )

Trigeminal nerve (V) ganglion and nuclei

Posterior ethmoidal nerve Anterior ethmoidal nerve Infratrochlear nerve Internal nasal branches and External nasal branches of anterior ethmoidal nerve

Maxillary nerve (V2 ) Infraorbital nerve

Nasal branches (posterior superior lateral, nasopalatine, and posterior superior medial) Greater and lesser palatine nerves

Mandibular nerve (V3 )

Figu re 11-18

NO SE AND NASAL CAVITY 295

11

NASAL CAVITY • Nerve Supply of the Nasal Cavity Olfaction • The olfactory epithelium is found in the roof of the nasal cavity including the adjacent superior portions of the lateral wall of the nasal cavity and the nasal septum • Roughly 20 to 25 sm all olfactory n. bers, which collectively form the olfactory nerves per side, travel superiorly through the cribriform plate into the anterior cranial fossa to join the olfactory bulb

Cribriform plate of ethmoid bone

O lfactory bulb A. Distribution of olfactory epithelium (blue area)

Lateral nasal wall

Septum B. Schema of section through olfactory mucosa Cribriform plate Schwann cell O lfactory gland Unmyelinated olfactory axons Basement membrane Sustentacular cells Endoplasmic reticulum Nucleus O lfactory cells Dendrites Terminal bars (desmosomes) O lfactory rod (vesicle) Villi Cilia Mucus

Figu re 11-19

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11

OPHTHALMIC DIVISION OF THE TRIGEMINAL Sensory Arises from the m ain nerve in the m iddle cranial fossa Passes anterior on the lateral wall of the cavernous sinus im m ediately inferior to the oculom otor and trochlear nn., but superior to the m axillary division of the trigem inal n. Im m ediately before entering the orbit, through the superior orbital ssure, it divides into 3 m ajor branches: • Lacrim al • Frontal • Nasociliary The nasociliary branch term inates as the: • Anterior ethm oid n. • Infratrochlear n.

Nerve

Source

Course

Anterior ethm oid

Nasociliary n.

Enters the anterior ethm oid foram en and travels through the canal to enter the anterior cranial fossa While descending toward the nasal cavity, it provides innervation to the anterior parts of the m iddle and inferior conchae, as well as the region anterior to the nasal concha Speci cally, it supplies the skin on the internal surface of the nasal cavity as the: • Medial internal nasal n. • Lateral internal nasal n.

MAXILLARY DIVISION OF THE TRIGEMINAL Sensory Travels along the lateral wall of the cavernous sinus Passes from the m iddle cranial fossa into the pterygopalatine fossa via the foram en rotundum Within the pterygopalatine fossa, it gives rise to 4 branches: • Infraorbital—this is the continuation of the m axillary • Posterior superior alveolar • Zygom atic • Ganglionic Infraorbital

Continuation of m axillary division of the trigem inal n.

Passes through the inferior orbital ssure to enter the orbit Passes anteriorly through the infraorbital groove and infraorbital canal and exits onto the face via the infraorbital foram en While in the infraorbital canal, it gives rise to the: • Anterior superior alveolar n. The anterior superior alveolar n. has a sm all branch that supplies the nasal cavity in the region of the inferior m eatus and inferior corresponding portion of the nasal septum (in addition to supplying the m axillary sinus; the m axillary central incisor, lateral incisor, and canine teeth; and the gingiva and m ucosa alongside these teeth)

Nasopalatine

Pterygopalatine ganglion

Passes through the sphenopalatine foram en to enter the nasal cavity Passes along the superior portion of the nasal cavity to the nasal septum , where it travels anteroinferiorly to the incisive canal supplying the septum Continued on next page

NO SE AND NASAL CAVITY 297

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NASAL CAVITY • Nerve Supply of the Nasal Cavity MAXILLARY DIVISION OF THE TRIGEMINAL Continued Posterior inferior lateral nasal

Greater palatine

The greater palatine n. branches from the pterygopalatine ganglion in the pterygopalatine fossa It descends through the greater palatine canal to enter the hard palate via the greater palatine foram en While descending in the palatine canal, it gives rise to a: • Posterior inferior lateral nasal branch Supplies the posterior part of the lateral wall of the nasal cavity in the region of the m iddle m eatus

Posterior superior nasal

Pterygopalatine ganglion

Passes through the sphenopalatine foram en to enter the nasal cavity and branches into 2 nerves: • Posterior superior m edial nasal • Posterior superior lateral nasal

Posterior superior lateral nasal

Posterior superior nasal n. from the pterygopalatine ganglion

Supplies the posterosuperior portion of the lateral wall of the nasal cavity in the region of the superior and m iddle concha

Posterior superior m edial nasal

Supplies the posterior portion of the nasal septum

O lfactory nerves (I) O lfactory nerves (I) Lateral internal nasal External nasal branches of anterior ethmoidal nerve (V1 ) Internal nasal branches of infraorbital nerve (V2 )

Pterygopalatine ganglion

Nasopalatine nerve (V2 )

Sphenopalatine foramen (dissected aw ay) Nerve (vidian) of pterygoid canal

Nasal branch of anterior superior alveolar nerve (V2 )

Medial internal nasal branches of anterior ethmoidal nerve (V1 )

Posterior superior lateral nasal (V2 ) Greater and lesser palatine nerves (V2 ) Posterior inferior lateral nasal branch of greater palatine nerve (V2 ) Lesser palatine nerves (V2 )

Lateral wall of nasal cavity

Greater palatine nerve (V2 )

Figu re 11-20

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NASAL CAVITY • Nerve Supply of the Nasal Cavity Communicating branch

11

Anterior ethmoidal nerve

Posterior ethmoidal nerve

Supraorbital nerve Supratrochlear nerve

Long and short ciliary nerves

Lacrimal gland Ciliary ganglion

Infratrochlear nerve (from nasociliary nerve)

Lacrimal nerve Nasociliary nerve

Zygomaticotemporal nerve

Frontal nerve

Zygomaticofacial nerve O phthalmic nerve (V1 )

External nasal branch of anterior ethmoidal nerve

Trigeminal (semilunar) ganglion Trigeminal nerve (V)

Foramen rotundum

Infraorbital nerve

Foramen ovale

Anterior superior alveolar nerve

Mandibular nerve (V3 )

Nasal branch

Maxillary nerve (V2 )

Middle superior alveolar nerve

Zygomatic nerve Nerve (vidian) of pterygoid canal Pterygopalatine ganglion Greater and lesser palatine nerves

Infraorbital nerve entering infraorbital canal

Ganglionic branches to pterygopalatine ganglion Posterior superior alveolar nerve O lfactory bulb Cribriform plate O lfactory tract

Medial internal nasal branch of anterior ethmoidal nerve (V1 ) O lfactory nerves (I) Nasopalatine nerve (V2 ) Incisive canal

Nasal septum

Figu re 11-21

NO SE AND NASAL CAVITY 299

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NASAL CAVITY • Nerve Supply of the Nasal Cavity • •

Au ton om ic f bers are distribu ted th rou gh th e sen sory bran ch es o th e m axillary d ivision o th e trigem in al n erve via th e p terygop alatin e gan glion (p arasym p ath etics) an d th e su p erior cervical gan glion (sym p ath etics) Au ton om ics travel to th e glan d s an d blood vessels o th e n asal cavity AUTONOMIC INNERVATION Anatomic Pathway for Parasympathetics of the Nasal Cavity Characteristics of Cell Body

Type of Neuron

Name of Cell Body

Course of the Neuron

Preganglionic neuron

Superior salivatory nucleus

A collection of nerve cell bodies located in the pons Travel through the nervus interm edius of the facial nerve into the internal acoustic m eatus In the facial canal, the facial nerve gives rise to 2 parasym pathetic branches: • Greater petrosal n. • Chorda tym pani n.

Gre ate r Pe tro s al Ne rve Greater petrosal n. exits the hiatus for the greater petrosal n. toward the foram en lacerum , where it joins the deep petrosal n. (sym pathetics) to form the nerve of the pterygoid canal (vidian n.) Vidian n. passes through the pterygoid canal and enters the pterygopalatine fossa, where it joins with the pterygopalatine ganglion

Postganglionic neuron

Pterygopalatine ganglion

Pterygopalatine ganglion is a collection of nerve cell bodies located in the pterygopalatine fossa Postganglionic parasym pathetic bers that arise in the pterygopalatine ganglion are distributed to the ophthalm ic and m axillary divisions of the trigem inal n. to the: • Lacrim al gland • Nasal glands • Palatine glands • Pharyngeal glands • Paranasal sinus glands

Maxillary Divis io n Dis tributio n Postganglionic bers travel along the m axillary division of the trigem inal n. to be distributed along its branches that are located in the nasal cavity, oral cavity, and pharynx (e.g., nasopalatine, greater palatine) These bers innervate: • Nasal glands • Palatine glands • Pharyngeal glands • Paranasal sinus glands

Anatomic Pathway for Sympathetics of the Nasal Cavity Type of Neuron

Name of Cell Body

Preganglionic neuron

Interm ediolateral horn nucleus

Characteristics of Cell Body Collection of nerve cell bodies located in the lateral horn nucleus of the spinal cord between spinal segm ents T1 and T3 (and possibly T4)

Course of the Neuron Arise from the interm ediolateral horn nuclei from T1 to T3 (4) Travel through the ventral root of the spinal cord to the spinal nerve Enter the sym pathetic chain via a white ram us com m unicans Once in the sym pathetic chain, the preganglionic bers for the eye ascend and synapse with postganglionic bers in the superior cervical ganglion Continued on next page

300

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

NASAL CAVITY • Nerve Supply of the Nasal Cavity

11

AUTONOMIC INNERVATION Continued Anatomic Pathway for Sympathetics of the Nasal Cavity Type of Neuron

Name of Cell Body

Postganglionic neuron

Superior cervical ganglion

Characteristics of Cell Body Collection of nerve cell bodies located in the superior cervical ganglion, which is located at the base of the skull Postganglionic sym pathetic bers follow the internal carotid or external carotid a. to pass near their respective effector organs (e.g., nasal cavity)

Course of the Neuron Nas al Cavity, Paranas al Sinus e s , and Palate • Postganglionic sym pathetic bers follow both the internal and external carotid aa. • Postganglionic bers will form the internal carotid nerve, which travels along the internal carotid a. form ing the internal carotid plexus • Postganglionic sym pathetic bers from the internal carotid plexus branch in the region of the foram en lacerum to form the deep petrosal n. • The deep petrosal n. joins the greater petrosal n. (parasym pathetics) to form the nerve of the pterygoid canal (vidian n.) • Postganglionic sym pathetic bers travel along the branches of the m axillary division of the trigem inal n. associated with the pterygopalatine ganglion to be distributed along its branches in the nasal cavity, paranasal sinuses, and palate • Postganglionic sym pathetic bers from the external carotid branch and follow the m axillary a. • These bers travel along the branches of the m axillary a. to be distributed along the nasal cavity, paranasal sinuses, and palate

NO SE AND NASAL CAVITY 301

11

NASAL CAVITY • Nerve Supply of the Nasal Cavity

O culomotor nerve (III)

Internal carotid artery (cerebral part) Abducent nerve (VI) Artery and nerve of pterygoid canal O phthalmic nerve Sphenoidal sinus Maxillary nerve Pterygopalatine ganglion Ciliary ganglion O phthalmic artery Infraorbital nerve O ptic nerve (II) Maxillary ostium

Internal carotid artery (cavernous part) Trochlear nerve (IV) Superior petrosal sinus Trigeminal nerve (V) Greater petrosal nerve Internal carotid artery (petrosal part) and venous plexus Cochlea Anterior semicircular canal Inferior tympanic artery and tympanic nerve Facial nerve (VII) Stapedius Sigmoid sinus

C1

Mastoid cells Internal carotid nerve and sympathetic plexus

Maxillary artery Maxillary sinus

Inferior ganglion of glossopharyngeal nerve

Right medial pterygoid plate

Accessory nerve (XI)

Descending palatine artery

Inferior ganglion of vagus nerve

Greater and lesser palatine arteries and nerves

Hypoglossal nerve (XII) Internal jugular vein

Ascending pharyngeal artery Vagus nerve (X)

Glossopharyngeal nerve (IX) Common carotid artery

Superior cervical ganglion External carotid artery Internal carotid artery

Figu re 11-22

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NASAL CAVITY • Nerve Supply of the Nasal Cavity

11

Superior salivatory nucleus (parasympathetic) Facial nerve (VII) Geniculum Greater petrosal nerve (parasympathetic) Deep petrosal nerve (sympathetic) Nerve (vidian) of pterygoid canal Maxillary nerve (V2 ) entering foramen rotundum Pterygopalatine ganglion in pterygopalatine fossa Lateral and medial posterior superior nasal branches in pterygopalatine fossa Infraorbital nerve Posterior superior and inferior lateral nasal nerves (cut ends)

Tympanic cavity

Medulla oblongata Spinal cord Sympathetic trunk

Internal carotid nerve Greater and lesser palatine nerves

Internal carotid artery

Superior cervical ganglion

Posterior superior alveolar nerves

Maxillary sinus

Nasopalatine nerve

Postsynaptic fibers to vessels (sympathetic) and glands (parasympathetic) of nasal cavity, maxillary sinus and palate

T1 T2

Presynaptic parasympathetic fibers

T3

Postsynaptic parasympathetic fibers Presynaptic sympathetic fibers Presynaptic sympathetic cell bodies in intermediolateral nucleus (lateral horn) of gray matter

Postsynaptic sympathetic fibers

Figu re 11-23

NO SE AND NASAL CAVITY 303

11

CLINICAL CORRELATES • Epistaxis • •

Epistaxis, or n osebleed , is a h em orrh age rom th e n asal cavity or n ose Classif ed by bleedin g location : • An terior • Posterior

CAUSES

•

May be localized or system ic: • Trau m a (blows to th e ace, ractu res, n ose p ickin g) • Sin u s in ection s • Rh in itis • Arid en viron m en t • Hyp erten sion • Hem atologic d isord ers • Neop lasm s

ANTERIOR EPISTAXIS

• • • • • •

Th e m ost com m on orm (in abou t 90% o cases) Usu ally ou n d alon g th e n asal sep tu m an d resu lts rom bleed in g alon g Kiesselbach ’s p lexu s Man y n osebleed s are d u e to trau m a to th e sep tal bran ch o th e su p erior labial artery rom th e acial artery Typ ically m an aged with local p ressu re May be con trolled by m ean s o cau tery with a silver n itrate stick or with u se o an terior n asal p ackin g i bleed in g is p ersisten t With an terior ep istaxis, an oth er treatm en t, alth ou gh som ewh at d rastic, is sep tal d erm op lasty • Th e th in sep tal m u cosa is rep laced by a th icker gra t o skin • O ten u sed to treat n osebleed s cau sed by h ered itary h em orrh agic telan giectasia or sep tal p er oration s

POSTERIOR EPISTAXIS

• • •

304

Usu ally ou n d alon g th e p osterior p art o th e n asal cavity More d i f cu lt to treat; u se o p osterior n asal p ackin g or a balloon cath eter u su ally is su ccess u l Severe p osterior ep istaxis m ay req u ire ligation o th e m axillary artery

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

CLINICAL CORRELATES • Epistaxis

Cauterization of Anterior Nasal Bleeding

11

Placement of Anterior Pack 2 or 3 petrolatum gauze packs placed vertically side by side

Kiesselbach’s plexus on septum Suction

2.5” Silver nitrate stick

1”

Septal Dermoplasty for Recurrent Severe Anterior Epistaxis

A. Incision

B. Flap elevated exposing telangiectasia on septal mucosa

C. Septal mucosa excised in area of telangiectasia; perichondrium preserved

D. Split-thickness skin graft applied

E. Flap sutured; intranasal pack (finger cot) then applied over Silastic sheet

Transantral Ligation of Maxillary Artery

A. 3rd part of maxillary artery exposed via supragingival transantral approach

Maxillary nerve emerging from foramen rotundum Sphenopalatine artery clipped and divided Sphenopalatine artery entering sphenopalatine foramen to divide into posterior lateral nasal and posterior septal nasal arteries

Infraorbital nerve and artery Maxillary artery Post. sup. alveolar artery

Pterygopalatine ganglion (sphenopalatine) Nerve of pterygoid canal (vidian nerve) Palatine nerves and arteries

B. View through operating microscope

Figu re 11-24

NO SE AND NASAL CAVITY 305

11

CLINICAL CORRELATES • Deviated Septum •

Deviated septum : a severe sh i t o th e n asal sep tu m rom th e m id lin e

CAUSES

•

May be acq u ired or con gen ital: • Trau m a • Birth d e ects

CLINICAL MANIFESTATIONS

• •

Occlu sion o 1 sid e, eith er p artial or com p lete, p rod u cin g d i cu lty in breath in g or blocked air f ow on th at sid e May also cau se: • Sin u sitis • Ep istaxis • Nasal con gestion

TREATMENT

•

May be treated by sep top lasty

O rbital cavity Ethmoidal cells Middle turbinate Semilunar hiatus O rifice of maxillary sinus Infundibulum Maxillary sinus

Pus

Septum Inferior turbinate A. Septal bulge occluding airway unilaterally

C. Septum impinging on middle turbinate and causing pain via maxillary division of trigeminal nerve

E. Septum dislocated from maxillary crest

B. Septum occluding semilunar hiatus and obstructing outflow from maxillary sinus with resultant infection

D. S-shaped septal deformity occluding airway bilaterally

F. Excessive “wings” on maxillary crest

G. Anteroposterior S-shaped septal bulge (horizontal section)

Figu re 11-25

30 6 NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

CLINICAL CORRELATES • Rhinitis •

• •

11

Rhinitis: an in f am m ation o th e m u cosa o th e n asal cavity th at resu lts in : • Nasal con gestion • Sn eezin g • Rh in orrh ea • Nasal itch in g May in volve th e eyes, ears, sin u ses, an d th roat an d cau se h ead ach es Most com m on ly cau sed by allergic rh in itis

ALLERGIC RHINITIS

• • • •

Can be associated with n asal p olyp s, d eviated sep tu m , an d asth m a Cau sed by an allergen in d u cin g an im m u n oglobu lin E (IgE)-m ediated resp on se on th e m ast cells Becau se m ast cells are located on th e n asal m u cosa, an allergen can bin d to th e m ast cell, resu ltin g in th e release o h istam in es, p rostaglan d in s, cytokin es, an d leu kotrien es Typ ically treated with decon gestan ts, an tih istam in es, an d steroids

Mechanism of Type 1 (Immediate) Hypersensitivity Genetically atopic patient exposed to specific antigen (ragweed pollen illustrated)

Antigen Pollen

Disulfide bonds Heavy chain Fc fragment Light chain Fab fragment

Sensitization

Antigen-presenting cell (APC)

Nasal septum

Polyp

Polyp Nasal and sinus polyps common in allergic rhinitis

Middle turbinate

Polyp Endoscopic view of nasal polyp protruding from middle meatus

Nasal polyps most often bilateral in allergic sinusitis

Figu re 11-26

NO SE AND NASAL CAVITY 307

11

IMAGING Crista galli Perpendicular plate of the ethmoid Vomer

Maxillary sinus

Septal cartilage

Inferior nasal concha

Middle nasal concha

Sphenoid sinus

Maxillary sinus

Uncinate process

Inferior nasal concha

Concha bullosa

Maxillary sinus

Deviated septum

Maxillary sinus

Figu re 11-27

30 8 NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

Deviated septum

IMAGING Inferior concha Middle concha Superior concha

Paradoxical turbinate

Nasal polyp

Nasolacrimal duct

11

Nasal polyp

Nasolacrimal duct

Inferior concha

Figu re 11-28

NO SE AND NASAL CAVITY 309

This pa ge inte ntiona lly le ft bla nk

CHAPTER 12

PARANASAL SINUSES

Overview and Topographic Anatomy

312

Frontal Sinus

316

Ethmoid Sinus

320

Maxillary Sinus

325

Sphenoid Sinus

329

Clinical Correlates

333

12

OVERVIEW AND TOPOGRAPHIC ANATOMY • General Information • •

• • •

Th e paranasal sinuses are in vagin ation s from th e n asal cavity th at d rain in to sp aces associated with th e lateral n asal wall Th ere are 4 p aran asal sin u ses: • Fron tal • Maxillary • Eth m oid • Sp h en oid Each p aran asal sin u s is n am ed after th e bon e in wh ich it is located Each is lin ed by a resp iratory ep ith eliu m (p seu dostrati ed colu m n ar ep ith eliu m with cilia) Morp h ology of th e sin u ses is h igh ly variable

Section of nasal or sinus wall

Direction of mucociliary flow

Mucus (gel layer) Mucous gland

Mucus (sol layer) Ciliated cells Goblet cell

Submucosal capillary bed Venous sinus

Periosteum Bone

Arteriovenous (AV) shunt Artery Vein

Paranasal sinus infection that spreads to skull bones

Figu re 12-1

312

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OVERVIEW AND TOPOGRAPHIC ANATOMY • General Information

12

Frontal sinus Nasofrontal duct Ethmoid sinuses Nasal septum Middle meatus Infundibulum of maxillary sinus Uncinate process Natural ostium of maxillary sinus Maxillary sinus Middle turbinate Inferior meatus Frontal view

Coronal section

O stiomeatal complex

Figu re 12-2

FEATURES OF THE PARANASAL SINUSES Sinus

Location

Comment

Artery

Nerve

Frontal

Within frontal bone

Flattened triangular shape Manifests as a sm all outpouching at birth

Ophthalm ic branches

Ophthalm ic division of the trigem inal n.

Maxillary

Within m axillary bone

Pyram idal shape Sm all sinus is present at birth

Maxillary branches

Maxillary division of the trigem inal n.

Ethm oid

Within ethm oid bone

3 to 18 irregularly shaped cells Sm all sinus is present at birth

Ophthalm ic and m axillary branches

Sphenoid

Within sphenoid bone

Cuboid shape No pneum atization at birth

Ophthalm ic and m axillary divisions of the trigem inal n.

PARANASAL SINUSES

313

12

OVERVIEW AND TOPOGRAPHIC ANATOMY • General Information

Frontal sinus Maxillary sinus

Sphenoid sinus

Ethmoid sinuses

Superior view

O ptic chiasm Internal carotid artery Cavernous sinus Intercavernous portion of internal carotid artery Sphenoid sinus Posterior ethmoid air cells Frontal sinus Anterior ethmoid air cells Natural ostium of maxillary sinus Maxillary sinus Lateral view (orbital aspect)

Figu re 12-3

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OVERVIEW ANDTOPOGRAPHICANATOMY • Drainage ofthe Paranasal Sinuses and Associated Structures • •

12

All p aran asal sin u ses d rain in to th e n asal cavity Differen t sin u ses serve as drain age con d u its for differen t region s

SUMMARY OF PARANASAL SINUS DRAINAGE Region Drained

Location

Structure(s) Drained

Sphenoethm oidal recess

Superior to the superior concha

Sphenoid sinus

Superior m eatus

Inferior to the superior concha

Posterior ethm oid sinus

Middle m eatus

Inferior to the m iddle concha

Anterior ethm oid sinus Middle ethm oid sinus Maxillary sinus Frontal sinus

Inferior m eatus

Inferior to the inferior concha

Nasolacrim al duct

Anatomy of the nose O rifice of sphenoidal sinus Cut edge of superior turbinate O rifices of posterior ethmoidal cells

Frontal sinus Sphenoidal sinus Cribriform plate of ethmoid

Cut edge of middle turbinate O rifice of frontal sinus Uncinate process Ethmoidal bulla Semilunar hiatus O rifices of ant. ethmoidal cells in infundibulum O rifices of middle ethmoidal cells Cut edge of inferior turbinate O rifice of maxillary sinus

O rifice of auditory (eustachian) tube

O rifice of nasolacrimal duct

Sinus representing 1 or more anterior air cells of ethmoid bone opening into hiatus semilunaris of middle meatus Sinus representing 1 or more middle air cells of ethmoid bone opening into middle meatus Portion of nasolacrimal Frontal bone Sinuses representing 2 or more posterior air cells duct that formed of ethmoid bone opening into superior meatus in depths of Sphenoid sinus within a bony shell (sphenoid concha) naso-optic furrow located anterior and lateral to body of sphenoid bone Nasal bone Broken line outlines portion lateral to sphenoid body Body of sphenoid bone Lacrimal bone Hypophyseal fossa Nasolacrimal foramen (becomes Vestigial remnant a bony canal) of Rathke’s pouch Portion of Medial pterygoid nasolacrimal duct lamina of within nasal cavity sphenoid bone with slitlike opening in Lower border of supreme concha inferior meatus Lower border of superior concha Maxilla Superior meatus Palatine bone Uncinate process Cut edge of middle concha (inferior of ethmoid bone concha completely removed) Hiatus semilunaris Hamulus Bones of nasal cavity and nasal sinuses

Maxillary sinus with opening into hiatus semilunaris (striped arc represents membrane forming most of medial wall of sinus)

Figu re 12-4 PARANASAL SINUSES

315

12

FRONTAL SINUS • General Information • • • • • • •

• • •

Th e 2 frontal sinuses typ ically are asym m etric Usu ally n ot p resen t at birth , or th ere is a sm all ou tp ou ch in g Th e m ost com m on of th e p aran asal sin u ses to u n dergo ap lasia Is th e last p aran asal sin u s to begin to p n eu m atize—begin n in g arou n d th e 2n d year Usu ally well d evelop ed by th e age of 7 or 8 years A p rim e exp an sion in size occu rs wh en th e 1st d ecid u ou s m olars eru p t an d an oth er wh en th e p erm an en t m olars begin to ap p ear at abou t age 6 Th e ad u lt fron tal sin u s h as 2 exten sion s: • Fron tal—wh ich exten d s su p eriorly in to th e fron tal bon e in th e region of th e foreh ead • Orbital—wh ich exten d s p osteriorly in to th e fron tal bon e over th e m ed ial p art of th e orbit Drain age varies; m ay d rain in fron t of, above, or in to th e eth m oid al in fu n dibu lu m Prim ary lym p h atic d rain age is to th e su bm an d ibu lar lym p h n od es Th e fron tal sin u s receives its n erve su p p ly from bran ch es of th e op h th alm ic d ivision of th e trigem in al n erve

RELATIONS OF SINUS

• • • • •

Superior: an terior cran ial fossa an d con ten ts Inferior: orbit, an terior eth m oid al sin u ses, n asal cavity Anterior: foreh ead , su p erciliary arch es Posterior: an terior cran ial fossa an d con ten ts Medial: oth er fron tal sin u s

LOCATION OF OSTIUM

•

Mid dle m eatu s

Sagittal section

Frontal sinus

Frontal sinus

Ethmoid sinuses O pening of frontonasal duct Semilunar hiatus Uncinate process

Inferior nasal concha

Frontal view

Figu re 12-5

316

O pening of sphenoidal sinus Sphenoidal sinus Middle nasal concha (cut aw ay)

O pening of maxillary sinus Maxillary sinus

Ethmoidal cells

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

FRONTAL SINUS • Arterial Supply Artery

Source

Course

Anterior ethm oid

Ophthalm ic a. (from the internal carotid a.)

Enters the anterior ethm oid foram en with the nerve to pass through the canal At this location, it supplies the anterior and m iddle ethm oid air cells and the frontal sinus

Supraorbital

12

Branches from the ophthalm ic a. when crossing the optic n. Ascends m edial to both the levator palpebrae superioris and the superior rectus m m . At this location, it runs with the supraorbital n. and is found between the levator palpebrae superioris m . and the periosteum of the orbit Travels to the supraorbital foram en (notch) At the level of the supraorbital m argin, it supplies the frontal sinus

Superior view Supratrochlear a. Dorsal nasal a. Supraorbital a. Anterior ethmoidal a.

Posterior ciliary aa.

Posterior ethmoidal a. Lacrimal a. Central retinal a. O phthalmic a. Internal carotid a.

Supratrochlear a. Supraorbital a.

Lacrimal a.

Anterior ethmoidal a.

O ptic nerve O phthalmic a.

Long ciliary aa.

Central artery of the retina Posterior ethmoidal a.

Figu re 12-6

PARANASAL SINUSES

317

12

FRONTAL SINUS • Nerve Supply Nerve

Source

Course

Supraorbital

Ophthalm ic division of the trigem inal n.

Passes between the levator palpebrae superioris m . and periosteum of the orbit Continues anteriorly to the supraorbital foram en (notch) At the level of the supraorbital m argin, it sends nerve supply to the frontal sinus

Medial branch Supraorbital n. Lateral branch

Superior view Supratrochlear n.

Lacrimal n.

Infratrochlear n.

Frontal n.

Nasociliary n.

O phthalmic n. (V1 )

Supratrochlear n. Supraorbital n. Infratrochlear n.

O ptic nerve Lacrimal n. Frontal n. Nasociliary n. Ciliary ganglion with short ciliary nn.

Anterior ethmoidal n.

Long ciliary n.

Posterior ethmoidal n. Central artery of the retina

Figu re 12-7

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FRONTAL SINUS • Imaging

Eyes

12

Frontal sinus

Frontal sinus

Frontal sinus

Figu re 12-8

PARANASAL SINUSES

319

12

ETHMOID SINUS • General Information • • • • • • • • • •

Eth m oid sin u ses form with in th e eth m oid as m an y in divid u al air cells An atom ically th ey are located between th e su p erior p ortion of th e n asal cavity an d th e orbit, an d th e su rrou n d in g bon e is very th in From 3 to 18 total eth m oid air cells m ay be p resen t on each side Divid ed in to an an terior an d a p osterior grou p , or in to an terior, m id dle, an d p osterior grou p s, by d ifferen t au th ors Th e m ost an terior eth m oid sin u s is called th e agger n asi Th e eth m oid al bu lla, wh ich p rotru d es from th e lateral wall of th e n asal cavity, rep resen ts th e largest grou p of eth m oid al air cells Th e m ost p osterior grou p of eth m oidal air cells is closely related to th e orbit Eth m oid air cells m ay in vad e an y of th e oth er 3 sin u ses Th e m id d le eth m oid air cells p rod u ce th e swellin g on th e lateral wall of th e m id d le m eatu s called th e eth m oid bu lla Prim ary lym p h atic drain age is to th e su bm an d ibu lar lym p h n od es for th e an terior an d m idd le eth m oid sin u ses, an d th e retrop h aryn geal lym p h n od es for th e p osterior eth m oid sin u s

RELATIONS OF SINUS

• • •

Superior: an terior cran ial fossa an d con ten ts, fron tal bon e with sin u s Medial: n asal cavity Lateral: orbit

LOCATION OF OSTIUM

• • •

Anterior: m id d le m eatu s (fron ton asal d u ct or eth m oid al in fu n d ibu lu m ) Middle: m id d le m eatu s (on or above eth m oid bu lla) Posterior: su p erior m eatu s

Sagittal section Ethmoidal cells Frontal sinus

O pening of sphenoidal sinus

O pening of frontonasal duct Sphenoidal sinus

Semilunar hiatus

Middle nasal concha (cut aw ay)

Uncinate process O pening of maxillary sinus Inferior nasal concha

Figu re 12-9

320

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ETHMOID SINUS • General Information

12

Horizontal section

Nasal cavity

Ethmoidal cells Periorbita Medial rectus muscle and fascial sheath

O ptic nerve (II) and outer sheath Sphenoidal sinus

Frontal section

Periorbita Lacrimal gland Ethmoidal cell

Infraorbital nerve (V2 )

Retrobulbar fat (orbital fat body)

Figu re 12-10

PARANASAL SINUSES 321

12

ETHMOID SINUS • Arterial Supply Artery

Source

Course

Anterior ethm oid

Ophthalm ic a. (from the internal carotid)

Enters the anterior ethm oid foram en with the nerve to pass though the canal There it supplies the anterior and m iddle ethm oid air cells and som etim es the frontal sinus

Posterior ethm oid

Posterior lateral nasal branches

Passes through the posterior ethm oid foram en to enter the canal There it supplies the posterior ethm oid air cells and sphenoid sinus Sphenopalatine a. (from the m axillary a. from the external carotid a.)

Anastom ose with the ethm oidal arteries to help supply the ethm oid air cells and sphenoid sinus

Anterior ethmoidal a.

Posterior ethmoidal a.

Branch of posterior ethmoidal a. supplying the sphenoidal sinus

Branch of posterior lateral nasal a. supplying the sphenoidal sinus

Sphenopalatine a. Posterior lateral nasal a.

Branch of posterior lateral nasal a. supplying the posterior ethmoidal sinus

Figu re 12-11

322

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

ETHMOID SINUS • Nerve Supply Nerve

Source

Course

Anterior ethm oid

Nasociliary n. on the m edial wall of the orbit (from the ophthalm ic division of the trigem inal n.)

Enters the anterior ethm oid foram en and travels through the canal to enter the anterior cranial fossa While descending toward the nasal cavity, it provides innervation to the anterior and m iddle ethm oid air cells

Posterior ethm oid

Posterior lateral superior nasal

12

Enters the posterior ethm oid foram en to supply the posterior ethm oid air cells Also innervates the sphenoid sinus at this location Pterygopalatine ganglion in the pterygopalatine fossa (from the m axillary division of the trigem inal n.)

Passes through the sphenopalatine foram en to enter the nasal cavity Branches supply the posterior ethm oid air cells at this location

Superior view: levator palpebrae superioris, superior rectus, and superior oblique muscles partially cut away

Long ciliary nn. Short ciliary nn. Lacrimal n.

Supratrochlear nerve (cut)

Ciliary ganglion

Supraorbital nerve branches (cut) Infratrochlear n. Anterior ethmoidal n. Posterior ethmoidal n. Nasociliary n.

Lacrimal n. Frontal n. (cut) O phthalmic n. (V1 )

Anterior ethmoidal n. Posterior ethmoidal n. Branch of posterior ethmoidal n. supplying the sphenoidal sinus Branch of posterior lateral superior nasal n. supplying posterior ethmoidal sinus Pterygopalatine ganglion Nerve of the pterygoid canal Nasopalatine n. Posterior lateral superior nasal n. Lesser palatine n. Greater palatine n. Branch of posterior lateral inferior nasal a. from the greater palatine n. supplying the posterior ethmoidal sinus

Figu re 12-12

PARANASAL SINUSES 323

12

ETHMOID SINUS • Imaging

Ethmoid sinus Ethmoid sinus

Ethmoid sinus

Ethmoid sinusitis

Ethmoid sinus

Sphenoid sinus

Figu re 12-13

324

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

MAXILLARY SINUS • General Information • • • • • • • •

12

Th e m axillary sinus (also referred to as th e an tru m of High m ore) is a large p yram idal cavity th at is p resen t at birth Pn eu m atization occu rs rap idly d u rin g th e early years, with th e oor of th e sin u s bein g su p erior to th e u n eru p ted p erm an en t teeth As th e p erm an en t teeth eru p t in to th e oral cavity, th e m axillary sin u s p n eu m atizes in to th e alveolar bon e Th e ep ith eliu m of th e m axillary sin u s is often called th e Sch n eiderian m em bran e in clin ical texts Becau se th e oor of th e adu lt m axillary sin u s typ ically is in close p roxim ity to th e roots of th e m axillary m olars an d p rem olars, it is n ot u n com m on for a m axillary sin u s in fection to m an ifest as tooth p ain (via referred p ain ) Th e m axillary sin u s ten d s to be m ore p ron e to sin u s in fection s becau se th e ostiu m is located at th e su p erior p art of th e sin u s Th e m axillary sin u s is th in -walled an d m ay be d ivid ed by sep ta Prim ary lym p h atic d rain age is to th e su bm an d ibu lar lym p h n od es

RELATIONS OF SINUS

• • • • •

Superior: orbit, in fraorbital n erve an d vessels Inferior: roots of m olars an d p rem olars Medial: n asal cavity Lateral and anterior: ch eek Posterior: in fratem p oral fossa, p terygop alatin e fossa an d con ten ts

LOCATION OF OSTIUM

•

Mid dle m eatu s

Brain

O pening into middle nasal meatus

O rbit

Maxillary sinus Pterygopalatine fossa

Frontal sinus

Nasal cavity Zygoma

O rbit

Antrum Inferior nasal concha Buccinator muscle Vestibule of mouth Geniohyoid muscle Hyoglossus muscle Mylohyoid muscle Submandibular gland

Roots of teeth Lateral dissection

Digastric muscle Vertical (frontal) section

Platysma

Figu re 12-14

PARANASAL SINUSES 325

12

MAXILLARY SINUS • Arterial Supply Artery

Source

Course

Anterior superior alveolar

Maxillary a. from the external carotid a.

Arises from the infraorbital a. of the m axillary a. after it passes through the inferior orbital ssure and into the infraorbital canal Descends via the alveolar canals to supply the sinus

Middle superior alveolar

When present, it arises from the infraorbital a. of the m axillary a. after passing through the inferior orbital ssure and into the infraorbital canal Descends via the alveolar canals to supply the sinus

Posterior superior alveolar

Arises from the 3rd part of the m axillary a. before the m axillary a. enters the pterygopalatine fossa Enters the infratem poral surface of the m axilla to supply the sinus

O phthalmic artery Maxillary artery

Angular artery

Superficial temporal artery

Infraorbital artery Superior alveolar arteries

Posterior Middle Anterior

Facial nerve Inferior alveolar artery and nerve Sphenomandibular ligament

Facial artery Mental branch of inferior alveolar artery

External carotid artery Facial artery Lingual artery

Submental artery

Figu re 12-15

326

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

MAXILLARY SINUS • Nerve Supply Nerve

Source

Course

Anterior superior alveolar

Infraorbital n., which is the continuation of the m axillary division of the trigem inal n.

Branches from the infraorbital n. as it travels in the infraorbital canal As it descends to form the superior dental plexus, it innervates part of the m axillary sinus

Middle superior alveolar

Posterior superior alveolar

12

When present, it branches from the infraorbital n. as it travels in the infraorbital canal As it descends to form the superior dental plexus, it innervates part of the m axillary sinus Maxillary division of the trigem inal n.

Arises in the pterygopalatine fossa Travels laterally through the pterygom axillary ssure to enter the infratem poral fossa Enters the infratem poral surface of the m axilla As it descends to form the superior dental plexus, it innervates part of the m axillary sinus

O phthalmic nerve (V1 ) Trigeminal (semilunar) ganglion Trigeminal nerve (V)

Infraorbital nerve Anterior superior alveolar nerve Mandibular nerve (V3 )

Middle superior alveolar nerve

Maxillary nerve (V2 )

Mucous membrane of maxillary sinus Dental and gingival branches Pterygopalatine ganglion Infraorbital nerve entering infraorbital canal

Posterior superior alveolar nerve

Figu re 12-16 PARANASAL SINUSES

327

12

MAXILLARY SINUS • Imaging Maxillary sinus*

*Root of 3rd m axillary m olar protruding into sinus

Nasolacrimal duct Maxillary sinus O stium of maxillary sinus

Uncinate process Maxillary sinus

Figu re 12-17

328

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SPHENOID SINUS • General Information • • • • •

12

Th e sphenoid sinus con sists of 2 large, irregu larly sh ap ed cavities Sep arated by an irregu lar sep tu m Pn eu m atization begin s arou n d 7 to 8 m on th s after birth Sp h en oid sin u s an atom y is im p ortan t in tran ssp h en oid al ap p roach es to th e p itu itary glan d Prim ary lym p h atic d rain age is to th e retrop h aryn geal lym p h n od es

RELATIONS OF SINUS

• • • • •

Superior: h yp op h yseal fossa, p itu itary glan d , op tic ch iasm Inferior: n asop h aryn x, p terygoid can al Medial: oth er sp h en oid bon e Lateral: cavern ou s sin u s, in tern al carotid artery, cran ial n erves III, IV, V1 , V2 , an d VI Anterior: n asal cavity

LOCATION OF OSTIUM

•

Sp h en oeth m oid al recess

Coronal section through cavernous sinus

Cavernous sinus

O ptic chiasm Posterior communicating artery

O culomotor nerve (III) Trochlear nerve (IV)

Internal carotid artery

Abducens nerve (VI) O phthalmic nerve (V1 )

Hypophysis (pituitary gland)

Maxillary nerve (V2 )

Sphenoidal sinus Pterygoid canal Vidian nerve Artery of pterygoid canal

Nasopharynx Anatomy and relations of the pituitary gland

O ptic chiasm Diaphragma sellae Pituitary gland Sphenoidal sinus Nasal septum Nasopharynx

Figu re 12-18 PARANASAL SINUSES 329

12

SPHENOID SINUS • Arterial Supply Artery

Source

Course

Posterior ethm oid

Ophthalm ic a. (from the internal carotid a.)

Passes through the posterior ethm oid foram en to enter the canal There it supplies the sphenoid sinus and the posterior ethm oid air cells

Posterior lateral nasal branches

Sphenopalatine a. from the m axillary a. (from the external carotid a.)

These branches anastom ose with the ethm oidal arteries to help supply the sphenoid sinus and the ethm oid air cells

Branch of posterior ethmoidal a. supplying the sphenoidal sinus

Branch of posterior lateral nasal a. supplying the sphenoidal sinus Sphenopalatine a.

Posterior lateral nasal a.

Figu re 12-19

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SPHENOID SINUS • Nerve Supply Nerve

Source

Course

Posterior ethm oid

Ophthalm ic division of the trigem inal n.

A branch of the nasociliary n. that lies on the m edial wall of the orbit Enters the posterior ethm oid foram en to supply the sphenoid sinus Also innervates the posterior ethm oid air cell at this location

Orbital branch from the pterygopalatine ganglion

Maxillary division of the trigem inal n.

Orbital branches arising from the pterygopalatine ganglion enter the orbit through the inferior orbital ssure Som e of these branches supply the sphenoid sinus at this location, but this is m ainly for secretom otor function

12

Branch of posterior ethmoidal n. supplying the sphenoidal sinus Pterygopalatine ganglion

O rbital branch from the pterygopalatine ganglion supplying the sphenoidal sinus arising from the deep surface

Nerve of the pterygoid canal

Nasopalatine n. Posterior lateral superior nasal n. Lesser palatine n. Greater palatine n.

Figu re 12-20

PARANASAL SINUSES 331

12

SPHENOID SINUS • Imaging Sphenoid sinus

Pituitary gland

Sphenoid sinus

Sphenoid sinus

Sphenoid sinus

Pituitary adenoma

Figu re 12-21

332

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CLINICAL CORRELATES • Sinusitis • • •

12

Sinusitis: an in am m ation of th e m em bran e of th e sin u s cavities cau sed by in fection s (by bacteria or viru ses) or n on in fectiou s m ean s (su ch as allergy) 2 typ es of sin u sitis: acu te an d ch ron ic Com m on clin ical m an ifestation s in clu d e sin u s con gestion , d isch arge, p ressu re, face p ain , h ead ach es

ACUTE SINUSITIS

• • • •

Th e m ost com m on form of sin u sitis Typ ically cau sed by a cold th at resu lts in in am m ation of th e sin u s m em bran es Norm ally resolves in 1 to 2 weeks Som etim es a secon dary bacterial in fection m ay settle in th e p assageways after a cold ; bacteria n orm ally located in th e area (Streptococcus pneum oniae an d Haem ophilus inf uenzae) m ay th en begin to in crease, p rod u cin g an acu te bacterial sin u sitis

CHRONIC SINUSITIS

• • • •

An in fection of th e sin u ses th at is p resen t for lon ger th an 1 m on th an d req u ires lon ger-d u ration m ed ical th erap y Typ ically eith er ch ron ic bacterial sin u sitis or ch ron ic n on in fectiou s sin u sitis Ch ron ic bacterial sin u sitis is treated with an tibiotics Ch ron ic n on in fectiou s sin u sitis often is treated with steroids (top ical or oral) an d n asal wash es

LOCATIONS

• • • •

Maxillary: th e m ost com m on location for sin u sitis; associated with all of th e com m on sign s an d sym p tom s bu t also resu lts in tooth p ain , u su ally in th e m olar region Sp h en oid : rare, bu t in th is location can resu lt in p roblem s with th e p itu itary glan d , cavern ou s sin u s syn d rom e, an d m en in gitis Fron tal: u su ally associated with p ain over th e foreh ead an d p ossibly fever; rare com p lication s in clu d e osteom yelitis Eth m oid : p oten tial com p lication s in clu d e m en in gitis an d orbital cellu litis

Tooth pain Areas of pain and tenderness Fever (green). Pain caused by pressure in obstructed sinus

Figu re 12-22 PARANASAL SINUSES 333

12

CLINICAL CORRELATES • Sinusitis

Allergy Infection Inflammation

Structural abnormalities Mucosal congestion

Anoxia in sinus increases mucosal hypoxia, edema, and fluid leakage

O utflow obstruction decreases mucociliary clearance, resulting in pooling of secretions

O bstruction of ostiomeatal complex or sinus ostia

O bstruction

Sinus obstruction

O2 O bstruction decreases oxygen in sinus

Fluid

Inflamed mucous membrane Chronic sinusitis

Antibiotics drainage

Bacterial infection of stagnant secretions causes acute sinusitis

Maxillary inflammation

Concha bullosa

Figu re 12-23

334

Resolution of obstruction and infection

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

CLINICAL CORRELATES • Potential Spread of Infection via the Paranasal Sinuses

12

Direct extension Venous spread Arterial spread

Routes of spread of sinus infection to orbit

Pituitary gland O culomotor n. (III) Trochlear n. (IV) Abducens n. (VI) Trigeminal n. (V)

Cross section of cavernous sinus

Anterior spread (Pott’s puffy tumor)

O steomyelitis

Posterior spread (epidural abscess)

Posterior spread (subdural abscess) Venous spread (frontal lobe abscess)

Cerebral and dural abscesses

Routes of intracranial spread of frontal sinusitis

Figu re 12-24

PARANASAL SINUSES 335

12

CLINICAL CORRELATES • Surgical Procedures FRONTAL SINUS OBLITERATION

• • •

In a frontal sinus obliteration p roced u re, th e fron tal sin u s is com p letely rem oved to treat p roblem atic cases of fron tal sin u s in fection , osteom yelitis, an d trau m a On ce th e sin u s is op en ed , all of th e sin u s m em bran e is rem oved with a bu rr; oth erwise, an y rem ain in g m em bran e m ay form a m u cocele Th e rem ain in g area often is lled with adip ose tissu e from th e p atien t becau se it is th ou gh t to im p ede regrowth of th e m u cop eriosteu m

Frontal sinus opened and diseased mucous membrane stripped. Mucosal remnants removed with burr

Mucosal remnants

Burr

Bone flap closed

Frontal sinus

Nasofrontal duct

Skin flap Bone flap (anterior wall of frontal sinus)

Figu re 12-25

336

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

Adipose tissue

Stripped sinus packed with adipose tissue

CLINICAL CORRELATES • Surgical Procedures

12

CALDWELL-LUC PROCEDURE

• • • •

Th e in traoral Caldwell-Luc procedure allows d irect en try in to th e m axillary sin u s Also p rovid es access to th e eth m oid sin u s Th e m axillary sin u s is en tered th rou gh th e can in e fossa above th e m axillary p rem olar teeth Th e m axillary an tru m is op en ed , th e sin u s m em bran e is strip p ed , an d an ad dition al an trostom y is m ade between th e m axillary sin u s an d th e in ferior m eatu s

Conditions Treated

• • • •

Th e an trostom y allows d rain age of th e m axillary sin u s in to th e n asal cavity With th e adven t of fu n ction al en doscop ic sin u s su rgery for an trostom ies, th e Cald well-Lu c p roced u re often is u sed for exp osu re an d rem oval of tu m ors Used to be com m on ly p erform ed to treat ch ron ic m axillary sin u sitis Was also u sed for p rocedu res su ch as rem oval of ben ign tu m ors an d foreign bod ies, access to th e p terygop alatin e fossa, an d closu re of d en tal stu las in to th e m axillary sin u s

Diseased mucous membrane

Clinical appearance of opened sinus after stripping Infraorbital nerve

Nasoantral window

Sinus opened and diseased mucous membrane stripped Nasoantral window

O romaxillary opening

Interior of maxillary sinus

Nasoantral window created and oromaxillary opening closed

Ethmoid inflammation

Nasoantral window

Figu re 12-26

PARANASAL SINUSES

337

12

CLINICAL CORRELATES • Surgical Procedures MAXILLARY IMPLANTS

• • • • •

Placem en t of m axillary im plants is a com m on d en tal p roced u re to ad d xed m axillary teeth to th e oral cavity Patien t sh ou ld be in relatively good h ealth Patien t m u st h ave su f cien t bon e in a location su itable for p lacem en t of an im p lan t It is becom in g m ore com m on to u se bon e graftin g before th e su rgical im p lan t is p laced Bon e grafts to p rovid e ad eq u ate bed for im p lan ts m ay be h arvested from th e bod y or as allografts, or m ay be su p p lied as xen ografts or syn th etic bon e su bstitu tes

Maxillary implants before teeth are placed

Maxillary implants after teeth are placed on the implant

Nasopalatine canal Maxillary implant

Figu re 12-27

338

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CLINICAL CORRELATES • Surgical Procedures

12

SINUS LIFT PROCEDURE

• • • • • • •

•

A sinus lift procedure is also called m axillary sin u s au gm en tation It is a su rgical p roced u re im p ortan t for m axillary den tal im p lan ts W h en teeth are lost, th e alveolar bon e is resorbed, wh ich can affect n eigh borin g teeth Ad dition ally, wh en p osterior teeth are lost (m axillary p rem olars an d m olars), th e sin u s will p n eu m atize, with redu ction in th e am ou n t of bon e available in th ose areas Becau se a d en tal im p lan t relies h eavily on osseoin tegration of th e im p lan t in to th e bon e, if th ere is n ot en ou gh bon e to allow osseoin tegration , a d en tal im p lan t will fail Th e goal of th e p roced u re is to in crease th e am ou n t of bon e, to allow for p rop er osseoin tegration For th is su rgical p roced u re: • Th e sin u s m em bran e n eed s to be carefu lly elevated from th e oor of th e m axilla • Bon e graft m aterial is p laced on to th e m axilla, th e sin u s m em bran e is allowed to rest on th e bon e graft m aterial, an d th e access site is closed • Great care is n eed ed to p reven t p erforation of th e sin u s m em bran e Th e p resen ce of sep ta with in th e m axillary sin u s com p licates th e su rgery becau se th e sin u s m em bran e ten d s to attach m ore rm ly to th e bon e at th e sep ta

Augmented floor

Augmented floor

Maxillary implant

Maxillary implant

Site of future sinus lift augmentation Note lack of bone

Figu re 12-28

PARANASAL SINUSES 339

12

CLINICAL CORRELATES • Surgical Procedures FUNCTIONAL ENDOSCOPIC SINUS SURGERY

• • • • •

In functional endoscopic sinus surgery, an en d oscop e is in serted in to th e n ose to view th e n asal cavity an d sin u ses, th ereby elim in atin g an extern al in cision Often p erform ed as an ou tp atien t p rocedu re Provides in creased visu alization of th e area, m akin g it easier to rem ove d iseased tissu e an d leave a greater am ou n t of n orm al tissu e in tact Stan d ard su rgical treatm en t for sin u sitis for p eop le wh ose ch ron ic sin u s p roblem s d o n ot resp on d to m edical th erap y Also u sed for rem oval of p olyp s, m u coceles, tu m ors, an d foreign bod ies an d for con trol of ep istaxis

Ethmoid bulla Uncinate process O stiomeatal obstruction

Ethmoid bulla Middle turbinate Nasal septum

Uncinate process Preoperative cross section

Incision (broken line) to expose ostiomeatal complex

Nasofrontal duct Stump of uncinate process O stium of maxillary sinus Anterior ethmoid air cells opened Ethmoid bulla opened

Middle turbinate Nasal septum

Nasofrontal duct opened

Ethmoidectomy Drainage from frontal sinus Dome of ethmoid sinus Drainage from maxillary sinus Anterior ethmoid artery Posterior ethmoid air cell opened Drainage from sphenoid sinus

Stump of uncinate process

Postoperative cross section

Figu re 12-29

340

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

CHAPTER 13

ORAL CAVITY

Overview and Topographic Anatomy

342

External Anatomy

343

Boundaries of the Oral Cavity

348

Teeth

357

Vascular Supply of the Oral Cavity

36 8

Nerve Supply of the Oral Cavity

373

Salivary Glands

381

Clinical Correlates

38 8

Imaging

395

13

OVERVIEW AND TOPOGRAPHIC ANATOMY • General Information •

Oral cavity: th e sp ace located between th e lip s an d ch eeks on th e extern al su rface to th e p alatoglossal fold on th e in tern al su rface • Th e oral cavity is im p ortan t in m astication , tastin g, an d talkin g • Th e area of th e oral cavity can be d ivid ed in to: • Vestibu le—th e area between th e teeth an d lip s or ch eek • Oral cavity p rop er—th e area located in tern al to th e teeth • Posteriorly, th e oral cavity is con tin u ou s with th e orop h aryn x • Th e h ard p alate an d th e soft p alate are im p ortan t bou n d aries with in th e oral cavity • Th e ton gu e is a m ajor stru ctu re located on th e oral cavity oor • All of th e m ajor salivary glan d s (p arotid, su bm an dibu lar, an d su blin gu al) an d m in or salivary glan ds (lin gu al, p alatal, bu ccal, an d labial) em p ty in to th e oral cavity • Th e m u scles of th e oral cavity in clu d e th ose of th e m ou th , ch eeks, ton gu e,* an d soft p alate Wald eyer’s rin g is th e an atom ical n am e for th e rin g of lym p h atic tissu e in th e p h aryn x an d oral cavity: • Lin gu al ton sil (p osterior 1/ 3rd of ton gu e) • Palatin e ton sil (orop h aryn x) • Tu bal ton sil (n asop h aryn x) • Ph aryn geal ton sil (n asop h aryn x)

Philtrum of lip Vestibule Soft palate Palatopharyngeal arch Uvula Palatoglossal arch Palatine tonsil Posterior wall of pharynx

Frenulum of upper lip Lingual minor salivary gland Deep lingual artery and veins and lingual nerve Fimbriated fold Submandibular duct Sublingual gland Frenulum of tongue Sublingual fold with openings of sublingual ducts Sublingual caruncle with opening of submandibular duct Frenulum of lower lip

Figu re 13-1 *Th e m u scles of th e ton gu e are covered in Ch ap ter 14.

342

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EXTERNAL ANATOMY • External Features Structure

Comments

Lips

Divided into an upper and a lower lip that surround the opening of the oral cavity Both lips have a m uscular “skeleton” com posed of the orbicularis oris m . Upper lip is separated from the cheek by the nasolabial groove Lower lip is separated from the chin by the labiom ental groove Upper and lower lips m eet at the labial com m issures Verm ilion zone—the red area of the lip that is clearly dem arcated from the skin of the face at the verm ilion border and is lined by a thinly keratinized layer of strati ed squam ous epithelium which changes upon transition to the m ucous m em brane of the oral cavity; also known as the red zone Philtrum —the depressed area located between the base of the nose and the verm ilion border of the upper lip Many m ucus-secreting labial glands are located within the subm ucosal layer of the lips at the area of transition to m ucous m em brane of the oral cavity, which is nonkeratinized strati ed squam ous epithelium Vestibule—the region between the lips or cheeks and the teeth The fold of tissue created by the vestibule between the lip and teeth is called the vestibular or m ucolabial fold As the vestibular fold re ects on the alveolar bone holding the teeth, the m ucous m em brane abruptly changes into the gingiva Within the vestibular fold are bands of tissue known as labial frenula The labial frenula are pronounced at the m axillary and m andibular m idline as the upper and lower frenula, respectively Other accessory frenula also are located in the vestibule

Cheek

Located between the labial com m issure and the m ucosa overlying the ram us of the m andible Has a m uscular “skeleton” com posed of the buccinator m . Many m ucus-secreting glands, known as buccal glands, are located within the subm ucosal layer of the inside of the cheeks, which is lined by m ucous m em brane of the oral cavity (nonkeratinized strati ed squam ous epithelium ) Vestibule continues from the region between the lips and teeth posteriorly, to be located between the cheek and the teeth The fold of tissue created by the vestibule between the lip and the teeth is called the vestibular or m ucobuccal fold The retrom olar region is the only area in which the vestibule and the oral cavity proper com m unicate The parotid duct drains into the oral cavity at the parotid papilla, located along the m ucous m em brane of the cheek opposite the 2nd m axillary m olar Fordyce spots, ectopic sebaceous glands found in the m ucosa of the cheeks appearing as yellowish spots, can be observed in the cheek

13

O ral cavity proper

Commissure of lips

Philtrum Vestibule

Nasolabial sulcus Tubercle of superior lip Vermilion zone Mental protuberance

Lingual O ropharynx tonsil

Labiomental groove

Figu re 13-2 O RAL CAVITY 343

13

EXTERNAL ANATOMY • Vascular Supply of the Lips and Cheek ARTERIAL SUPPLY Artery

Source

Comments

Superior labial branch of the facial

Facial a. off the external carotid a.

Supplies the structures associated with the upper lip Gives rise to the septal branch that travels to the nasal septum

Superior labial branch of the infraorbital

Infraorbital a. off the m axillary a.

A continuation of the 3rd part of the m axillary a. 1 of the 3 term inal branches of the infraorbital a., along with the inferior palpebral branch and the nasal branch Accom panied by the nerve and vein of the sam e nam e Helps supply the upper lip

Inferior labial branch of the facial

Facial a. off the external carotid a.

Supplies the structures associated with the lower lip

Mental

Inferior alveolar a.

A term inal branch from the inferior alveolar a., which arises from the 1st part of the m axillary a. Em erges from the m ental foram en to supply the chin region

Buccal

Maxillary a.

A branch of the 2nd part of the m axillary a. A sm all artery that runs obliquely in an anterior direction between the m edial pterygoid and the insertion of the tem poralis m . until it reaches the outer surface of the buccinator m . to supply that m uscle and the face

Infraorbital artery

Superior labial artery Buccal artery Inferior labial artery Mental branch of inferior alveolar artery Inferior alveolar artery and lingual branch Facial artery

Figu re 13-3

344

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EXTERNAL ANATOMY • Vascular Supply of the Lips and Cheek

13

VENOUS DRAINAGE Vein

Comments

Superior labial branch of the facial

Drains the upper lip and joins the facial v.

Inferior labial branch of the facial

Drains the lower lip and joins the facial v.

Mental

Drains the chin and lower lip and joins the pterygoid plexus of veins

Buccal

Drains the cheek and joins the pterygoid plexus of veins

Pterygoid plexus Superior labial vein

Inferior labial vein Mental vein Facial vein

Figu re 13-4

O RAL CAVITY 345

13

EXTERNAL ANATOMY • Muscles Muscle

Origin

Insertion

Actions

Nerve

Comments

Orbicularis oris

Bone: anterior m idline of the m axilla and m andible Muscular: angle of the m outh where bers blend with levator anguli oris, depressor anguli oris, zygom aticus m ajor, and risorius m m .

Skin along the m outh

Closes lips Protrusion of lips Pursing of lips

Facial (buccal and m andibular branches)

Sphincter of the m outh Muscle bers encircle the m outh

Buccinator

Pterygom andibular raphe Alveolar m argins of the m axilla and m andible

Som e bers blend and provide origin for the orbicularis oris Som e bers blend into the upper and lower lips

Aids in m astication, keeping the bolus between cheek and teeth Helps forcibly expel air Helps create a sucking action

Facial (buccal branch)

Creates the fram ework of the cheek

Parotid duct Buccinator muscle

O rbicularis oris muscle

Figu re 13-5

346

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

EXTERNAL ANATOMY • Nerve Supply

13

SENSORY INNERVATION Nerve

Source

Course

• All sensory innervation to the skin of this region is supplied by the trigem inal n. Superior labial branch of the infraorbital

Infraorbital n. (a continuation of the m axillary division of the trigem inal n.)

1 of the 3 term inal branches of the infraorbital n., along with the inferior palpebral and the nasal, as it exits onto the face via the infraorbital foram en Supplies the skin of the upper lip

Mental

Inferior alveolar n.

1 of the 2 term inal branches of the inferior alveolar n. Em erges through the m ental foram en of the m andible in the region of the 2nd m andibular prem olar Supplies the skin of the lower lip, chin, and facial gingiva as far posteriorly as the 2nd m andibular prem olar

Buccal branch of the m andibular division of the trigem inal

Mandibular division of the trigem inal n.

Passes anteriorly between the 2 heads of the lateral pterygoid m . Descends inferiorly along the lower part of the tem poralis m . to em erge from deep to the anterior border of the m asseter m . Supplies the skin over the buccinator m . before passing through it to supply the m ucous m em brane lining its inner surface and the gingiva along the m andibular m olars

Maxillary nerve (V2 ) Infraorbital nerve (V2 )

Superior labial of the infraorbital

Buccal nerve (V3 )

Mental nerve (V3 )

Figu re 13-6

O RAL CAVITY 347

13

BOUNDARIES OF THE ORAL CAVITY • General Information Boundary

Structure

Superior

Hard palate

Posterosuperior

Soft palate

Lateral

Cheeks

Inferior

The oor of the oral cavity (which is located along the lingual border of the m andible, form ing a horseshoe-shaped region)

Pharyngeal opening of pharyngotympanic (auditory) tube

Frontal sinus Sphenoidal sinus Nasal septum Nasopharynx Soft palate Palatine glands Hard palate O ral cavity

Pharyngeal tonsil Pharyngeal tubercle of occipital bone Pharyngeal raphe

Anterior arch of atlas (C1 vertebra)

Palatine tonsil Body of tongue O ropharynx

Dens of axis (C2 vertebra) C1

C1

Lingual tonsil Genioglossus muscle

C2

C3

Root of tongue

Figu re 13-7

348

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

Pharyngeal constrictor muscles

BOUNDARIES OF THE ORAL CAVITY • Superior Border: Hard Palate • • • • • • • • • • • •

13

Th e su p erior bord er (or roof) of th e oral cavity is th e h ard p alate, com p risin g th e an terior 2/ 3 of th e en tire p alate Sep arates th e oral cavity from th e n asal cavity Com p osed of: • Palatal p rocess of th e m axilla • Horizon tal p rocess of th e p alatin e In th e an terior m id lin e, an in cisive foram en is located on th e righ t an d left sid es th at tran sm its th e term in al bran ch es of th e n asop alatin e n erve an d sp h en op alatin e vessels In th e p osterolateral region of th e h ard p alate, th e greater an d lesser p alatin e foram in a are located on th e righ t an d left sid es; th ese op en in gs tran sm it th e greater an d lesser p alatin e n n . an d vessels Th e bon es of th e h ard p alate are covered by a th ick m u cou s m em bran e, kn own as m asticatory m u cosa (keratin ized strati ed sq u am ou s ep ith eliu m ) Th e m u cou s m em bran e h as a sm all elevation in th e an terior m idlin e called th e in cisive p ap illa th at overlies th e in cisive foram en Th e m u cou s m em bran e in th e an terior region is tigh tly attach ed to th e u n d erlyin g p alatal p rocess of th e m axilla Th e m u cou s m em bran e in th e an terior region is freq u en tly avu lsed from th e p alatal p rocess of th e m axilla d u rin g th e ad m in istration of a Nasop alatin e n erve block Movin g p osteriorly from th e in cisive p ap illa, th e m u cou s m em bran e h as a th ick m id lin e p alatal rap h e Lateral tran sverse rid ges called tran sverse ru gae (p licae) are located alon g th e m u cou s m em bran e of th e h ard p alate Deep to th e m u cou s m em bran e of th e h ard p alate are n u m erou s m u cu s-secretin g glan d s called p alatal (p alatin e) glan d s

O RAL CAVITY 349

13

BOUNDARIES OF THE ORAL CAVITY • Superior Border: Hard Palate Incisive papilla

Incisive fossa

Transverse palatine folds

Greater palatine artery and nerve Greater palatine foramen

Palatine raphe

Lesser palatine foramen

Palatine process of maxilla

Lesser palatine artery and nerves

Palatine glands

Tendon of tensor veli palatini muscle

Horizontal plate of palatine bone

Pterygoid hamulus

Palatine aponeurosis (from tensor veli palatini muscle)

Interdigitating fibers of levator veli palatini muscle Buccinator muscle

Uvular muscle

Pterygomandibular raphe Superior pharyngeal constrictor muscle

Molar minor salivary glands Palatopharyngeus muscle

Palatoglossus muscle

Palatine tonsil Anterior view Central incisor Incisive fossa

Lateral incisor Canine

Palatine process of maxilla

1st premolar 2nd premolar

Horizontal plate of palatine bone

1st molar 2nd molar 3rd molar

Greater and lesser palatine foramina Upper permanent teeth

Figu re 13-8

350

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

BOUNDARIES OF THE ORAL CAVITY • Posterosuperior Border: Soft Palate • • • • •

• •

•

13

Th e p osterosu p erior bord er of th e oral cavity is th e soft p alate Th e soft p alate is th e con tin u ation of th e p alate p osteriorly an d m akes u p ap p roxim ately 1/ 3 of th e en tire p alate Th e soft p alate sep arates th e oral cavity from th e orop h aryn x An abu n d an ce of m u cu s-secretin g p alatal glan d s, wh ich are con tin u ou s with th e h ard p alate, are located in th e soft p alate Th e soft p alate h as 3 m argin s: • An teriorly, it is con tin u ou s with th e h ard p alate at th e vibratin g lin e • Posterolaterally, it form s th e su p erior p ortion of th e p alatoglossal an d p alatop h aryn geal fold s • Posteriorly, th e u vu la h an gs in th e cen ter of th e p osterior free m argin Th e th ick p alatin e ap on eu rosis form s th e fou n d ation of th e soft p alate Th e soft p alate is com p osed of 5 m u scles: • Mu scu lu s u vu lae • Ten sor veli p alatin i • Levator veli p alatin i • Palatop h aryn geu s • Palatoglossu s (som etim es con sid ered in th e grou p in g of ton gu e m u scles) Th e soft p alate h elp s close off th e n asop h aryn x du rin g d eglu tition by form in g a seal at th e fold of Passavan t

Medial view Median (sagittal) section

Pharyngeal recess Soft palate Uvula Palatine tonsil Palatopharyngeal arch Palatoglossal arch

Pharyngeal mucosa removed Tensor veli palatini muscle and tendon Levator veli palatini muscle

Palatoglossus muscle Palatopharyngeus muscle

Figu re 13-9

O RAL CAVITY 351

13

BOUNDARIES OF THE ORAL CAVITY • Posterosuperior Border: Soft Palate MUSCLES OF THE SOFT PALATE Muscle

Origin

Insertion

Actions

Nerve Supply

Comment

Tensor veli palatini

Cartilaginous part of the auditory tube Scaphoid fossa of the sphenoid

Palatine aponeurosis

Pulls the soft palate laterally, which broadens it

Mandibular division of the trigem inal n.

The tendon of the tensor veli palatini m . wraps around the pterygoid ham ulus

Musculus uvulae

Posterior nasal spine Palatine aponeurosis

Fibers insert into the m ucosa of the uvula

Retracts uvula Pulls uvula in a posterosuperior direction

May be bi d

Levator veli palatini

Cartilaginous portion of the auditory tube Petrous portion of the tem poral bone

Palatine aponeurosis Fibers also insert into the m uscle of the opposite side

Elevates soft palate Pulls soft palate posterosuperiorly which acts to help close the nasopharynx

Pharyngeal plexus (the m otor portion of this plexus is form ed by the pharyngeal branch of the vagus n.)

Palatopharyngeus

Posterior border of hard palate Palatine aponeurosis

Posterior border of the lam ina of the thyroid cartilage

Elevates the pharynx and larynx Acts to help close the nasopharynx

Grouped either with soft palate m uscles or with m uscles of the pharynx

Palatoglossus

Palatine aponeurosis (oral surface)

Lateral aspect of the tongue where som e bers interm ix with the transverse m . and som e along the dorsal surface of the tongue

Elevation of the root of the tongue Narrows the oropharyngeal isthm us for deglutition

Grouped either with extrinsic m uscles of the tongue or with m uscles of the soft palate

The levator veli palatini m . passes through an aperture superior to the superior constrictor m.

Cartilaginous part of pharyngotympanic (auditory) tube

Levator veli palatini muscle (cut) Tensor veli palatini muscle

Levator veli palatini muscle

Medial pterygoid muscle (cut)

Choanae

Medial pterygoid plate

Pterygoid hamulus

Pterygoid hamulus

Superior pharyngeal constrictor muscle (cut)

Tendon of tensor veli palatini muscle Levator veli palatini muscle (cut)

Palatopharyngeus muscle

Palatopharyngeus muscle (cut) Uvular muscle Posterior view

Figu re 13-10

352

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

BOUNDARIES OF THE ORAL CAVITY • Posterosuperior Border: Soft Palate Section through cartilaginous part of pharyngotympanic (auditory) tube, with tube closed

Section through cartilaginous part of pharyngotympanic (auditory) tube, with tube open Trigeminal ganglion

Trigeminal ganglion Internal carotid artery in carotid canal Dura mater

13

Internal carotid artery in carotid canal Dura mater Lateral lamina of cartilage

Lateral lamina of cartilage Medial lamina of cartilage Auditory tube lumen

Medial lamina of cartilage Auditory tube lumen Tensor veli palatini muscle

Tensor veli palatini muscle Levator veli palatini muscle Salpingopharyngeus muscle Nasopharynx

Levator veli palatini muscle Salpingopharyngeus muscle Nasopharynx

Pharyngotympanic (auditory) tube closed by elastic recoil of cartilage, tissue turgidity, and tension of salpingopharyngeus muscles

Lumen opened chiefly when attachment of tensor veli palatini muscle pulls wall of tube laterally during swallowing

Medial pterygoid plate Cartilaginous part of pharyngotympanic (auditory) tube Tensor veli palatini muscle Pharyngobasilar fascia Levator veli palatini muscle Palatine aponeurosis and tendon of tensor veli palatini muscle

C1

Salpingopharyngeus muscle Muscles of soft palate C2

Pterygoid hamulus Superior pharyngeal constrictor muscle Pterygomandibular raphe Palatopharyngeus muscle Buccinator muscle

C3

Stylopharyngeus muscle

Middle pharyngeal constrictor muscle

Figu re 13-11

O RAL CAVITY 353

13

BOUNDARIES OF THE ORAL CAVITY • Lateral Border: Cheek • • • • • •

Th e lateral bord er of th e oral cavity exten d s an teriorly from th e labial com m issu re, p osteriorly to th e ram u s of th e m an d ible Su p erior lim it of th e ch eek is th e m axillary vestibu le; in ferior lim it is th e m an d ibu lar vestibu le Mu cou s m em bran e of th e ch eek is strati ed sq u am ou s ep ith eliu m Ford yce sp ots are ectop ic sebaceou s glan d s th at m ay be observed on th e in n er su rface of th e ch eek Parotid p ap illa is located in th e ch eek op p osite th e m axillary 2n d m olar Pterygom an d ibu lar rap h e is located in th e p osterior p ortion an d serves as a lan dm ark for th e p terygom an dibu lar sp ace for in ferior alveolar n erve blocks

Parotid papilla with opening of parotid duct

Figu re 13-12

354

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

BOUNDARIES OF THE ORAL CAVITY • Inferior Border: Floor of the Oral Cavity • • • • •

13

Th e in ferior bord er is th e oor of th e oral cavity It is located alon g th e lin gu al bord er of th e m an dible form in g a h orsesh oe-sh ap ed region Th e m yloh yoid m . serves as th e slin g of th e oor of th e oral cavity an d stru ctu res su p erior to it are th e m ajor con ten ts Th e largest stru ctu re is th e ton gu e an d related m u scu latu re Please see Ch ap ter 14 on th e ton gu e for a d etailed exp lan ation of th e m u scu latu re of th e ton gu e Structure

Comments

Tongue

Largest structure in the oor (see Chapter 14)

Lingual frenulum

A m idline fold of tissue located at the base of the tongue and extends along the inferior surface of the tongue

Mucous m em brane

Strati ed squam ous epithelium that extends from the tongue to the m andible

Sublingual papilla

A swelling located on both sides of the lingual frenulum at the base of the tongue Continuous with the sublingual folds overlying the sublingual glands on the oor of the oral cavity Marks the entrance of the saliva from the subm andibular glands into the oral cavity

Subm andibular duct

Lies along the sublingual gland under the m ucosa

Lingual n.

Crosses the subm andibular duct passing lateral, inferior, and m edial to the duct to reach the tongue and supply general sensation to the anterior 2/ 3

Plica m briata

Fim briated folds located lateral to the lingual frenulum

Mylohyoid m .

Form s the m uscular sling of the oor of the oral cavity Passes from the m ylohyoid line of the m andible to the opposite m ylohyoid m . in the m idline at the m ylohyoid raphe and attaches posteriorly to the hyoid bone

Geniohyoid m m .

Lie superior to the m ylohyoid m m . Attach from the inferior genial tubercles of the m andible to the hyoid bone

MUSCLES OF THE FLOOR OF THE ORAL CAVITY Muscle

Origin

Insertion

Actions

Nerve Supply

Comment

Mylohyoid

Mylohyoid line of the m andible

Mylohyoid raphe Body of the hyoid bone

Raises the oor of the oral cavity Can elevate the hyoid bone

Mylohyoid n. from the inferior alveolar branch of the m andibular division of the trigem inal n.

Form s the sling of the oral cavity

Geniohyoid

Inferior genial tubercle

Body of the hyoid bone

Elevates the hyoid bone

C1 ventral ram us, which follows the hypoglossal n.

Superior to the m ylohyoid m.

O RAL CAVITY 355

13

BOUNDARIES OF THE ORAL CAVITY • Inferior Border: Floor of the Oral Cavity Sublingual gland Lingual nerve

Posterosuperior view

Inferior alveolar nerve and artery Mylohyoid nerve and artery Submandibular gland and duct Mylohyoid muscle Geniohyoid muscle Superior mental spine for origin of genioglossus muscle

Lesser horn Hyoid bone

Body Hyoglossus muscle (cut)

Greater horn

Buccinator muscle Muscles of facial expression Hyoglossus muscle Genioglossus muscle Sublingual salivary gland Submandibular duct Lingual nerve Nerve to mylohyoid Lingual artery Facial artery Hypoglossal nerve (XII) Mylohyoid muscle Facial vein Hyoid bone

Frenulum of upper lip Lingual minor salivary gland Deep lingual artery and veins and lingual nerve Fimbriated fold Submandibular duct Sublingual gland Frenulum of tongue Sublingual fold with openings of sublingual ducts Sublingual caruncle with opening of submandibular duct Frenulum of lower lip

Figu re 13-13

356

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

Frontal section behind 1st molar tooth (anterior view) demonstrating beds of sublingual and submandibular glands

TEETH • General Information • • • •

13

Teeth are h ard stru ctu res attach ed to th e jaws an d in volved p rim arily in eatin g 2 arch es con tain th e teeth : • Maxillary arch • Man dibu lar arch Hu m an s h ave 2 sets of teeth d u rin g a lifetim e: • Decid u ou s teeth —th e p rim ary d en tition • Perm an en t teeth —th e secon d ary d en tition Between th e ages of 6 an d 12 years, th ere is a m ixed d en tition , in wh ich both p rim ary an d p erm an en t teeth are p resen t in th e oral cavity at th e sam e tim e

DECIDUOUS TEETH

• • •

Th ere are 20 total d ecid u ou s teeth : 2 in cisors, 1 can in e, an d 2 m olars in each of th e 4 q u adran ts of th e oral cavity Th e p rim ary d en tition is rep resen ted by th e form u la I 22 C 11 M 22 , wh ich sp eci es th e total n u m ber of teeth (10) on each sid e of th e oral cavity No d ecid u ou s teeth are p resen t at birth ; h owever, by th e 3rd year of life, all 20 d ecid u ou s teeth h ave eru p ted

PERMANENT TEETH

• • •

• •

Th ere are 32 total p erm an en t teeth : 2 in cisors, 1 can in e, 2 p rem olars, an d 3 m olars in each of th e 4 q u ad ran ts of th e oral cavity Th e p erm an en t d en tition is rep resen ted by th e form u la I 22 C 11 P 22 M 33 , wh ich sp eci es th e total n u m ber of teeth (16) on each sid e of th e oral cavity Th e 1st p erm an en t tooth to eru p t in to th e oral cavity n orm ally is th e m an dibu lar 1st m olar • Th is eru p tion occu rs at abou t 6 years of age • It eru p ts d istal to th e p rim ary d en tition Th e p rim ary teeth even tu ally are rep laced by th e p erm an en t teeth Th e rep lacem en t teeth are term ed su ccedan eou s teeth SURFACES OF A TOOTH Labial

The surface of the anterior teeth that is closest to the lip

Buccal

The surface of the posterior teeth that is closest to the cheek

Facial

Used as a synonym for labial or buccal

Lingual

Opposite the tongue in the m andibular arch and opposite the hard palate of the m axillary arch

Mesial

Closest to the m idline of the dental arch

Distal

Farthest from the m idline of the dental arch

Occlusal

Used for chewing in posterior teeth

Incisal

The cutting edge of anterior teeth Labial surface

Condyle

Mesial

Lingula (covering the opening of the mandibular foramen)

Distal Buccal surface

Coronoid process

Buccal shelf

Lingual surface

Mental foramen Lower permanent teeth

O RAL CAVITY 357

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TEETH • Surfaces of a Tooth Deciduous (primary) Usual age of eruption

Permanent (colored blue) Usual age of eruption

Central incisor (8–10 months) Lateral incisor (8–10 months) Canine (cuspid) (16–20 months) 1 st molar (15–21 months)

Central incisor (7 th year) Lateral incisor (8 th year) Canine (cuspid) (11 th –12 th year) 1 st premolar (9 th year) 2 nd premolar (10 th year) 1 st molar (6 th year) 2 nd molar (12 th –13 th year)

2 nd molar (20–24 months) 2 nd molar (20–24 months) 1 st molar (15–21 months) Canine (cuspid) (16–20 months) Lateral incisor (15–21 months) Central incisor (6–9 months)

3 rd molars (17 th –25 th year) 2 nd molar (12 th –13 th year) 1 st molar (6 th year) 2 nd premolar (10 th year) 1 st premolar (9 th year) Canine (cuspid) (11 th –12 th year) Lateral incisor (8 th year) Central incisor (7 th year) (R) Central incisor

11

(R) Lateral incisor

13 4

7

10

6

1

(R) First molar

46

28

(L) Third molar

N I V F D E I L E

S

H

A L

T

F

G I R

Lower (mandibular)

31

7

18

30

6

19

29

5

20

28 4

44

26

43

25

5

2

1

42 41

3

23

24

36 35

34

31

(R) Central incisor (L) Central incisor

Figu re 13-14

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

(L) Lateral incisor

(L) Second molar

(L) Second premolar (L) First premolar

(L) Canine

32

(L) Third molar

(L) First molar

33

2

1

37

6

4

22

3

(R) Lateral incisor

7

21 27

38

8

17

(R) Canine

358

8

32

(R) Second premolar 45 (R) First premolar

16

R

T

F

(R) Second molar 47

(L) Second molar

U

A R S E I

R M E D L V I

A P

N U

8

27

P

8

7

A

(R) Third molar 18

15

L

2

(L) First molar

26

6

14

Upper (maxillary)

25 (L) Second premolar

5

13

L

7

24 (L) First premolar

4

12

3

(R) Second molar 17

(R) Third molar 48

3

11

4

6

(L) Canine

23

5

5

16

2

M

(R) First molar

22

9

E

(R) Second premolar 15

(L) Lateral incisor

R

14

1 8

2 3

(R) First premolar

21 1

12

(R) Canine

(L) Central incisor

TEETH • Basic Anatomy of a Tooth Crown

Anatom ic crown: the portion of the tooth that has a surface of enam el Clinical crown: the portion of the tooth that is exposed within the oral cavity

Root

Anatom ic root: the portion of the tooth that has a surface of cem entum Clinical root: the portion of the tooth that is entrenched within the m axilla or m andible and is not exposed to the oral cavity

Apex of the root

The end tip of the root, which also is the location of a sm all aperture at the point of each root, which provides an entrance for the neurovascular connective tissue into the pulp cavity

Cervical line

The anatom ic dem arcation between the crown and the root It often is term ed the cem entoenam el junction (CEJ)

Enam el

The hard, shiny surface of the anatom ic crown The hardest portion of the tooth Made of sm all hexagonal rods, called enam el prism s, that are parallel to one another

Cem entum

A thin, dull layer on the surface of the anatom ic root Sim ilar in structure and chem ical com position to bone With age, cem entum increases in thickness

Dentin

The hard tissue that underlies both the enam el and cem entum and constitutes the m ajor portion of the tooth A m odi cation of osseous tissue Com posed of a num ber of dental tubules (sm all wavy and branching tubes) that are located in a dense m atrix

Cusp

An elevation on the occlusal surface of m olars and prem olars that m akes up a divisional part of the tooth The incisal edge of canines is referred to as a cusp and is used for prehension (grasping and tearing) of food

Pulp cavity

Contains the dental pulp (highly neurovascular connective tissue) Separated into the pulp cham ber, located in the coronal portion of the tooth, and the pulp canal, located in the root portion of the tooth

Cingulum

A convex elevation that is located on the lingual surface of the crowns of anterior teeth just incisal to the CEJ

13

Enamel Dentine and dentinal tubules Crown

Neck

Root

Interglobular spaces O dontoblast layer Interproximal spaces Dental pulp containing vessels and nerves Gingival (gum) epithelium (stratified) Gingival groove Lamina propria of gingiva (gum) (mandibular or maxillary periosteum) Periodontium (alveolar periosteum) Papilla Cement Root (central) canals containing vessels and nerves Bone Apical foramina

Figu re 13-15 O RAL CAVITY 359

13

TEETH • Types of Teeth in the Permanent De nition • • •

• •

Th ere are 32 p erm an en t teeth in th e oral cavity: • 16 m axillary teeth • 16 m an d ibu lar teeth To aid th e clin ician in effective d iscu ssion of sp eci c teeth , a d en tal n otation system is req u ired Th e m ajor d en tal n otation system s are: • FDI World Den tal Federation Notation System • Palm er Notation System • Un iversal Nu m berin g System In th e Un ited States, th e m ost com m on ly u sed system is th e Un iversal Nu m berin g System In th e Un iversal Nu m berin g System , th e n u m berin g begin s with th e righ t 3rd m axillary m olar as n u m ber 1, con tin u in g over to th e left 3rd m axillary m olar as n u m ber 16, th en m ovin g to th e m an dibu lar arch with th e left 3rd m an dibu lar m olar as n u m ber 17 an d con tin u in g over to th e righ t 3rd m an d ibu lar m olar as n u m ber 32 MAXILLARY INCISORS Tooth

Crown

Surfaces

Root(s)

Comments

Central incisor

The widest of all of the anterior teeth, nearly as wide as it is long Cingulum : well developed

From a labial view, the distal surface is m ore convex than the m esial surface Mam elons: 3 elevations on the incisal edge of anterior teeth that denote centers of form ation Observed in central incisors before they are worn away during function

1 conical root that is triangular in cross section

Incisors are cutting teeth

Lateral incisor

More narrow than the central incisor in a m esial-to-distal m easurem ent

Labial surface: convex Incisal edges on the m esial and distal surfaces: m ore convex than central incisors Mam elons: tend to be less prom inent on the lateral incisor Lingual surface: m ore concave than on the central incisors Mesial and distal m arginal ridges m ore prom inent than central incisor and typically dem onstrate a lingual pit

1 conical root that is oval in cross section

36 0 NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

TEETH • Types of Teeth in the Permanent De nition

13

MAXILLARY CANINE Tooth

Crown

Surfaces

Root(s)

Comments

Canine

Cingulum : prom inent

Labial surface: convex Incisal edge: rounded into a cusp that displays a m esial and distal cusp ridge Lingual surface: exhibits a strong ridge from the cusp tip to the cingulum , which divides the lingual surface into a m esial and a distal fossa

1 long and conical root that is rectangular in cross section, with depressions on the m esial and distal surfaces

Also called cuspid; longest tooth in the oral cavity Prehensile tooth

Incisal view Incisal view

Labial view

Lingual view

Maxillary central incisor (right side)

Labial view Lingual view Maxillary lateral incisor (right side)

Incisal view

Labial view Lingual view Maxillary canine (right side)

Figu re 13-16

O RAL CAVITY 361

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TEETH • Types of Teeth in the Permanent De nition MAXILLARY PREMOLARS Tooth

Crown

Surfaces

Root(s)

Comments

1st prem olar

Shorter than the anterior teeth Wider in a facial-lingual dim ension than in a m esialdistal dim ension

Has a lingual and a facial cusp Facial surface: convex Facial cusp: long and sim ilar in appearance to the cusp of the canine Lingual cusp: shorter than the facial cusp and positioned m esial of the m esial distal m idline Displays a m esial m arginal developm ental groove

Usually 2 roots—a facial and a lingual root

Often referred to as bicuspid teeth, but a m ore accepted designation would be prem olar teeth Prehensile tooth

2nd prem olar

Not as angular in shape as the 1st prem olar

Facial surface: convex Has a lingual and a facial cusp Facial cusp: not as sharp as the facial cusp of the 1st prem olar Lingual cusp: nearly equal in size and sim ilar in shape to the facial cusp

Usually 1 root

Occlusal surface contains supplem ental grooves, which gives it a wrinkled appearance Supplem ents the m olars in function

O cclusal view

Buccal view

O cclusal view

Lingual view

Buccal view

Maxillary 1st premolar (right side)

Maxillary 2nd premolar (right side)

Figu re 13-17

362

Lingual view

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

TEETH • Types of Teeth in the Permanent De nition

13

MAXILLARY MOLARS Tooth

Crown

Surfaces

Root(s)

Comments

3 roots: • Mesiobuccal root • Distobuccal root (sm allest) • Lingual root (largest)

Usually the largest of the m olar teeth

• The m olar teeth are used for crushing and chewing 1st m olar

Larger in a faciallingual dim ension than it is in a m esial-distal dim ension From an occlusal view, the crown is rhom boidal in form

5 • • • • •

2nd m olar

Supplem ents the 1st m olar in function 2 form s: • Resem bles the 1st m olar with a m ore extrem e rhom boidal form • A heart-shaped form with a poorly developed distolingual cusp

4 • • • •

cusps: Mesiobuccal cusp Distobuccal cusp Mesiolingual cusp Distolingual cusp (som etim es absent) There is no 5th cusp

3 roots: • Mesiobuccal root • Distobuccal root • Lingual root

Sm aller than the 1st m olar

3rd m olar

Great variation in the crown (it m ay resem ble the 1st or 2nd m olar)

3-cusp form is m ore com m on: • Mesiobuccal cusp • Distobuccal cusp • Mesiolingual cusp

3 roots: • Mesiobuccal root • Distobuccal root • Lingual root The roots usually are fused, functioning as 1 large root

Variable in size Often extracted as a preventive m easure

O cclusal view

Buccal view

Lingual view

Maxillary 1st molar (right side)

cusps: Mesiobuccal cusp Distobuccal cusp Mesiolingual cusp Distolingual cusp 5th cusp: present on the lingual surface of the m esiolingual cusp and term ed the cusp of Carabelli

O cclusal view

Buccal view

Lingual view

Maxillary 2nd molar (right side)

O cclusal view

Buccal view

Lingual view

Maxillary 3rd molar (right side)

Figu re 13-18

O RAL CAVITY 363

13

TEETH • Types of Teeth in the Permanent De nition MANDIBULAR CANINE Tooth

Crown

Surfaces

Root(s)

Comments

Canine

Longer than the m axillary canine Cingulum : not as prom inent as on the m axillary canine

Incisal edge: rounded into a cusp Mam elons: not usually located on canine teeth Mesial surface of crown and root: relatively straight, without m uch convexity

1 long and conical root

Also called cuspids Sm aller and m ore sym m etric than the m axillary canine

Incisal view

Labial view

Lingual view

Mandibular canine (right side)

Figu re 13-19

364

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

TEETH • Types of Teeth in the Permanent De nition

13

MANDIBULAR INCISORS Tooth

Crown

Surfaces

Root(s)

Comments

Central incisor

2/ 3 the width of the m axillary central incisor Appears bilaterally sym m etric Cingulum : sm all and poorly developed

Labial surface: convex Lingual surface: concave Mam elons: observed in central incisors before wear Lingual fossa: poorly developed

1 root that is attened and is wide in a facial-lingual direction

Incisors are cutting teeth

Lateral incisor

Not bilaterally sym m etric

Labial surface : convex Lingual fossa: poorly developed

1 root sim ilar in shape to the central incisor

When viewed from the incisal aspect, the crown appears twisted distally on the root Incisors are cutting teeth

Incisal view

Labial view

Lingual view

Mandibular central incisor (right side)

Incisal view

Lingual view Labial view Mandibular lateral incisor (right side)

Figu re 13-20 O RAL CAVITY 365

13

TEETH • Types of Teeth in the Permanent De nition MANDIBULAR PREMOLARS Tooth

Crown

Surfaces

Root(s)

Comments

1st prem olar

Diam ondshaped

Facial surface: convex Has a lingual and a buccal cusp • Buccal cusp—well developed • Lingual cusp—sm all and not well developed Displays a m esial lingual developm ental groove

1 root that is oval in cross section, with a slight lingual taper

The sm allest of the prem olar teeth

2nd prem olar

Convex

Dem onstrates either of 2 occlusal schem es: • A 2-cusp form , with a facial and a lingual cusp • A 3-cusp form , with 2 lingual cusps and a single facial cusp—predom inant form Facial and lingual surfaces are convex Facial cusp is not as sharp as that of the 1st prem olar Lingual cusp(s) are sm aller than the facial cusp

1 root that is oval in cross section, with a slight lingual taper

Differs in appearance from the 1st prem olar Much larger than the 1st prem olar

O cclusal view Buccal view Lingual view st Mandibular 1 premolar (right side)

O cclusal view

Buccal view Lingual view Mandibular 2 nd premolar (right side)

Figu re 13-21

366

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TEETH • Types of Teeth in the Permanent De nition

13

MANDIBULAR MOLARS Tooth

Crown

Surfaces

Root(s)

Comments

1st m olar

Wider in a m esial-distal dim ension than in a facial-lingual length

5 cusps: • Mesiobuccal cusp (largest) • Distobuccal cusp • Distal cusp (sm allest) • Mesiolingual cusp • Distolingual cusp

2 roots: • Mesial root (containing 2 pulp canals) • Distal root (containing 1 pulp canal)

Used for crushing and chewing

2nd m olar

Norm ally the 2nd m olar is sm aller than the 1st m olar

4 • • • •

2 roots: • Mesial root (containing 2 pulp canals) • Distal root (containing 1 pulp canal)

Supplem ents the 1st m olar in function

3rd m olar

Developm ent is sim ilar to that of the 2nd m olar

4 cusps of variable shape and size

2 roots: • Mesial root • Distal root Roots are often fused

Variable, but not as variable as the m axillary 3rd m olar Often the sm allest of the m olar teeth Often extracted as a preventive m easure

cusps: Mesiobuccal cusp Distobuccal cusp Mesiolingual cusp Distolingual cusp

O cclusal view Buccal view

O cclusal view Buccal view

Lingual view

Mandibular 1 st molar (right side)

Buccal view

Lingual view

Mandibular 2 nd molar (right side)

O cclusal view

Lingual view

Mandibular 3 rd molar (right side)

Figu re 13-22

O RAL CAVITY 367

13

VASCULAR SUPPLY OF THE ORAL CAVITY • Arterial Supply ARTERIAL SUPPLY OF THE PALATE Artery

Source

Course

Maxillary

External carotid a.

Gives rise to a series of branches; 3 supply the palate: • Sphenopalatine • Greater palatine • Lesser palatine Gives rise to 3 branches that supply the m axillary arch: • Anterior superior alveolar • Middle superior alveolar • Posterior superior alveolar Gives rise to 1 branch that supplies the m andibular arch: • Inferior alveolar

Sphenopalatine

3rd part of the m axillary a.

Enters the nasal cavity after passing through the sphenopalatine foram en On entering the nasal cavity, gives rise to the posterior superior nasal branches: • Posterior superior lateral branch • Posterior superior m edial branch, which continues along the nasal septum to enter the hard palate via the incisive canal

Greater palatine

Descending palatine a. from the 3rd part of the m axillary a.

A branch of the descending palatine a. that travels in the palatine canal Within the canal, the descending palatine a. splits into the: • Lesser palatine a. • Greater palatine a. The greater palatine a. exits the greater palatine foram en and passes anteriorly toward the incisive foram en to supply the hard palate gingiva, m ucosa, and palatal glands and anastom ose with the term inal branch of the sphenopalatine a., which exits the incisive foram en

Lesser palatine

Descending palatine a. from the 3rd part of the m axillary a.

A branch of the descending palatine a. that travels in the palatine canal Within the canal, the descending palatine a. splits into the: • Greater palatine a. • Lesser palatine a. Lesser palatine a. supplies the soft palate and palatine tonsil

External carotid a.

Arises in the carotid triangle of the neck Passes superiorly im m ediately deep to the posterior belly of the digastric m . and the stylohyoid m . Passes along the subm andibular gland, giving rise to the subm ental a., which helps supply the gland Passes superiorly over the body of the m andible at the m asseter

Facial a.

Supplies the soft palate Ascends between the styloglossus and stylopharyngeus m m . along the side of the pharynx Divides near the levator veli palatini m . A branch follows the levator veli palatini, supplying the soft palate and the palatine glands A 2nd branch pierces the superior constrictor m . to supply the palatine tonsil and auditory tube Anastom oses with the ascending pharyngeal and tonsillar aa.

External carotid a.

Arises in the carotid triangle of the neck Lies deep to the other branches of the external carotid a. and under the stylopharyngeus m . Gives rise to pharyngeal, inferior tym panic, posterior m eningeal, and palatine branches The palatine branch passes over the superior constrictor m . and sends branches to the soft palate, tonsil, and auditory tube

Facial

Ascending palatine

Ascending pharyngeal

36 8 NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

VASCULAR SUPPLY OF THE ORAL CAVITY • Arterial Supply

Sphenopalatine artery

Infraorbital artery

Artery of pterygoid canal Pharyngeal artery Sphenopalatine foramen

Posterior superior alveolar artery

13

Accessory meningeal artery Middle meningeal artery

Auriculotemporal nerve

Descending palatine artery in pterygopalatine fossa Superficial temporal artery Ascending pharyngeal artery Ascending palatine artery Tonsillar branches Tonsillar artery External carotid artery Facial artery

Anastomosis in incisive canal Left and right greater palatine arteries Left and right lesser palatine arteries

Sphenopalatine artery Descending palatine artery

Maxillary artery Ascending pharyngeal artery

Ascending palatine artery Facial artery Lingual artery Ascending pharyngeal artery

Facial artery

Figu re 13-23

O RAL CAVITY 369

13

VASCULAR SUPPLY OF THE ORAL CAVITY • Arterial Supply ARTERIAL SUPPLY OF THE FLOOR OF THE ORAL CAVITY Artery

Source

Course

Facial

External carotid a.

Arises in the carotid triangle of the neck Passes superiorly im m ediately deep to the posterior belly of the digastric m . and the stylohyoid m . Passes along the subm andibular gland, giving rise to the subm ental a. that helps supply the gland Passes superiorly over the body of the m andible at the m asseter m .

Ascending palatine

Facial a.

Supplies the soft palate Ascends between the styloglossus and stylopharyngeus m m . along the side of the pharynx Divides near the levator veli palatini m . A branch follows the levator veli palatini, supplying the soft palate and the palatine glands A 2nd branch pierces the superior constrictor m . to supply the palatine tonsil and auditory tube Anastom oses with the ascending pharyngeal and tonsillar aa.

Subm ental

Facial a.

Arises in the subm andibular triangle of the neck Supplies the subm andibular gland and surrounding m uscles

External carotid a.

Passes superiorly and m edially toward the hyoid bone Curves inferiorly and anteriorly, form ing a loop that lies on the m iddle constrictor m . and is passed super cially by the hypoglossal n. Passes deep to the posterior belly of the digastric m . and the stylohyoid m ., traveling anteriorly Passes deep to the hyoglossus m . and ascends along the tongue Gives rise to dorsal lingual branches, a sublingual branch, and the deep lingual branch Sublingual branch begins at the anterior m argin of the hyoglossus and travels anteriorly between the genioglossus and m ylohyoideus m m . to supply the sublingual gland, surrounding m uscles, and m ucous m em brane of the oral cavity and gingiva Deep lingual branch passes anteriorly under the surface of the tongue, then anastom oses with the opposite deep lingual a. at the tip of the tongue

Lingual

Pharyngeal mucosa removed Tensor veli palatini muscle and tendon Levator veli palatini muscle Ascending palatine artery Salpingopharyngeus muscle Pterygoid hamulus Pterygomandibular raphe Palatoglossus muscle External carotid artery Lingual artery

Suprahyoid artery

Palatopharyngeus muscle Facial artery Hyoglossus muscle Middle pharyngeal constrictor muscle

Stylopharyngeus muscle

Figu re 13-24

370

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VASCULAR SUPPLY OF THE ORAL CAVITY • Arterial Supply

13

ARTERIAL SUPPLY OF THE MAXILLARY AND MANDIBULAR TEETH Artery

Source

Course

Maxillary

External carotid a.

Gives rise to 3 branches that form a plexus to supply the m axillary arch: • Anterior superior alveolar • Middle superior alveolar • Posterior superior alveolar • Gives rise to 1 branch that supplies the m andibular arch: • Inferior alveolar

Maxillary Teeth Anterior superior alveolar

Infraorbital a. (of the m axillary a.)

Arises after the infraorbital a. passes through the inferior orbital ssure and into the infraorbital canal Descends via the alveolar canals to supply part of the m axillary arch Supplies the m axillary sinus and the anterior teeth

Middle superior alveolar

Infraorbital a.

May or m ay not be present If present, arises from the infraorbital a. of the m axillary after it passes through the inferior orbital ssure and into the infraorbital canal Descends via the alveolar canals to supply the m axillary sinus and supplies the plexus at the canine

Posterior superior alveolar

3rd part of the m axillary a.

Arises before the m axillary a. enters the pterygopalatine fossa Enters the infratem poral surface of the m axilla to supply the m axillary sinus, prem olars, and m olars

Mandibular Teeth Inferior alveolar

3rd part of the m axillary a.

Descends inferiorly following the inferior alveolar n. to enter the m andibular foram en Term inates into the m ental and incisive aa. at the region of the 2nd prem olar Supplies all of the m andibular teeth

Mental

Inferior alveolar a.

Supplies the labial gingiva of the anterior teeth

Incisive

Inferior alveolar a.

Supplies the anterior teeth

Maxillary artery Superior alveolar arteries

Posterior Middle Anterior

Inferior alveolar artery and nerve

Incisive artery Mental branch of inferior alveolar artery

Figu re 13-25 O RAL CAVITY 371

13

VASCULAR SUPPLY OF THE ORAL CAVITY • Venous Drainage of the Oral Cavity VENOUS DRAINAGE OF THE PALATE AND FLOOR OF THE ORAL CAVITY Vein

Course

Greater palatine

Connect to the pterygoid plexus

Lesser palatine Sphenopalatine Lingual

Receives tributaries from the deep lingual vv. on the ventral surface, and dorsal lingual vv. from the dorsal surface of the tongue Passes with the lingual a., deep to the hyoglossus m ., and ends in the internal jugular v. The vena com itans nervi hypoglossi, or accom panying vein of the hypoglossal n., begins at the apex of the tongue and m ay either join the lingual v. or accom pany the hypoglossal n. and enter the com m on facial v., which em pties into the internal jugular v.

Subm ental

Anastom oses with the branches of the lingual v. and the inferior alveolar v. Parallels the subm ental a. on the super cial surface of the m ylohyoid m . Ends in the facial v.

Pharyngeal plexus

Located along the lateral pterygoid m . Most of the vessels in the infratem poral fossa and oral cavity drain into the pterygoid plexus Connected to the cavernous sinus, the pterygoid plexus of veins, and the facial v. Valveless Eventually drains into the m axillary v.

VENOUS DRAINAGE OF THE TEETH Vein

Course

Anterior superior alveolar

Drain onto the pterygoid plexus of veins

Middle superior alveolar Posterior superior alveolar Inferior alveolar

Emissary vein (Vesalius) communicating with cavernous sinus Posterior superior alveolar veins Palatine vein Inferior alveolar vein and artery

Maxillary veins

Facial vein

Submental vein

Figu re 13-26

372

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

NERVE SUPPLY OF THE ORAL CAVITY • General Information •

13

Th e oral cavity receives its sen sory in n ervation from bran ch es of th e m axillary an d m an d ibu lar d ivision s of th e trigem in al n erve

O phthalmic nerve (V1 ) Trigeminal (semilunar) ganglion Trigeminal nerve (V)

Infraorbital nerve Anterior superior alveolar nerve

Mandibular nerve (V3 )

Middle superior alveolar nerve

Maxillary nerve (V2 )

Dental and gingival branches Superior dental plexus Infraorbital nerve entering infraorbital canal Lateral view

Anterior division

Posterior superior alveolar nerve

Posterior division

Inferior alveolar nerve (cut)

Mental nerve Inferior alveolar nerve (cut)

Figu re 13-27

O RAL CAVITY 373

13

NERVE SUPPLY OF THE ORAL CAVITY • Sensory Innervation MAXILLARY TEETH Nerve

Source

Course

Maxillary

Trigem inal n.

Sensory in function Travels along the lateral wall of the cavernous sinus Passes from the m iddle cranial fossa into the pterygopalatine fossa via the foram en rotundum Within the pterygopalatine fossa, it gives rise to 4 branches: • Infraorbital (continuation of the m axillary) • Ganglionic • Posterior superior alveolar • Zygom atic The infraorbital n. gives rise to 2 branches that form a plexus with the posterior superior alveolar to supply the m axillary arch: • Anterior superior alveolar • Middle superior alveolar

Continuation of the m axillary division of the trigem inal n.

Passes through the inferior orbital ssure to enter the orbit Passes anteriorly through the infraorbital groove and infraorbital canal and exits onto the face via the infraorbital foram en Once the infraorbital n. exits onto the face, it divides into 3 term inal branches: • Nasal—supplies the ala of the nose • Inferior palpebral—supplies the skin of the lower eyelid • Superior labial—supplies the skin of the upper lip

Infraorbital n. as it travels in the infraorbital canal

As it descends to form the superior dental plexus, it innervates part of the m axillary sinus and generally the incisors and canines

Infraorbital

• Anterior superior alveolar • Middle superior alveolar

Posterior superior alveolar

374

A variable nerve As it descends to form the superior dental plexus, it innervates part of the m axillary sinus and the prem olars and possibly the m esiobuccal root of the 1st m olar Maxillary n. in the pterygopalatine fossa

Travels laterally through the pterygom axillary ssure to enter the infratem poral fossa Enters the infratem poral surface of the m axilla As it descends to form the superior dental plexus, it innervates part of the m axillary sinus and the m olars, with the possible exception of the m esiobuccal root of the 1st m olar

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

NERVE SUPPLY OF THE ORAL CAVITY • Sensory Innervation

13

MANDIBULAR TEETH Nerve

Source

Course

Mandibular

Trigem inal n.

This division has m otor function in addition to sensory function The largest of the 3 divisions of the trigem inal n. Created by a large sensory and a sm all m otor root that unite just after passing through the foram en ovale to enter the infratem poral fossa Im m ediately gives rise to a m eningeal branch and divides into an anterior and a posterior division Anterior division is sm aller and m ainly m otor, with 1 sensory branch (buccal): • Masseteric • Anterior and posterior deep tem poral • Medial pterygoid • Lateral pterygoid • Buccal Posterior division is larger and m ainly sensory, with 1 m otor branch (m ylohyoid): • Auriculotem poral • Lingual • Inferior alveolar • Mylohyoid

The largest branch of the m andibular division

Descends, following the inferior alveolar a. inferior to the lateral pterygoid and, last, between the sphenom andibular ligam ent and the ram us of the m andible until it enters the m andibular foram en, where it term inates as the m ental and incisive nn. in the area of the 2nd prem olar Innervates all m andibular teeth (via inferior alveolar and incisive nn.), periodontal ligam ents (via inferior alveolar and incisive nn.), and the gingiva from the prem olars anteriorly to the m idline (via the m ental branch)

Inferior alveolar n.

Supplies the chin, lip, and facial gingiva and m ucosa from the 2nd prem olar anteriorly

Inferior alveolar

• Mental • Incisive

Supplies the teeth and periodontal ligam ents from the 1st prem olar anteriorly (depends on the location of the branching of the inferior alveolar n. into the incisive and m ental nn.)

O RAL CAVITY 375

13

NERVE SUPPLY OF THE ORAL CAVITY • Sensory Innervation

Trigeminal nerve (V)

Maxillary nerve (V2 ) O phthalmic nerve (V1 )

Glossopharyngeal nerve (IX)

Mandibular nerve (V3 )

Internal carotid nerve

Inferior alveolar nerve

Glossopharyngeal nerve (IX)

Figu re 13-28

376

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

NERVE SUPPLY OF THE ORAL CAVITY • Floor of the Oral Cavity Nerve

Source

Course

Lingual

Mandibular division of the trigem inal n.

Lies inferior to the lateral pterygoid and m edial nn. and anterior to the inferior alveolar n. within the infratem poral fossa The chorda tym pani branch of the facial n. also joins the posterior part of the lingual n. Passes between the m edial pterygoid m . and the ram us of the m andible to pass obliquely to enter the oral cavity, bounded by the superior pharyngeal constrictor m ., the m edial pterygoid, and the m andible Enters the oral cavity lying against the lingual tuberosity of the m andible The subm andibular ganglion is suspended from the lingual n. at the posterior border of the hyoglossus Continues anteriorly and passes on the lateral surface of the hyoglossus Passes from the lateral side, inferiorly, and m edially to the subm andibular duct to reach the m ucosa of the tongue Supplies general som atic afferent (GSA) bers to the m ucous m em brane and papilla of the anterior 2/ 3 of the tongue and gingiva and m ucosa on the lingual side of the m andibular teeth

Glossopharyngeal

Medulla oblongata

Passes through the jugular foram en with the vagus and accessory nn. As it passes through the foram en, it passes between the internal carotid a. and the internal jugular v. Continues to pass inferiorly and travels posterior to the stylopharyngeus m . Passes anteriorly with the stylopharyngeus m . and travels between the superior and m iddle constrictor m m . to be located by the palatine tonsils Sm all lingual branches arise from it and distribute GSA bers to the m ucous m em brane of the posterior 1/ 3 of the tongue, in addition to the pillars of the fauces In addition, sm all lingual branches arise from it and distribute special visceral afferent (SVA) bers to the taste buds in the m ucous m em brane of the posterior 1/ 3 of the tongue and the circum vallate papillae

Internal laryngeal

Superior laryngeal branch of the vagus n.

Vagus n. branches from the m edulla oblongata and passes through the jugular foram en with the glossopharyngeal and accessory nn. As the vagus n. passes through the foram en, it passes between the internal carotid a. and the internal jugular v. A series of nerves branch from the vagus in the neck, including the superior laryngeal n. Superior laryngeal n. travels inferiorly posterior to the internal carotid a. and on the side of the pharynx and divides into the internal and external laryngeal nn. Internal laryngeal n. passes inferiorly to the larynx and passes through the thyrohyoid m em brane along with the superior laryngeal vessels Branches of the internal laryngeal n. distribute the GSA bers to the base of the tongue at the epiglottic region and to the m ucous m em branes of the larynx as far inferiorly as the false vocal folds In addition, the branches distribute SVA bers to the taste buds scattered at the base of the tongue at the epiglottic region

13

Continued on next page

O RAL CAVITY 377

13

NERVE SUPPLY OF THE ORAL CAVITY • Floor of the Oral Cavity Nerve

Source

Course

Chorda tym pani

Facial n. in the tym panic cavity

Carries the preganglionic parasym pathetic bers to the subm andibular ganglion and taste bers to the anterior 2/ 3 of the tongue Passes anteriorly to enter the tym panic cavity and lies along the tym panic m em brane and m alleus until exiting the petrotym panic ssure Once it exits the petrotym panic ssure, the chorda tym pani joins the posterior border of the lingual n. The lingual n. is distributed to the anterior 2/ 3 of the tongue and the SVA bers from the chorda tym pani travel to the taste buds in this region

General Somatic Afferent (GSA) (Pain, temperature, discriminative touch)

Special Visceral Afferent (SVA) (Taste)

Vagus (X)

Vagus (X)

O verlap of Vagus (X) on posterior tongue

Glossopharyngeal (IX)

Glossopharyngeal (IX)

O verlap of nerves

Trigeminal (V) Facial (VII) (intermediate nerve)

Via lingual nerve

Taste via chorda tympani

Figu re 13-29

378

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

NERVE SUPPLY OF THE ORAL CAVITY • Palate Nerve

Source

Course

Maxillary

Trigem inal n.

Sensory in function Travels along the lateral wall of the cavernous sinus Passes from the m iddle cranial fossa into the pterygopalatine fossa via the foram en rotundum Within the pterygopalatine fossa, it gives rise to 4 branches: • Infraorbital (considered the continuation of the m axillary) • Ganglionic • Posterior superior alveolar • Zygom atic The infraorbital passes through the inferior orbital ssure to enter the orbit and passes anteriorly through the infraorbital groove and canal and exits onto the face via the infraorbital foram en Once the infraorbital n. exits onto the face, it divides into 3 term inal branches: • Nasal—supplies the ala of the nose • Inferior palpebral—supplies the skin of the lower eyelid • Superior labial—supplies the skin of the upper lip; 3 of its branches form a plexus to supply the m axillary arch: • Anterior superior alveolar • Middle superior alveolar • Posterior superior alveolar

Maxillary division of the trigem inal n. via the pterygopalatine ganglion in the pterygopalatine fossa

Passes through the sphenopalatine foram en to enter the nasal cavity Passes along the superior portion of the nasal cavity to the nasal septum , where it travels anteroinferiorly to the incisive canal supplying the septum Once entering the oral cavity, it provides sensory innervation to the palatal gingiva and m ucosa from the area anterior to the prem olars

Nasopalatine

Greater palatine

Passes through the palatine canal to enter the hard palate via the greater palatine foram en Provides sensory innervation to the palatal gingiva and m ucosa from the prem olars to the posterior border of the hard palate

Lesser palatine

Passes through the palatine canal to enter the hard palate via the lesser palatine foram en Provides sensory innervation to the soft palate

Glossopharyngeal

Medulla oblongata

13

Passes through the jugular foram en with the vagus and accessory nn. As it passes through the foram en, it passes between the internal carotid a. and internal jugular v. Continues to pass inferiorly and travels posterior to the stylopharyngeus m . Passes anteriorly with the stylopharyngeus and travels between the superior and m iddle constrictor m m . to be located by the palatine tonsils Sm all lingual branches arise from it and distribute general som atic afferent bers to the m ucous m em brane of the posterior 1/ 3 of the tongue, in addition to the pillars of the fauces

O RAL CAVITY 379

13

NERVE SUPPLY OF THE ORAL CAVITY • Palate

Maxillary nerve (V2 ) (sphenopalatine foramen dissected away) Pterygopalatine ganglion Greater petrosal nerve Deep petrosal nerve Nerve (vidian) of pterygoid canal Nasopalatine nerve (V2 ) passing to septum (cut) Lateral wall of nasal cavity Greater Palatine nerves (V2 ) Lesser

O lfactory nerves (I) Nasopalatine nerve (V2 ) Nasal septum

Trigeminal (V) (maxillary V2 ) Via superior alveolar nerves Via pterygopalatine ganglion and nasopalatine and greater and lesser palatine nerves

Facial (VII) (intermediate nerve) Via greater petrosal nerve, pterygopalatine ganglion, and greater and lesser palatine nerves Glossopharyngeal (IX) Via pharyngeal plexus Via tonsillar branches Taste plus general sensation via lingual branches Trigeminal nerve (V) Glossopharyngeal nerve (IX) Vagus nerve (X) Facial nerve (VII) Vagus (X) Via internal branch of superior laryngeal nerve

Figu re 13-30

38 0 NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

SALIVARY GLANDS • General Information •

• • •

13

Th ere are 3 p airs of m ajor salivary glan ds: • Parotid glan d • Su bm an d ibu lar glan d • Su blin gu al glan d Th ey secrete saliva in to th e oral cavity to aid in th e d igestion , m astication , an d d eglu tition of food Saliva is m u cou s or serou s in con sisten cy Man y m in or salivary glan ds are u biq u itou sly d istribu ted th rou gh ou t th e oral m u cosa of th e oral cavity

Superficial temporal artery and vein and auriculotemporal nerve

Parotid duct Buccinator muscle (cut) Masseter muscle

Sublingual fold with openings of sublingual ducts

Parotid gland

Sublingual caruncle with opening of submandibular duct Sublingual gland Submandibular duct

Submandibular gland

Parotid gland: totally serous

Submandibular gland: mostly serous, partially mucous

Sublingual gland: almost completely mucous

Figu re 13-31

O RAL CAVITY 381

13

SALIVARY GLANDS • General Information FEATURES OF THE MAJOR SALIVARY GLANDS

382

Gland

Duct

Comment

Autonomic Innervation

Parotid

Parotid duct (Stensen’s duct)

The largest salivary gland Pyram idal in shape, with up to 5 processes (or extensions) Saliva created by the parotid is serous Facial n. splits the parotid gland into a super cial lobe and a deep lobe, which are connected by an isthm us The parotid duct (Stensen’s duct) form s within the deep lobe and passes from the anterior border of the gland across the m asseter m . super cially, through the buccinator m . into the oral cavity opposite the 2nd m axillary m olar

Glossopharyngeal n.

Subm andibular

Subm andibular duct (Wharton’s duct)

2nd largest salivary gland A m ixed salivary gland, secreting both serous and m ucous saliva, but predom inantly serous-secreting Wraps around the posterior border of the m ylohyoid m ., to be located in the subm andibular triangle of the neck and the oor of the oral cavity The part of the subm andibular gland located in the subm andibular triangle is referred to as the super cial portion and is surrounded by the investing layer of deep cervical fascia Facial a. crosses between the subm andibular gland and the m andible before giving off the subm ental a., while the facial v. norm ally lies super cial to the gland Deep portion of the subm andibular gland lies in the oral cavity between the hyoglossus m . and the m andible and ends at the posterior border of the sublingual gland The subm andibular duct lies along the sublingual gland and em pties into the oral cavity at the sublingual papilla

Facial n.

Sublingual

Num erous sm all ducts opening along the sublingual fold

Sm allest of the 3 m ajor salivary glands A m ixed salivary gland, secreting both m ucous and serous saliva, but predom inantly m ucus-secreting Located in the oral cavity between the m ucosa of the oral cavity and the m ylohyoid m . Creates a sublingual fold in the oor of the oral cavity Lies between the sublingual fossa of the m andible and the genioglossus m . of the tongue The subm andibular duct lies on the sublingual gland Bartholin’s duct, a com m on duct that drains the anterior part of the gland in the region of the sublingual papilla, m ay be present

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

SALIVARY GLANDS • General Information

}

Incisor teeth (cutting action) Bicuspid and molar teeth (grinding action)

13

Aromatic substances released from food

From teeth and palate Saliva entering mouth Key Afferents (other than) Proprioception Somatic efferents

d Parotid an h t gland te e Fro m

Sublingual gland

t

g on

ue

To muscles of mastication Submandibular gland

Food particles progressively reduced in size and mixed with saliva. Tongue aids in mixing process

From back of tongue Afferents “report” on character of food and progress of mastication Proprioceptive bers “report” on pressure

Figu re 13-32

O RAL CAVITY 383

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SALIVARY GLANDS • Autonomics of the Salivary Glands PARASYMPATHETICS OF THE PAROTID GLAND

384

Characteristics of Cell Body

Type of Neuron

Name of Cell Body

Course of the Neuron

Preganglionic neuron

Inferior salivatory nucleus

A collection of nerve cell bodies located in the m edulla

Preganglionic parasym pathetic bers arise from the inferior salivatory nucleus in the m edulla Travel through the glossopharyngeal n. and exit the jugular foram en Gives rise to the tym panic branch of cranial n. IX, which reenters the skull via the tym panic canaliculus The tym panic branch of IX form s the tym panic plexus along the prom ontory of the ear The plexus re-form s as the lesser petrosal n., typically exiting the foram en ovale to enter the infratem poral fossa Lesser petrosal n. joins the otic ganglion

Postganglionic neuron

Otic ganglion

A collection of nerve cell bodies located inferior to the foram en ovale, m edial to the m andibular division of the trigem inal

Postganglionic parasym pathetic bers arise in the otic ganglion These bers travel to the auriculotem poral branch of the trigem inal n. Auriculotem poral n. travels to parotid gland Postganglionic parasym pathetic bers innervate the: • Parotid gland

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

SALIVARY GLANDS • Autonomics of the Salivary Glands

13

Trigeminal ganglion

Mandibular nerve (V3 )

Lesser petrosal nerve

O tic ganglion

Chorda tympani nerve O phthalmic nerve (V1 )

Trigeminal nerve (V) Facial nerve (VII)

Maxillary nerve (V2 )

Glossopharyngeal nerve (IX)

Auriculotemporal nerve

Inferior salivatory nucleus

Superficial temporal artery

Pons

Parotid gland Maxillary artery Medulla oblongata Tympanic plexus Inferior alveolar nerve

Tympanic nerve (Jacobson) Inferior ganglion (IX)

Lingual nerve

Superior cervical sympathetic ganglion Sympathetic trunk T1 and T2 spinal nerves Thoracic spinal cord

External carotid artery

Dorsal root Internal carotid artery

Common carotid artery White

Gray

Rami communicantes Sympathetic presynaptic fibers Sympathetic postsynaptic fibers Parasympathetic presynaptic fibers Parasympathetic postsynaptic fibers

Ventral root

Sympathetic presynaptic cell bodies in intermediolateral nucleus (lateral horn) of gray matter

Figu re 13-33

O RAL CAVITY 385

13

SALIVARY GLANDS • Autonomics of the Salivary Glands PARASYMPATHETICS OF THE SUBMANDIBULAR, SUBLINGUAL, AND MINOR SALIVARY GLANDS Characteristics of Cell Body

Type of Neuron

Name of Cell Body

Course of the Neuron

Preganglionic neuron

Superior salivatory nucleus

A collection of nerve cell bodies located in the pons Travel through the nervus interm edius of the facial n. into the internal acoustic m eatus In the facial canal, the facial n. gives rise to 2 parasym pathetic branches: • Greater petrosal n. • Chorda tym pani n.

Gre ate r Pe tro s al Ne rve Exits along the hiatus for the greater petrosal n. toward the foram en lacerum , where it joins the deep petrosal n. (sym pathetics) to form the nerve of the pterygoid canal (vidian n.) Vidian n. passes through the pterygoid canal and enters the pterygopalatine fossa, where it joins with the pterygopalatine ganglion Cho rda Tympani Ne rve Exits the petrotym panic ssure to enter the infratem poral fossa, where it joins the lingual n. Preganglionic bers travel with the lingual n. into the oor of the oral cavity, where it joins with the subm andibular ganglion

Postganglionic neuron

Pterygopalatine ganglion

A collection of nerve cell bodies located in the pterygopalatine fossa Postganglionic parasym pathetic bers that arise in the pterygopalatine ganglion are distributed to the ophthalm ic and m axillary divisions of the trigem inal n. to the: • Lacrim al gland • Nasal glands • Palatine glands • Pharyngeal glands • Paranasal sinus glands

Ophthalmic and Maxillary Divis io n Dis tributio n Postganglionic bers travel along the zygom atic branch of the m axillary division for a short distance to enter the orbit A short com m unicating branch joins the lacrim al n. of the ophthalm ic division of the trigem inal n. These bers innervate: • Lacrim al gland, to cause the secretion of tears Maxillary Divis io n Dis tributio n Postganglionic bers travel along the m axillary division of the trigem inal n. to be distributed along its branches that are located in the nasal cavity, oral cavity, and pharynx (e.g., nasopalatine, greater palatine) These bers innervate: • Nasal glands • Palatine glands • Pharyngeal glands • Paranasal sinus glands

Subm andibular ganglion

A collection of nerve cell bodies in the oral cavity Suspended from the lingual n. at the posterior border of the m ylohyoid m . im m ediately superior to the deep portion of the subm andibular gland

Postganglionic parasym pathetic bers arise in the subm andibular ganglion and are distributed to the: • Subm andibular gland • Sublingual gland

38 6 NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

SALIVARY GLANDS • Autonomics of the Salivary Glands

Trigeminal ganglion Deep petrosal nerve Greater petrosal nerve

O phthalmic nerve (V1 ) Mandibular nerve (V3 ) O tic ganglion Lingual nerve Maxillary nerve (V2 ) Nerve (vidian) of pterygoid canal Pterygopalatine ganglion Lacrimal gland

Descending palatine nerves

13

Chorda tympani nerve Trigeminal nerve (V) Facial nerve (VII) (intermediate nerve) Superior salivatory nucleus

Pharyngeal nerve Maxillary artery

Posterior nasal nerves

Internal carotid nerve

Palatine nerves

Glossopharyngeal nerve (IX) Superior cervical sympathetic ganglion Sympathetic trunk T1 and T2 spinal nerves

Greater Lesser

Thoracic spinal cord

Submandibular ganglion

Dorsal root Sublingual gland White

Submandibular gland

Gray

Rami communicantes Ventral root

Facial artery Lingual artery

Internal carotid artery

External carotid artery and plexus Common carotid artery

Sympathetic presynaptic cell bodies in intermediolateral nucleus (lateral horn) of gray matter

Sympathetic presynaptic fibers Sympathetic postsynaptic fibers Parasympathetic presynaptic fibers Parasympathetic postsynaptic fibers

Figu re 13-34

O RAL CAVITY 387

13

CLINICAL CORRELATES • Gingivitis • • • • • • •

Gingivitis: an in am m ation of th e gin giva th at occu rs wh en bacteria accu m u late between th e teeth an d gin giva In add ition to th e in am m ation , th e gu m s m ay dem on strate irritation an d bleed in g W h en p laq u e (com p osed of bacteria, food d ebris, an d saliva) is d ep osited on th e teeth , it can form tartar if it is n ot rem oved Plaq u e an d tartar cau se irritation to th e gin giva, an d th e bacteria (an d th eir toxin s) fu rth er irritate th e gin giva, lead in g to bleed in g an d swellin g If gin givitis rem ain s u n treated , it m ay p rogress to m ore seriou s gin gival diseases, su ch as p eriodon titis Lon g-term u n treated gin givitis m ay lead to dam age of bon e an d loss of teeth Risk factors for gin givitis in clu d e p oor d en tal h ygien e, p regn an cy, d iabetes, illn ess, an d h u m an im m u n od e cien cy viru s (HIV) in fection

Marginal gingivitis

Hypertrophic gingivitis

Figu re 13-35

38 8 NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

CLINICAL CORRELATES • Dental Caries • • • • • • • • • • •

13

Dental caries (tooth d ecay), lead in g to “cavities,” are cau sed by bacteria in th e oral cavity Th e bacteria con vert foods in to acid s an d h elp form p laq u e (m ade of bacteria, food d ebris, an d saliva), wh ich is d ep osited on th e teeth Plaq u e th at is n ot rem oved from th e teeth can m in eralize to form tartar Plaq u e is m ost p rom in en t on dif cu lt-to-reach teeth , su ch as th e p osterior m olars Acid s form ed in th e p laq u e begin to erode th e en am el on th e su rface of th e tooth , cau sin g a “cavity” If n ot treated , th e cavity grows in size, with on set of p ain as th e n erves an d blood vessels of th e affected teeth becom e irritated Con su m in g food s rich in su gar an d starch in creases th e risk of d en tal caries Den tal caries can be d etected on rou tin e d en tal exam in ation s Th e d am age associated with d en tal caries can n ot be rep aired by th e affected tooth , wh ich n ow m u st be restored Flu orid e is u sed to red u ce th e risk of den tal caries by in h ibitin g d em in eralization an d p rom otin g rem in eralization of tooth stru ctu re Saliva h elp s p rom ote th e rem in eralization p rocess; m ed ication s th at d ecrease salivary ow (su ch as an tich olin ergics) p rom ote d en tal caries

Food impaction Caries

Effect of missing tooth

Dental caries

Figu re 13-36

O RAL CAVITY 389

13

CLINICAL CORRELATES • Torus • • •

•

Torus: a n on p ath ologic bon y elevation th at occu rs in th e oral cavity Th e p resen ce of a toru s does n ot im p ede eatin g or verbal com m u n ication bu t can cau se d if cu lty in th e ap p lication of a d en tal ap p lian ce, su ch as a d en tu re 2 m ajor typ es: • Palatin e–a down growth of bon e in th e m idlin e of th e h ard p alate • Man dibu lar–an ou tgrowth of bon e th at occu rs on th e lin gu al su rface of th e m an d ible A toru s d oes n ot req u ire treatm en t u n less it in terferes with n orm al fu n ction or ap p lication of d en tal ap p lian ces

Torus palatinus

Figu re 13-37

39 0 NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

CLINICAL CORRELATES • Mucocele • • • • •

13

Mucocele: a m u cou s cyst th at resu lts from obstru ction of th e d u cts of m in or salivary glan ds (th is lesion also can be associated with blockage of th e m ajor salivary glan ds) Often cau sed by trau m a to th e du ct system Usu ally located on th e lin gu al asp ect of th e lip Th ese lesion s con tain m u cin an d gran u lation tissu e Persisten t m u coceles often are excised

Mucocele of lip

Figu re 13-38

O RAL CAVITY 391

13

CLINICAL CORRELATES • Herpes Simplex • • • • • • • • •

• •

Herpes sim plex is th e m ost com m on cau se of viral stom atitis Cau sed by exp osu re to h erp es sim p lex viru s typ e 1 (HSV-1) HSV-1 u su ally affects th e region s above th e waist, cau sin g fever blisters Most affected p eop le acq u ire th e in fection as a ch ild Du rin g th e p rim ary in fection with HSV-1, m u ltip le vesicles ap p ear on th e lip s, gin giva, h ard p alate, an d ton gu e Th ese vesicles ru p tu re, p rod u cin g u lcers th at h eal in 7 to 10 d ays After in itial exp osu re, th e viru s is tran sp orted alon g a retrograde p ath in to th e trigem in al gan glion , wh ere it stays in active an d d oes n ot rep licate Ep isod es m ay recu r Som e recu rren ce triggers: • Stress • Fever • An xiety • Exp osu re to th e su n • Su p p ressed im m u n e system In fection can be sp read th rou gh con tact with in fected lip s System ic ad m in istration of an tiviral agen ts, su ch as acyclovir, d ecreases th e d u ration of th e recu rren t ep isod es

Meningeal branches

O phthalmic branch

Trigeminal ganglion

HSV Maxillary branch

Mandibular branch

CN-V

Primary Infection

Latent Phase

Virus enters via cutaneous or mucosal surfaces to infect sensory or autonomic nerve endings with transport to cell bodies in ganglia.

Virus replicates in ganglia before establishing latent phase.

Figu re 13-39

392

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

CLINICAL CORRELATES • Tonsillitis • •

• •

• • •

13

Tonsillitis: an in am m ation of th e ton sils, th e lym p h n od es located in th e oral cavity an d p h aryn x Th ere are 3 sets of ton sils: • Ph aryn geal (ad en oid s) • Palatin e (between th e p alatoglossal an d p alatop h aryn geal arch es) • Lin gu al (on p osterior 1/ 3 of th e ton gu e) Th ese 3 sets of ton sils form Wald eyer’s rin g Sym p tom s of ton sillitis: • Sore th roat • Dysp h agia • Fever • Headach e Ton sillitis often is cau sed by a viru s or bacteriu m W h en cau sed by a bacterial in fection , it m ay be treated by an tibiotics If n ecessary, a ton sillectom y is p erform ed to rem ove th e ton sils. Palatin e ton sils are rem oved in a ton sillectom y (alth ou gh th e p h aryn geal ton sils also m ay be rem oved at th e sam e tim e, esp ecially if th ey are obstru ctin g n asal breath in g)

Acute follicular tonsillitis

Figu re 13-40

O RAL CAVITY 393

13

CLINICAL CORRELATES • Sialolithiasis • • • • • • •

Sialolithiasis is a con d ition in wh ich ston es or calcu li form in th e salivary glan d s or d u cts Greater th an 80% of sialolith s are of su bm an d ibu lar glan d origin More com m on in m en th an in wom en W h en saliva d im in ish es in ow, it is easier for ston es or calcu li to form Certain m edication s, su ch as an tich olin ergics, d im in ish salivary ow, m akin g th e p atien t m ore su scep tible to th e form ation of sialolith s Treatm en t in clu des con servative m eth od s su ch as h yd ration an d warm com p resses an d m ore sp eci c ap p roach es ran gin g from an tibiotics to su rgical in terven tion Oth er treatm en ts in clu d e sh ock-wave lith otrip sy an d en d oscop ic in tracorp oreal laser lith otrip sy to fractu re th e sialolith in to sm aller p ieces to p ass

Sialolith of the sublingual gland

Sialolith of the submandibular gland

Figu re 13-41

394

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

IMAGING

13

Incisive fossa

Maxillary sinus Greater palatine foramen Lesser palatine foramen

Incisive fossa Palatine process of the maxilla

Intermaxillary suture Transverse palatine suture

Greater palatine foramen

Horizontal plate of the palatine Lesser palatine foramen

Cone beam CT of patient. Note canal filled with gutta percha from endodontic treatment

Figu re 13-42

O RAL CAVITY 395

13

IMAGING

Dental Procedures and Findings Amalgam restoration on right mandibular 1st molar Root tip

Root canal treatment

Root tip

Area of missing left lateral incisor

Left central incisor

Post in the left canine

Bridge between the left central incisor and the left canine (with a post) Panoramic X-rays Impacted right 3rd maxillary molar (protruding into maxillary sinus)

Impacted left 3rd maxillary molar (protruding into maxillary sinus)

Impacted right 3rd mandibular molar

Impacted left 3rd mandibular molar

Mandibular Condyle fossa

Maxillary sinus

Mental foramen

Maxillary and Mandibular Radiographs

2nd maxillary molar (porcelain fused to metal crown – PFM)

1st maxillary molar (with metallic restoration)

2nd maxillary premolar (with metallic restoration)

Figu re 13-43

396

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

Caries on left 3rd maxillary molar

Mandibular canal

IMAGING

13

Maxillary and Mandibular Radiographs

1st maxillary premolar (with metallic restoration)

Maxillary canine

Maxillary Fractured central incisors incisal edge

Maxillary Maxillary central incisor lateral incisor (with fractured (with metallic incisal edge) restoration)

1st mandibular molar 2nd mandibular molar 3rd mandibular (with PFM restoration) (with PFM restoration) molar

Mandibular lateral incisor

Mandibular central incisors

1st and 2nd mandibular premolars (with PFM 1st and 2nd mandibular molars metallic restorations) (with PFM restorations)

Post

Lingual foramen

Root canal treatment

Figu re 13-44

O RAL CAVITY 397

This pa ge inte ntiona lly le ft bla nk

CHAPTER 14

TONGUE

Overview and Topographic Anatomy

400

Gross Anatomy

402

Muscles

40 6

Nerve Supply

410

Vascular Supply

416

Clinical Correlates

420

14

OVERVIEW AND TOPOGRAPHIC ANATOMY • General Information • • • •

Tongue: a m u scu lar stru ctu re in th e oral cavity, d ivid ed in to 2 p arts: • Oral (p resu lcal), m ovable p art—th e an terior 2/ 3 of th e ton gu e • Ph aryn geal (p ostsu lcal), n on m ovable p art—th e p osterior 1/ 3 of th e ton gu e Th e su lcu s term in alis, a V-sh ap ed groove im m ed iately p osterior to th e circu m vallate p ap illa, sep arates th e oral p art from th e p h aryn geal p art of th e ton gu e Th e foram en cecu m , wh ich was th e in itial develop m en t site for th e th yroid glan d , is located at th e tip (or an gle) of th e V Med ian brou s sep tu m sep arates th e ton gu e in to h alves

FUNCTIONS

• • • •

Mastication Taste Talkin g Deglu tition

APPEARANCE

• •

•

Th e ton gu e typ ically is p in k an d covered with n u m erou s sm all bu m p s called p ap illa Ch an ge in color or textu re m ay re ect h ealth p roblem s: • Leu kop lakia • Sq u am ou s cell carcin om a • Nu trition al de cien cies An u n u su al ap p earan ce of th e ton gu e m ay rep resen t a ben ign h arm less con d ition : • Fissu red ton gu e • Black h airy ton gu e • Geograp h ic ton gu e

MUSCLE TYPES

• •

Extrinsic—m ove th e ton gu e as an an atom ic stru ctu re Intrinsic—ch an ge th e ton gu e’s sh ap e Palatine tonsil Palatoglossus muscle in palatoglossal arch

Palatopharyngeus muscle in palatopharyngeal arch

Styloglossus muscle Inferior alveolar artery, vein and nerve Ramus of mandible Medial pterygoid muscle Lingual nerve Superior pharyngeal constrictor muscle Masseter muscle Buccal nerve Pterygomandibular raphe Buccinator muscle O rbicularis oris muscle Horizontal section below lingula of mandible (superior view) demonstrating bed of parotid gland

Figu re 14-1

400

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OVERVIEW AND TOPOGRAPHIC ANATOMY • General Information

14

Fissured tongue

Hairy tongue

Geographic tongue

Figu re 14-2

TO NGUE 401

14

GROSS ANATOMY • Parts of the Tongue ORAL PART (PRESULCAL) • The oral part of the tongue is also known as the anterior 2/ 3 of the tongue • Develops from the 2 lateral lingual swellings and tuberculum im par of the 1st pharyngeal arch—thus m ucosa is innervated by the nerve of the 1st arch, which is the trigem inal nerve (lingual n.) • Has a dorsal and a ventral surface

Dorsal Surface • The m ucosa is keratinized strati ed squam ous epithelium • Is bounded posteriorly by the sulcus term inalis

402

Structures

Comments

Median sulcus

A groove that travels anteriorly in the m idline Represents the location of the m edian septum that divides the tongue in halves The septum is thicker posteriorly but thinner anteriorly

Papillae—there are 4 types of papillae on the dorsal surface of the tongue: • Filiform —lack taste buds Most num erous type of papillae Have thick keratin on epithelium • Fungiform —have taste buds that receive taste innervation from the facial nerve (chorda tym pani branch) Scattered throughout the dorsum of the oral part Lack keratin on the epithelium • Foliate—have taste buds that receive taste innervation from the facial nerve (chorda tym pani branch) Are located on the sides of the tongue in 4 to 5 folds im m ediately anterior to the palatoglossal fold Lack keratin on the epithelium • Circum vallate—have taste buds that receive taste innervation from the glossopharyngeal nerve Generally a nonkeratinized epithelium Lie in a row im m ediately anterior to the sulcus term inalis

Papillae are raised projections that increase the surface area 5 basic types of taste are differentiated by the taste buds: • Bitter • Salt • Sweet • Sour • Um am i

Glands

There are num erous m ucous and serous glands on the dorsal surface

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

GROSS ANATOMY • Parts of the Tongue

14

Epiglottis Median glossoepiglottic fold Lateral glossoepiglottic fold Vallecula Palatopharyngeal arch and muscle (cut) Palatine tonsil (cut) Lingual tonsil (lingual nodules) Palatoglossal arch and muscle (cut) Foramen cecum Terminal sulcus Vallate papillae

Pharyngeal part

Foliate papillae Filiform papillae O ral part Fungiform papilla Midline groove (median sulcus) Dorsum of tongue Apex Lingual tonsil

Filiform papillae Fungiform papilla Keratinized tip of papilla

Crypt

Intrinsic muscle Duct of gland

Schematic stereogram: area indicated above

Lymph follicles Mucous glands Vallate papilla Taste buds Furrow Lingual glands (serous glands of von Ebner)

Stratified squamous epithelium Sustentacular cell Sensory cell Taste pore Lamina propria Section of taste bud

Figu re 14-3

TO NGUE 403

14

GROSS ANATOMY • Parts of the Tongue Ventral Surface • The m ucosa is nonkeratinized strati ed squam ous epithelium

Structures

Comments

Lingual frenulum

A m idline fold of tissue Connects the ventral surface of the tongue to the oor of the oral cavity

Sublingual papilla

A swelling on both sides of the lingual frenulum at the tongue base Marks the entrance of saliva from the subm andibular glands into the oral cavity Continuous with the sublingual folds overlying the sublingual glands on the oor of the oral cavity

Plica m briata

Fim briated folds Lateral to the lingual frenulum

Deep lingual veins

Can be observed through the m ucosa between the plica m briata and the lingual frenulum

Frenulum of upper lip Lingual minor salivary gland Deep lingual artery and veins and lingual nerve Fimbriated fold Submandibular duct Sublingual gland Frenulum of tongue Sublingual fold with openings of sublingual ducts Sublingual caruncle with opening of submandibular duct Frenulum of lower lip

Figu re 14-4

404

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GROSS ANATOMY • Parts of the Tongue

14

PHARYNGEAL PART (POSTSULCAL) • The pharyngeal part of the tongue is also known as the posterior 1/ 3 of the tongue • Develops from the hypobranchial em inence of the 3rd pharyngeal arch—thus m ucosa is innervated by the nerve of the 3rd arch (the glossopharyngeal nerve) • The area im m ediately posterior to the palatoglossal folds (also called the anterior pillar of the fauces) is the oropharynx • Has a dorsal surface only • Does not possess any papilla

Dorsal Surface • The m ucosa is nonkeratinized strati ed squam ous epithelium

Structures

Comments

Lingual tonsils

Large nodules of lym phatic tissue Cover the pharyngeal surface of the tongue

Glossoepiglottic folds

Mucous m em brane of nonkeratinized strati ed squam ous epithelium from the pharyngeal part and lateral wall of pharynx that re ects onto the anterior epiglottis, form ing: • Median glossoepiglottic fold • 2 lateral glossoepiglottic folds The m edian glossoepiglottic fold is bordered by a depression on each side: • Vallecula Connect the posterior portion of the pharyngeal part of the tongue with the epiglottis of the larynx

Epiglottis Median glossoepiglottic fold Lateral glossoepiglottic fold Vallecula

Pharyngeal part

Palatopharyngeal arch and muscle (cut) Palatine tonsil (cut) Lingual tonsil (lingual nodules) Palatoglossal arch and muscle (cut) Foramen cecum Terminal sulcus Vallate papillae Foliate papillae Filiform papillae

O ral part Fungiform papilla Midline groove (median sulcus) Dorsum of tongue Apex

TO NGUE 405

14

MUSCLES • Extrinsic Tongue Muscles Muscle

Origin

Insertion

Actions

Genioglossus

Superior genial tubercle of the m andible

Hypoglossal Superior bers Protrusion of n. fan into the the tongue entire ventral Bilaterally—the surface of the 2 m uscles will tongue while depress the interm ixing with central the intrinsic portion of the m uscles) tongue, which m akes the Interm ediate dorsal surface bers fan concave posteriorly in attach to the Unilaterally— posterior m akes the tongue tongue deviate to the Inferior bers contralateral insert into the side body of the hyoid via an aponeurosis

The lingual a. is located between the genioglossus and hyoglossus mm.

Hyoglossus

Greater cornu and anterior portion of the body of the hyoid

Lateral portion of the tongue between the styloglossus m . and the inferior longitudinal m .

Depresses the tongue

The lingual n., hypoglossal n., and subm andibular duct are located on the lateral surface of the hyoglossus m . Som e authors describe the chondroglossus as a separate m uscle or as part of the hyoglossus

Styloglossus

Anterolateral portion near the apex of the styloid process Stylom andibular ligam ent

Longitudinal portion inserts into the dorsolateral part of the tongue to interm ix with the inferior longitudinal m . Oblique portion inserts into the dorsolateral portion of the tongue to interm ix with the hyoglossus m.

Retrusion of the tongue Elevation of the tongue

Sm allest of the extrinsic tongue m uscles

Palatoglossus

Palatine aponeurosis (oral surface)

Lateral side of the Elevation of the Pharyngeal Grouped as tongue where root of the either an plexus som e bers extrinsic tongue tongue (the m otor interm ix with portion of m uscle of the Narrows the the transverse this plexus tongue or a oropharyngeal m . and som e is form ed m uscle of the isthm us for along the dorsal by the soft palate deglutition surface of the pharyngeal tongue branch of the vagus n.)

40 6 NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

Nerve

Comment

MUSCLES • Extrinsic Tongue Muscles

14

Palatopharyngeus muscle Palatoglossus muscle Inferior longitudinal muscle of tongue

Mastoid process Digastric muscle (posterior belly) (cut) Styloid process Pharyngobasilar fascia Superior pharyngeal constrictor muscle Stylohyoid ligament Styloglossus muscle Glossopharyngeal part of superior pharyngeal constrictor Stylopharyngeus muscle Stylohyoid muscle Middle pharyngeal constrictor muscle Digastric muscle (posterior belly) (cut) Hyoglossus muscle Intermediate tendon of digastric muscle (cut)

Genioglossus muscle

Fibrous loop for intermediate digastric tendon Hyoid bone

Mylohyoid muscle (cut) Geniohyoid muscle

Figu re 14-5

Palatoglossus Genioglossus

Salpingopharyngeus

Deep lingual artery

Palatopharyngeus Superior constrictor

Artery of lingual foramen

Glossopharyngeal nerve Dorsal lingual artery Lingual artery

Sublingual artery

Middle constrictor

Geniohyoid Hypoglossal nerve Hyoglossus

Stylohyoid ligament

Figu re 14-6

TO NGUE 407

14

MUSCLES • Intrinsic Tongue Muscles Muscle

Origin

Insertion

Actions

Nerve

Comment

Superior longitudinal

Median septum Subm ucous layer near epiglottis

Lingual m argins

Shortens Curls the tongue’s apex and lateral m argins upward, which m akes the dorsal surface concave

Hypoglossal n.

Located im m ediately deep to the m ucous m em brane of the tongue’s dorsal surface

Inferior longitudinal

Root of the tongue Body of the hyoid

Apex of the tongue

Shortens Curls the tongue’s apex downward, which m akes the dorsal surface convex

Runs the length of the tongue between the hyoglossus and genioglossus mm.

Transverse

Median septum

Fibrous tissue in the subm ucosa of the lingual m argins Som e bers interm ix with palatoglossus

Narrows Lengthens

Runs the width of the tongue

Vertical

Subm ucosa of dorsal surface of tongue

Subm ucosa of ventral surface of tongue

Broadens Flattens

Runs from the dorsal to the ventral tongue surface

40 8 NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

MUSCLES • Intrinsic Tongue Muscles

Superior longitudinal muscle Vertical and transverse muscles Inferior longitudinal muscle Styloglossus muscle Buccinator muscle Muscles of facial expression Hyoglossus muscle Genioglossus muscle

14

of tongue

Mandibular canal, inferior alveolar artery, vein, and nerve Lingual nerve Nerve to mylohyoid Vena comitans of hypoglossal nerve (to lingual vein) Lingual artery Hypoglossal nerve (XII) Submandibular salivary gland Mylohyoid muscle

Hard palate

Hyoid bone

Frontal section behind 1st molar tooth (anterior view) demonstrating beds of sublingual and submandibular glands

O ral cavity Palatine tonsil Body of tongue O ropharynx Foramen cecum Lingual tonsil Genioglossus muscle Root of tongue Epiglottis Mandible Geniohyoid muscle Hyoid bone

Figu re 14-7

TO NGUE 409

14

NERVE SUPPLY • Sensory Innervation TYPES OF SENSORY NERVE SUPPLY Type

Function

Nerves

General som atic afferent (GSA)

Pain, tem perature, discrim inative touch

Trigem inal (via lingual), glossopharyngeal, and vagus (via internal laryngeal), to innervate the m ucosa

Special visceral afferent (SVA)

Taste

Facial (via chorda tym pani), glossopharyngeal, and vagus (via internal laryngeal), to innervate the taste buds

A. Tongue

B. Section through vallate papilla Taste buds Duct of gustatory (Ebner’s) gland

Foliate papillae

C. Taste bud Epithelium Fungiform papillae

Basement membrane

Vallate papillae

Nerve plexus Microvilli

Nerve fibers emerging from taste buds

Taste pore Taste cells

Desmosomes Epithelium Microvilli

Basement membrane Large nerve fiber Small nerve fiber Granules Intercellular space Large nerve fiber

D. Detail of taste pore

E. Detail of base of receptor cells

Figu re 14-8

410

Fibroblast Schwann cell Collagen

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

NERVE SUPPLY • Sensory Innervation General Somatic Afferent (GSA) (Pain, temperature, discriminative touch)

14

Special Visceral Afferent (SVA) (Taste) Vagus (X)

Vagus (X) O verlap of Vagus (X) on posterior tongue

Glossopharyngeal (IX)

Glossopharyngeal (IX) O verlap of nerves Trigeminal (V) Via lingual nerve

Facial (VII) (intermediate nerve) Taste via chorda tympani

Figu re 14-9 GENERAL SENSORY INNERVATION (GENERAL SOMATIC AFFERENT) Nerve

Source

Course

Lingual

Mandibular division of the trigem inal n.

Lies inferior to the lateral pterygoid m . and m edial and anterior to the inferior alveolar nn. within the infratem poral fossa Chorda tym pani branch of the facial n. joins its posterior part Lingual n. passes between the m edial pterygoid m . and the ram us of the m andible to pass obliquely, entering the oral cavity bounded by the superior pharyngeal constrictor m ., the m edial pterygoid, and the m andible Enters the oral cavity lying along the lingual tuberosity of the m andible The subm andibular ganglion is suspended from the lingual n. at the posterior border of the hyoglossus m . Continues anteriorly and passes onto the lateral surface of the hyoglossus Passes from the lateral side inferiorly and m edial to the subm andibular duct to reach the m ucosa of the tongue Supplies GSA bers to the epithelium and papillae of the tongue’s anterior 2/ 3, m ucosa along the oor of the oral cavity (linguoalveolar ridge), and gingiva on the lingual aspect of the m andibular teeth

Glossopharyngeal

Arises as a cranial nerve from the m edulla oblongata

Passes through the jugular foram en with the vagus and accessory nn. Within the foram en, it passes between the internal carotid a. and the internal jugular v. Continues inferiorly and posteriorly relative to the stylopharyngeus m. Passes anteriorly with the stylopharyngeus m . and travels between the superior and m iddle constrictor m m . to becom e located by the palatine tonsils Sm all lingual branches distribute GSA bers to the epithelium of the tongue’s posterior 1/ 3, in addition to the fauces

Internal laryngeal

Superior laryngeal branch of the vagus n.

Vagus n. branches from the m edulla oblongata and passes through the jugular foram en with the glossopharyngeal and accessory nn. Within the foram en, it passes between the internal carotid a. and the internal jugular v. A series of nerves branch from the vagus in the neck, including the superior laryngeal n., which travels inferiorly posterior to the internal carotid a. on the side of the pharynx and divides into the internal and external laryngeal nn. The internal laryngeal n. passes inferior to the larynx and passes through the thyrohyoid m em brane with the superior laryngeal vv. Distributes GSA bers to the tongue’s base at the epiglottic region and the m ucous m em branes of the larynx as far inferiorly as the false vocal folds

TO NGUE 411

14

NERVE SUPPLY • Sensory Innervation SPECIAL SENSORY INNERVATION (SPECIAL VISCERAL AFFERENT)

412

Nerve

Source

Course

Chorda tym pani

Facial n. in the tym panic cavity

Carries preganglionic parasym pathetic bers to the subm andibular ganglion and taste bers to the anterior 2/ 3 of the tongue Passes anteriorly to enter the tym panic cavity and lies along the tym panic m em brane and m alleus until exiting the petrotym panic ssure Joins the posterior border of the lingual n. Lingual n. is distributed to the anterior 2/ 3 of the tongue, and the SVA bers from the chorda tym pani travel to the taste buds in this region

Glossopharyngeal

Arises as a cranial nerve from the m edulla oblongata

Passes through the jugular foram en with the vagus and accessory nn. Within the foram en, it passes between the internal carotid a. and the internal jugular v. Continues inferiorly and travels posterior to the stylopharyngeus m . Passes anteriorly with the stylopharyngeus m . and travels between the superior and m iddle constrictor m m ., to be located by the palatine tonsils Sm all lingual branches distribute SVA bers to the taste buds in the m ucous m em brane of the tongue’s posterior 1/ 3 and the circum vallate papilla

Internal laryngeal

Superior laryngeal branch of the vagus n.

Vagus n. branches from the m edulla oblongata and passes through the jugular foram en with the glossopharyngeal and accessory nn. Within the foram en, it passes between the internal carotid a. and the internal jugular v. A series of nerves branch from the vagus in the neck, including the superior laryngeal n., which travels inferiorly posterior to the internal carotid on the side of the pharynx and divides into the internal and external laryngeal nn. The internal laryngeal n. passes inferior to the larynx and passes through the thyrohyoid m em brane with the superior laryngeal vv. Distributes SVA bers to the taste buds scattered at the base of the tongue at the epiglottic region

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

NERVE SUPPLY • Sensory Innervation

14

Internal carotid nerve Glossopharyngeal nerve (IX) Laryngopharyngeal sympathetic branch

C1

Vagus nerve (X) (cut) Superior cervical sympathetic ganglion C2

Pharyngeal plexus

C3

Pharyngeal branch of vagus nerve External carotid artery and plexus

C4 Gray rami communicantes

Superior laryngeal nerve Internal carotid artery and carotid branch (of Hering) of glossopharyngeal nerve Carotid body Carotid sinus

C5 C6

Phrenic nerve (cut) Middle cervical sympathetic ganglion Common carotid artery and plexus

C7

Vertebral ganglion Vertebral artery and plexus Recurrent laryngeal nerve Cervicothoracic (stellate) ganglion

C8 T1

Vagus nerve (X) (cut)

Gray and white rami communicantes Subclavian artery Anterior division Posterior division

Chorda tympani nerve Inferior alveolar nerve (cut) Lingual nerve Stylohyoid muscle Hypoglossal nerve Lateral view

Pharyngeal mucosa removed Salpingopharyngeus muscle Lesser palatine artery Pterygoid hamulus Pterygomandibular raphe Superior pharyngeal constrictor muscle Palatopharyngeus muscle Palatoglossus muscle Glossopharyngeal nerve (IX) and tonsillar branch Stylohyoid ligament Hyoglossus muscle Middle pharyngeal constrictor muscle Stylopharyngeus muscle

Figu re 14-10

TO NGUE 413

14

414

NERVE SUPPLY • Motor Innervation Nerve

Source

Course

Hypoglossal

Arises as a series of rootlets from the m edulla oblongata and passes through the hypoglossal canal

Travels inferiorly and is located between the internal carotid a. and the internal jugular v. Passes anteriorly as it wraps around the occipital a. Passes super cial to the external carotid and the loop of the lingual a. in its anterior path Passes deep to the posterior belly of the digastric and the stylohyoid m . and lies super cial to the hyoglossus m . with the accom panying vein of the hypoglossal n. Passes deep to the m ylohyoid m . and continues anteriorly in the genioglossus m . Muscular branches supply: • All intrinsic tongue m uscles • Hyoglossus m . • Styloglossus m . • Genioglossus m .

Pharyngeal plexus

Pharyngeal plexus (the m otor portion of this plexus is form ed by the pharyngeal branch of the vagus n.)

Arises from the upper part of the inferior ganglion of the vagus n. Lies along the upper border of the m iddle constrictor m ., where it form s the pharyngeal plexus Motor branches from the plexus are distributed to the m uscles of the pharynx and soft palate (with the exception of the tensor veli palatini m .) In the tongue, it innervates: • Palatoglossus m .

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

NERVE SUPPLY • Motor Innervation

Hypoglossal nerve (XII) (in hypoglossal canal)

Transverse and vertical Inferior longitudinal

Meningeal branch Hypoglossal nucleus

Superior longitudinal

Intrinsic muscles of tongue

14

Styloglossus muscle

O ccipital condyle Inferior ganglion of vagus nerve Ventral rami of C1, 2, 3 form ansa cervicalis of cervical plexus Superior cervical sympathetic ganglion Superior root of ansa cervicalis

Genioglossus muscle

Internal carotid artery

Geniohyoid muscle

Inferior root of ansa cervicalis

Hyoglossus muscle Thyrohyoid muscle

Ansa cervicalis

O mohyoid muscle (superior belly)

Internal jugular vein Common carotid artery

Sternohyoid muscle Sternothyroid muscle O mohyoid muscle (inferior belly)

Efferent fibers Afferent fibers

Figu re 14-11

TO NGUE 415

14

VASCULAR SUPPLY • Arterial Supply Artery

Source

Course

Lingual

External carotid a. within the carotid triangle

Passes superiorly and m edially (obliquely) toward the greater cornu of the hyoid bone and m akes a loop by passing anteriorly and inferiorly while traveling super cial to the m iddle constrictor m . While form ing a loop, the artery is crossed super cially by the hypoglossal n. Passes deep to the posterior belly of the digastric m . and the stylohyoid m . as it travels anteriorly, where it gives off a suprahyoid branch that travels on the superior surface of the hyoid bone, supplying the m uscles in that area The lingual a. passes deep to the hyoglossus m . and travels anteriorly between it and the genioglossus m . After passing deep to the hyoglossus, 2 to 3 sm all dorsal lingual aa. are given off at the posterior border of the hyoglossus. The lingual a. continues to pass anteriorly and gives off the sublingual branch at the anterior border of the hyoglossus The deep lingual a., the term inal branch or continuation of the lingual a. once the sublingual a. is given off, travels superiorly to reach the tongue’s ventral surface

Lingual

After passing deep to the hyoglossus, 2 to 3 sm all dorsal lingual aa. are given off at the posterior border of the hyoglossus; they pass in a superior direction to the posterior 1/ 3 of the dorsum of the tongue and provide vascular supply to the m ucous m em brane in this region, the palatoglossal arch, the palatine tonsil, the epiglottis, and the surrounding soft palate

Dorsal lingual

Deep lingual

The deep lingual a., the term inal branch or continuation of the lingual a. once the sublingual a. is given off, travels superiorly to reach the tongue’s ventral surface Located between the inferior longitudinal m . of the tongue and the m ucous m em brane, the deep lingual a. is accom panied by branches of the lingual n., and it anastom oses with its counterpart from the other side

Sublingual

The sublingual branch arises at the anterior border of the hyoglossus The sublingual a. passes anteriorly between the genioglossus and m ylohyoid m m . to the sublingual gland and provides vascular supply to the gland and the m uscles and m ucosa in the area Typically has 2 branches of signi cance: • Branch that passes m ylohyoid to anastom ose with subm ental a. • Branch that passes deep to the gingiva to anastom ose with branch from contralateral side • At this anastom osis, typically 1 branch (although m ay be m ultiple branches) arises to enter a sm all lingual foram en superior to the genial tubercles in the posterior m idline

Subm ental

A branch of the facial a. from the external carotid a.

Tonsillar

Ascending pharyngeal

416

Given off at the subm andibular gland, travels anteriorly super cial to the m ylohyoid m . Anastom oses with a branch from the sublingual branch of the lingual a. to help supply the tongue While ascending superiorly along the lateral side of the pharynx, it passes into and supplies the superior constrictor m . until reaching the palatine tonsil and root of the tongue

External carotid a.

The sm allest branch arising from the external carotid a. Ascends superiorly between the lateral aspect of the pharynx and the internal carotid a. Has branches supplying the palatine tonsil that anastom ose with tonsillar branch of facial and dorsal lingual branches at root of the tongue

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

VASCULAR SUPPLY • Arterial Supply

14

Superior pharyngeal constrictor muscle

Lingual nerve Submandibular ganglion

Styloglossus muscle Palatoglossus muscle

Deep lingual artery and venae comitantes

Stylohyoid ligament Stylopharyngeus muscle Hyoglossus muscle (cut)

Artery to frenulum

Lingual artery External carotid artery

Submandibular duct

Internal jugular vein Facial vein

Sublingual artery and vein Geniohyoid muscle

Lingual vein

Common trunk for facial, retromandibular and lingual veins

Suprahyoid artery

Hyoid bone Hypoglossal nerve

Dorsal lingual artery and vein Vena comitans of hypoglossal nerve

Figu re 14-12

TO NGUE 417

14

VASCULAR SUPPLY • Arterial Supply

Parotid space (bed): right lateral dissection External carotid artery Facial nerve (VII) (cut)

Glossopharyngeal nerve (IX)

Sternocleidomastoid muscle (cut) Digastric muscle (posterior belly) (cut) O ccipital artery and sternocleidomastoid branch

Stylohyoid muscle Hypoglossal nerve (XII) Facial artery Lingual artery

Accessory nerve (XI)

Mylohyoid muscle

Ansa cervicalis Superior root Inferior root

Hyoglossus muscle

Vagus nerve (X)

Digastric muscle (anterior belly)

Ascending pharyngeal artery Carotid branch of glossopharyngeal nerve (IX) and carotid body Internal carotid artery Internal jugular vein

Hyoid bone Branch to thyrohyoid muscle (from ansa cervicalis) Superior laryngeal artery Superior thyroid artery External carotid artery Common carotid artery

Mental branch of inferior alveolar artery Inferior alveolar artery and lingual branch

Facial artery Lingual artery

Facial artery Submental artery

Internal carotid artery

Mylohyoid branch of inferior alveolar artery Submandibular gland Hypoglossal nerve (XII) External carotid artery

Figu re 14-13

418

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

VASCULAR SUPPLY • Venous Drainage Vein

Course

Lingual

Receives tributaries from the deep lingual vv. on the ventral surface, and the dorsal lingual vv. from the dorsal surface Passes with the lingual a., deep to the hyoglossus m ., and ends in the internal jugular v. The vena com itans nervi hypoglossi, or accom panying vein of the hypoglossal n., begins at the tongue’s apex and m ay either join the lingual v. or accom pany the hypoglossal n. and enter the com m on facial v., which em pties into the internal jugular

Subm ental

Anastom oses with the branches of the lingual v. Parallels the subm ental a. on the super cial surface of the m ylohyoid m . and ends in the facial v.

Facial vein and artery

14

Inferior alveolar vein and artery

Mental vein

Hypoglossal nerve (XII)

Submandibular gland

Common facial vein

Submental vein Vena comitans of hypoglossal nerve

Internal jugular vein

Dorsal lingual vein coursing medial to hypoglossus muscle Lingual vein Communication to anterior jugular vein (cut)

Figu re 14-14

TO NGUE 419

14

CLINICAL CORRELATES • Ankyloglossia • •

Ankyloglossia: con d ition in wh ich th e lin gu al fren u lu m is restricted becau se of an in crease in tissu e, lead in g to redu ced ton gu e m obility Also kn own as ton gu e-tie

PRESENTATIONS

• • •

Ton gu e m ay n ot be cap able of p rotru sion beyon d th e in cisors Ton gu e m ay n ot be cap able of tou ch in g th e p alate Ton gu e m ay h ave a V-sh ap ed n otch at its tip or m ay ap p ear bilobed on p rotru sion

COMPLICATIONS

• • •

Cau ses p roblem s for babies wh o breastfeed If th e ton gu e can n ot clear th e oral cavity of food , caries, p eriod on tal d isease, an d h alitosis can resu lt If con d ition is severe, can cau se a sp eech im p ed im en t

TREATMENT

•

If n ecessary, th e lin gu al fren u lu m m ay be cu t (fren ectom y)

Ankyloglossia

Figu re 14-15

420

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

CLINICAL CORRELATES • Hypoglossal Nerve Paralysis • •

14

Hypoglossal nerve lesions p aralyze th e ton gu e on 1 sid e On p rotru sion , th e ton gu e d eviates to th e ip silateral (sam e) or con tralateral sid e, d ep en din g on th e lesion site

LOWER MOTOR NEURON LESION

•

Lesion s to th e h yp oglossal n erve cau se p aralysis on th e ip silateral sid e: • Ton gu e d eviates to th e p aralyzed sid e on p rotru sion (th e p aralyzed m u scles will lag, cau sin g th e tip to d eviate) • Mu scu latu re atrop h ies on th e p aralyzed sid e • Ton gu e fascicu lation s occu r on th e p aralyzed sid e Exam ple: With a n eck wou n d th at cu ts th e righ t h yp oglossal n erve, th e ton gu e d eviates to th e righ t on p rotru sion , an d th e righ t h alf of th e ton gu e will later dem on strate atrop h y an d fascicu lation s

UPPER MOTOR NEURON LESION

•

Cau ses p aralysis on th e con tralateral sid e: • Ton gu e d eviates to th e sid e opposite th e lesion • Mu scu latu re atrop h ies on side opposite th e lesion Exam ple: After a stroke on th e righ t sid e of th e brain th at affects th e righ t u p p er m otor n eu ron s, th e ton gu e deviates to th e left on p rotru sion , an d th e left h alf of th e ton gu e will atrop h y

Hypoglossal Nerve (CN-XII) Sites of lesions affecting hypoglossal nerve (CN-XII) Motor cortex

Lesion Nucleus Lesions of CN-XII nucleus of CN XII or nerve proper result in ipsilateral deficit. CN-XII

Subtle weakness of tongue may be tested by asking patient to press tongue against cheek (shown) or against a tongue depressor. CN-XII

Lesion

Atrophy

Patient with right-sided CN-XII lesion

Fasciculation When hypoglossal nerve or its nucleus is damaged, atrophy and fasciculation of the tongue are noted on evaluation.

If hypoglossal nerve is affected on 1 side, the tongue often deviates toward the side of the lesion on protrusion (due to imbalance of genioglossus contraction).

Figu re 14-16 TO NGUE 421

14

CLINICAL CORRELATES • Squamous Cell Carcinoma • • • • • •

Squam ous cell carcinom a accou n ts for m ost can cers of th e oral cavity In th e ton gu e, u su ally located on th e an terolateral asp ect Alcoh ol an d tobacco u se are risk factors Prem align an t lesion s, su ch as eryth rop lasia an d leu kop lakia, sh ou ld be id en ti ed, becau se early d iagn osis an d treatm en t are p aram ou n t for lon g-term su rvival Rad iograp h ic im agin g h elp s reveal th e tu m or’s exten t an d location Stagin g of th e tu m or gu id es p rogn osis

TREATMENT

• • •

Excision or rad iation th erap y, or p ossibly in com bin ation with ch em oth erap y If lesion is d etected early, excision m ay su f ce With later tu m or stages, a 2n d p rim ary sq u am ou s cell carcin om a m u st be exclu d ed

Squamous cell carcinoma of tongue Squamous cell carcinoma of floor of mouth invading mandible

Squamous cell carcinoma of base of the tongue

Squamous cell carcinoma

Figu re 14-17

422

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

CLINICAL CORRELATES • Leukoplakia • • •

•

14

Leukoplakia: a com m on p rem align an t con d ition of th e oral cavity in volvin g th e form ation of wh ite sp ots on th e m u cou s m em bran es of th e ton gu e an d in sid e th e m ou th Hairy leu kop lakia is a typ e observed in p erson s with com p rom ised im m u n e system s Risk factors: • Tobacco u se • Alcoh ol u se • Hu m an im m u n od e cien cy viru s (HIV) in fection • Ep stein -Barr viru s in fection Alth ou gh a p recan cerou s lesion , it m ay n ot p rogress to oral can cer

Early leukoplakia

Moderately advanced leukoplakia of tongue and cheek

Advanced leukoplakia of tongue

Figu re 14-18

TO NGUE 423

This pa ge inte ntiona lly le ft bla nk

CHAPTER 15

PHARYNX

Overview and Topographic Anatomy

426

Parts of the Pharynx

428

Muscles

430

Potential Apertures in Pharyngeal Wall

434

Vascular Supply

435

Nerve Supply

439

Clinical Correlates

442

15

OVERVIEW AND TOPOGRAPHIC ANATOMY • General Information • • • • •

• •

•

Pharynx: 5-in ch m u scu lar tu be from base of th e sku ll (p osterior p ortion of th e bod y of th e sp h en oid bon e an d basilar p ortion of th e occip ital bon e) to th e lower bord er of th e cricoid cartilage (C6), wh ere it is con tin u ou s with th e esop h agu s Is fu n n el-sh ap ed Posterior p ortion of th e p h aryn x lies again st th e p revertebral fascia Th e retrop h aryn geal an d p arap h aryn geal sp aces su rrou n d th e p h aryn x Lies p osterior to th e n asal an d oral cavities an d th e laryn x an d th u s is d ivid ed in to 3 p arts: • Nasop h aryn x • Orop h aryn x • Laryn gop h aryn x Resp on sible for p rop erly con d u ctin g food to th e esop h agu s an d air to th e lu n gs Com p osed of: • 3 con strictor m u scles • 3 lon gitu din al m u scles • Cartilagin ou s p art of th e p h aryn gotym p an ic tu be • Soft p alate Th e wall of th e p h aryn x h as 5 layers: • Mu cou s m em bran e—th e in n erm ost layer • Su bm u cosa • Ph aryn gobasilar fascia—th e brou s layer attach ed to th e sku ll an ch orin g th e p h aryn x • Mu scu lar—3 in n er lon gitu d in al an d 3 ou ter circu lar (con strictor) m u scles th at overlap su ch th at th e su p erior con strictor is th e in n erm ost, wh ereas th e in ferior con strictor is th e ou term ost m u scle • Bu ccop h aryn geal fascia—loose layer of con n ective tissu e con tin u ou s with th e fascia over th e bu ccin ator an d p h aryn geal m u scles, an d th e location of th e p h aryn geal p lexu s of n erves an d th e p h aryn geal p lexu s of vein s Sella turcica Pharyngeal opening of pharyngotympanic (auditory) tube Spheno-occipital synchondrosis Pharyngeal tonsil

Sphenoidal sinus Nasopharynx Soft palate Palatine glands Hard palate O ral cavity Palatine tonsil Body of tongue O ropharynx Foramen cecum

C1

C1

Lingual tonsil Root of tongue Epiglottis Mandible Hyoid bone

C2

Pharyngeal constrictor muscles

C3

Buccopharyngeal fascia

C4

Laryngopharynx Laryngeal inlet (aditus) Thyroid cartilage

C5 C6

Vocal fold Cricoid cartilage Trachea Esophagus Thyroid gland Surface projection

Investing layer of (deep) cervical fascia

Figu re 15-1

426

Retropharyngeal space

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

C7 T1

OVERVIEW AND TOPOGRAPHIC ANATOMY • General Information

15

Pharyngeal tonsil Basilar part of occipital bone

Pharyngeal tubercle

Cartilaginous part of pharyngotympanic (auditory) tube

Styloid process Digastric m. (posterior belly)

Pharyngobasilar fascia

Stylohyoid m.

Choana Levator veli palatini m.

Stylopharyngeus m.

Superior pharyngeal constrictor m.

Accessory m. bundle from petrous part of temporal bone

Salpingopharyngeus m. Uvula

Medial pterygoid m.

Palatopharyngeus m.

Pharyngobasilar fascia Pharyngeal raphe

Middle pharyngeal constrictor m. Stylopharyngeus m.

Superior pharyngeal constrictor m. Hyoid bone (tip of greater horn) Middle pharyngeal constrictor m.

Pharyngoepiglottic fold Aryepiglottic fold Inferior pharyngeal constrictor m. (cut edge) Longitudinal pharyngeal mm.

Epiglottis

Superior horn of thyroid cartilage

Inferior pharyngeal constrictor m.

Thyrohyoid membrane

Cuneiform tubercle

Internal branch of superior laryngeal nerve

Corniculate tubercle (Transverse and oblique) arytenoid mm.

Pharyngeal aponeurosis Cricopharyngeus m. (part of inferior pharyngeal constrictor)

Posterior cricoarytenoid m.

Posterior border of thyroid cartilage lamina

Cricopharyngeal m. (part of inferior pharyngeal constrictor)

Cricoid attachment of longitudinal esophageal m.

Longitudinal esophageal m.

Circular esophageal m.

Figu re 15-2

•

Wald eyer’s rin g is th e an atom ical n am e for th e rin g of lym p h atic tissu e in th e p h aryn x an d oral cavity: • Lin gu al ton sil (p osterior 1/ 3rd of ton gu e) • Palatin e ton sil (orop h aryn x) • Tu bal ton sil (n asop h aryn x) • Ph aryn geal ton sil (n asop h aryn x)

P HARYNX 427

15

PARTS OF THE PHARYNX • Nasopharynx, Oropharynx, Laryngopharynx NASOPHARYNX Boundaries

Major Anatomic Features

Comments

Vertebral Level

Roof—posterior portion of the body of the sphenoid bone and basilar portion of the occipital bone Floor—soft palate (upper surface) Anterior—choanae of the nasal cavity Posterior—m ucosa covering superior constrictor Lateral—m ucosa covering superior constrictor

Ostium of the auditory tube opens into the nasopharynx Torus tubarius is an elevation form ed by the base of the cartilaginous portion of the auditory tube, which lies superior to the ostium of the tube Torus levatorius is an elevation of m ucous m em brane that lies over the levator veli palatini m . Salpingopharyngeal fold is m ucous m em brane that lies over the salpingopharyngeus m ., connecting the torus tubarius to the lateral wall of the pharynx Pharyngeal recess is located posterior to the salpingopharyngeal fold and contains the pharyngeal tonsil (adenoid) Pharyngeal tonsil (adenoid) is m ucosa-associated lym phatic tissue (MALT) located along the m idline Tubal tonsils are MALT located posterior to the opening of each auditory tube and are considered by som e authors to be extensions of the pharyngeal tonsil Nasopharynx epithelium : • Anterior—pseudostrati ed colum nar with cilia in anterior portion near nasal cavity • Posterior—strati ed squam ous nonkeratinized in posterior portion

Has a respiratory function The auditory tube connects the m iddle ear with the nasopharynx, which helps equalize air pressure on both sides of the tym panic m em brane The cartilaginous portion of the auditory tube norm ally is closed, except during deglutition and yawning The auditory tube allows spread of infections between the m iddle ear and the nasopharynx The roof and walls tend to be rm and do not close during m uscular contraction of the pharyngeal and palatal m uscles

C1 (and dens of C2)

OROPHARYNX

428

Boundaries

Major Anatomic Features

Comment

Superior—nasopharynx Inferior—superior border of epiglottis Anterior—palatoglossal fold of the oral cavity (oropharyngeal isthm us) Posterior—m ucosa covering the superior and m iddle constrictor mm. Lateral—m ucosa covering the superior and m iddle constrictor m m .

Palatine tonsils are located in the oropharynx between the palatoglossal and palatopharyngeal folds (tonsillar sinus) Palatopharyngeal fold is an elevation of m ucous m em brane that lies over the palatopharyngeal m . Epiglottic vallecula is the depression im m ediately posterior to the root of the tongue Oropharynx epithelium is strati ed squam ous nonkeratinized

Has a respiratory and a digestive function

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

Vertebral Level C2-C3

PARTS OF THE PHARYNX • Nasopharynx, Oropharynx, Laryngopharynx

15

LARYNGOPHARYNX Vertebral Level

Boundaries

Major Anatomic Features

Comment

Superior—oropharynx Inferior—inferior border of cricoid cartilage (where becom es continuous with esophagus) Anterior—larynx Posterior—m ucosa covering m iddle and inferior constrictor m m . Lateral—m ucosa covering m iddle and inferior constrictor m m .

Piriform recess is a sm all depression located on the lateral wall of the laryngopharyngeal cavity on either side of the entrance to the larynx Laryngopharynx epithelium is strati ed squam ous nonkeratinized

Com m unicates with the larynx The piriform recess is a potential location for objects to becom e lodged

Choanae

C4-C6

Base of skull (basilar part of occipital bone) Pharyngeal tonsil

Styloid process Nasal septum Torus tubarius Pharyngeal opening of pharyngotympanic (auditory) tube Pharyngeal recess Parotid gland Torus levatorius (fold caused by levator veli palatini muscle) Salpingopharyngeal fold Soft palate

Nasopharynx

Uvula Palatine tonsil Root of tongue Palatopharyngeal arch Prominence caused by greater horn of hyoid bone Epiglottis Laryngeal inlet (aditus) Prominence caused by superior horn of thyroid cartilage Aryepiglottic fold Piriform fossa

O ropharynx

Laryngopharynx

Fold over internal branch of superior laryngeal nerve

Esophagus

Trachea

Figu re 15-3 P HARYNX 429

15

430

MUSCLES • Overview Muscle

Origin

Insertion

Actions

Nerve Supply

Superior constrictor

Pterygoid ham ulus Pterygom andibular raphe Retrom olar trigone of m andible Side of tongue

Pharyngeal tubercle Pharyngeal raphe

Constricts the upper portion of the pharynx

Pharyngeal plexus (the m otor portion of this plexus is form ed by the pharyngeal branch of the vagus n.)

Middle constrictor

Stylohyoid lig. Lesser cornu of hyoid Greater cornu of hyoid

Pharyngeal raphe

Constricts the m iddle portion of the pharynx

Inferior constrictor (divided by som e authors into: • Thyropharyngeus • Cricopharyngeus)

Oblique line of thyroid cartilage Side of cricoid cartilage

Palatopharyngeus

Posterior border of hard palate Palatine aponeurosis

Salpingopharyngeus

Cartilage of auditory tube

Stylopharyngeus

Medial aspect of base of styloid process

Posterior border of the lam ina of the thyroid cartilage

Constricts the lower portion of the pharynx

Pharyngeal plexus (the m otor portion of this plexus is form ed by the pharyngeal branch of the vagus n.) External laryngeal n. of the vagus (also helps supply the cricopharyngeus portion of the inferior constrictor) Recurrent laryngeal n. of the vagus (also helps supply the cricopharyngeus portion of the inferior constrictor)

Elevates pharynx Helps close the nasopharynx

Pharyngeal plexus (the m otor portion of this plexus is form ed by the pharyngeal branch of the vagus n.)

Elevates the upper and lateral portions of the pharynx Elevates pharynx Expands the sides of the pharynx

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

Glossopharyngeal n.

MUSCLES • Overview

15

Tensor veli palatini muscle Pharyngobasilar fascia Lateral pterygoid plate Levator veli palatini muscle Pterygoid hamulus

Digastric muscle (posterior belly) (cut)

Buccinator muscle (cut)

Styloid process

Pterygomandibular raphe

Superior pharyngeal constrictor muscle Styloglossus muscle Stylohyoid ligament Stylopharyngeus muscle Middle pharyngeal constrictor muscle Hyoglossus muscle Greater horn of hyoid bone Superior horn of thyroid cartilage Thyrohyoid membrane Inferior pharyngeal constrictor muscle Tendinous arch Zone of sparse muscle fibers Cricopharyngeus muscle (part of inferior pharyngeal constrictor)

Buccinator crest of mandible O blique line of mandible Digastric muscle (anterior belly) Mylohyoid muscle Hyoid bone Stylohyoid muscle (cut) Thyroid cartilage Median cricothyroid ligament Cricothyroid muscle Cricoid cartilage

Figu re 15-4

P HARYNX 431

15

MUSCLES • Overview

Cartilaginous part of pharyngotympanic (auditory) tube at base of skull: inferior view

Palatine process of maxilla

Pterygoid hamulus and medial pterygoid plate

Horizontal plate of palatine bone

Lateral pterygoid plate

Choana of cartilaginous part of Lateral lamina Medial lamina pharyngotympanic (auditory) tube

Scaphoid fossa Foramen ovale

Foramen lacerum

Foramen spinosum

Petrous part of temporal bone

Spine of sphenoid bone Internal carotid artery entering carotid canal

O ccipital condyle

Mastoid process Foramen magnum

Section through cartilaginous part of pharyngotympanic (auditory) tube, with tube closed Trigeminal ganglion Internal carotid artery in carotid canal Dura mater Lateral lamina of cartilage Medial lamina of cartilage Auditory tube lumen Tensor veli palatini muscle Levator veli palatini muscle Salpingopharyngeus muscle Nasopharynx

Section through cartilaginous part of pharyngotympanic (auditory) tube, with tube open Trigeminal ganglion Internal carotid artery in carotid canal Dura mater Lateral lamina of cartilage Medial lamina of cartilage Auditory tube lumen Tensor veli palatini muscle Levator veli palatini muscle Salpingopharyngeus muscle Nasopharynx

Pharyngotympanic (auditory) tube closed by elastic recoil of cartilage, tissue turgidity, and tension of salpingopharyngeus muscles

Lumen opened chiefly when attachment of tensor veli palatini muscle pulls wall of tube laterally during swallowing

Figu re 15-5

432

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

MUSCLES • Overview

15

Medial pterygoid plate Cartilaginous part of pharyngotympanic (auditory) tube Tensor veli palatini muscle Pharyngobasilar fascia Levator veli palatini muscle Palatine aponeurosis and tendon of tensor veli palatini muscle Pharyngeal tubercle (basilar part of occipital bone) Pharyngeal raphe

Salpingopharyngeus muscle

C1

Muscles of soft palate Palatopharyngeal sphincter (Passavant’s ridge) Pterygoid hamulus

C2

Superior pharyngeal constrictor muscle Pterygomandibular raphe Palatopharyngeus muscle Buccinator muscle C3 Stylopharyngeus muscle Stylohyoid ligament Styloglossus muscle Middle pharyngeal constrictor muscle C4

Buccopharyngeal fascia and retropharyngeal space Prevertebral fascia and anterior longitudinal ligament Internal branch of superior laryngeal nerve Longitudinal pharyngeal muscles Inferior pharyngeal constrictor muscle

C5 Hyoid bone

Pharyngeal aponeurosis Cricopharyngeus muscle (part of inferior pharyngeal constrictor)

C6

Thyroid cartilage

Cricoid attachment of longitudinal esophageal muscle Circular esophageal muscle

Arytenoid cartilages

C7

Longitudinal esophageal muscle

Cricoid cartilage Trachea Margins of middle pharyngeal constrictor muscle Margins and attachments of inferior pharyngeal constrictor muscle

Figu re 15-6

P HARYNX 433

15

POTENTIAL APERTURES IN PHARYNGEAL WALL • Locations and Structures • •

Th e overlap p in g arran gem en t of th e 3 con strictor m u scles leaves 4 p oten tial ap ertu res in th e p h aryn geal m u scu latu re An atom ic stru ctu res en ter an d exit th e p h aryn x th rou gh th ese p oten tial ap ertu res

OVERVIEW OF POTENTIAL APERTURES Location

Anatomic Structures That Pass Through

Between base of the skull and the superior constrictor m.

Auditory tube Levator veli palatini m . Ascending pharyngeal a. Ascending palatine a.

Between the superior and m iddle constrictor m m .

Stylopharyngeus m . Glossopharyngeal n. Tonsillar branch of the ascending palatine a. Stylohyoid lig.

Between the m iddle and inferior constrictor m m .

Internal laryngeal n. Superior laryngeal a. and v.

Inferior to the inferior constrictor m .

Recurrent laryngeal n. Inferior laryngeal a. and v.

Pharyngobasilar fascia Tensor veli palatini muscle Levator veli palatini muscle Lateral pterygoid plate Potential aperture between base of skull and superior constrictor

Pterygoid hamulus Buccinator muscle (cut)

Digastric muscle (posterior belly) (cut) Styloid process

Pterygomandibular raphe Superior pharyngeal constrictor muscle Styloglossus muscle Stylohyoid ligament

O blique line of mandible

Stylopharyngeus muscle Middle pharyngeal constrictor muscle Hyoglossus muscle Greater horn of hyoid bone Superior horn of thyroid cartilage

Potential aperture between superior constrictor and middle constrictor

Potential aperture between middle constrictor and inferior constrictor

Hyoid bone Stylohyoid muscle (cut) Thyroid cartilage

Thyrohyoid membrane Inferior pharyngeal constrictor muscle

Cricothyroid muscle Cricoid cartilage Trachea

Cricopharyngeus muscle (part of inferior pharyngeal constrictor)

Potential aperture inferior to the inferior constrictor

Esophagus

Figu re 15-7

434

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

VASCULAR SUPPLY • Arterial Supply Artery

Source

Course

Ascending pharyngeal

The posterior portion of the external carotid a. near the bifurcation of the com m on carotid a.

The sm allest branch arising from the external carotid a. Ascends superiorly between the lateral aspect of the pharynx and the internal carotid a. Has 2 m ajor sets of branches: • Pharyngeal—a series of 3 sm all branches that supplies the stylopharyngeus and the m iddle and inferior constrictor m m . • Palatine—supplies the superior constrictor, palatine tonsil, soft palate, and auditory tube

Ascending palatine

Facial a.

Ascends superiorly along the lateral side of the pharynx, typically between the stylopharyngeus and the styloglossus m m . Passes through the aperture between the base of the skull and the superior constrictor m . to supply it and the soft palate

Tonsillar

15

While ascending superiorly along the lateral side of the pharynx, it passes into and supplies the superior constrictor m . until reaching the palatine tonsil and root of the tongue

Pharyngeal

The 3rd part of the m axillary a. in the pterygopalatine fossa

Passes posteriorly with the pharyngeal n. into the pharyngeal canal Em erges to supply the superior portion of the nasopharynx and the auditory tube

Artery of the pterygoid canal

The 3rd part of the m axillary a. in the pterygopalatine fossa

Passes posteriorly into the pterygoid canal, accom panying the nerve of the pterygoid canal (vidian n.) Helps supply the auditory tube

Lesser palatine

Descending palatine a. from the 3rd part of the m axillary a.

A branch of the descending palatine a. that travels in the palatine canal Within the canal, the descending palatine a. splits into the: • Greater palatine a. • Lesser palatine a. Lesser palatine a. supplies the soft palate and palatine tonsil

Superior thyroid

The 1st branch of the external carotid a.

Passes inferiorly along the inferior constrictor m ., providing sm all m uscular branches as it descends to supply the thyroid gland

Inferior thyroid

Thyrocervical trunk

Has a series of m uscular branches that supply the pharynx

P HARYNX 435

15

VASCULAR SUPPLY • Arterial Supply

Medial view sagittal section

Pharyngeal opening of pharyngotympanic (auditory, eustachian) tube Soft palate

Torus tubarius

Palatine glands

Sphenoidal sinus

Hard palate

Pharyngeal tonsil Pharyngeal tubercle (basilar part of occipital bone) Pharyngeal raphe Pharyngeal recess Salpingopharyngeal fold Uvula Semilunar fold Supratonsillar fossa

O ropharynx Palatopharyngeal arch Tongue (draw n anteriorly and inferiorly)

Palatine tonsil Epiglottis

Palatoglossal arch

Lingual tonsil

Triangular fold

Vallecula

Figu re 15-8

436

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

VASCULAR SUPPLY • Arterial Supply

15

Superior pharyngeal constrictor muscle Ascending pharyngeal artery Ascending palatine artery Tonsillar artery Ascending pharyngeal artery External carotid artery Superior laryngeal artery Superior thyroid artery Common carotid artery Inferior thyroid artery Transverse cervical artery Suprascapular artery Thyrocervical trunk

External carotid artery

Superior pharyngeal constrictor muscle

Internal carotid artery Facial artery Lingual artery

Middle pharyngeal constrictor muscle

Superior laryngeal nerve Internal branch External branch Superior thyroid artery

Inferior pharyngeal constrictor muscle Pharyngeal raphe

Superior laryngeal artery Common carotid artery Internal jugular vein Thyroid gland (right lobe) Superior parathyroid gland Inferior parathyroid gland

Inferior thyroid vein

Inferior thyroid artery Right recurrent laryngeal nerve Transverse cervical artery

Trachea Vertebral artery

Suprascapular artery Thyrocervical trunk Right subclavian artery and vein

Internal thoracic artery and vein Left recurrent laryngeal nerve

Right vagus nerve (X) Left vagus nerve (X)

Figu re 15-9

P HARYNX 437

15

VASCULAR SUPPLY • Venous Drainage Vein

Course

Pharyngeal plexus

Located on the outer surface of the pharynx in the buccopharyngeal fascia Gives rise to pharyngeal vv., which drain into the internal jugular v. and also into the pterygoid plexus of veins along the lateral pterygoid m . The pharyngeal vv. also m ay drain into the facial, lingual, or superior thyroid v.

Communication with internal jugular vein Pharyngeal plexus

Communication with internal jugular vein

Figu re 15-10

438

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

NERVE SUPPLY • General Information • • •

15

Su p p lies a m ajority of th e m otor an d sen sory in n ervation to th e p h aryn x Is located on th e lateral asp ect of th e m idd le con strictor m u scle Com p osed of: • Ph aryn geal bran ch of th e glossop h aryn geal n erve • Ph aryn geal bran ch of th e vagu s n erve • Sym p ath etic bers (laryn gop h aryn geal bran ch es) from th e su p erior cervical gan glion (p ostgan glion ic bers)

Pharyngeal Plexus

•

Nerve

Function

Course

Sensory

Motor

Pharyngeal branch of the glossopharyngeal

The m ajor branch of the glossopharyngeal n. that contributes to the pharyngeal plexus Sensory

3 or 4 lam ents unite to form 1 pharyngeal branch opposite the m iddle constrictor m. This branch, along with the pharyngeal branch of the vagus and laryngopharyngeal branches from the sym pathetics, form s the pharyngeal plexus

Sensory branches contributing to the plexus perforate the pharyngeal m uscles and supply its m ucous m em branes (m ainly oropharynx and laryngopharynx region)

Pharyngeal branch of the vagus

The m ajor branch of the vagus n. that contributes to the pharyngeal plexus Motor

Arises from the upper part of the inferior ganglion of the vagus n. Lies along the upper border of the m iddle constrictor m ., where it form s the pharyngeal plexus From the plexus, the m otor branches are distributed to the pharyngeal and soft palate m uscles (with the exception of the stylopharyngeus m . and tensor veli palatini m .)

Superior constrictor, m iddle constrictor, inferior constrictor, palatopharyngeus, salpingopharyngeus mm.

Sym pathetic bers (laryngopharyngeal branches) from the superior cervical ganglion

Vasom otor

A series of laryngopharyngeal branches pass along the lateral side of the m iddle constrictor m .

Vasom otor

N.B.—some authors still describe the cranial root of the accessory n. as a component of the pharyngeal plexus—however, literature regarding the cranial root is controversial and many authors argue that what is described as the cranial root of the accessory n. is actually part of the vagus n. because the bers arise from the nucleus ambiguus.

P HARYNX 439

15

440

NERVE SUPPLY • Other Innervation of the Pharynx Nerve

Function

Course

Sensory

Recurrent laryngeal branch of the vagus

A sm all contributor to the m otor innervation of the m uscles of the pharynx Provides signi cant innervation to the larynx

Branch of the vagus n. Wraps around the aorta posterior to the ligam entum arteriosum on the left side Wraps around the right subclavian a. on the right side Ascends on the lateral aspect of the trachea until reaching the pharynx, where it passes deep to the inferior constrictor to reach the larynx

Part of the inferior constrictor m . (cricopharyngeus portion)

External laryngeal n.

A sm all contributor to the m otor innervation of the m uscles of the pharynx Provides innervation to the cricothyroid m.

A branch of the superior laryngeal n. that branches from the vagus n. Descends posterior to the sternohyoid, traveling with the superior thyroid a. Lies along the inferior constrictor m. Passes deep to the inferior constrictor m . to travel anteriorly to the cricothyroid m .

Part of the inferior constrictor m . (cricopharyngeus portion)

Pharyngeal

A sm all sensory nerve

Arises from the m axillary division of the trigem inal in the pterygopalatine fossa Passes posteriorly through the pharyngeal canal with the artery to enter the nasopharynx

Supplies sensory bers to the nasopharynx and the auditory tube

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

Motor

NERVE SUPPLY • Other Innervation of the Pharynx

15

Internal carotid nerve Glossopharyngeal nerve (IX) Laryngopharyngeal sympathetic branch Vagus nerve (X) (cut)

C1

Superior cervical sympathetic ganglion

Pharyngeal branch of vagus nerve

C2

Pharyngeal plexus External carotid artery and plexus

C3

Superior laryngeal nerve C4

Internal carotid artery and carotid branch (of Hering) of glossopharyngeal nerve

Gray rami communicantes

Carotid body Carotid sinus Phrenic nerve (cut) Middle cervical sympathetic ganglion Common carotid artery and plexus

C5 C6

Vertebral ganglion

C7

Vertebral artery and plexus C8 T1

Recurrent laryngeal nerve Cervicothoracic (stellate) ganglion Vagus nerve (X) (cut)

Subclavian artery

Gray and white rami communicantes Tympanic cavity and plexus Stylomastoid foramen

Caroticotympanic nerve (from internal carotid plexus)

Geniculate ganglion Tympanic nerve (Jacobson) of facial nerve

Greater petrosal nerve Deep petrosal nerve Nerve (vidian) of pterygoid canal Lesser petrosal nerve Pterygopalatine ganglion Mandibular nerve (V3 ) O tic ganglion Auriculotemporal nerve Parotid gland Tubal branch of tympanic plexus Pharyngotympanic (auditory) tube and pharyngeal opening Stylopharyngeus muscle (and branch from glossopharyngeal nerve) Taste and somatic sensation: posterior 1 ⁄3 of tongue Efferent fibers Afferent fibers Parasympathetic fibers Pharyngeal plexus Pharyngeal, tonsillar, and lingual branches of glossopharyngeal nerve Pharyngeal branch of vagus nerve

Inferior salivatory nucleus Solitary tract nucleus Nucleus ambiguus Spinal tract and spinal nucleus of trigeminal nerve Glossopharyngeal nerve (IX) Jugular foramen Communication to auricular branch of vagus nerve Superior and Inferior ganglia of Glossopharyngeal nerve Communication to facial nerve (VII) Vagus nerve (X) Superior cervical sympathetic ganglion Sympathetic trunk Carotid branch of glossopharyngeal nerve Internal carotid artery External carotid artery Carotid sinus Carotid body Common carotid artery

Figu re 15-11 P HARYNX 441

15

CLINICAL CORRELATES • Deglutition • • • • • • • • • • • •

Deglutition, or swallowin g, is a com bin ation of volu n tary an d in volu n tary m u scu lar con traction s to m ove a bolu s of food from th e oral cavity to th e esop h agu s Deglu tition begin s wh en th e tip of th e ton gu e is p laced in to con tact with th e an terior p ortion of th e p alate an d th e bolu s is p u sh ed p osteriorly Th e soft p alate begin s to elevate, an d Passavan t’s rid ge starts to form in th e p osterior wall of th e p h aryn x an d m oves closer to th e soft p alate As m ore of th e ton gu e is p u sh ed again st th e h ard p alate, th e bolu s is m oved in to th e orop h aryn x, an d th e soft p alate m akes con tact with Passavan t’s rid ge to close off th e n asop h aryn x from th e orop h aryn x On ce th e bolu s reach es th e ep iglottic vallecu la, th e h yoid an d laryn x are elevated an d th e tip of th e ep iglottis is tip p ed down sligh tly over th e laryn geal ad itu s A “strip p in g wave” is created on th e p osterior wall of th e p h aryn x to h elp m ove th e bolu s Bolu s sp lits in to 2 stream s th at ow on eith er sid e of th e ep iglottis an d u n ite to en ter th e esop h agu s Th e soft p alate is p u lled down by th e p alatop h aryn geu s m u scles an d th e p ressu re of th e wave from th e m ovem en t of th e bolu s, wh ile th e strip p in g wave con tin u es to h elp m ove th e bolu s from th e orop h aryn x Th e cricop h aryn geal p ortion of th e in ferior con strictor relaxes to h elp th e bolu s en ter th e esop h agu s Laryn geal vestibu le an d rim a glottid is are closed to p reven t th e bolu s from en terin g th e laryn x Strip p in g wave em p ties th e last of th e bolu s from th e ep iglottic vallecu la, an d th e m ajor p ortion of th e bolu s is alread y in th e esop h agu s All stru ctu res retu rn to th eir in itial p osition as th e strip p in g wave m oves in to th e esop h agu s

Bolus

Bolus

A. The tip of the tongue contacts the anterior part of palate while the bolus is pushed posteriorly in a groove between tongue and palate. The soft palate is drawn upward as a bulge forms in the upper part of posterior pharyngeal wall (Passavant’s ridge) and approaches the rising soft palate.

Transverse intrinsic musculature of tongue

B. The bolus lies in a groove on the dorsal surface of the tongue created by contraction of genioglossus and transverse intrinsic mm.

Figu re 15-12

Figure continued on next page

442

Genioglossus muscles

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

CLINICAL CORRELATES • Deglutition

15

Soft palate Root of tongue

Bolus

Epiglottis turned down

C. As tongue gradually presses more of its Laryngeal dorsal surface against aditus the hard palate, the bolus is pushed posteriorly into E. The epiglottis is tipped D. When the bolus the oropharynx. The soft inferiorly over the laryngeal has reached the palate is drawn superiorly aditus but does not completely vallecula, the hyoid and larynx to contact Passavant’s ridge and closes off close it. The bolus flows in 2 move superior and anterior while the nasopharynx. A receptive space is streams around each side of the epiglottis is tipped inferiorly. A created in the oropharynx as the root of epiglottis to the piriform fossae “stripping wave” on the posterior the tongue moves slightly anterior. The and unite to enter the pharyngeal wall moves inferiorly. stylopharyngeus and upper pharyngeal esophagus. A trickle of food constrictor mm. contract to raise the may enter the laryngeal aditus. pharyngeal wall over the bolus. Soft palate Root of tongue Vallecula Epiglottis turned down (sectioned) Thyroid cartilage Aryepiglottic fold F. The soft palate is pulled inferiorly and approximated to the root of tongue by contraction of the palatopharyngeus and pressure of the descending “stripping wave.” The oropharyngeal cavity is closed by contraction of upper pharyngeal constrictors. Relaxation of the cricopharyngeus permits entry of the bolus into the esophagus. A trickle of food may enter the laryngeal aditus.

H. “Stripping wave” reaches vallecula and presses out the last of the bolus. The cricopharyngeus remains relaxed and the bolus has largely passed into the esophagus.

Ventricle of larynx Cricoid cartilage

G. Laryngeal vestibule is closed by approximation of aryepiglottic and ventricular folds, preventing entry of food beyond aditus into the larynx.

I. “Stripping wave” passes the J. pharynx and the epiglottis begins to turn superiorly as the hyoid and larynx descend. Communication with the nasopharynx is reestablished.

All structures of the pharynx return to their resting position as the “stripping wave” passes into the esophagus, pushing the bolus before it.

Figu re 15-12, co n t’d P HARYNX 443

15

CLINICAL CORRELATES • Pharyngitis • • •

Pharyngitis is an in am m ation of th e p h aryn x often cau sed by an u p p er resp iratory in fection Th e m ost com m on sym p tom is a sore th roat (alth ou gh often accom p an ied by a cou gh ) Ph aryn gitis also can cau se th e ton sils to en large an d becom e in am ed , lead in g to ton sillitis

ETIOLOGY

•

Variou s etiologic agen ts m ay cau se in fection associated with p h aryn gitis: • Viral • Ad en oviru s • Herp es sim p lex viru s • Ep stein -Barr viru s (in fectiou s m on on u cleosis) • In u en za viru s • Rh in oviru s • Bacterial • Corynebacterium diphtheriae (d ip h th eria) • Streptococcus (p eriton sillar abscess, “strep th roat”) • Fu n gal • Candida albicans (oral th ru sh )

TREATMENT

• •

Most treatm en t is sym p tom atic Bacterial an d fu n gal p h aryn gitis resp on d well to an tibiotics an d an tifu n gals

Infections of Pharynx

Acute follicular tonsillitis

Peritonsillar abscess (quinsy)

Adenitis Infectious mononucleosis

Diphtheria Corynebacterium diphtheriae (Klebs-Löffler bacilli)

Figu re 15-13

444

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

CHAPTER 16

LARYNX

Overview and Topographic Anatomy

446

Cartilages

448

Joints, Membranes, and Ligaments

454

Muscles

456

Vascular Supply

458

Nerve Supply

46 0

Clinical Correlates

462

16

OVERVIEW AND TOPOGRAPHIC ANATOMY • General Information • • • • • • • • • • • •

Larynx: con n ection between th e p h aryn x an d th e trach ea Preven ts foreign bod ies from en terin g th e airways Design ed for th e p rod u ction of sou n d (p h on ation ) Is m obile d u rin g d eglu tition Located in th e m id lin e op p osite th e 3rd to th e 6th cervical vertebrae (C3 to C6) Sh orter in wom en an d ch ild ren Prep u bescen t laryn x is sim ilar in size in fem ales an d m ales After th e on set of p u berty, th e laryn x in m ales en larges sign i can tly Form ed by 9 cartilages: 3 p aired an d 3 u n p aired Vallecu la is a d ep ression in th e m u cosa between th e p h aryn geal p ortion of th e ton gu e an d th e an terior border of th e ep iglottis Laryn geal ep ith eliu m is p rim arily p seu dostrati ed colu m n ar with cilia, excep t: • An terior su rface alon g th e ep iglottis—strati ed sq u am ou s n on keratin ized • Tru e vocal cord —strati ed sq u am ou s n on keratin ized Region s of th e laryn x: • Vestibu le (su p raglottic)—from th e laryn geal in let to th e vestibu lar fold s • Ven tricle—from th e vestibu lar fold to th e vocal fold • In fraglottic (su bglottic)—from vocal fold s to th e in ferior bord er of th e cricoid cartilage

RELATIONS OF THE LARYNX

• • • • •

Anterolateral—in frah yoid m u scles, p latysm a Lateral—lobes of th e th yroid glan d , carotid sh eath Posterior—it form s th e an terior wall of th e laryn gop h aryn x Superior—base of ton gu e an d vallecu la Inferior—trach ea

Lamina of thyroid cartilage Vocal ligament Rima glottidis

Thyroid cartilage Medial margin of sternocleidomastoid muscle Common carotid artery

Cupula (dome) of pleura Thyroid gland Cricothyroid muscle

Cricoid cartilage Cricothyroid ligament Trachea

Arytenoid cartilage Lamina of cricoid cartilage

Figu re 16-1

446

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

Posterior cricoarytenoid muscle Transverse and oblique arytenoid muscles

OVERVIEW AND TOPOGRAPHIC ANATOMY • General Information

C1

C1 C2

Genioglossus muscle Epiglottis Mandible Geniohyoid muscle Hyoid bone Hyoepiglottic ligament Thyrohyoid membrane Laryngopharynx Laryngeal inlet (aditus) Thyroid cartilage Vocal fold Transverse arytenoid muscle Cricoid cartilage Trachea Esophagus

16

Pharyngeal constrictor muscles

C3 C4 C5

Vertebral bodies

C6 C7 T1

Thyroid gland

Manubrium of sternum

Superior thyroid vv. Internal laryngeal n. Superior laryngeal a.

Vestibule region

Thyrohyoid Aryepiglottis Vestibular fold Thyroid Lateral cricoarytenoid

Ventricle region Vocal fold Vocalis

Cricothyroid Inferior constrictor Sternothyroid Cricoid

Superior thyroid vv. Infraglottic region

Thyroid gland Recurrent laryngeal n. Inferior laryngeal a.

Figu re 16-2

LARYNX 447

16

CARTILAGES • General Information Cartilage

Cartilage Type

Paired

Comments

Thyroid

Hyaline

No

Largest of the laryngeal cartilages Connects to the hyoid bone via the thyrohyoid m em brane, which allows the internal laryngeal n. and superior laryngeal vessels to pass through to enter the larynx Lies between C4 and C6

Cricoid

Only com plete ring of cartilage in the respiratory system Signet in shape Both intrinsic and extrinsic laryngeal m uscles attach to the cricoid Lies at C6

Arytenoid

Hyaline (m ajority of arytenoid cartilage) Elastic (only the apex and sm all portion of vocal process)

Yes

Form s fram ework of the true vocal cord

Epiglottis

Elastic

No

Helps prevent foreign bodies from entering the larynx

Yes

Minor cartilages that lie in the aryepiglottic fold

Corniculate (m inor) Cuneiform (m inor)

Epiglottis Hyoid bone Thyrohyoid membrane Superior horn of thyroid cartilage Corniculate cartilage Arytenoid cartilage Superior thyroid notch Thyroid cartilage lamina Vocal ligament Median cricothyroid ligament Inferior horn of thyroid cartilage Cricoid cartilage Trachea Anterosuperior view Posterior view

Epiglottis Anterior view Hyoid bone Thyrohyoid membrane

Hyoepiglottic ligament

Thyroid cartilage lamina Corniculate cartilage Arytenoid cartilage Muscular process Vocal process Vocal ligament

Thyroepiglottic ligament

Cricothyroid ligament

Cricoid cartilage Trachea Medial view, median (sagittal) section

Figu re 16-3

448

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

CARTILAGES • Thyroid Cartilage Anatomic Feature

Comments

2 lateral lam inae

2 plates that m eet at an acute angle in the anterior m idline

Laryngeal prom inence

Also known as the Adam ’s apple Form ed by the fusion of the 2 lateral lam ina The fusion of the 2 lateral lam ina form s an angle that is m ore acute in m ales (90 degrees) than fem ales (120 degrees) Larger in m ales than in fem ales

Thyroid notch

Superior portion of the laryngeal prom inence, which form s a V shape

Superior tubercle

Superior border of the oblique line

Oblique line

Attachm ent for sternothyroid, thyrohyoid, and inferior constrictor m m . (extrinsic m uscles of the larynx)

Inferior tubercle

Inferior border of the oblique line

Superior horn

Provides lateralm ost attachm ent for the thyrohyoid m em brane

Inferior horn

Articulates with the cricoid to form the cricothyroid joint

16

Hyoid bone Thyrohyoid membrane Superior horn of thyroid cartilage

Superior thyroid notch Thyroid cartilage lamina Median cricothyroid ligament Inferior horn of thyroid cartilage Cricoid cartilage Epiglottis

Hyoid bone Posterior view

Anterior view

Thyrohyoid membrane Thyroid cartilage lamina O blique line

Laryngeal prominence Median Lateral

Cricothyroid ligament Cricothyroid joint Right lateral view

Figu re 16-4

LARYNX 449

16

CARTILAGES • Cricoid Cartilage Anatomic Feature

Comments

Arch (anteriorly)

6 m m height Narrow Cricothyroid m . attaches to the arch Inferior portion of the inferior constrictor m . (cricopharyngeus) attaches to the arch posterior to the cricothyroid m .

Lam ina (posteriorly)

2 to 3 cm in height Posterior cricoarytenoid m . attaches to the lam ina

Superior border (on the lam ina)

Articulates with the arytenoid cartilage to form the cricoarytenoid joint

Inferior border (on the lam ina)

Articulates with the inferior cornu of the thyroid cartilage to form the cricothyroid joint

Median cricothyroid ligament Inferior horn of thyroid cartilage

Median Lateral

Cricothyroid ligament Cricoid cartilage Cricothyroid joint

Cricoid cartilage

Right lateral view

Anterior view

Corniculate cartilage Muscular process Arytenoid cartilage Vocal process

Cricoid cartilage

Lamina Arch

Anterosuperior view

Figu re 16-5

450

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CARTILAGES • Arytenoid Cartilage Anatomic Feature

Comments

Divided into:

Are paired Each arytenoid cartilage has: • 3 surfaces (anterolateral, posterior, m edial) • Apex • Base (with 2 processes)

Apex

Apex is the superior extension of the arytenoid cartilage Corniculate cartilage articulates with the apex Apex is com posed of elastic cartilage

Base

Base is the larger broad surface that articulates with the cricoid cartilage • Has a m uscular process (lateral process) that extends laterally and provides for m uscular attachm ent • Has a vocal process (anterior process) that extends anteriorly and gives rise to the true vocal cord Com posed of hyaline cartilage (except a sm all portion of the vocal process) Base articulates with cricoid to form the cricoarytenoid joint Arytenoid cartilage can dislocate between the base and cricoid cartilages as a com plication from instrum entation of the airway

16

Corniculate cartilage Arytenoid cartilage Corniculate cartilage Arytenoid cartilage Muscular process Vocal process Vocal ligament

Vocal ligament

Posterior view

Medial view, median (sagittal) section

Corniculate cartilage Apex Muscular process Vocal process

Arytenoid cartilage

Anterosuperior view

Figu re 16-6

LARYNX 451

16

CARTILAGES • Epiglottis Anatomic Feature

Comment

Epiglottic tubercle

Pear-shaped Connected to the thyroid cartilage by the thyroepiglottic ligam ent Connected to the hyoid bone by the hyoepiglottic ligam ent During deglutition (as the hyoid bone and rem ainder of larynx elevates), the epiglottis is positioned in a posterior direction, diverting food and liquid from the laryngeal inlet The m ucosa covering the anterior surface of the epiglottis is strati ed squam ous nonkeratinized epithelium The m ucosa covering the posterior surface of the epiglottis is pseudostrati ed colum nar epithelium with cilia

Epiglottis

Triticeal cartilage

Epiglottis Hyoepiglottic ligament

Thyroepiglottic ligament

Posterior view

Medial view, median (sagittal) section

Figu re 16-7

452

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CARTILAGES • Minor Cartilages Cartilage

Comments

Corniculate

Lies on the apex of the arytenoid cartilage Helps support the aryepiglottic fold

Cuneiform

Lies superior to the corniculate cartilage Helps support the aryepiglottic fold

Triticeal

Sm all piece of elastic cartilage that lies in the posterior border of the thyrohyoid m em brane

Cuneiform cartilage

Cuneiform cartilage

Corniculate cartilage

Corniculate cartilage Arytenoid cartilage

Arytenoid cartilage

Posterior view

16

Medial view, median (sagittal) section

Cuneiform cartilage Corniculate cartilage

Anterosuperior view

Figu re 16-8

LARYNX 453

16

JOINTS, MEMBRANES, AND LIGAMENTS • Major Joints Joint

Comments

Cricothyroid joint

Located between the inferior cornu of the thyroid cartilage and the inferior border of the lam ina of the cricoid cartilage Synovial joint Allows rotation between thyroid and cricoid cartilages

Cricoarytenoid joint

Located between the superior border of the lam ina of the cricoid cartilage and the base of the arytenoid cartilage Synovial joint 2 m ovem ents occur: • Rotation • Gliding Medial rotation and m edial gliding occur together to close the rim a glottidis Lateral rotation and lateral gliding occur together to open the rim a glottidis

Major Extrinsic Membranes and Ligaments Ligament

Location

Comments

Thyrohyoid m em brane

Thyroid cartilage to hyoid bone

Allows passage of the internal laryngeal n. and superior laryngeal a. and v.

Thyroepiglottic ligam ent

Thyroid cartilage to epiglottis

Holds epiglottis to the thyroid cartilage

Hyoepiglottic ligam ent

Hyoid bone to the epiglottis

Holds epiglottis to the hyoid bone

Cricotracheal ligam ent

Cricoid cartilage to trachea

Attaches the cricoid cartilage to the rst tracheal ring May be used in establishing an em ergency airway

Major Intrinsic Membranes and Ligaments Ligament

Location

Comments

Vocal ligam ent

Arytenoid (vocal process) to thyroid cartilage

Help form true vocal cord

Conus elasticus Divided into:

454

Also known as the cricovocal or cricothyroid m em brane

Lateral part of conus elasticus

Superior—thyroid, vocal lig., arytenoid (vocal process) Inferior—upper border of cricoid

Lateral part of the conus elasticus is bilateral Help form true vocal cord

Medial part of conus elasticus (also called m edian cricothyroid ligam ent)

Cricoid cartilage to thyroid cartilage

Prim ary site for establishing an em ergency airway

Quadrangular m em brane

Arytenoid to epiglottis

Help form false vocal cord

Vestibular ligam ent

Free edge of the inferior border of the quadrangular m em brane

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

JOINTS, MEMBRANES, AND LIGAMENTS • Major Joints

16

Epiglottis Hyoepiglottic ligament

Hyoid bone Thyrohyoid membrane Thyroid cartilage lamina Corniculate cartilage

Thyroepiglottic ligament

Arytenoid cartilage Vocal ligament

Cricothyroid ligament

Trachea

Medial view, median (sagittal) section

Epiglottis Hyoid bone

Hyoepiglottic ligament

Thyrohyoid membrane Q uadrangular membrane Corniculate cartilage Arytenoid cartilage

Thyroepiglottic ligament

Muscular process Conus elasticus

Vocal process

Cricothyroid ligament

Vocal ligament

Cricoid cartilage Vestibular ligament Trachea

Figu re 16-9

LARYNX 455

16

MUSCLES • Overview Muscle

Origin

Insertion

Action

Nerve Supply

Cricothyroid

Arch of cricoid

Lam ina and inferior cornu of thyroid

Increases (lengthens) tension on vocal ligam ents

External laryngeal n.

Thyroarytenoid

Angle of thyroid cartilage

Arytenoid (vocal process)

Decreases (relaxes) tension on vocal ligam ents

Recurrent laryngeal n.

(Vocalis—inferior bers of the thyroarytenoid)

Decreases (relaxes) tension on the posterior part of the vocal ligam ents

Posterior cricoarytenoid

Lam ina of cricoid

Lateral cricoarytenoid

Arch of cricoid (lateral portion)

Transverse arytenoid

Arytenoid (m uscular process)

Oblique arytenoid

Opens rim a glottidis Closes rim a glottidis

Opposite arytenoid (m uscular process) Opposite arytenoid (apex)

Aryepiglotticus

Arytenoid (apex)

Thyroepiglotticus

Thyroid lam ina

Aryepiglottic muscle O blique arytenoid muscle Transverse arytenoid muscle

Posterior view

Arytenoid (m uscular process)

Epiglottis

Helps close laryngopharyngeal opening

O blique and transverse arytenoid muscles Posterior cricoarytenoid muscle

Straight part

Cricothyroid O blique part muscle

Posterior cricoarytenoid muscle

Right lateral view Lateral dissection

Aryepiglottic muscle O blique and transverse arytenoid muscle Posterior cricoarytenoid muscle

Thyroepiglottic muscle Thyroarytenoid muscle

Lamina of cricoid cartilage Arytenoid cartilage

Lateral cricoarytenoid muscle

Cricothyroid muscle (cut aw ay) Posterior cricoarytenoid muscle Lateral cricoarytenoid muscle Transverse and oblique arytenoid muscle Cricothyroid muscle Thyroarytenoid muscle Vocalis muscle Vocal ligament

Lamina of thyroid cartilage Superior view

Figu re 16-10

456

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

MUSCLES • Overview

16

SUMMARY OF MUSCLE ACTIONS Altering the Rima Glottidis

Altering Tension on the Vocal Cords

Muscle

Action

Muscle

Action

Posterior cricoarytenoid

Opens the rim a glottidis

Cricothyroid

Increasing tension

Transverse arytenoids Oblique arytenoids Lateral cricoarytenoid

Close the rim a glottidis

Thyroarytenoid

Decreasing tension

Action of cricothyroid muscles Lengthening (increasing tension) of vocal ligaments

Cricothyroid joint (pivot point)

Action of posterior cricoarytenoid muscles Abduction of vocal ligaments

Action of transverse arytenoid muscles Adduction of vocal ligaments

Action of lateral cricoarytenoid muscles Adduction of vocal ligaments

Action of vocalis and thyroarytenoid muscles Shortening (relaxation) of vocal ligaments

Figu re 16-11

LARYNX 457

16

VASCULAR SUPPLY • Arterial Supply Artery

Source

Course

Superior laryngeal

Superior thyroid a., which arises from the external carotid a.

Passes through the thyrohyoid m em brane with the internal laryngeal n. to enter the deep surface of the larynx

Inferior laryngeal

Inferior thyroid a., which arises from the thyrocervical trunk

Passes superiorly on the trachea to reach the posterior border of the larynx Lies im m ediately deep to the inferior constrictor m . traveling beside the recurrent laryngeal n.

Internal carotid artery External carotid artery Superior laryngeal artery Superior thyroid artery Cricothyroid artery Inferior thyroid artery

Common carotid artery Subclavian artery

Internal laryngeal nerve Superior laryngeal artery and vein

Recurrent laryngeal nerve Inferior laryngeal artery and vein

Figu re 16-12

458

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

VASCULAR SUPPLY • Venous Drainage Vein

Course

Superior laryngeal

Begins in the deep surface of the superior part of the larynx Passes with the superior laryngeal a. and the internal laryngeal n. Passes through the thyrohyoid m em brane to lie on the super cial surface of the larynx Drains into the superior thyroid v., which drains into the internal jugular v.

Inferior laryngeal

Arises within the deep surface of the inferior part of the larynx Passes with the inferior laryngeal a. and the recurrent laryngeal n. Passes inferiorly deep to the inferior constrictor to exit the larynx Drains into the inferior thyroid v., which drains into the brachiocephalic vv.

16

Internal jugular vein

Superior laryngeal vein Superior thyroid vein Thyroid gland Middle thyroid vein Inferior thyroid veins

Subclavian vein

Figu re 16-13

LARYNX 459

16

NERVE SUPPLY • Motor and Sensory Branches From the Vagus Nerve Nerve

Type

Sensory Target

External laryngeal

Motor

Internal laryngeal

Sensory

Mucosa above the vocal folds

Recurrent laryngeal

Sensory and m otor

Mucosa below the vocal folds

Muscle(s) Innervated Cricothyroid

Comments Branch of superior laryngeal nerve from the vagus Branch of superior laryngeal nerve from the vagus Carries afferent bers responsible for the cough re ex

Thyroarytenoid Posterior cricoarytenoid Lateral cricoarytenoid Transverse arytenoid Oblique arytenoid Aryepiglotticus Thyroepiglotticus

Branch of the vagus Wraps around the aorta posterior to the ligam entum arteriosum on the left side Wraps around the right subclavian artery on the right side Ascends on the lateral aspect of the trachea until reaching the pharynx, where it passes deep to the inferior constrictor to reach the larynx

Longitudinal pharyngeal muscles

Inferior pharyngeal constrictor muscle

Internal branch of superior laryngeal nerve (Transverse and oblique) arytenoid muscles Posterior cricoarytenoid muscle

Figu re 16-14

46 0 NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

NERVE SUPPLY • Motor and Sensory Branches From the Vagus Nerve

16

Superior laryngeal nerve Internal branch External branch

Inferior pharyngeal constrictor muscle

Right lateral view Cricothyroid muscle

Cricopharyngeus muscle (part of inferior pharyngeal constrictor)

Recurrent laryngeal nerve

Internal branch of superior laryngeal nerve Sensory branches to larynx

Right lateral view: thyroid cartilage lamina removed

Anterior and posterior branches of inferior laryngeal nerve Recurrent laryngeal nerve

Figu re 16-15 LARYNX 461

16

CLINICAL CORRELATES • Emergency Airway: Cricothyrotomy • •

• • • •

Cricothyrotom y: a p roced u re for establish in g an em ergen cy airway wh en oth er m eth od s are u n su itable On ce th e an atom y of th e laryn x is id en ti ed, th e p roced u re can be p erform ed with 2 in cision s: • In cision th rou gh th e skin • In cision th rou gh th e cricoth yroid m em bran e Th e correct location for th e in cision is easiest to n d by id en tifyin g th e th yroid n otch on th e th yroid cartilage By slid in g th e exam in in g n ger in an in ferior direction , th e groove between th e th yroid an d cricoid cartilages can be located A 3-cm vertical in cision is m ade th rou gh th e skin , an d th e th yroh yoid m em bran e is located A sm all m id lin e in cision is m ad e, an d a trach eostom y tu be is in serted to establish an airway

Cricothyroid membrane identified by palpating for transverse indentation between thyroid cartilage and cricoid cartilage Thyroid cartilage Cricoid cartilage Thyroid gland

Cricothyroid membrane opened with scalpel, knife, or other sharp instrument which may be at hand. O pening may be enlarged by twisting instrument and patency preserved by inserting rubber tubing or any other suitable object available.

Figu re 16-16

462

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

CLINICAL CORRELATES • Laryngitis • • • • •

16

Laryngitis: an in am m ation of th e vocal cord s in th e laryn x th at typ ically d oes n ot p ersist lon ger th an 7 d ays Ch aracterized by a weak an d h oarse voice, sore th roat, an d cou gh Most com m on cau se is a viral in fection , alth ou gh it m ay be cau sed by a bacterial in fection Can also be cau sed by excessive yellin g (su ch as ch eerin g at a sp ortin g even t) an d sm okin g Becau se m ost cases of laryn gitis are viral in n atu re, an tibiotics gen erally are n ot u sed as treatm en t

Root of tongue (lingual tonsil)

Median glossoepiglottic ligament

Epiglottis Vocal folds (true cords)

Ventricular folds (false cords)

Trachea

Aryepiglottic fold

Piriform fossa

Cuneiform tubercle

Corniculate tubercle

Interarytenoid incisure Esophagus

Normal larynx: Inspiration

Acute laryngitis

Figu re 16-17

LARYNX 463

16

CLINICAL CORRELATES • Lesions Affecting the Voice • • • • • •

•

Th e vagu s n erve p rovid es all of th e m otor an d sen sory in n ervation to th e laryn x Th e su p erior laryn geal n erve d ivid es in to th e in tern al laryn geal (sen sory) an d extern al laryn geal (m otor to th e cricoth yroid ) Th e recu rren t laryn geal p rovid es sen sory an d m otor in n ervation to th e rem ain d er of th e m u scles of th e laryn x Lesion s of th e recu rren t laryn geal n erve resu lt in a p aralysis of th e ip silateral vocal fold Th is p roblem u su ally m an ifests clin ically as h oarsen ess with an in effective cou gh Com m on cau ses in clu d e: • Th yroid tu m ors • Neck tu m ors • Cerebrovascu lar accid en t (stroke) • Lu n g tu m ors • Su rgery • Th yroiditis Th e voice also m ay be affected in Parkin son ’s d isease an d m yasth en ia gravis

Nucleus

Superior laryngeal n. (SLN) Thyroid cartilage

Vagus n.

Left recurrent laryngeal n. (RLN)

Right recurrent laryngeal n. (RLN)

Posterior view Paralysis of left vocal fold Aortic arch

Lesions disrupting recurrent laryngeal n. result in paralysis of ipsilateral vocal fold.

Anterior view

CNS tumors involving vagus n.

Parkinson's disease

Causes of neurologic disorders of voice CN-XII CNS vascular Neck tumor occlusion involving (thyroid, vagal nuclei parathyroid) Neck surgery Lung tumor Amyotrophic lateral sclerosis involving nucleus of CN-XII

Dopamine

Neck lesions involving vagus, RLN, or SLN

Figu re 16-18

464

Normal right vocal fold

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

Myasthenia gravis

N-M junction

CHAPTER 17

CERVICAL FASCIA

Overview and Topographic Anatomy

466

Fascia of the Neck

46 8

Fascial Spaces

471

Clinical Correlates

479

17

OVERVIEW AND TOPOGRAPHIC ANATOMY • General Information •

Fascia: a ban d of con n ective tissu e th at su rrou n d s stru ctu res (su ch as en velop in g m u scles), givin g rise to p oten tial tissu e sp aces an d p ath ways th at allow in fection to sp read

SUPERFICIAL FASCIA

• •

Im m ediately d eep to th e skin Con tain s fat

DEEP FASCIA

• • • • •

•

•

Deep to th e su p er cial fascia Aids m u scle m ovem en ts Provides p assageways for n erves an d vessels Provides attach m en t for som e m u scles In th e n eck, it is d ivid ed in to 4 regions: • Visceral region • Mu scu loskeletal region • 2 n eu rovascu lar com p artm en ts Also d ivided in to 4 layers: • Su p er cial layer of d eep cervical fascia (in vestin g layer of deep cervical fascia) • Mid dle layer of deep cervical fascia • Deep layer of d eep cervical fascia • Carotid sh eath (com p osed of th e con tribu tion s of all 3 layers of deep cervical fascia) Th ere is n o d eep fascia in th e face, wh ich allows free sp read of u id

Platysma

Anterior jugular vein Thyroid gland

Sternohyoid muscle Sternothyroid muscle O mohyoid muscle Sternocleidomastoid muscle

Trachea Parathyroid gland

Recurrent laryngeal nerve

Interior jugular vein

Inferior thyroid artery

Common carotid artery

Anterior scalene muscle Longus colli muscle

Recurrent laryngeal nerve Vagus nerve Phrenic nerve Sympathetic trunk Esophagus

Vertebral body (C5) Middle and posterior scalene muscles

Figu re 17-1

466

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

OVERVIEW AND TOPOGRAPHIC ANATOMY • General Information

Sella turcica Frontal sinus Sphenoidal sinus

17

Pharyngeal opening of pharyngotympanic (auditory) tube

Nasopharynx Anterior arch of atlas (C1 vertebra)

O ral cavity

Dens of axis (C2 vertebra)

Palatine tonsil O ropharynx

C1

C1 C2 C3

Epiglottis Mandible

Retropharyngeal space

C4

Hyoid bone

Pharyngeal constrictor muscles Buccopharyngeal fascia

Prevertebral fascia and anterior longitudinal ligament

C5 Laryngopharynx C6

Vertebral bodies

Thyroid cartilage C7 Cricoid cartilage Trachea Esophagus

T1

Esophageal muscles Thyroid gland Investing layer of (deep) cervical fascia Pretracheal fascia Suprasternal space Manubrium of sternum

Figu re 17-2

CERVICAL FASCIA 467

17

FASCIA OF THE NECK • Superf cial Fascia • • • •

Su p er cial fascia lies d eep to th e skin an d con tain s th e cu tan eou s vessels an d n erves In th e n eck, th e p latysm a m u scle lies with in th e su p er cial fascia Has a variable am ou n t of ad ip ose tissu e, d ep en d in g on th e in d ivid u al p atien t Su p er cial fascia h as brou s sep ta wh ich can h elp localize in fection s

Investing layer of (deep) cervical fascia

Platysma muscle Sternohyoid muscle Trachea Sternothyroid muscle Thyroid gland Esophagus

Muscular portion of pretracheal layer of (deep) cervical fascia (of infrahyoid muscles) Visceral portion of pretracheal layer of (deep) cervical fascia Buccopharyngeal (visceral) fascia

O mohyoid muscle Sternocleidomastoid muscle

Carotid sheath Subcutaneous tissue Investing layer of (deep) cervical fascia roofing posterior triangle Fat in posterior triangle Prevertebral layer of (deep) cervical fascia Alar fascia Cross section

Subcutaneous tissue

Recurrent laryngeal nerve Common carotid artery Internal jugular vein Vagus nerve (X) Phrenic nerve Anterior scalene muscle Sympathetic trunk Spinal nerve Middle and posterior scalene muscles Longus colli muscle Levator scapulae muscle Trapezius muscle Deep cervical muscles Cervical vertebra (C7)

Sagittal section Mandible Pharynx Buccopharyngeal fascia

Geniohyoid muscle Geniohyoid fascia Investing layer of (deep) cervical fascia Fascia of infrahyoid muscles

Alar fascia

Pretracheal fascia

Prevertebral fascia

Thyroid gland

Trachea

Subcutaneous tissue

Esophagus

Suprasternal space Manubrium of sternum Aorta Pericardium

Figu re 17-3

46 8 NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

FASCIA OF THE NECK • Deep Fascia

17

SUPERFICIAL LAYER OF DEEP CERVICAL FASCIA Layer

Location

Attachment

Comments

Super cial layer of deep cervical fascia (also known as the investing layer of deep cervical fascia)

Im m ediately deep to the super cial fascia Encircles the neck com pletely When the layer approaches the sternocleidom astoid and trapezius m m ., it splits to lie on the super cial and deep surfaces

Anterior—chin, hyoid, sternum Posterior—spinous process of cervical vertebra and the ligam entum nuchae Superior—external occipital protuberance, superior nuchal line, m astoid process, inferior border of the zygom atic arch, inferior border of the m andible from the angle to the m idline Inferior—sternum (splitting into anterior and posterior parts), clavicle, acrom ion of the scapula

Form s the roof of the posterior triangle In the area between the m astoid process and the angle of the m andible, this layer form s the deep portion of the parotid fascia (evidence supports that the super cial portion is continuous with the platysm a fascia and is classi ed as part of the super cial m uscular aponeurotic system [SMAS], although som e claim the super cial portion is also from the super cial layer of deep cervical fascia) Helps de ne the m asticator space

MIDDLE LAYER OF DEEP CERVICAL FASCIA (sometimes collectively referred to as the Pretracheal fascia) Layer

Location

Attachment

Comments

Muscular portion: (Infrahyoid fascia)

Com pletely surrounds the strap m uscles of the neck

Superior—hyoid bone and thyroid cartilage Inferior—sternum

Is continuous across the m idline

Visceral portion: (Pretracheal layer of fascia)

Deep to the super cial layer of deep cervical fascia

Superior—larynx Inferior— brous pericardium in the superior m ediastinum of the thorax

Form s a covering around the visceral structures in the neck, such as the thyroid gland, esophagus, and trachea

Visceral portion: (Buccopharyngeal fascia)

Deep to the super cial layer of deep cervical fascia posterior to the pharynx

Superior—base of the skull Inferior—superior m ediastinum where the m iddle layer of deep cervical fascia joins the alar fascia

Continuous with the pretracheal layer of fascia posterior to the pharynx and the esophagus

DEEP LAYER OF DEEP CERVICAL FASCIA (sometimes collectively referred to as the Prevertebral fascia) Layer

Location

Attachment

Comments

Prevertebral layer of fascia

Com pletely encircles the cervical portion of the vertebral colum n with its associated pre- and postvertebral m uscles

Superior—base of skull Inferior—coccyx

Form s the oor of the posterior triangle Encloses the vertebral m uscles Form s the axillary sheath

Alar fascia

An anterior slip of prevertebral fascia found between the m iddle layer of deep cervical fascia and prevertebral layers of deep cervical fascia

Superior—base of skull Inferior—m erges with visceral portion of the m iddle layer of deep cervical fascia at about the level of T2

Separates the retropharyngeal space from the danger space

CERVICAL FASCIA 469

17

FASCIA OF THE NECK • Deep Fascia COMBINATION OF ALL 3 LAYERS Layer

Location

Attachment

Comments

Carotid sheath

In the neck between the investing layer, pretracheal layer, and the prevertebral layer

Superior—base of skull Inferior—m erges with connective tissue around arch of the aorta

Contains the internal or com m on carotid a., internal jugular v., and vagus n. (parts of the ansa cervicalis tend to be found with the carotid sheath)

Digastric muscle (anterior belly)

Masseter muscle

Mylohyoid muscle Parotid gland

Submandibular gland

Platysma muscle (cut aw ay)

Fibrous loop for intermediate digastric tendon

Mastoid process

Stylohyoid muscle Digastric muscle (posterior belly)

Hyoid bone

External carotid artery

Carotid sheath

Internal jugular vein Fascia of infrahyoid muscles and cut edge

Thyrohyoid muscle O mohyoid muscle (superior belly)

Thyroid cartilage

Sternohyoid muscle

Investing layer of (deep) cervical fascia and cut edge

Sternothyroid muscle Scalene muscles

Cricoid cartilage

Trapezius muscle Deltoid muscle

Clavicle O mohyoid muscle (inferior belly) Pretracheal layer of (deep) cervical fascia over thyroid gland and trachea

Pectoralis major muscle Clavicular head Sternocleidomastoid muscle Sternal head

Suprasternal space Manubrium of sternum

Jugular notch

Figu re 17-4

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FASCIAL SPACES • General Information • • • • • • •

• • •

•

17

Layers of fascia “create” p oten tial fascial sp aces All are lled by loose areolar con n ective tissu e In fection s or oth er in am m atory con d ition s sp read by th e p ath of least resistan ce to reach th e fascial sp aces Most od on togen ic in fection s are cau sed by en d ogen ou s bacteria Sp read typ ically is between con tigu ou s fascial layers, bu t bacteria release en zym es th at cau se cellu lar lysis, allowin g sp read between fascia sp aces th at are n ot con tin u ou s Th e h yoid bon e is th e m ost im p ortan t an atom ic stru ctu re in th e n eck th at lim its th e sp read of in fection Most are d ivid ed in to sp aces in relation to th e h yoid bon e: • Su p rah yoid • In frah yoid • En tire len gth of th e n eck In d en tistry, fascial sp aces are classi ed accord in g to m ode of sp read of od on togen ic in fection s Th u s fascial sp aces are d esign ated as eith er prim ary, with in fection occu rrin g by d irect sp read from in volved tissu e, or secondary, with in fection occu rrin g by con tin u ed sp read from an oth er sp ace A com m on ly accep ted classi cation is: • Prim ary m axillary sp aces: • Can in e • Bu ccal (bridges between m axillary an d m an dibu lar region s) • In fratem p oral • Prim ary m an d ibu lar sp aces: • Su bm an d ibu lar • Su bm en tal • Su blin gu al • Bu ccal (bridges between m axillary an d m an dibu lar region s) • Secon dary sp aces: • Masticator (p terygom an d ibu lar, su bm asseteric, tem p oral) • Lateral p h aryn geal • Retrop h aryn geal • Parotid • Prevertebral Som e of th e fascial sp aces are d irectly con tin u ou s with oth er fascial sp aces, wh ereas oth ers will com m u n icate if in fection s break th rou gh 1 of th e walls of a sp ace

CERVICAL FASCIA 471

17

FASCIAL SPACES • General Information

Horizontal section below lingula of mandible (superior view) demonstrating bed of parotid gland

Superior pharyngeal constrictor muscle

Palatine tonsil Palatopharyngeus muscle in palatopharyngeal arch

Parotid gland (space)

Superior cervical sympathetic ganglion Styloglossus muscle

Submasseteric space

Stylopharyngeus muscle

Pterygomandibular space Carotid sheath space

Internal jugular vein, internal carotid artery, and nerves IX, X and XII in carotid sheath

Peritonsillar space Lateral pharyngeal space Retropharyngeal space Alar fascia Danger space

Stylohyoid muscle Medial pterygoid muscle Digastric muscle (posterior belly) Parotid gland Sternocleidomastoid muscle

Axis (C2)

External carotid artery

Facial nerve

Retromandibular vein Inferior alveolar artery, vein, and nerve Ramus of mandible Masseter muscle Facial artery and vein Pterygomandibular raphe Buccinator muscle Palatoglossus muscle in palatoglossal arch

Buccal space Buccopharyngeal fascia

O rbicularis oris muscle

Figu re 17-5

472

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FASCIAL SPACES • Suprahyoid Fascial Spaces Comments and Potential for Infection

Space

Location

Direct Communications

Buccal

Lateral—skin and super cial fascia Medial—buccinator Superior—zygom atic process Inferior—m andible Anterior—m outh Posterior—m asseter

Buccal space com m unicates with: • Canine space • Pterygom andibular space • Infratem poral space • Subm asseteric space • Lateral pharyngeal space

Dental infections of the m axillary and m andibular m olars

Canine

Superior—levator labii superioris Inferior—levator anguli oris

Canine space com m unicates with: • Buccal space

Dental infections of the m axillary canine or m axillary 1st prem olar Infections can erode superiorly toward the orbit, in which case they can travel via the inferior ophthalm ic vein into the cavernous sinus

Infratem poral

Superior—infratem poral surface of greater wing of sphenoid Inferior—lateral pterygoid Lateral—tem poralis Medial—lateral pterygoid plate Anterior—m axilla Posterior—lateral pterygoid

Infratem poral space com m unicates with: • Buccal space • Pterygom andibular space

Dental infections are rare in the infratem poral space When they occur, they usually are the result of m axillary 3rd m olar infection Infections in this area are in close proxim ity to the pterygoid plexus and can travel to the cavernous sinus

Subm axillary (also called subm andibular, but then is confused with the sm aller subm andibular part)

Anterior and lateral— m andible Posterior—hyoid bone Superior—m ucosa of the oor of the oral cavity and the tongue Inferior—super cial layer of deep cervical fascia

Subm axillary space com m unicates with: • Lateral pharyngeal space

The anterior part of the peripharyngeal spaces, which create a ring around the pharynx (the retropharyngeal and lateral pharyngeal spaces are the other com ponents) Divided into 3 parts: • Sublingual space • Subm andibular space • Subm ental space

Between the m ucosa and the m ylohyoid m . Anterior and lateral— m andible Posterior—m uscles along the base of the tongue Superior—m ucosa of the oor of the oral cavity and the tongue Inferior—m ylohyoid m .

Sublingual space com m unicates with: • Lateral pharyngeal space • Subm andibular space

Contains the: • Hypoglossal n. • Lingual n. • Sublingual gland • Deep part of the subm andibular gland • Subm andibular duct Dental infections from the m andibular prem olars and m olars m ay spread to the sublingual space

Sublingual

17

Continued on next page

CERVICAL FASCIA 473

17

FASCIAL SPACES • Suprahyoid Fascial Spaces Space

Comments and Potential for Infection

Location

Direct Communications

Subm andibular

Between the m ylohyoid m . and the super cial layer of deep cervical fascia On the super cial surface of the m ylohyoid between the anterior and posterior bellies of the digastric m . and the m andible

Subm andibular space com m unicates with: • Lateral pharyngeal space • Sublingual space • Subm ental space

Contains the: • Subm andibular gland • Anterior digastric m . Continuous with the sublingual space along the posterior free border of the m ylohyoid m . Because the roots of the 1st, 2nd, and 3rd m olars are inferior to the attachm ent of the m ylohyoid on the m andible, dental infections of these teeth m ay pass into the subm andibular space, which is continuous with the lateral pharyngeal space Corresponds to the area of the subm andibular triangle

Subm ental

Between the m ylohyoid m . and the super cial layer of deep cervical fascia Bounded laterally by the anterior digastric m .

Subm ental space com m unicates with: • Subm andibular space

The subm ental space is an anterior extension of the subm andibular space Corresponds to the area of the subm ental triangle Infections of m andibular anterior teeth m ay pass into the subm ental space

On the lateral aspect of the pharynx, continuous with the retropharyngeal space posteriorly and the subm andibular space anteriorly Extends from the base of the skull to the hyoid bone Extends in an anterosuperior direction to the pterygom andibular raphe Bounded m edially by the m iddle layer of deep cervical fascia (buccopharyngeal fascia) covering the superior constrictor m . of the pharynx and laterally by the super cial layer of deep cervical fascia covering the m edial pterygoid m . and the deep portion of the parotid gland

Lateral pharyngeal space com m unicates with: • Subm andibular space • Retropharyngeal space • Pterygom andibular space • Peritonsillar space

Very susceptible to the spread of infections from the teeth, jaws, and pharynx, including the nasopharynx, adenoids, and tonsils Infections of m andibular 3rd m olars m ay spread to this space Tonsillar infections m ay spread to this space Tum ors of the lateral pharyngeal space also will spread through the space

Lateral pharyngeal (also called the parapharyngeal space)

Continued on next page

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FASCIAL SPACES • Suprahyoid Fascial Spaces

17

Comments and Potential for Infection

Space

Location

Direct Communications

Masticator

Form ed when the super cial layer of deep cervical fascia splits to enclose the ram us of the m andible and overlies the m asseter m . on the lateral surface and the m edial pterygoid m . and the lower portion of the tem poralis m . on the m edial surface

Masticator space com m unicates with: • Infratem poral space • Pterygom andibular space • Subm asseteric space • Tem poral space

Contains the: • Masseter m . • Medial pterygoid m . • Lateral pterygoid m . • Lower portion (insertion) of the tem poralis m . • Contents of the pterygom andibular space Is the collective space that can be divided into the: • Pterygom andibular • Subm asseteric • Tem poral

Pterygom andibular

Medial—m edial pterygoid Lateral—m andible Superior—lateral pterygoid Posterior—parotid gland Anterior—buccal space

Pterygom andibular space com m unicates with: • Subm asseteric space • Tem poral space • Buccal space

Dental infections that travel to this space are from m andibular 3rd m olars or m andibular 2nd m olars Contents include: • Inferior alveolar n., a., and v. • Sphenom andibular ligam ent

Subm asseteric

Anterior—m asseter Posterior—parotid gland Lateral—m asseter Medial—m andible Superior—zygom atic arch Inferior—m andible (inferior attachm ent of m asseter)

Subm asseteric space com m unicates with: • Pterygom andibular space • Buccal space

Dental infections in this space are rare Usually the result of an infection of an im pacted m andibular 3rd m olar

Tem poral

Form ed when the super cial layer of deep cervical fascia encloses the tem poralis m .

Tem poral space com m unicates with: • Infratem poral space • Pterygom andibular space (subdivision of m asticator space)

Can be further subdivided into a super cial and a deep space

Peritonsillar

Anterior—palatoglossal fold Posterior— palatopharyngeal fold Medial—palatine tonsil capsule Lateral—superior constrictor m .

Peritonsillar space com m unicates with: • Lateral pharyngeal space

Located within the wall of the pharynx Infections of the peritonsillar space m ay extend into the lateral pharyngeal space

Parotid gland [space]

Form ed when the super cial layer of deep cervical fascia encloses the parotid gland as a capsule

No direct com m unication

The parotid fascia is weaker on the m edial side, and infections of this space can break through the fascia to enter the lateral pharyngeal space

Subm andibular gland [space]

Form ed when the super cial layer of deep cervical fascia encloses the subm andibular gland as a capsule

No direct com m unication

The inner layer of the capsule is weaker, and infections of this space tend to break through the fascia to this side

CERVICAL FASCIA 475

17

FASCIAL SPACES • Suprahyoid Fascial Spaces

Buccopharyngeal fascia

Superior constrictor Temporalis

Peritonsillar space

Lateral pterygoid

Masseter Ramus of mandible

Superficial layer of deep cervical fascia

Medial pterygoid Middle constrictor

Superficial layer of deep cervical fascia surrounding masseter, lower portion of the temporalis, ramus of the mandible, and medial pterygoid forming the masticator space

Submandibular gland Mylohyoid

Inferior constrictor Lateral pharyngeal space

A

Coronal section posterior to 1st molar tooth (anterior view)

B

Maxillary sinus

Arrows indicate possible paths of infection

Abscess

Buccopharyngeal fascia

A Maxillary sinus B Buccal space C O ral cavity D Submandibular space E Sublingual space

C

Buccinator muscle

C

Abscess B E

Mandibular canal, inferior alveolar artery, vein, and nerve Sublingual salivary gland

Submandibular salivary gland

D

Mylohyoid muscle Hyoid bone

Figu re 17-6

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FASCIAL SPACES • Infrahyoid Fascial Spaces Space

Location

Direct Communications

Pretracheal (anterior visceral)

Superior—larynx Inferior—superior m ediastinum Com pletely surrounds the trachea and also contains the thyroid and esophagus

No direct com m unication

17

Comments and Potential for Infection Usually infections spread to the pretracheal space only by puncturing the esophagus anteriorly or by a perforation in the retropharyngeal space

Fascial Spaces Traversing the Length of the Neck Comments and Potential for Infection

Space

Location

Direct Communication

Super cial

Between the super cial fascia and the super cial layer of deep cervical fascia Surrounds the platysm a m.

Super cial space com m unicates with: • Super cial fascia of face

Infections are super cial and often observed early

Retropharyngeal

Posterior to the buccopharyngeal layer of the m iddle layer of cervical fascia covering the pharynx and esophagus, and anterior to the alar fascia Extends from the base of the skull to about the level of T2, where the 2 layers of fascia fuse The inferior portion of the retropharyngeal space (posterior to the esophagus) is som etim es called the retrovisceral space

Retropharyngeal space com m unicates with: • Lateral pharyngeal space

Infections in this space often are the result of infections in Waldeyer’s ring that spread to the retropharyngeal lym ph nodes Other nasal and pharyngeal infections m ay spread to the retropharyngeal space Dental infections that traverse the lateral pharyngeal space can travel to the retropharyngeal space Cellulitis or abscess m ay eventually result Retropharyngeal infections m ay continue to spread posteriorly into the danger space

“Danger space”

Posterior to the alar fascia (and fascia where the alar fascia and m iddle layer of the cervical fascia fuse) and anterior to the prevertebral fascia Extends from the base of the skull to the diaphragm

Not directly continuous with another fascial space Danger space is continuous with m ediastinum

Via the superior m ediastinum , it allows infection to spread into the thorax

Prevertebral

Between the prevertebral fascia and the vertebral colum n

Not directly continuous with another space

Closed off superiorly, laterally, and inferiorly, so spread of infections in this space is not com m on

Carotid sheath

A potential space is created by the carotid sheath Bounded superiorly by the skull base, inferiorly it m erges with connective tissue around the aortic arch

Not directly continuous with another space However, infections from surrounding areas m ay erode into carotid sheath

Infections from visceral spaces m ay enter and pass within the carotid sheath

CERVICAL FASCIA 477

17

FASCIAL SPACES • Fascial Spaces Traversing the Length of the Neck Superficial space Pretracheal space Retropharyngeal space Carotid space

Danger space

Prevertebral space

Cross section

Sagittal section

Retropharyngeal space

Superficial space Pretracheal space

Danger space

Prevertebral layer of deep cervical fascia Danger space Alar fascia Retropharyngeal space

Investing layer of deep cervical fascia

Buccopharyngeal (visceral) fascia

Prevertebral layer of deep cervical fascia

Alar fascia (beneath buccopharyngeal fascia) Carotid sheath Styloid process

Danger space Retropharyngeal space

Superficial layer of deep cervical fascia on medial pterygoid muscle Lateral pharyngeal space

Investing layer of deep cervical fascia

Retropharyngeal space

Investing layer of deep cervical fascia Muscular portion of pretracheal layer of deep cervical fascia Prevertebral layer of deep cervical fascia

Carotid sheath

Skin

Visceral portion of pretracheal layer of deep cervical fascia

Figu re 17-7

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CLINICAL CORRELATES • Ludwig’s Angina • •

• • • •

17

Ludwig’s angina: a severe cellu litis d u e to bacterial in fection (u su ally from Streptococcus, Actinom yces, Prevotella, Fusobacterium , or Staphylococcus) in th e oor of th e oral cavity u n d er th e ton gu e Often begin s in th e su blin gu al an d su bm an d ibu lar sp aces after in fection of th e p rem olar teeth or, m ore com m on ly, m olar teeth (su ch as an abscess of a m an d ibu lar m olar), becau se th eir roots exten d in ferior to th e m yloh yoid lin e of th e m an d ible May follow th e p lan es of th e fascial sp aces to sp read in th e n eck May cau se su f cien t n eck swellin g to block th e airway More com m on in ch ild ren An tibiotic th erap y, in cision of th e n eck to d rain th e in fection , an d excision of th e in fected tooth are th e p ossible treatm en ts

Ludwig’s angina

Figu re 17-8

CERVICAL FASCIA 479

17

CLINICAL CORRELATES • Abscesses •

Abscesses m ay sp read via th e fascial p lan es of th e n eck to becom e m ore seriou s, su ch as in Lu d wig’s an gin a

DENTOALVEOLAR ABSCESS (PERIAPICAL ABSCESS)

• • •

An acu te lesion ch aracterized by localization of p u s in th e stru ctu res su rrou n d in g th e ap ex of a tooth May origin ate in th e d en tal p u lp an d be secon d ary to den tal caries with erosion of en am el an d d en tin , or to trau m atic in ju ry to tooth , allowin g bacteria to in vad e th e d en tal p u lp Resu ltin g p u lp itis can p rogress to n ecrosis as bacteria in vad e th e su rrou n d in g alveolar bon e, cau sin g form ation of a local abscess

PERIODONTAL ABSCESS

•

Typ ically in volves th e su p p ortin g stru ctu res of th e teeth , su ch as th e p eriod on tal ligam en ts an d alveolar bon e, leadin g to form ation of a local abscess

PERICORONITIS

• •

An in am m ation arou n d th e crown of a tooth from an in fection of th e gin giva, lead in g to form ation of an abscess Most com m on ly affected tooth is a p artially eru p ted 3rd m an d ibu lar m olar

Abscess of the submandibular region Periodontal infection related to: A. Subgingival calculus B. O verhanging filling margin C. Poor contact and “tipping” of tooth

Origins of infection

Dento alveolar abscess

Pericoronal abscess about partially erupted 3rd molar

Figu re 17-9

48 0 NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

CLINICAL CORRELATES • Cervical Emphysema • • • •

17

Cervical em physem a: p resen ce of gas d eep to th e skin , wh ich m ay be iatrogen ic (e.g., from su rgery) or secon d ary to trau m a or in fection Som e cau ses in clu d e fractu res of th e h ead an d n eck, in trodu ction of air from a h igh -sp eed den tal d rill, an d su rgical p rocedu res su ch as root can als an d extraction s of m an d ibu lar 3rd m olars In th e h ead an d n eck, cervical em p h ysem a can sp read alon g th e fascial p lan es May be ben ign or fatal, dep en d in g on severity or p attern of sp read

* * * *

*

*

* *

* *

*

*

* * * Presence of air displaying extension of cervical emphysema

Figu re 17-10

CERVICAL FASCIA 481

This pa ge inte ntiona lly le ft bla nk

CHAPTER 18

EAR

Overview and Topographic Anatomy

484

Structures and Boundaries

487

Muscles

494

Nerve Supply

495

Vascular Supply

499

Clinical Correlates

50 6

18

OVERVIEW AND TOPOGRAPHIC ANATOMY • General Information • •

Du al fu n ction s: • Main tain s th e balan ce of th e body (vestibu lar) • Perceives sou n d (au ditory) 3 division s: • Extern al ear • Mid dle ear • In n er ear

EXTERNAL EAR

• •

Th e m ost su p er cial p ortion of th e ear, th e extern al ear in clu d es th e au ricle, extern al acou stic m eatu s, an d th e tym p an ic m em bran e Help s gath er sou n d an d direct it to th e tym p an ic m em bran e

MIDDLE EAR

• • • • •

Tran sm its sou n d vibration s from th e tym p an ic m em bran e to th e in n er ear via th e ear ossicles: m alleu s, in cu s, an d stap es Main ly with in th e p etrou s p ortion of th e tem p oral bon e Gen eral sh ap e resem bles a bicon cave len s Com p osed of th e tym p an ic cavity th at con n ects an teriorly with th e n asop h aryn x via th e au ditory tu be an d th e m astoid air cells p osteriorly Tym p an ic cavity con tain s th e ear ossicles (m alleu s, in cu s, an d stap es), m u scles (ten sor tym p an i an d stap ed iu s m u scles), n erves (ch ord a tym p an i, tym p an ic bran ch of th e glossop h aryn geal n erve, an d lesser p etrosal n erve), an d tym p an ic p lexu s (p arasym p ath etics from th e glossop h aryn geal n erve p lu s sym p ath etics from th e su p erior cervical gan glion via th e carotid p lexu s)

INNER EAR

•

• • • •

484

Vestibu lar an d au d itory stru ctu res, wh ich are lled with u id , m ake u p th e in n er ear: • Au ditory p ortion (coch lea) is stim u lated by th e m ovem en t of th e u id • Vestibu lar p ortion (u tricle, saccu le, an d sem icircu lar can als) is stim u lated by u id m ovem en t with in th ese ch am bers Con sists of a m em bran ou s labyrin th th at lies with in an osseou s labyrin th Th e recep tors for au d itory an d vestibu lar fu n ction are located with in th e m em bran ou s labyrin th Flu id s located in th e m em bran ou s labyrin th (en dolym p h ) an d osseou s labyrin th (p erilym p h ) stim u late th e au d itory an d vestibu lar recep tors Th e vestibu lococh lear n erve en ters th e in tern al ear via th e in tern al acou stic m eatu s

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

OVERVIEW AND TOPOGRAPHIC ANATOMY • General Information

18

Facial nerve (VII) (cut)

Frontal section Limbs of stapes Prominence of lateral semicircular canal Incus

Base of stapes in oval (vestibular) window Vestibule Semicircular ducts, ampullae, utricle, and saccule

Tegmen tympani Malleus (head)

Facial nerve (VII) (cut) Vestibular nerve

Epitympanic recess

Cochlear nerve

Auricle

Internal acoustic meatus Vestibulocochlear nerve (VIII)

External acoustic meatus

Helicotrema Scala vestibuli

Tympanic membrane Tympanic cavity Promontory Round (cochlear) window Pharyngotympanic (auditory) tube

Nasopharynx

Cochlear duct containing spiral organ (Corti) Scala tympani

Cochlea

N ote: Arrows indicate course of sound waves

Figu re 18-1

EAR 485

18

OVERVIEW AND TOPOGRAPHIC ANATOMY • General Information

Section through turn of cochlea

Scala vestibuli Vestibular (Reissner’s) membrane

O sseous spiral lamina

Cochlear duct Nerve fibers

Spiral ligament

Modiolus of cochlea

Tectorial membrane Spiral organ (Corti)

Spiral ganglion

Basilar membrane

Scala tympani

O sseous cochlea

Cochlear nerve

O uter hair cells Pillar (rod) cells Inner hair cell

Superior projection of right bony labyrinth on floor of skull

Groove for greater petrosal nerve Geniculum of facial nerve

Plane of anterior semicircular canal Cochlea Cochlear nerve

Facial nerve (VII) Internal acoustic opening Vestibulocochlear nerve (VIII)

Lateral semicircular canal

Vestibular nerve

Petrous part of temporal bone

External opening of vestibular aqueduct (for endolymphatic duct)

Figu re 18-2

48 6 NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

Plane of posterior semicircular canal

STRUCTURES AND BOUNDARIES • Structures of the External Ear Structure

Comments

Auricle

An irregularly shaped structure m ade of elastic cartilage and skin Superior portion has a skeleton of elastic cartilage Inferior portion is known as the lobule, and has no cartilage Helix: the outerm ost curved rim of the auricle, continues anteriorly to blend with the head at the crus helix Antihelix: the portion of cartilage that follows along the helix from the inside Scaphoid fossa: the depressed area between the helix and the antihelix Concha: dem arcated by the antihelix, it is the depressed area that leads to the external acoustic m eatus Tragus: extends from the face into the concha Antitragus: extends from the inferior portion of the antihelix into the concha and is separated from the tragus by the intertragic notch

External acoustic m eatus

The passageway connecting the concha of the auricle to the tym panic m em brane Covered by skin rich in sebaceous and cerum en-secreting glands About 2.5 cm in length Lateral 1/ 3: cartilaginous, extends into the tem poral bone Medial 2/ 3: osseous, form ed by the tym panic, squam ous, and petrous portions of the tem poral bone

Tym panic m em brane

The m ost m edial portion of the external ear that separates it from the m iddle ear Lies in a groove on the tym panic part of the tem poral bone A thin, sem itransparent, 3-layered m em brane: • External layer—derived from skin; com posed of strati ed squam ous epithelium • Middle layer— brous, with bers attaching to the m alleus • Inner layer—continuous with the m ucous m em brane of the m iddle ear cavity; com posed of colum nar epithelium with cilia Anterior and posterior m alleolar folds lie on the superior portion of the tym panic m em brane Tense and loose portions are called the pars tensa and pars accida, respectively

18

External acous tic meatus Semicircular canals

Auditory os s icles Cochlea

Internal acous tic meatus

Odontoid proces s (dens )

Odontoid proces s (dens )

Figu re 18-3

EAR 487

18

STRUCTURES AND BOUNDARIES • Structures of the External Ear

Right auricle (pinna) Helix Triangular fossa

Scaphoid fossa

Crux of helix

Crura of antihelix

External acoustic meatus

Auricular tubercle (of Darwin)

Tragus

Antihelix

Intertragic notch

Concha of auricle

Antitragus

Lobule of auricle

Otoscopic view of right tympanic membrane Pars flaccida

Lateral process of malleus

Posterior mallear fold Anterior mallear fold Long limb of incus Handle of malleus Umbo Cone of light Pars tensa Coronal oblique section of external acoustic meatus and middle ear (tympanic cavity) Epitympanic recess

Tegmen tympani Dura mater Head of malleus

Superior ligament of malleus

Long limb of incus

Short limb of incus

Footplate of stapes

Chorda tympani nerve (cut)

Handle of malleus

Anterior ligament of malleus (cut)

Promontory with tympanic plexus Tensor tympani muscle

Tympanic membrane External acoustic meatus Tympanic cavity

Figu re 18-4

48 8 NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

Tensor veli palatini muscle Auditory (pharyngotympanic, eustachian) tube

STRUCTURES AND BOUNDARIES • Boundaries of the Middle Ear Boundary

Comments

Roof

Made by the tegm en tym pani, separating the m iddle ear from the tem poral lobe of the m iddle cranial fossa

Floor

Thin bone separates the m iddle ear from the internal jugular v. Tym panic canaliculus, located in the oor of the m iddle ear; allows the tym panic branch of the glossopharyngeal n. to enter the m iddle ear

Anterior wall

Auditory tube: located in the m iddle ear’s anterior wall; connects the m iddle ear with the nasopharynx; equilibrates pressure on either side of the tym panic m em brane, and allows proper drainage of the m iddle ear Lesser petrosal n. exits the m iddle ear through the anterior wall Postganglionic sym pathetic nerve bers from the internal carotid a. pass through the anterior wall to enter the m iddle ear

Posterior wall

Facial canal: passes superoinferiorly im m ediately posterior to the m iddle ear until it term inates at the stylom astoid foram en Mastoid antrum : located in the superior portion of the posterior wall near the junction with the roof of the m iddle ear Pyram id: a hollow projection from the posterior wall; contains the tendon of the stapedius m . Posterior cranial fossa and sigm oid sinus are located posterior to the posterior wall

Medial wall

The m edial wall separates the m iddle ear from the inner ear Prom ontory: a large protuberance created by the cochlea of the inner ear In the superior portion of the m edial wall is a protuberance form ed by the lateral sem icircular canal Inferior to the lateral sem icircular canal on the opposite side of the m edial wall is the horizontal portion of the facial canal Fenestra vestibuli (oval window—where the footplate of the stapes is located) and fenestra cochleae (round window—an opening covered by a m em brane): located in a superior-inferior relationship on the m edial wall posterior to the prom ontory Tendon of the tensor tym pani m . enters the m iddle ear through the m edial wall

Lateral wall

The lateral wall separates the m iddle ear from the external ear; m ainly created by the tym panic m em brane, with the m alleus attached to the m em brane at the um bo Epitym panic recess: the region superior to the tym panic m em brane that houses portions of the m alleus and incus Chorda tym pani n. lies along the tym panic m em brane and m alleus until exiting the petrotym panic ssure

18

Auditory ossicles Articular surface for incus

Head

Malleus

Anterior process

Short limb

Neck

Handle

Lateral process

Body

Base

Malleus: lateral view

Lenticular process of incus

Articular surface for malleus Long limb

Incus: lateral view

Incus

Stapes Ossicles articulated: medial view

Posterior limb Head

Anterior limb

Stapes: superolateral view

Figu re 18-5 EAR 489

18

STRUCTURES AND BOUNDARIES • Boundaries of the Middle Ear Pyramidal eminence (cut)

Mastoid antrum

Chorda tympani Anterior tympanic artery Tensor tympani muscle and tendon (cut)

Stapedial branch of stylomastoid artery

Arteries of mallear stria Handle of malleus Tubal artery

Mastoid cells Pharyngotympanic (auditory, eustachian) tube Marginal arterial rete

Facial nerve

Tympanic membrane Inferior tympanic artery Deep auricular artery Posterior tympanic branch of stylomastoid artery Descending branch of superficial petrosal artery Stapes Posterior crural artery

Stylomastoid artery Styloid process Anterior Tensor Geniculate Lesser petrosal nerve tympani ganglion crural and superior tympanic Labyrinthine artery muscle artery artery Superficial petrosal artery and greater petrosal nerve

Stapedius muscle

Facial nerve and nervus intermedius Artery and nerve of pterygoid canal

Stapedial branch of stylomastoid artery Chorda tympani

O tic ganglion Tubal artery

Posterior tympanic branch of stylomastoid artery Facial nerve

Lesser petrosal nerve and superior tympanic artery Meningeal accessory artery

Deep auricular artery Anterior tympanic artery Stylomastoid artery Superficial temporal artery Posterior auricular artery Internal jugular vein External carotid artery

Middle meningeal artery Tympanic plexus Maxillary artery Caroticotympanic artery and nerve

Maxillary artery

Internal carotid artery and carotid plexus Inferior tympanic artery and nerve

Ascending Inferior ganglion of pharyngeal glossopharyngeal nerve artery

Right tympanic cavity after removal of tympanic membrane (lateral view) Lateral process of malleus Chorda tympani nerve

Tendon of tensor tympani muscle

Long limb of incus Prominence of facial canal Pyramidal eminence and tendon of stapedius muscle

Handle of malleus

Stapes Lesser petrosal nerve Fossa of round window Tympanic nerve Tympanic plexus on promontory

Figu re 18-6

49 0 NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

STRUCTURES AND BOUNDARIES • Structures of the Inner Ear Structure

Description

Osseous labyrinth

Located in the petrous portion of the tem poral bone Surrounds the m em branous labyrinth and contains perilym ph Connects to the m iddle ear via the fenestra vestibuli and the fenestra cochleae Divided into 3 parts: vestibule, cochlea, and sem icircular canals

Vestibule

The m iddle portion of the osseous labyrinth, it contains the saccule and utricle of the m em branous labyrinth Contains an opening for the vestibular aqueduct containing the endolym phatic duct

Cochlea

Anterior portion of the osseous labyrinth contains the cochlear duct of the m em branous labyrinth Like a seashell, it spirals around a central point (the m odiolus), which carries branches of the cochlear n. to the cochlear duct, for 2 3 4 turns, getting progressively sm aller while approaching its apex As the cochlea spirals, the spiral lam ina is raised from the m odiolus Within the spiral lam ina, the cochlear duct lies between the scala vestibuli and the scala tym pani Scala vestibuli and scala tym pani are continuous at the helicotrem a at the apex An opening for the aqueduct of the cochlea allows perilym ph to drain into the cerebrospinal uid

Sem icircular canals

The posterior portion of the osseous labyrinth 3 sem icircular canals: anterior, posterior, and lateral Am pulla: a dilated end of each Anterior and posterior sem icircular canals have a com m on crus

Mem branous labyrinth

18

Located within the osseous labyrinth; contains endolym ph Divided into 4 parts: cochlear duct, saccule, utricle, and sem icircular ducts

Cochlear duct

A spiral structure located within the cochlea Begins at a blind end of the cochlea at the apex and ends where it joins the saccule via the ductus reuniens Triangular in shape, with a base created by the endosteum of the canal known as the spiral ligam ent and the stria vascularis Roof is form ed by the vestibular m em brane that separates the cochlear duct from the scala vestibuli Floor is form ed by the basilar m em brane, on which lies the organ of Corti; separates the duct from the scala tym pani

Saccule

A sm all structure located within the vestibule of the osseous labyrinth Connected to the utricle via the utriculosaccular duct and the endolym phatic duct Sensory receptors (the m aculae) are located in the saccule

Utricle

Located within the vestibule of the osseous labyrinth Sensory receptors (m aculae) are located in the utricle

Sem icircular ducts

Correspond to the sem icircular canals of the osseous labyrinth (anterior, posterior, and lateral) Open into the utricle via 5 openings Sensory receptors known as crista are located in the am pullae of the sem icircular ducts

EAR 491

18

STRUCTURES AND BOUNDARIES • Structures of the Inner Ear

Right membranous labyrinth with nerves: posteromedial view Superior part of vestibular nerve (from utricle and anterior and lateral membranous ampullae)

Anterior semicircular duct Anterior membranous ampulla

Utricle

Lateral membranous ampulla Cochlear duct (basal turn) Common membranous limb

Cochlear nerve

Lateral semicircular duct Posterior semicircular duct

Vestibulocochlear nerve (VIII) Vestibular nerve

Posterior membranous ampulla

Saccule Vestibular ganglion Inferior part of vestibular nerve (from saccule and posterior membranous ampulla)

Endolymphatic duct

Bony and membranous labyrinths: schema Anterior semicircular canal and duct

Ampullae Dura mater

Posterior semicircular canal and duct

Endolymphatic sac

Common bony and membranous limbs Lateral semicircular canal and duct

Endolymphatic duct in vestibular aqueduct Utricle Saccule

O tic capsule Stapes in oval (vestibular) window

Helicotrema of cochlea Ductus reuniens

Incus

Scala vestibuli

Malleus

Cochlear duct

Tympanic cavity

Scala tympani

External acoustic meatus Umbo Tympanic membrane Round (cochlear) window (closed by secondary tympanic membrane)

Cochlear aqueduct Vestibule

O tic capsule

Pharyngotympanic (auditory) tube

Figu re 18-7

492

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

STRUCTURES AND BOUNDARIES • Structures of the Inner Ear

18

Membranous labyrinth within bony labyrinth (path of sound waves) Cochlear nerve Semicircular canals

Utricle Saccule

Scala vestibuli Cochlear duct (scala media)

Scala tympani

Round window

O val window and stapes

Section through turn of cochlea Vestibular (Reissner’s) membrane

Scala vestibuli (perilymph); weakly positive

Cochlear duct (scala media; endolymph)

+80 mV

Efferent nerve fibers

Tectorial membrane Spiral ligament Bone

Afferent nerve fibers

Scala tympani (perilymph); 0 mV

O uter hair cells;

60 mV

Basilar membrane Spiral ganglion

Inner hair cell;

60 mV

Spiral organ of Corti Tectorial membrane

Hair cells Inner

O uter Stereocilia

Rods and tunnel of Corti

Basilar membrane Supporting cells Spiral lamina Spiral ganglion

Afferent nerve fibers Efferent nerve fibers

As basilar membrane moves up, hairs are deflected outward, causing depolarization of hair cells and increased firing of afferent nerve fibers

Figu re 18-8

EAR 493

18

MUSCLES • Overview Muscle

Origin

Insertion

Actions

Nerve Supply

Tensor tym pani

Bony canal at auditory tube Cartilaginous part of auditory tube Greater wing of the sphenoid

Handle of the m alleus

Tenses the tym panic m em brane and helps dam pen sound vibrations

Mandibular division of the trigem inal n.

Stapedius

Pyram id on posterior wall of the tym panic cavity

Neck of the stapes

Dam pens excessive sound vibrations

Stapedius branch of the facial n.

Lesser petrosal nerve and superior tympanic artery Anterior crural artery Stapes Descending branch of Stapedial superficial petrosal artery branch of Posterior crural artery stylomastoid Stapedius muscle artery

Geniculate ganglion Tensor tympani muscle Lesser petrosal nerve and superior tympanic artery Superficial petrosal artery and greater petrosal nerve Labyrinthine artery Facial nerve and nervus intermedius

Artery and nerve of pterygoid canal O tic ganglion

Facial nerve Chorda tympani Posterior auricular artery Stylomastoid artery Posterior tympanic branch of stylomastoid artery Superficial temporal artery Internal jugular vein Deep auricular artery External carotid artery Anterior tympanic artery

Tubal artery Meningeal accessory artery Maxillary artery Middle meningeal artery Tympanic plexus Internal carotid artery and carotid plexus Caroticotympanic artery and nerve Inferior tympanic artery and nerve Ascending pharyngeal artery Inferior ganglion of glossopharyngeal nerve Maxillary artery

Figu re 18-9

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NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

NERVE SUPPLY • Sensory Innervation of the External Ear Nerve

Source

Course

Great auricular

Cervical plexus, form ed by contributions of C2 and C3 ventral ram i

After passing posterior to the sternocleidom astoid m . at Erb’s point, it ascends along the sternocleidom astoid, dividing into anterior and posterior branches The posterior branch innervates the skin over the m astoid process, the posterior portion of the auricle, and the concha and lobule

Lesser occipital

Cervical plexus, form ed by contributions from C2 ventral ram us

After passing posterior to the sternocleidom astoid m . at Erb’s point, it ascends posterior to the sternocleidom astoid along the posterior portion of the head Continues on the head posterior to the auricle Supplies the skin posterior to the auricle

Auriculotem poral

Posterior part of the m andibular division of the trigem inal n.

Norm ally arises by 2 roots, between which the m iddle m eningeal a. passes Runs posteriorly just inferior to the lateral pterygoid m . and continues to the m edial aspect of the neck of the m andible Turns superiorly with the super cial tem poral vessels between the auricle and condyle of the m andible deep to the parotid gland On exiting the parotid gland, ascends over the zygom atic arch Innervates the skin in the region of the tragus, crus helix, anterior portion of the external acoustic m eatus, and outer surface of the tym panic m em brane

Auricular branch of the vagus

Superior ganglion of the vagus n.

Travels posterior to the internal jugular v. and passes along the tem poral bone Crosses the facial canal superior to the stylom astoid foram en Enters the m astoid canaliculus between the m astoid process and the tym panic part of the tem poral bone and gives rise to 2 branches: • 1 branch joins the posterior auricular branch of the facial n. • The 2nd branch innervates the skin of the back of the auricle and the posterior portion of the external acoustic m eatus

Tym panic branch of glossopharyngeal

Branches from the inferior ganglion of the vagus n., located in the petrous portion of the tem poral bone

Passes superiorly through the tym panic canaliculus to enter the m iddle ear In the m iddle ear, it divides into branches that form part of the tym panic plexus Tym panic plexus gives rise to: • Preganglionic parasym pathetic bers to the parotid gland • Postganglionic sym pathetic bers to the parotid gland • Sensory bers to the m iddle ear cavity, including the tym panic m em brane and auditory tube (m ainly from the tym panic branch of the glossopharyngeal n.)

18

EAR 495

18

NERVE SUPPLY • Sensory Innervation of the External Ear

Auriculotemporal n.

Posterior division Anterior division

Great auricular nerve

Hypoglossal nerve (XII)

C1

Lesser occipital nerve

C2

Efferent fibers Afferent fibers Proprioceptive fibers

C3 C4 Transverse cervical nerve

Ansa cervicalis

Phrenic nerve

C5

Supraclavicular nerves (medial, intermediate, and lateral)

Glossopharyngeal nerve (IX) Auricular branch of vagus nerve Pharyngotympanic (auditory) tube

Vagus nerve (X) Jugular foramen Superior ganglion of vagus nerve Inferior ganglion of vagus nerve Efferent fibers Afferent fibers Parasympathetic fibers

Figu re 18-10

496

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

NERVE SUPPLY • Sensory Innervation of the Middle Ear Nerve

Source

Course

Tym panic plexus

Form ed by the: • Tym panic branch of the glossopharyngeal n. (arises from the inferior ganglion located in the petrous portion of the tem poral bone) • Caroticotym panic nn. (arise from the carotid plexus on the internal carotid a.)

Tym panic branch of the glossopharyngeal n. passes superiorly through the tym panic canaliculus to enter the m iddle ear In the m iddle ear, it divides into branches that form the tym panic plexus Caroticotym panic nn. join the tym panic branch of the glossopharyngeal n. Tym panic plexus gives rise to: • Preganglionic parasym pathetic bers to the parotid gland • Postganglionic sym pathetic bers to the parotid gland • Sensory bers to the m iddle ear cavity, including the tym panic m em brane and auditory tube (m ainly from the tym panic branch of the glossopharyngeal)

Facial

Cranial n. VII has m ultiple m otor and sensory functions Created by: • Nervus interm edius, which contains the sensory bers and the parasym pathetic bers • Motor portion that innervates the m uscles derived from the 2nd pharyngeal arch

Nervus interm edius and m otor portions—enter the internal acoustic m eatus of the tem poral bone Facial n. then passes through the facial canal until it exits the stylom astoid foram en, initially traveling horizontally along the outside of the m edial wall of the m iddle ear; then it bends posteriorly and inferiorly to the m iddle ear Where the nerve changes direction is in the geniculate ganglion; here the greater petrosal n. is given off to travel anteriorly toward the pterygopalatine fossa Within the facial canal, the nerve gives rise to the nerve to the stapedius m . and the chorda tym pani n. Chorda tym pani passes anteriorly along the tym panic m em brane and the m alleus until it exits via the petrotym panic ssure Chorda tym pani carries preganglionic parasym pathetic bers to the subm andibular ganglion of the oral cavity, and taste bers to the anterior 2/ 3 of the tongue Stapedius n. innervates the stapedius m .

18

Medial view

Tympanic cavity Chorda tympani nerve

Mandibular nerve (V3 )

Facial nerve (VII)

O tic ganglion

Lesser petrosal nerve Auriculotemporal nerve

Figu re 18-11

EAR 497

18

NERVE SUPPLY • Sensory Innervation of the Inner Ear Nerve

Source

Course

Vestibulocochlear

Also called cranial n. VIII, it em erges between the pons and the m edulla oblongata

Enters the internal acoustic m eatus with the facial n. Within the internal acoustic m eatus, it divides into vestibular branches and the cochlear branch

Vestibular

The vestibular portion has nerve cell bodies in the vestibular ganglion (Scarpa’s ganglion)

Divides into superior and inferior branches: • Superior vestibular branch innervates the m aculae of the saccule and utricle and the am pulla of the anterior and lateral sem icircular ducts • Inferior vestibular branch innervates the m acula of the saccule and the am pulla of the posterior sem icircular duct

Cochlear

The cochlear portion has nerve cell bodies in the spiral ganglion

Utilizes the spiral ganglion within the m odiolus to pass to the organ of Corti

Afferent fibers

Facial canal

Tympanic cavity

Geniculum of facial nerve (site of geniculate ganglion)

Chorda tympani nerve

Greater petrosal nerve

Head of malleus

Cochlear (spiral) ganglion

Incus

Vestibular nerve Cochlear nerve Motor root of facial nerve and intermediate nerve Vestibulocochlear nerve (VIII) Medulla oblongata (cross section)

Ampulla of lateral semicircular duct Internal acoustic meatus

Medial Vestibular nuclei (diagrammatic)

Superior Inferior Lateral

Anterior Posterior

Ampulla of superior semicircular duct Utricle

Cochlear nuclei

Inferior cerebellar peduncle (to cerebellum) Vestibular ganglion

Ampulla of posterior semicircular duct Saccule Superior division Inferior division

Figu re 18-12

498

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

of vestibular nerve

VASCULAR SUPPLY • Arterial Supply of the External Ear Artery

Source

Course

Super cial tem poral

A term inal branch of the external carotid a. that arises within the parotid gland

Within the parotid gland, it gives off a transverse facial a. Em erges from the superior part of the parotid gland im m ediately posterior to the tem porom andibular joint and anterior to the external auditory m eatus Passes super cial to the root of the zygom atic arch just anterior to the auriculotem poral n. and the auricle While passing superiorly, it gives off branches that supply the auricle and the external acoustic m eatus

Posterior auricular

External carotid a. within the parotid gland

Passes superiorly between the m astoid process and cartilage of the ear During its path to anastom ose with the super cial tem poral and the occipital aa., it supplies the auricle and external acoustic m eatus A stylom astoid branch arises from the posterior auricular and enters the stylom astoid foram en to supply the internal surface of the tym panic m em brane

Deep auricular

A branch of the m axillary a. (1 of the term inal branches of the external carotid a.) Arises in the sam e area as the anterior tym panic a.

Lies in the parotid gland, posterior to the tem porom andibular joint, where it supplies that joint Passes into the external acoustic m eatus to supply it; then supplies the outer surface of the tym panic m em brane

Anterior tym panic

A branch of the m axillary a. (1 of the term inal branches of the external carotid a.)

Given off in the sam e area as for the deep auricular a. Passes superiorly im m ediately posterior to the tem porom andibular joint Enters the tym panic cavity through the petrotym panic ssure Aids in supplying the inner surface of the tym panic m em brane

18

EAR 499

18

VASCULAR SUPPLY • Arterial Supply of the External Ear

Superficial temporal artery

Parotid space (bed): right lateral dissection

Maxillary artery External carotid artery Posterior auricular artery

Joint capsule

Middle meningeal artery

Zygomatic process Deep temporal artery Anterior tympanic artery

Transverse facial artery Maxillary artery Masseteric artery Lateral pterygoid muscle (cut) Sphenomandibular ligament

Superficial temporal artery Deep auricular artery

Facial artery

Inferior alveolar artery External carotid artery

Lingual artery

Figu re 18-13

500

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

VASCULAR SUPPLY • Arterial Supply of the Middle Ear Artery

Source

Course

Posterior auricular

External carotid a. within the parotid gland

Passes superiorly between the m astoid process cartilage of the ear During its path to anastom ose with the super cial tem poral and the occipital aa., it supplies the auricle and external acoustic m eatus A stylom astoid branch arises from the posterior auricular a. and enters the stylom astoid foram en to supply the internal surface of the tym panic m em brane

Anterior tym panic

Maxillary a. (1 of the term inal branches of the external carotid a.)

Given off in the sam e area as for the deep auricular a. Passes superiorly im m ediately posterior to the tem porom andibular joint Enters the tym panic cavity through the petrotym panic ssure Aids in supplying the outer surface of the tym panic m em brane and the anterior portion of the tym panic cavity

Inferior tym panic

Ascending pharyngeal a. of the external carotid a.

Ascends deep to the other branches of the external carotid a. and m ore superiorly to the stylopharyngeus m . Passes into the m iddle ear through the petrous portion of the tem poral bone Helps supply the m edial wall of the tym panic cavity

Superior tym panic

Middle m eningeal a. of the m axillary a.

Arises from the m iddle m eningeal a. im m ediately after passing through the foram en spinosum within the m iddle cranial fossa Passes in the canal of the tensor tym pani m . to help supply the tensor tym pani and its bony canal

Caroticotym panic branch of the internal carotid

Internal carotid a.

Passes into the tym panic cavity through an aperture in the carotid canal Helps supply the m iddle ear

18

EAR 501

18

VASCULAR SUPPLY • Arterial Supply of the Middle Ear

Superior branch of anterior tympanic

Anterior tympanic Incudal branch from the anterior tympanic

Mallear branch from the anterior tympanic

Stylomastoid branch of the posterior auricular

Deep auricular branch Descending branch of superficial petrosal artery Stapes

Anterior Tensor Geniculate Lesser petrosal nerve tympani ganglion crural and superior tympanic muscle artery artery

Posterior crural artery Stapedius muscle

Chorda tympani

O tic ganglion Tubal artery

Posterior tympanic branch of stylomastoid artery

Lesser petrosal nerve and superior tympanic artery

Facial nerve

Meningeal accessory artery

Deep auricular artery Anterior tympanic artery Stylomastoid artery Superficial temporal artery Internal jugular vein External carotid artery

Middle meningeal artery

Maxillary artery

Ascending Inferior ganglion of pharyngeal glossopharyngeal nerve artery

Figu re 18-14

502

Superficial petrosal artery and greater petrosal nerve Facial nerve and nervus intermedius Artery and nerve of pterygoid canal

Stapedial branch of stylomastoid artery

Posterior auricular artery

Labyrinthine artery

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

Tympanic plexus Maxillary artery Caroticotympanic artery and nerve Internal carotid artery and carotid plexus Inferior tympanic artery and nerve

VASCULAR SUPPLY • Arterial Supply of the Inner Ear Artery

Source

Course

Labyrinthine

Basilar a., which gives rise to the circle of Willis

Passes through the internal acoustic m eatus, where it further divides into cochlear and vestibular branches that supply the cochlear and vestibular structures

Posterior auricular

External carotid a. within the parotid gland

Passes superiorly between the m astoid process and cartilage of the ear Anastom oses with the super cial tem poral and the occipital aa. A stylom astoid branch arises from the posterior auricular a., enters the stylom astoid foram en, and continues to the inner ear During its path to anastom ose with the super cial tem poral and the occipital aa., it supplies the auricle and external acoustic m eatus Stylom astoid branch supplies the internal surface of the tym panic m em brane and the posterior portion of the tym panic cavity; then helps supply the inner ear

18

Anterior vestibular Common cochlear artery artery Vestibulocochlear artery

Posterior vestibular artery

Labyrinthine artery Superficial temporal artery

Transverse facial artery Digastric muscle (phantom )

Maxillary artery Posterior auricular artery

O ccipital artery Descending branch

Facial artery Lingual artery

Sternocleidomastoid branch

Ascending pharyngeal artery Internal carotid artery

Superior thyroid artery and superior laryngeal branch

External carotid artery

O mohyoid muscle (phantom )

Common carotid artery

External carotid branches: schema

Thyrocervical trunk

Figu re 18-15 EAR 503

18

VASCULAR SUPPLY • Venous Drainage Venous Drainage of the External Ear Vein

Comments

Super cial tem poral

Descends posterior to the zygom atic root of the tem poral bone alongside the auriculotem poral n. to enter the substance of the parotid gland Unites with the m axillary v. to form the retrom andibular v. Along its path, receives tributaries from the auricle

Posterior auricular

Arises from a plexus of veins created by the occipital and super cial tem poral vv. Descends posterior to the auricle to unite with the posterior division of the retrom andibular v. to form the external jugular v. Along its path, receives blood from the stylom astoid branch of the posterior auricular v., which drains the auricle, external acoustic m eatus, and tym panic m em brane

Maxillary

A short vein, som etim es paired, form ed by the convergence of the tributaries of the pterygoid plexus Enters the substance of the parotid gland, traveling posteriorly between the sphenom andibular lig. and the neck of the m andible Unites with the super cial tem poral v. to form the retrom andibular v. Helps drain blood from the external acoustic m eatus and tym panic m em brane

Pterygoid plexus

An extensive network of veins that parallels the 2nd and 3rd parts of the m axillary a. Receives branches that correspond to the sam e branches of the m axillary a. Tributaries eventually converge to form a short m axillary v. Com m unicates with the cavernous sinus, pharyngeal venous plexus, and facial vein via the deep facial v. and ophthalm ic vv. Helps drain the external acoustic m eatus

Transverse sinus

1 of the deep venous sinuses that helps drain the brain Aids in receiving blood from the tym panic m em brane

Venous Drainage of the Middle Ear Vein

Comments

Pterygoid plexus

An extensive network of veins that parallels the 2nd and 3rd parts of the m axillary a. Receives branches that correspond to the sam e branches of the m axillary a. Tributaries eventually converge to form a short m axillary v. Com m unicates with the cavernous sinus, pharyngeal venous plexus, and facial vein via the deep facial v. and ophthalm ic vv. Helps drain the tym panic cavity

Superior petrosal sinus

1 of the deep venous sinuses that helps drain the brain, running along the superior m argin of the petrous portion of the tem poral bone Aids in receiving blood from the tym panic cavity

Venous Drainage of the Inner Ear

504

Vein

Comments

Labyrinthine

Begins in the cochlear and vestibular structures and passes m edially through the internal acoustic m eatus alongside the labyrinthine a. Drains into the superior petrosal sinus

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

VASCULAR SUPPLY • Venous Drainage

18

Lateral projection of right membranous labyrinth

Geniculum of facial nerve

Auricle (retracted anteriorly)

Cochlear duct Cochlear nerve

Trigeminal nerve (V)

Superior part of vestibular nerve

Vestibulocochlear nerve (VIII)

Internal jugular vein Inferior part of vestibular nerve

Anterior semicircular duct

Lateral semicircular duct Cerebellum Posterior semicircular duct Superior petrosal sinus Confluence of sinuses

Sigmoid sinus Transverse sinus

Pterygoid plexus Superficial temporal vein and artery Maxillary vein Posterior auricular vein

Figu re 18-16

EAR 505

18

CLINICAL CORRELATES • Acute Otitis Externa • • •

Acute otitis externa: in fection or in am m ation of th e au ricle an d extern al au d itory can al located in th e extern al ear, cau sin g ear p ain (otalgia) Also called “swim m er’s ear” 2 m ajor bacteria are in volved : Staphylococcus aureus an d Pseudom onas aeruginosa

PATHOGENESIS

• •

Excess water from swim m in g rem oves som e of th e ceru m in ou s wax th at lin es th e extern al au d itory can al Becau se th e wax h elp s m ain tain a h ealth y can al, loss of th e wax p redisp oses th e can al to bacterial in fection s

Marked inflammation and edema of walls of external auditory canal narrows Crura of stapes canal lumen Tympanic membrane (eardrum) Malleus

Footplate of stapes in oval window Semicircular canals

Incus

Auricle (pinna)

Vestibular n.

Facial n. Internal acoustic meatus

External acoustic meatus (ear canal)

Cochlear n.

Middle ear Round window

Eustachian tube Cochlea

Scala Cochlear Scala tympani duct vestibuli

In otitis externa, inflammation, edema, and discharge are limited to external auditory canal and its walls

Malleus Wall of external auditory canal Inflammation, edematous lining of external auditory canal (discharge and debris may also be present in canal)

O toscopic view demonstrating clinical appearance of otitis externa

Figu re 18-17

50 6 NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

CLINICAL CORRELATES • Acute Otitis Media • • •

18

Acute otitis m edia: an in am m ation of th e m id d le ear cavity More com m on in ch ild ren 2 m ajor bacteria are in volved : Streptococcus pneum oniae an d Haem ophilus inf uenzae

PATHOGENESIS

• • • •

Often resu lts from au d itory tu be dysfu n ction Becau se th e au d itory tu be allows d rain age from th e tym p an ic cavity in to th e n asop h aryn x, an y blockage lead s to a bu ildu p of u id in th e tym p an ic cavity W h en th e u id sits in th e tym p an ic cavity, it p red isp oses th e region to a bacterial in fection Th e resu ltin g in am m ation leads to ear p ain (otalgia) an d often d im in ish ed h earin g

Air-fluid level (may not be present) Malleus Bulging tympanic membrane (purulent fluid trapped behind membrane in middle ear) External auditory canal Bulging tympanic membrane Purulent fluid in middle ear

O toscopic view demonstrating clinical appearance of otitis media

O ssicles Section through middle ear in otitis media

Crura of stapes Tympanic membrane (eardrum) Auricle (pinna)

Malleus

Footplate of stapes in oval window Semicircular canals Vestibular n.

Incus

Facial n. Internal acoustic meatus

External acoustic meatus (ear canal)

Cochlear n.

Middle ear Round window

Eustachian tube

Cochlea

Scala Cochlear Scala tympani duct vestibuli

Figu re 18-18

EAR 507

18

CLINICAL CORRELATES • Mastoiditis • •

Mastoiditis: a bacterial in fection of th e m astoid air cells More com m on in ch ild ren th an in ad u lts

PATHOGENESIS

• • •

Alth ou gh less com m on sin ce th e adven t of an tibiotics, form erly it often occu rred as a com p lication of acu te otitis m edia, wh en in fection sp read from th e m id dle ear cavity to th e m astoid air cells On ce with in th e m astoid air cells, th e in fection can lead to in am m ation an d d estru ction of th e m astoid bon e Becau se of th e in fection ’s location , it m ay lead to p artial (or total) h earin g loss, d am age to th e m astoid bon e, or form ation of an ep id u ral abscess, or it m ay sp read to in volve th e brain

TREATMENT

• • •

Can be dif cu lt becau se m ed ication s can n ot read ily reach th e m astoid air cells In som e cases, a m astoid ectom y m ay be p erform ed to d rain th e m astoid if an tibiotic th erap y is n ot su ccessfu l A m yrin gotom y (creatin g an op en in g in th e m idd le ear cavity th rou gh th e tym p an ic m em bran e) is p erform ed to d rain th e ear in acu te otitis m ed ia

Swelling and redness posterior to the ear in mastoiditis

Figu re 18-19

50 8 NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

CHAPTER 19

EYE AND ORBIT

Overview and Topographic Anatomy of the Orbit

510

Osteology of the Orbit

512

Contents of the Orbit

514

Clinical Correlates

537

19

OVERVIEW AND TOPOGRAPHIC ANATOMY OF THE ORBIT • General Information • •

Orbit: a p yram id -sh ap ed bon y recess in th e an terior p art of th e sku ll, lin ed by p eriosteu m called th e p eriorbital fascia Con ten ts in clu d e: • Eye—organ associated with vision • Extrin sic m u scles • Op tic n erve • Ocu lom otor n erve • Ciliary gan glion • Troch lear n erve • Op h th alm ic division of th e trigem in al n erve • Abdu cen s n erve • Op h th alm ic artery an d bran ch es • Su p erior an d in ferior op h th alm ic vein s • Lacrim al ap p aratu s • Mu ch fatty tissu e

Superior palpebral conjunctiva: tarsal glands shining through Seen through cornea

Superior lacrimal papilla and punctum Plica semilunaris

Pupil Iris

Lacrimal caruncle in lacrimal lake (lacus lacrimalis) Inferior lacrimal papilla and punctum

Bulbar conjunctiva over sclera Inferior conjunctival fornix Inferior palpebral conjunctiva: tarsal glands shining through Frontal bone Insertion of levator palpebrae superioris muscle O rbital septum

Supraorbital artery and nerve

Superior tarsus

Supratrochlear artery and nerve Dorsal nasal artery and infratrochlear nerve

Lateral palpebral ligament and overlying raphe

Lacrimal sac

Inferior tarsus

Medial palpebral ligament

O rbital septum

Maxilla (frontal process)

Zygomatic bone

Infraorbital artery and nerve

Figu re 19-1

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OVERVIEW AND TOPOGRAPHIC ANATOMY OF THE ORBIT • General Information

Horizontal section Zonular fibers (suspensory ligament of lens)

Cornea Anterior chamber Lens

Scleral venous sinus (Schlemm’s canal)

19

Posterior chamber

Iris Ciliary processes

Ciliary body and ciliary muscle

Bulbar conjunctiva

Ciliary part of retina

O ra serrata

O ptic (visual) part of retina Vitreous body

Choroid

Hyaloid canal Sclera

Lamina cribrosa of sclera

Fascial sheath of eyeball (Tenon’s capsule)

O ptic nerve (II)

Fovea centralis in macula (lutea)

Central retinal artery and vein

O uter sheath of optic nerve Subarachnoid space

Figu re 19-2

EYE AND O RBIT 511

19

512

OSTEOLOGY OF THE ORBIT • Openings in the Orbit Opening

Bony Boundaries

Structures Passing Through Opening

Optic canal

Lesser wing o the sphenoid

Optic n. Ophthalm ic a. (branch o internal carotid a.)

Superior orbital f ssure

Between the: • Greater wing o the sphenoid, and • Lesser wing o the sphenoid

3 • • • 3

In erior orbital f ssure

Between the: • Greater wing o the sphenoid, and • Maxilla and orbital portion o the palatine bones

In raorbital n. (branch o m axillary division o trigem inal) In raorbital a. (branch o m axillary a.) In raorbital v. (drains into pterygoid plexus) Zygom atic n. (branch o m axillary division o trigem inal) Branch o in erior ophthalm ic v. that connects to the pterygoid plexus (when present)

Supraorbital oram en (som etim es occurs as a notch)

Frontal

Supraorbital n. (branch o ophthalm ic division o trigem inal) Supraorbital a. (branch o ophthalm ic a.) Supraorbital v. (drains into angular v.)

In raorbital groove and canal

Maxilla

In raorbital n. (branch o m axillary division o trigem inal) In raorbital a. (branch o m axillary a.) In raorbital v. (drains into pterygoid plexus)

Zygom atic oram en (1or 2 openings)

Zygom atic

Zygom aticotem poral n. (branch o m axillary division o trigem inal) Zygom atico acial n. (branch o m axillary division o trigem inal)

Nasolacrim al canal

Lacrim al

Nasolacrim al duct

Anterior ethm oidal oram en

Between the: • Frontal and • Ethm oid

Anterior ethm oidal n. (branch o ophthalm ic division o trigem inal) Anterior ethm oidal a. (branch o ophthalm ic a.) Anterior ethm oidal v. (drains into superior ophthalm ic v.)

Posterior ethm oidal oram en

Between the: • Frontal and • Ethm oid

Posterior ethm oidal n. (branch o ophthalm ic division o trigem inal) Posterior ethm oidal a. (branch o ophthalm ic a.) Posterior ethm oidal v. (drains into superior ophthalm ic v.)

m ajor branches o ophthalm ic division o trigem inal n: Lacrim al branch Frontal branch Nasociliary branch cranial nerves innervating the extraocular m uscles o the eye: • Oculom otor n. • Trochlear n. • Abducens n. Superior ophthalm ic v. (drains into cavernous sinus) In erior ophthalm ic v. (on occasion—when present, drains into cavernous sinus)

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

OSTEOLOGY OF THE ORBIT • Bones and Walls of the Orbit

19

BONES CREATING THE ORBITAL MARGIN

• • •

Fron tal Zygom atic Maxilla

WALLS OF THE ORBIT Superior

Frontal (orbital plate) Lesser wing of the sphenoid

Inferior

Maxilla Zygom atic Palatine (orbital process)

Medial

Ethm oid (lam ina papyracea) Lacrim al Sphenoid Maxilla

Lateral

Zygom atic Greater wing of the sphenoid

Right orbit: frontal and slightly lateral view O rbital surface of frontal bone

Posterior and Anterior ethmoidal foramina

O rbital surface of lesser wing of sphenoid bone Superior orbital fissure

O rbital plate of ethmoid bone

O ptic canal (foramen)

Lacrimal bone

O rbital surface of greater wing of sphenoid bone

Fossa for lacrimal sac O rbital process of palatine bone

O rbital surface of zygomatic bone

O rbital surface of maxilla

Inferior orbital fissure Infraorbital groove Muscle attachments and nerves and vessels entering orbit

Levator palpebrae superioris m.

Superior orbital fissure

Superior oblique m.

Lacrimal n. (V1 )

Superior rectus m.

Frontal n. (V1 )

Medial rectus m.

Trochlear n. (IV)

O ptic n. (II)

Superior ophthalmic v.

in optic canal

Lateral rectus m.

O phthalmic a.

Superior branch of oculomotor n. (III) Inferior orbital fissure

Abducens n. (VI)

Inferior rectus m. Inferior branch of oculomotor n. (III) Nasociliary n. (V1 )

Figu re 19-3 EYE AND O RBIT 513

19

CONTENTS OF THE ORBIT • Eye • • •

•

Eye: a sp h erical globe with a d iam eter of ap p roxim ately 2.5 cm th at lies in th e orbit’s an terior p ortion Su rrou n ded by a th in cap su le called th e fascia bu lbi (Ten on ’s cap su le): • Provides su p p ort • Allows for m ovem en t Com p osed of 3 coats: • Sclera • Uveal tract • Retin a Divid ed in to an an terior an d a p osterior segm en t:

ANTERIOR SEGMENT

• • • •

Filled with aq u eou s h u m or Sep arated in to an terior an d p osterior ch am bers by th e iris Con tain s aq u eou s h u m or secreted by th e ciliary body an d d rain ed th rou gh a trabecu lated n etwork even tu ally in to th e su p erior op h th alm ic vein In traocu lar p ressu re is m easu red in th e an terior segm en t, n orm ally 10 to 20 m m Hg

POSTERIOR SEGMENT

• •

Filled with vitreou s u id Called th e vitreou s cavity

Levator palpebrae superioris muscle O rbital septum Sclera

Superior tarsal (Müller’s) muscle (smooth)

Bulbar conjunctiva

Superior conjunctival fornix O rbicularis oculi muscle (palpebral part)

Palpebral conjunctiva

Superior tarsus

Cornea

Tarsal glands

Lens

Sebaceous glands

Anterior chamber

Eyelashes (cilia) Iris

O penings of tarsal glands

Posterior chamber

Inferior tarsus O rbicularis oculi muscle (palpebral part) Inferior conjunctival fornix O rbital septum

Figu re 19-4

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CONTENTS OF THE ORBIT • Eye

19

Cornea Anterior chamber Scleral venous sinus (Schlemm’s canal)

Posterior chamber Zonular fibers

Iris

Ciliary body

Lens

O ra serrata Vitreous chamber

Retina

Choroid Sclera

Central retinal artery and vein

Superior macular arteriole and venule

O ptic nerve (II)

Superior nasal retinal arteriole and venule

Superior temporal retinal arteriole and venule

O ptic disc Inferior nasal retinal arteriole and venule Inferior macular arteriole and venule

Macula and fovea centralis Inferior temporal retinal arteriole and venule

Right retinal vessels: ophthalmoscopic view

Eyeball sectioned in frontal plane: anterior segment viewed from behind

Sclera Choroid O ptic part of retina O ra serrata O rbiculus ciliaris of ciliary body covered by ciliary part of retina Anterior Ciliary processes Lens chamber Zonular fibers Lens Iris Posterior chamber Ciliary body Ciliary process Zonular fibers

O rbiculus ciliaris of ciliary body Horizontal section O ra serrata O ptic part of retina O ra serrata O rbiculus ciliaris of ciliary body covered by ciliary part of retina O ptic part of retina Ciliary Zonular fibers fanning Zonular fibers processes out and blending into Iris lens capsule Lens

Enlargement of segment outlined in top illustration (semischematic)

Figu re 19-5 EYE AND O RBIT 515

19

CONTENTS OF THE ORBIT • Components SCLERA

• •

Th e ou term ost layer, very brou s W h ite alon g th e p erip h ery, excep t for th e an terior p ortion –th e corn ea, wh ich is tran sp aren t

UVEAL TRACT

•

Com p osed of ch oroid layer, ciliary bod y, an d iris

Choroid

• •

Th e p igm en ted vascu lar layer between th e sclera an d th e retin a Exten ds p osteriorly from th e region of th e op tic n erve an teriorly, wh ere it is con tin u ou s with th e ciliary bod y n ear th e ora serrata (an terior m argin of th e retin a)

Ciliary Body

• • •

Located between th e ch oroid an d th e iris Rin g-sh ap ed ; h as a series of tran sp aren t bers th at form th e su sp en sory ligam en t of th e len s With in it is th e ciliary m u scle, wh ich ch an ges th e sh ap e of th e len s

Iris

• • •

A th in d isclike stru ctu re with a cen tral op en in g–th e p u p il Sep arates th e aq u eou s h u m or in to th e an terior ch am ber (an terior to th e iris) an d th e p osterior ch am ber (between th e iris an d th e len s) Con tain s th e sp h in cter an d d ilator p u p illae m u scles, wh ich ch an ge th e p u p il’s sh ap e in resp on se to ligh t

LENS

• • •

Located p osterior to th e iris A tran sp aren t bicon cave stru ctu re resp on sible for focu sin g Con n ected to th e ciliary bod y by th e su sp en sory ligam en ts

RETINA

• • •

Th e in n erm ost coat of th e eye Th in an d h igh ly vascu lar 3 areas located on th e retin a’s p osterior p ortion : • Op tic disc • Macu la lu tea • Fovea cen tralis

Optic Disc

• •

Area wh ere th e op tic n erve en ters th e retin a is called th e “blin d sp ot” Retin a’s cen tral artery en ters th e eye th rou gh th e op tic disc an d divid es in to su p erior an d in ferior bran ch es

Ma cula Lutea a nd Fovea Centra lis

• • •

516

Macu la lu tea—lateral to th e op tic d isc A d ep ressed , yellow-ap p earin g area th at con tain s th e fovea cen tralis in its cen ter Fovea Cen tralis—area of h igh est visu al acu ity an d con tain s h igh con cen tration of con e p h otorecep tors

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

CONTENTS OF THE ORBIT • Muscles

19

ASSOCIATED EXTRINSIC MUSCLE OF THE ORBIT Muscle

Origin

Insertion

Actions

Nerve

Comment

Levator palpebrae superioris

Sphenoid (Lesser wing)

Skin o the upper eyelid

Raises the upper eyelid

Superior division o the oculom otor Sym pathetic f bers to the superior tarsal m uscle (sm ooth m uscle)

Opposed by the palpebral part o the orbicularis oculi m . There are sm ooth m uscle f bers that insert into the superior tarsal plate and are innervated by sym pathetic f bers Lesions o the sym pathetics will lead to a ptosis, or drooping o the upper eyelid

EXTRINSIC MUSCLES OF THE EYE Action(s) on Eye

Nerve

Comment

Muscle

Origin

Insertion

Superior rectus

Com m on tendinous ring on sphenoid

Superior sclera

Elevation Adduction Intorsion

Superior division o the oculom otor

A check ligam ent attaches it to the levator palpebrae superioris m . to help elevate the upper eyelid

In erior rectus

In erior sclera

Depression Adduction Extorsion

In erior division o the oculom otor

A check ligam ent attaches it to the in erior tarsal plate to help depress the lower eyelid

Medial rectus

Medial sclera

Adduction

Lateral rectus

Lateral sclera

Abduction

Abducens

Im paired in abducens n. palsy

The m ost m edial o the extraocular m uscles

Superior oblique

Body o the sphenoid

Superior portion o the posterolateral sclera

Depression Abduction Intorsion

Trochlear

Tendon passes through the trochlea, a f brocartilaginous pulley

In erior oblique

Maxilla (lateral to the lacrim al groove)

In erior portion o the posterolateral sclera

Elevation Abduction Extorsion

In erior division o the oculom otor

Only extraocular m uscle that attaches to the m axilla

EYE AND O RBIT 517

19

CONTENTS OF THE ORBIT • Muscles

Superior oblique Superior rectus Trochlear nerve O culomotor nerve Lateral rectus Inferior rectus Abducens nerve Inferior oblique Medial rectus

Superior oblique muscle Right lateral view Levator palpebrae superioris muscle

Trochlea (pulley)

Superior rectus muscle

O ptic nerve (II)

Medial rectus muscle

Lateral rectus muscle (cut) Common tendinous ring Lateral rectus muscle (cut)

Inferior oblique muscle

Inferior rectus muscle

Superior tarsus

Superior view

Levator palpebrae superioris muscle (cut) Superior oblique muscle

Superior rectus muscle (cut)

Medial rectus muscle

Lateral rectus muscle

Inferior rectus muscle

O ptic nerve (II)

Common tendinous ring

Superior rectus muscle (cut) Levator palpebrae superioris muscle (cut)

Figu re 19-6

518

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CONTENTS OF THE ORBIT • Muscles

19

Innervation and action of extrinsic eye muscles: anterior view Superior oblique muscle

Trochlear nerve (IV)

Lateral rectus muscle

Abducens nerve (VI)

Levator palpebrae superioris muscle Superior rectus muscle

Oculomotor nerve (III)

Medial rectus muscle Inferior rectus muscle

N ote: Arrows indicate direction of eye movement produced by each muscle

Inferior oblique muscle Frontal section

Levator palpebrae superioris m. and fascial sheath Superior oblique m. and fascial sheath Medial rectus m. and fascial sheath

Superior rectus m. and fascial sheath

Periorbita

Lacrimal gland Lateral rectus m. and fascial sheath

Ethmoidal cell

Periorbita Sclera

Sclera Fascial sheath of eyeball (Tenon’s capsule)

Fascial sheath of eyeball (Tenon’s capsule)

Episcleral space Infraorbital n. (V2 ) Retrobulbar fat (orbital fat body)

Inferior oblique m. and fascial sheath

Inferior rectus m. and fascial sheath

Figu re 19-7 Nerve Supply ORBITAL INNERVATION Orbital Innervation

Description

Sensory

2 Major Type s Vision (special som atic afferent, or SSA) via the optic n. General sensation (general som atic afferent, or GSA) via the ophthalm ic (and som e m axillary) division of the trigem inal n.

Motor

2 Major Type s Motor to the extraocular m uscles (general som atic efferent, or GSE) via the oculom otor, trochlear, and abducens nn. Autonom ics to the intrinsic m uscles of the eye (general visceral efferent, or GVE) via: • Parasym pathetics associated with the ciliary ganglion • Sym pathetics associated with the superior cervical ganglion

Cranial nn.

5 cranial nerves provide innervation to the orbit: • Optic—vision • Oculom otor—extraocular m otor and autonom ics to the intrinsic m uscles of the eye • Trochlear—extraocular m otor • Trigem inal—general sensation • Abducens—extraocular m otor

EYE AND O RBIT 519

19

CONTENTS OF THE ORBIT • Muscles

Section through retina

Eyeball

Suspensory ligament

Iris

Lens

O ra serrata

Axons at surface of retina passing via optic nerve, chiasm, and tract to lateral geniculate body

Cornea Ciliary body

Anterior chamber

Inner limiting membrane

Ganglion cell

Posterior chamber

Müller cell (supporting glial cell)

containing aqueous humor

Amacrine cell Bipolar cell Horizontal cell Rod Cone Pigment cells of choroid

Vitreous humor Retina Choroid Sclera Fovea O ptic nerve

Nasociliary nerve Trigeminal nerve (V)

O culomotor nerve (III)

O phthalmic nerve (V1 )

Sensory Sympathetic Parasympathetic

Roots of ciliary ganglion

Ciliary ganglion Long ciliary nerve Short ciliary nerves

Figu re 19-8

520

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CONTENTS OF THE ORBIT • Muscles

19

OPTIC NERVE (VISION)

• • •

Abou t 25 m m in len gth , allows for eye m ovem en t via th e extraocu lar m u scles Covered by an ou ter layer of d u ra m ater an d an in n er layer of arach n oid , wh ich attach an teriorly to th e eye, wh ere th e op tic n . en ters th e sclera, an d p osteriorly, wh ere it m erges with th e p eriosteu m lin in g th e orbit at th e op tic foram en Cen tral a. of th e retin a en ters th e op tic n . p osterior to th e bu lb of th e eye

Course

• • • • •

Axon s from th e gan glion ic cells of th e retin a com p rise th e op tic n . an d com e togeth er at th e op tic d isc Th ey leave th e eye an d travel as th e op tic n . p osteriorly an d m ed ially th rou gh th e orbit Posteriorly, th e op tic n . p asses th rou gh th e op tic foram en to en ter th e cran ial cavity Th e 2 op tic n n . m eet at th e op tic ch iasm , located su p erior to th e h yp op h yseal fossa Op tic ch iasm gives rise to th e op tic tracts, wh ich term in ate in th e lateral gen icu late n u cleu s of th e th alam u s before givin g rise to th e op tic rad iation s th at term in ate in th e occip ital lobes

Retinal nerve fibers Retina

Optic nerve layers Nerve fiber layer

Choroid Sclera

Prelaminar layer

Central retinal vessels Vascular circle of Zinn-Haller

Laminar layer

Short posterior ciliary a. Lamina cribrosa

Retrolaminar layer

Nerve fiber bundles

Pial layer Arachnoid layer Dura mater

Figu re 19-9

EYE AND O RBIT 521

19

CONTENTS OF THE ORBIT • Muscles GENERAL SENSATION Ophthalmic Division of the Trigeminal Nerve • This division, being a branch o the trigem inal n., is sensory in unction • Arises rom the m ain nerve in the m iddle cranial ossa • Passes anterior on the lateral wall o the cavernous sinus im m ediately in erior to the oculom otor and trochlear nn., but superior to the m axillary division o the trigem inal • Be ore entering the orbit, it gives rise to a sm all tentorial branch • Im m ediately be ore entering the orbit, through the superior orbital f ssure, it divides into 3 m ajor branches: lacrim al, rontal, and nasociliary nn.

Nerve

Source

Course

Lacrim al

Ophthalm ic division o the trigem inal n.

Sm allest branch o the ophthalm ic division o the trigem inal n. Passes anteriorly to enter the orbit through the superior orbital f ssure In the orbit, it travels on the superior border o the lateral rectus m . with the lacrim al a. Be ore reaching the lacrim al gland, it com m unicates with the zygom atic branch o the m axillary division o the trigem inal to receive autonom ic nervous f bers Enters the lacrim al gland and supplies it and the conjunctiva be ore piercing the orbital septum to supply the skin o the upper eyelid

Frontal

Supraorbital

Largest branch o the ophthalm ic division o the trigem inal n. Passes anteriorly to enter the orbit through the superior orbital f ssure In the orbit it passes anteriorly between the periosteum o the orbit and the levator palpebrae superioris m . About hal way in the orbit, it divides into its 2 term inal nerves: • supraorbital n. • supratrochlear n. Frontal n. ( rom the ophthalm ic division o the trigem inal n.)

Supratrochlear

Nasociliary

522

Passes between the levator palpebrae superioris m . and the periosteum o the orbit Continues anteriorly to the supraorbital oram en (notch) At the level o the supraorbital m argin, it sends nerve supply to the rontal sinus and ascends superiorly along the scalp Divides into m edial and lateral branches, which travel up to the vertex o the scalp Once the supratrochlear a. joins it within the orbit, it continues to pass anteriorly toward the trochlear In the trochlear region, it o ten supplies the rontal sinus be ore exiting the orbit Ascends along the scalp, at 1st deep to the m usculature in the region be ore piercing them to reach the cutaneous innervation along the scalp

Ophthalm ic division o the trigem inal n.

Passes anteriorly to enter the orbit through the superior orbital f ssure Enters the orbit lateral to the optic n. Travels across the optic n. anteriorly and m edially to lie between the m edial rectus and the superior oblique m m . along the m edial wall o the orbit All along its path, it gives rise to other nerves, including the sensory root o the ciliary ganglion, and the long ciliary and posterior ethm oidal nn., until term inating into the anterior ethm oidal and in ratrochlear nn. near the anterior ethm oidal oram en

Sensory root of the ciliary ganglion

Nasociliary n.

Travels anteriorly on the lateral side o the optic n. to enter the ciliary ganglion Carries general sensory f bers, which are distributed by the short ciliary nn.

Short ciliary

Ciliary ganglion

Arises rom the ciliary ganglion to travel to the posterior sur ace o the eye Supplies the sensory f bers to the eye and helps carry the postganglionic parasym pathetic f bers to the sphincter pupillae and the ciliary m uscle

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

CONTENTS OF THE ORBIT • Muscles Nerve Long ciliary

Source

Course

Nasociliary n.

There are 2 to 4 branches that travel anteriorly to enter the posterior part of the sclera of the eye

Posterior ethm oidal

Travels deep to the superior oblique m . to pass through the posterior ethm oidal foram en Supplies the sphenoid sinus and the posterior ethm oidal sinus

Anterior ethm oidal

Arises on the m edial wall of the orbit Enters the anterior ethm oidal foram en and travels through the canal to enter the anterior cranial fossa Supplies the anterior and m iddle ethm oidal sinuses before entering and supplying the nasal cavity Term inates as the external nasal n. on the face

Infratrochlear

1 of the term inal branches of the nasociliary n. Passes anteriorly on the superior border of the m edial rectus m . Passes inferior to the trochlea toward the m edial angle of the eye Supplies the skin of the eyelids and bridge of the nose, the conjunctiva, and all of the lacrim al structures

Medial branch Lateral branch

Superior view

19

Supraorbital nerve

Supratrochlear nerve Lacrimal gland Lacrimal nerve

Infratrochlear nerve Nasociliary nerve

Frontal nerve

Trochlear nerve (IV)

Maxillary nerve (V2 )

O phthalmic nerve (V1 )

Mandibular nerve (V3 )

O ptic nerve (II)

O culomotor nerve (III) Trochlear nerve (IV)

Trigeminal (semilunar) ganglion

Abducens nerve (VI)

Long ciliary nerves

Superior view: levator palpebrae superioris, superior rectus, and superior oblique muscles partially cut away Supratrochlear nerve (cut)

Short ciliary nerves Lacrimal nerve Ciliary ganglion Parasympathetic root of ciliary ganglion (from inferior branch of oculomotor nerve) Sympathetic root of ciliary ganglion (from internal carotid plexus) Sensory root of ciliary ganglion (from nasociliary nerve) Branches to inferior and medial rectus muscles

Supraorbital nerve branches(cut) Infratrochlear nerve Anterior ethmoidal nerve O ptic nerve (II) Posterior ethmoidal nerve Superior branch of oculomotor nerve (III) (cut) Nasociliary nerve

Abducens nerve (VI) Inferior branch of oculomotor nerve (III)

Internal carotid plexus

Lacrimal nerve Frontal nerve (cut) O phthalmic nerve (V1 )

Trochlear nerve (IV) (cut) O culomotor nerve (III) Abducens nerve (VI)

Figu re 19-10 EYE AND O RBIT 523

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CONTENTS OF THE ORBIT • Muscles GENERAL SENSATION Maxillary Division of the Trigeminal Nerve • • • •

Travels along the lateral wall o the cavernous sinus Be ore exiting the m iddle cranial ossa, it gives o a m eningeal branch that innervates the dura m ater Passes rom the m iddle cranial ossa into the pterygopalatine ossa via the oram en rotundum Within the pterygopalatine ossa, it gives rise to 4 branches: posterior superior alveolar n., zygom atic n., ganglionic branches, and in raorbital n. • The zygom atic and in raorbital continue within the orbit

Nerve

Source

Course

Zygom atic

Maxillary division o the trigem inal n.

Enters the orbit via the in erior orbital f ssure Within the orbit, it divides into the zygom aticotem poral and zygom atico acial branches, which exit the orbit along the lateral wall via 1 or 2 zygom atic oram ina

In raorbital

Considered the continuation o the m axillary division o the trigem inal n. Passes through the in erior orbital f ssure to enter the orbit Passes anteriorly through the in raorbital groove and in raorbital canal and exits onto the ace via the in raorbital oram en Within the in raorbital canal, it gives rise to the anterior superior alveolar and m iddle superior alveolar nn. Once the in raorbital n. exits onto the ace, it divides into 3 term inal branches: • In erior palpebral—supplies the skin o the lower eyelid and conjunctiva • Nasal—supplies the skin o the ala o the nose • Superior labial—supplies the skin o the upper lip

Communicating branch

Anterior ethmoidal nerve

Posterior ethmoidal nerve

Supraorbital nerve Supratrochlear nerve

Long and short ciliary nerves

Infratrochlear nerve (from nasociliary nerve)

Ciliary ganglion Lacrimal nerve

Cutaneous branch of lacrimal nerve

Nasociliary nerve

Zygomaticotemporal nerve Zygomaticofacial nerve External nasal branch of anterior ethmoidal nerve

Frontal nerve

O phthalmic nerve (V1 ) Trigeminal (semilunar) ganglion Trigeminal nerve (V)

Foramen rotundum

Infraorbital nerve

Maxillary nerve (V2 ) Zygomatic nerve Nerve (vidian) of pterygoid canal Infraorbital nerve entering infraorbital canal

Pterygopalatine ganglion Ganglionic branches to pterygopalatine ganglion

Posterior superior alveolar nerve

Figu re 19-11

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CONTENTS OF THE ORBIT • Muscles

19

GENERAL MOTOR Nerve

Source

Course

Oculom otor (cranial n. III)

Ventral sur ace o the m idbrain

Innervates 4 o the extraocular m uscles—superior rectus, in erior rectus, m edial rectus, and in erior oblique m m .—as well as the levator palpebrae superioris m . Also provides parasym pathetic innervation to the intrinsic m uscles o the eye Passes anterior on the lateral wall o the cavernous sinus im m ediately superior to the trochlear n. Im m ediately be ore entering the orbit, it divides into superior and in erior divisions; both enter the orbit through the superior orbital f ssure

Superior division o the oculom otor

Oculom otor

Enters the orbit via the superior orbital f ssure Travels superior to the optic n. to enter the in erior border o the superior rectus m . Passes through the superior rectus to give rise to a branch that enters the in erior sur ace o the levator palpebrae superioris m .

In erior division o the oculom otor

Enters the orbit via the superior orbital f ssure Im m ediately divides into 3 m uscular branches that enter: • The lateral sur ace o the m edial rectus • The superior sur ace o the in erior oblique • The superior sur ace o the in erior rectus Gives rise to the parasym pathetic root o the ciliary ganglion

Trochlear (cranial n. IV)

Dorsal sur ace o the m idbrain

Innervates the superior oblique Passes anterior on the lateral wall o the cavernous sinus im m ediately in erior to the oculom otor n. Enters the orbit via the superior orbital f ssure and im m ediately enters the superior oblique to innervate it

Abducens (cranial n. VI)

Ventral sur ace o the pons

Travels anteriorly within the cavernous sinus beside the internal carotid a. Enters the orbit via the superior orbital f ssure Travels anteriorly to enter the m edial sur ace o the lateral rectus to innervate it

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CONTENTS OF THE ORBIT • Muscles

Long ciliary nerve

Ciliary ganglion

Short ciliary nerves Sensory root of ciliary ganglion Superior oblique muscle Levator palpebrae superioris muscle

Sympathetic root of ciliary ganglion Superior division of oculomotor nerve Frontal nerve (cut) Lacrimal nerve (cut) Nasociliary nerve Trochlear nerve (IV) Oculomotor nerve (III) O phthalmic nerve (V1 )

Infraorbital nerve Zygomatic nerve (cut) Inferior oblique muscle Ciliary muscle Dilator muscle of pupil Sphincter muscle of pupil Efferent fibers Afferent fibers Sympathetic fibers Parasympathetic fibers

Pterygopalatine ganglion Inferior division of oculomotor nerve Medial rectus muscle Inferior rectus muscle

Parasympathetic root of ciliary ganglion

Figu re 19-12

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NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

Abducens nerve (VI) Mandibular nerve (V3 ) Internal carotid artery and nerve plexus Maxillary nerve (V2 ) Lateral rectus muscle and abducens nerve (turned back)

CONTENTS OF THE ORBIT • Muscles

19

PARASYMPATHETICS OF THE EYE Type of Neuron

Location of Cell Body

Preganglionic neuron

Postganglionic neuron

Characteristics of Cell Body

Course of the Neuron

EdingerWestphal nucleus

A collection o nerve cell bodies located in the m idbrain

Arise rom the Edinger-Westphal nucleus in the m idbrain rom the oculom otor n. Oculom otor n. passes anteriorly on the lateral wall o the cavernous sinus im m ediately superior to the trochlear n. Im m ediately be ore entering the orbit, the nerve divides into the superior and in erior divisions Both the superior and in erior divisions o the oculom otor enter the orbit through the superior orbital f ssure Preganglionic parasym pathetic f bers travel in the in erior division A sm all parasym pathetic root passes rom the in erior division o the oculom otor to the ciliary ganglion, carrying the preganglionic parasym pathetic f bers

Ciliary ganglion

Located anterior to the optic oram en between the optic n. and the lateral rectus 3 roots connect to the ciliary ganglion: • Sensory root rom the ophthalm ic division o the trigem inal, which carries general sensation f bers to the eye via the short ciliary nn. • Parasym pathetic root rom the in erior division o the oculom otor, carrying preganglionic parasym pathetic f bers to the ganglion • Sym pathetic root that arises rom the postganglionic sym pathetic f bers, which were carried by the internal carotid a. The short ciliary nn. usually num ber about 8 Short ciliary nn. arise rom the ciliary ganglion to enter the posterior portion o the eye Fibers rom all 3 roots pass through the ciliary ganglion and short ciliary nn. to enter the eye Only the parasym pathetic f bers synapse in the ciliary ganglion

Arise in the ciliary ganglion, ollowing a synapse with the preganglionic parasym pathetic f bers Travel through the short ciliary nn. to enter the eye’s posterior portion Innervate: • sphincter pupillae m . • ciliary m .

EYE AND O RBIT 527

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CONTENTS OF THE ORBIT • Muscles

Sphincter muscle of pupil Dilator muscle of pupil Ciliary muscle

Short ciliary nerves Ciliary ganglion

Accessory oculomotor O culomotor (Edinger-Westphal) (parasympathetic) root of ciliary ganglion nucleus (parasympathetic)

Superior colliculus Lateral geniculate body

?

?

O ptic nerve (II) Nasociliary nerve Long ciliary nerve Nasociliary (sensory) root of ciliary ganglion Sympathetic root of ciliary ganglion O phthalmic artery

O phthalmic nerve (V1 ) Trigeminal ganglion Internal carotid plexus

Tympanic plexus Tectospinal tract Thoracic part of spinal cord

Internal carotid artery

Superior cervical sympathetic ganglion 1st thoracic sympathetic trunk ganglion

Presynaptic Postsynaptic Presynaptic Postsynaptic

Gray ramus communicans White Sympathetic fibers ramus communicans Parasympathetic fibers T1 spinal nerve

Afferent fibers Visual pathway Descending pathway

Figu re 19-13

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NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

Presynaptic sympathetic cell bodies in intermediolateral nucleus (lateral horn) of gray matter

CONTENTS OF THE ORBIT • Muscles

19

ANATOMIC PATHWAY FOR SYMPATHETICS OF THE EYE Type of Neuron

Name of Cell Body

Characteristics of Cell Body

Preganglionic neuron

Interm ediolateral horn nucleus

Collection o nerve cell bodies located in the lateral horn nucleus o the spinal cord between spinal segm ents T1 and T3 (and possibly T4)

Arise rom the interm ediolateral horn nuclei rom T1 to T3 (or T4) Travel through the ventral root o the spinal cord to the spinal n. Enter the sym pathetic chain via a white ram us com m unicans Once in the sym pathetic chain, the preganglionic f bers or the eye will ascend and synapse with postganglionic f bers in the superior cervical ganglion

Postganglionic neuron

Superior cervical ganglion

Collection o nerve cell bodies located in the superior cervical ganglion, which is located at the base o the skull

Arise in the superior cervical ganglion Postganglionic f bers will ollow the internal carotid a. on the internal carotid plexus As the internal carotid a. nears the orbit, the postganglionic f bers branch rom the internal carotid plexus and ollow various structures that connect to the eye, such as the ophthalm ic a. and its branches, and the long ciliary nn. that arise rom the ophthalm ic division o the trigem inal n. In the eye, the postganglionic f bers innervate: • dilator pupillae m .

Course of the Neuron

EYE AND O RBIT 529

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CONTENTS OF THE ORBIT • Vascular Supply ARTERIAL SUPPLY Artery

Source

Course

Ophthalm ic

Internal carotid a.

Enters the orbit through the optic oram en im m ediately in erior and lateral to the optic n. Crosses the optic n. to reach the m edial part o the orbit While in the orbit, the artery gives rise to a series o arteries that supply the orbit and associated structures The term inal aa. o the ophthalm ic a. anastom ose along the scalp and ace with the superf cial tem poral, acial, and in raorbital branches o the m axillary a.

Ophthalm ic a.

Arises near the optic oram en 1 o the ophthalm ic’s largest branches Follows the lacrim al n. along the superior border o the lateral rectus m . o the eye to reach and supply the lacrim al gland Gives rise to a series o term inal branches, such as the lateral palpebral, that supply the eyelids and conjunctiva Gives rise to a zygom atic branch that then gives rise to the zygom aticotem poral and zygom atico acial aa. Supply those regions o the ace

Lacrim al

530

Supratrochlear

It exits the orbit at the m edial angle accom panied by supratrochlear n. Ascends on the scalp, anastom osing with the supraorbital a. and supratrochlear a. rom the opposite side

Supraorbital

Branches rom the ophthalm ic a. as it passes the optic n. Passes on the m edial side o the levator palpebrae superioris and superior rectus m m . to join the supraorbital n. Passes through the supraorbital oram en (notch) and ascends superiorly along the scalp Anastom oses with the supratrochlear a. and superf cial tem poral a.

Anterior ethm oidal

Travels with the nerve through the anterior ethm oidal canal to supply the anterior and m iddle ethm oidal sinuses Continues to give rise to a m eningeal branch and nasal branches that supply the lateral wall and septum o the nose Then gives rise to the term inal external nasal branch that supplies the external nose

• External nasal

A term inal branch o the anterior ethm oidal a.

Supplies the area along the external nose at the junction between the nasal bone and the lateral nasal cartilage

Posterior ethm oidal

Ophthalm ic a.

Travels through the posterior ethm oidal canal to supply the posterior ethm oidal sinus Gives rise to m eningeal and nasal branches that anastom ose with branches o the sphenopalatine

Medial palpebral (superior and inferior)

Ophthalm ic a. o the internal carotid a.

Arise near the trochlea and exit the orbit to pass along the upper and lower eyelids These arteries anastom ose with the other arteries supplying the ace in the region

Dorsal nasal (infratrochlear)

1 o the ophthalm ic a.’s term inal branches

Exits the orbit along the superom edial border along with the in ratrochlear n. Supplies the area along the bridge o the nose

Muscular

Ophthalm ic a. rom the internal carotid a.

Supply the extraocular m uscles o the orbit

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

CONTENTS OF THE ORBIT • Vascular Supply

19

ARTERIAL SUPPLY Artery

Source

Course

Anterior ciliary

Muscular branches from the ophthalm ic a.

Pass anteriorly to the anterior surface of the eye following the tendons of the extraocular m uscles

Short posterior ciliary

Ophthalm ic a. from the internal carotid a.

Usually 6 to 10 arise Travel anteriorly around the optic n. to enter the posterior portion of the eye

Long posterior ciliary

Usually 2 arise Travel anteriorly to enter the posterior portion of the eye near the optic n.

Central a. of the retina

Branches from the ophthalm ic a. early on its entrance into the orbit Follows the optic n. and enters the nerve about halfway into the orbit Supplies the retina

Maxillary

Infraorbital

1 of 2 term inal branches of the external carotid a.

Gives rise to a series of branches Only the infraorbital branch supplies the orbit

Maxillary a.

Once the infraorbital exits the infraorbital foram en, the inferior palpebral a. supplies the lower eyelid Supplies som e m uscles along the oor of the orbit near the inferior orbital canal Medial palpebral artery

Superior view

Lateral palpebral artery

Supratrochlear artery

Lacrimal gland

Dorsal nasal artery

Supraorbital artery

Anterior meningeal artery

Zygomatic branches

Anterior ethmoidal artery

Posterior ciliary arteries

Posterior ethmoidal artery

Muscular branch

Continuation of ophthalmic artery

Lacrimal artery Central retinal artery

Muscular branch O phthalmic artery Internal carotid artery

Supraorbital artery Supratrochlear artery

X

Dorsal nasal artery

Anterior view Frontal branch of superficial temporal artery

X

Angular artery

X

Superior lateral palpebral artery Inferior lateral palpebral artery

Superior medial palpebral artery

X

Inferior medial palpebral artery Superior and inferior palpebral arterial arches

Zygomaticofacial artery

Facial artery

Transverse facial artery Infraorbital artery

(X = anastomosis of vessels from external and internal carotid arteries)

Figu re 19-14 EYE AND O RBIT 531

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CONTENTS OF THE ORBIT • Vascular Supply VENOUS DRAINAGE Vein

Course Superf cial Veins

Supraorbital

Begins on the orehead, where it com m unicates with the superf cial tem poral v. Passes in eriorly superf cial to the rontalis m . and joins the supratrochlear v. at the m edial angle o the orbit to orm the angular v.

Supratrochlear

Begins on the orehead, where it com m unicates with the superf cial tem poral v. Passes in eriorly along the orehead, parallel with the vein o the opposite side At the m edial angle o the orbit, the supratrochlear joins the supraorbital v. to orm the angular v.

Angular

Form s rom the con uence o the supraorbital and supratrochlear vv. along the m edial part o the eye Travels along the lateral aspect o the nose to becom e the acial v.

Facial

Begins as the angular v. Passes in eriorly along the side o the nose, receiving the lateral nasal v. Continues posteroin eriorly across the angle o the m outh to the cheek receiving the superior and in erior labial vv. While passing toward the m andible, the deep acial v. connects to the pterygoid plexus In the subm andibular triangle the acial v. joins the anterior branch o the retrom andibular to orm the com m on acial v. The acial v. has no valves that can allow blood to back ow

Deep Veins Cavernous sinus

A reticulated venous structure located on the lateral aspect o the body o the sphenoid bone Drain posteriorly into the superior and in erior petrosal sinuses Receives blood rom the superior and in erior ophthalm ic vv. Oculom otor and trochlear nn. and ophthalm ic and m axillary divisions o the trigem inal n. lie along the lateral wall o the sinus Abducens n. and internal carotid a. lie in the sinus

Pterygoid plexus

An extensive network o veins that parallels the 2nd and 3rd parts o the m axillary a. Receives branches that correspond to the sam e branches o the m axillary a. Tributaries to the pterygoid plexus eventually converge to orm a short m axillary v. Com m unicates with the cavernous sinus, pharyngeal venous plexus, acial v. via the deep acial v., and ophthalm ic vv.

Communicating Veins

532

Superior ophthalm ic

Receives blood rom the roo o the orbit and the scalp Travels posteriorly to com m unicate with the cavernous sinus

In erior ophthalm ic

Receives blood rom the oor o the orbit O ten splits into 2 branches 1 branch travels posteriorly with the in raorbital v. that passes through the in erior orbital f ssure to com m unicate with the pterygoid plexus The other branch travels posteriorly to com m unicate directly with the superior ophthalm ic v. in the superior orbital f ssure, or it will pass through the f ssure to com m unicate with the cavernous sinus

In raorbital

Receives blood rom the m id ace via the lower eyelid, lateral side o the nose, and the upper lip Eventually com m unicates with the pterygoid plexus o veins

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

CONTENTS OF THE ORBIT • Vascular Supply

19

Supratrochlear vein Lateral view

Supraorbital vein Superior ophthalmic vein

Angular vein

Cavernous sinus

Vorticose veins Facial vein

Inferior ophthalmic vein Pterygoid plexus Maxillary vein Deep facial vein

Retromandibular vein Skull sectioned horizontally: superior view

Hypophysis (pituitary gland) O ptic nerve (II) Internal carotid artery O culomotor nerve (III)

Superior ophthalmic vein Anterior and posterior intercavernous sinuses Superficial middle cerebral vein (cut)

Sphenoparietal sinus Trochlear nerve (IV) O phthalmic nerve (V1 ) Maxillary nerve (V2 )

Cavernous sinus

Trigeminal ganglion

Basilar venous plexus Superior petrosal sinus

Mandibular nerve (V3 ) Middle meningeal artery Abducens nerve (VI)

Inferior petrosal sinus

Coronal section through cavernous sinus Cavernous sinus

O ptic chiasm Posterior communicating artery

O culomotor nerve (III) Trochlear nerve (IV)

Internal carotid artery

Abducens nerve (VI) O phthalmic nerve (V1 )

Hypophysis (pituitary gland)

Maxillary nerve (V2 )

Sphenoidal sinus Pterygoid canal Vidian nerve Artery of pterygoid canal

Nasopharynx

Figu re 19-15

EYE AND O RBIT 533

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CONTENTS OF THE ORBIT • Lacrimal Apparatus OVERVIEW Structure/Function

Description

Lacrim al apparatus

Com posed of: • Lacrim al gland • Lacrim al canaliculi • Lacrim al sac • Nasolacrim al duct Secretes and drains all tears

Lacrim al gland

Located in the anterolateral part of the orbit Secretes serous uid Divided into 2 parts by the lateral tendon of the levator palpebrae superioris m .

Tear form ation and absorption

Tears coat the external surface of the eye to prevent drying, act as a lubricant, and contain bactericidal enzym es With blinking, tears are carried across the eye to collect near the m edial canthus Tears enter through the lacrim al puncta into the lacrim al canaliculi Lacrim al canaliculi carry the tears to the lacrim al sac Lacrim al sac carries the tears inferiorly through the nasolacrim al duct, which term inates in the inferior m eatus

Superior lacrimal papilla and punctum O rbital part of lacrimal gland

Lacrimal canaliculi

Palpebral part of lacrimal gland

Lacrimal sac

Excretory ducts of lacrimal gland

Nasolacrimal duct

Plica semilunaris

O pening of nasolacrimal duct

Lacrimal caruncle

Inferior lacrimal papilla and punctum Superior lacrimal papilla and punctum Frontal bone (cut aw ay) Lacrimal canaliculi

O rbital part of lacrimal gland

Lacrimal sac

Palpebral part of lacrimal gland

Nasolacrimal duct

Excretory ducts of lacrimal gland

Middle nasal concha

Plica semilunaris and lacrimal lake

Nasal cavity Lacrimal caruncle Inferior nasal concha (cut)

Inferior lacrimal papilla and punctum O pening of nasolacrimal duct

Inferior nasal meatus

Figu re 19-16

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CONTENTS OF THE ORBIT • Lacrimal Apparatus

19

PARASYMPATHETICS OF THE LACRIMAL GLAND Type of Neuron

Name of Cell Body

Characteristics of Cell Body

Course of the Neuron

Preganglionic neuron

Superior salivatory nucleus

A collection o nerve cell bodies located in the pons Travel through the nervus interm edius o the acial n. into the internal acoustic m eatus In the acial canal, the acial n. gives rise to 2 parasym pathetic branches: • Greater petrosal n. • Chorda tym pani n

Lacrim al gland uses the greater petrosal n. Gre ate r Pe tro s al Ne rve Exits along the hiatus or the greater petrosal n. toward the oram en lacerum , where it joins the deep petrosal n. (sym pathetics) to orm the nerve o the pterygoid canal (vidian n.) Vidian n. passes through the pterygoid canal and enters the pterygopalatine ossa, where it joins with the pterygopalatine ganglion

Postganglionic neuron

Pterygopalatine ganglion

A collection o nerve cell bodies located in the pterygopalatine ossa Postganglionic parasym pathetic f bers that arise in the pterygopalatine ganglion are distributed to the ophthalm ic and m axillary divisions o the trigem inal n. to the: • Lacrim al gland • Nasal glands • Palatine glands • Pharyngeal glands • Paranasal sinus glands

Lacrim al gland uses the ophthalm ic and m axillary divisions Ophthalmic and Maxillary Divis io n Dis tributio n Postganglionic f bers travel along the zygom atic branch o the m axillary division or a short distance to enter the orbit A short com m unicating branch joins the lacrim al n. o the ophthalm ic division o the trigem inal n. These f bers innervate: • Lacrim al gland to cause the secretion o tears

EYE AND O RBIT 535

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CONTENTS OF THE ORBIT • Lacrimal Apparatus

Trigeminal ganglion Deep petrosal nerve Greater petrosal nerve Chorda tympani nerve Trigeminal nerve (V) Facial nerve (VII) (intermediate nerve) Superior salivatory nucleus

O phthalmic nerve (V1 ) Mandibular nerve (V3 ) O tic ganglion Lingual nerve Maxillary nerve (V2 ) Nerve (vidian) of pterygoid canal Pterygopalatine ganglion Lacrimal gland

Descending palatine nerves Posterior nasal nerves

Pharyngeal nerve Maxillary artery Internal carotid nerve

Palatine nerves

Glossopharyngeal nerve (IX) Superior cervical sympathetic ganglion Sympathetic trunk

Greater Lesser

T1 and T2 spinal nerves Thoracic spinal cord

Submandibular ganglion

Dorsal root Sublingual gland White

Submandibular gland Facial artery Lingual artery External carotid artery and plexus Common carotid artery

Gray

Rami communicantes Ventral Sympathetic root presynaptic cell bodies in Internal carotid artery intermediolateral nucleus (lateral horn) of gray matter Sympathetic presynaptic fibers Sympathetic postsynaptic fibers Parasympathetic presynaptic fibers Parasympathetic postsynaptic fibers

Figu re 19-17

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CLINICAL CORRELATES • Testing the Extraocular Muscles • • • •

19

Extraocular m uscle testing exam in es th e fu n ction of each of th e 6 extraocu lar m u scles W h ile sittin g u p righ t (or stan din g), th e p atien t xates th e gaze u p on an object h eld 12 to 6 in ch es in fron t of th e eyes Th e object is m oved u p an d down an d from sid e to side in an H-sh ap ed p attern , wh ile th e h ead is kep t still, to test th e 6 card in al p osition s of gaze Disord ers of m ovem en t m ay be d u e to de cits in th e extraocu lar m u scles, n erves, or areas of th e brain th at con trol th e m u scles

Gaze to right and up (SR)

Gaze to right and up (IO )

Right gaze (LR)

Right gaze (MR)

Gaze to right and down (IR)

Gaze to right and down (SO )

RIGHT EYE Right gaze: Lateral rectus (CN VI) Right gaze-up: Superior rectus (CN III) Right gaze-down: Inferior rectus (CN III)

LEFT EYE Right gaze: Medial rectus (CN III) Right gaze-up: Inferior oblique (CN III) Right gaze-down: Superior oblique (CN IV)

Gaze to left and up (IO )

Gaze to left and up (SR)

Left gaze (MR)

Left gaze (LR)

Gaze to left and down (SO ) RIGHT EYE Left gaze: Medial rectus (CN III) Left gaze-up: Inferior oblique (CN III) Left gaze-down: Superior oblique (CN IV)

Gaze to left and down (IR)

LEFT EYE Left gaze: Lateral rectus (CN VI) Left gaze-up: Superior rectus (CN III) Left gaze-down: Inferior rectus (CN III)

Figu re 19-18

EYE AND O RBIT 537

19

CLINICAL CORRELATES • Cerebral Aneurysms Causing Ophthalmoplegia • •

Becau se of th e close p roxim ity of th e ocu lom otor, troch lear, an d abd u cen s n erves to blood vessels su p p lyin g th e brain , aneurysm s alon g th ese vessels m ay lead to a p aralysis of th e m u scles th at th ey in n ervate Com m on ly affected vessels in clu de th e basilar, p osterior cerebral, an d p osterior com m u n icatin g arteries

NEUROMUSCULAR DISORDERS Abducens Pa lsy

• • •

Affected eye tu rn s m edially May be 1st m an ifestation of in tracavern ou s carotid an eu rysm Pain above eye or on sid e of face m ay be secon d ary to trigem in al (V) n erve in volvem en t

Oculomotor Palsy

• •

Ptosis; eye tu rn s laterally an d in feriorly; p u p il d ilated Com m on n d in g with cerebral an eu rysm s, esp ecially carotid –p osterior com m u n icatin g artery an eu rysm s Neuromuscular disorders Abducens palsy: Affected eye turns medially. May be 1st manifestation of intracavernous carotid aneurysm. Pain above eye or on side of face may be secondary to trigeminal (V) nerve involvement.

O culomotor palsy: Ptosis, eye turns laterally and inferiorly, pupil dilated; common finding with cerebral aneurysms, especially carotid–posterior communicating artery aneurysms R. trochlear (IV) n. R. oculomotor (III) n.

Basilar a. Tentorium (divided)

Posterior clinoid process

R. trigeminal (V) n.

Middle fossa Pons

R. internal carotid a. R. ophthalmic a. R. optic (II) n.

Cerebellum

R. anterior cerebral a.

R. superior cerebellar a. R. middle cerebral a.

Aneurysm R. posterior cerebral a.

R. posterior communicating a. Temporal lobe (elevated)

Internal carotid a.

O culomotor (III) n. (divided) Posterior communicating a.

Cavernous sinus Oculomotor (III) n. (divided) Trochlear (IV) n. Trigeminal (V) n.

Posterior cerebral a.

Basilar a.

Figu re 19-19

538

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

Abducens (VI) n.

CLINICAL CORRELATES • Glaucoma •

19

Glaucom a: d am age to th e op tic n erve often d u e to in creased in traocu lar p ressu re

OPEN ANGLE GLAUCOMA

• • • •

Th e m ost com m on form Grad u al an d can resu lt in grad u al loss of vision In traocu lar p ressu re elevates owin g to in su f cien t d rain age with in th e eye’s can al system , located in th e an gle of th e an terior ch am ber of th e an terior segm en t Variou s m edication s are su ccessfu l in treatin g th is form

CLOSED ANGLE GLAUCOMA

•

Resu lt of an an atom ic blockage of th e can al system at th e an gle of th e an terior ch am ber of th e an terior segm en t Exam ple: W h en th e iris op en s th e p u p il very wid e with con seq u en t closu re of th e an gle, in traocu lar p ressu re can rise q u ickly if blockage occu rs as an abru p t even t

Early Right eye, nasal side

Funduscopy: notching of contour of physiologic cup in optic disc with slight focal pallor in area of notching; occurs almost invariably in superotemporal or inferotemporal (as shown) quadrants

Minimally advanced Right eye, nasal side

Funduscopy: increased notching of rim of cup; thinning of rim of cup (enlargement of cup); deepening of cup; lamina cribrosa visible in deepest areas.

Figu re 19-20

EYE AND O RBIT 539

19

CLINICAL CORRELATES • Glaucoma

Normal

Increased O utflow

O utflow

Inflow

Dynamic equilibrium between aqueous production and drainage

Corneal edema

Imbalance in aqueous production and drainage Inflow

Pupillary block

Plateau iris Primary block in angle

Secondary block in angle Primary block at pupil

Hyperemia

Closed angle

Central anterior chamber shallow

Central anterior chamber Angle closure may result from primary pupillary block with bulging iris or from less common plateau iris (primary occlusion at periphery of iris)

Acute angle closure results in marked increase in intraocular pressure with conjunctival hyperemia, corneal edema, and fixed mid-dilated pupil. Subacute and chronic forms may be asymptomatic. Fixed, mid-dilated pupil

Consensual response

Corneal edema White light

Inflamed eye with nonreactive, middilated pupil typical of acute attack Synechia

Synechial closure persists

Corneal edema diffracts light, causing rainbow halos around objects and lights Synechiae

Trabecular meshwork

Synechial closure with peripheral anterior synechiae

Compression gonioscopy Appositional closure opened Long-term angle closure may result in synechiae that can permanently close angle. Compression gonioscopy differentiates appositional closure from synechial closure

Appositional closure opened by compression gonioscopy

Figu re 19-21

540

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CLINICAL CORRELATES • Diabetic Retinopathy • •

19

Diabetic retinopathy: p ath ologic ch an ges to th e retin a resu ltin g from d am age to th e blood vessels in th e retin a d u e to d iabetes Can occu r in all p eop le with diabetes (typ es 1 an d 2)

PATHOPHYSIOLOGY

• • • •

As th e retin al blood vessels becom e dam aged, th ey leak u id in to th e eye If th e u id accu m u lates arou n d th e m acu la lu tea (wh ich con tain s th e largest am ou n t of con es for acu te vision ), m acu la ed em a occu rs in wh ich visu al loss is n oted As th e p erm eability of th e vessels worsen s, lip op rotein is d ep osited, lead in g to form ation of h ard exu d ates with in th e retin a As n ew blood vessels form , th ey are fragile an d bleed , allowin g blood to en ter th e eye, h elp in g to clou d an d d estroy th e retin a

Interaction between hematogenous iron and vitreous accelerates shrinkage and traction Fibrovascular proliferation on optic disc and on vessels

Vitreoretinal traction

Vitreous hemorrhage

Fibrovascular proliferation and vitreous contraction cause traction retinal detachment

Vitreous contraction

Traction retinal detachment

Figu re 19-22

EYE AND O RBIT 541

19

CLINICAL CORRELATES • Ametropias •

A series of refractive disord ers of th e eye th at cau se blu rrin g of th e im age on th e retin a

TYPES Myopia

• •

Im age is focu sed an terior to th e retin a Com m on ly referred to as n earsigh ted n ess

Hyperopia

• •

Im age is focu sed p osterior to th e retin a Com m on ly referred to as farsigh ted n ess

Astigma tism

•

A n on sp h erical eye allows th e p arts of th e im age to focu s at m u ltip le location s, rath er th an in a sin gle area

Myopia and Other Refractive Errors Normal Eye (Emmetropia) Lightrays are bent (refracted) by cornea and lens (primarily cornea) to focus image on macular portion of retina Distant target

Near target Macula

Elasticity of lens allows it to change shape in order to focus divergent rays from near targets. Loss of this elasticity with aging causes decrease in near vision (presbyopia) Myopia: If corneal curvature is too steep or axial length of eye too long, light is focused short of retina (nearsighted) Hyperopia: If corneal curvature is too flat or axial length of eye too short, image is focused behind retina (farsighted)

Spectacle lens

Astigmatism: Irregular corneal curvature results in light from different axes being brought to focus at different points

Treatment Options Contact lens

Spectacle lens bends (refracts) light rays to focus image on retina

Surgically altered corneal curvature

Contact lens performs as a “corrected” corneal surface, focusing image on retina

Figu re 19-23

542

Lens

Cornea

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

Surgical alteration of abnormal corneal curvature allows clear focusing of image on retina

CHAPTER 20

AUTONOMICS OF THE HEAD AND NECK

Overview of the Autonomic Nervous System

544

Sympathetics of the Head and Neck

551

Autonomic Pathways of the Head and Neck

553

Clinical Correlate

566

20

OVERVIEW OF THE AUTONOMIC NERVOUS SYSTEM • General Information • •

• • •

•

•

•

544

Th e au ton om ic n ervou s system (ANS) h as con trol over th e fu n ction s of m an y organ system s an d tissu es Provides in n ervation to: • Card iac m u scle • Sm ooth m u scle • Glan d s Also p rovid es in n ervation to th e organ s of th e im m u n e system an d m etabolic organ s (m ain ly th rou gh th e sym p ath etics) Th e h yp oth alam u s exerts con trol over th e ANS an d h elp s th e body m ain tain h om eostasis Th e ANS u ses a 2-n eu ron ch ain system : • Pregan glion ic n eu ron s—th e cell bodies are located in th e cen tral n ervou s system (CNS) (i.e., th e brain an d sp in al cord), an d th eir m yelin ated axon s p ass ou t to th e au ton om ic gan glia • Postgan glion ic n eu ron s—th e cell bod ies are located in th e au ton om ic gan glia, wh ich are ou tsid e of th e CNS, an d th eir u n m yelin ated axon s travel to th e effector organ Th e ANS is d ivid ed in to 2 p arts: • Parasym p ath etic—th e p ortion resp on sible for p reservin g an d restorin g en ergy • Sym p ath etic—th e p ortion resp on sible for p rep arin g th e bod y for em ergen cy situ ation s Organ s typ ically receive du al in n ervation , wh ich h as an an tagon istic action , alth ou gh th ere are som e n otable excep tion s, su ch as th e arrector p ili m u scles (wh ich are sym p ath etic on ly) an d th e m ale sexu al resp on se (erection is p arasym p ath etic, ejacu lation is sym p ath etic) Acetylch olin e an d n orep in ep h rin e are th e 2 m ajor n eu rotran sm itters u sed in syn ap ses of th e ANS

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

OVERVIEW OF THE AUTONOMIC NERVOUS SYSTEM • General Information

20

Sympathetic Nervous System Superior cervical ganglion

Internal carotid nerve and plexus

First thoracic ganglion Gray rami communicantes

External carotid nerve and plexus

Lacrimal gland Eye 8

Parotid gland

–

C

Innervation to arrector pili muscles, vascular smooth muscle, and sweat glands of skin

C

1

Sublingual gland Submandibular gland Larynx Trachea Bronchi Lungs Cardiac branches Greater splanchnic nerve

–

T

1

2

Heart

Celiac ganglion

T

1

Lesser splanchnic nerve Stomach Aorticorenal ganglion Liver Gallbladder Bile ducts

White ramus communicans Gray ramus communicans

Pancreas

Least splanchnic nerve Suprarenal gland Kidneys Superior mesenteric ganglion Intestines Lumbar splanchnic nerves

First lumbar ganglion

L 1 –

Superior hypogastric plexus

L 5

Descending Inferior mesenteric colon ganglion Sigmoid colon

S 5

First sacral ganglion

Sacral splanchnic nerves

S1

–

Rectum Urinary bladder

Inferior hypogastric plexus

Prostate Preganglionic fibers Postganglionic fibers

External genitalia

Figu re 20-1

AUTO NO MICS O F THE HEAD AND NECK 545

20

OVERVIEW OF THE AUTONOMIC NERVOUS SYSTEM • General Information Parasympathetic Nervous System Branch of oculomotor nerve (III) Branch of facial nerve (VII)

Ciliary ganglion

Pterygopalatine ganglion Lacrimal glands Eye

Mucous glands of nose, paranasal sinuses, palate Parotid glands

Medulla oblongata Branch of glossopharyngeal nerve (IX) O tic ganglion Submandibular ganglion

Vagus nerve (X)

Celiac ganglion

Larynx Trachea Bronchi Lungs

Sublingual glands Submandibular glands

Heart

Stomach Liver Superior mesenteric ganglion

Gallbladder Bile ducts Pancreas

Kidneys

Intestines Descending colon Sigmoid colon S2

Rectum

S3 S4 Preganglionic fibers Postganglionic fibers

Pelvic splanchnic nerves External genitalia

Figu re 20-2

546

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

Urinary bladder Prostate

OVERVIEW OF THE AUTONOMIC NERVOUS SYSTEM • Divisions and Functions

20

DIVISIONS OF THE AUTONOMIC NERVOUS SYSTEM Parasympathetic

Sympathetic

Re erred to as craniosacral f bers

Re erred to as thoracolum bar f bers

Arise rom : • Cranial nerves III, VII, IX, and X • Sacral f bers 2 to 4

Arise rom : • Thoracic f bers 1 to 12 • Lum bar f bers 1 to 2/ 3

Preganglionic f bers are m yelinated and travel rom the CNS to their autonom ic ganglia (located near their respective e ector organ in the head and neck), utilizing acetylcholine as the neurotransm itter at the synapse with the nicotinic receptor

Preganglionic f bers are m yelinated and travel rom the CNS to their autonom ic ganglia (located in the sym pathetic chain or the head and neck), utilizing acetylcholine as the neurotransm itter at the synapse with the nicotinic receptor

Postganglionic f bers are unm yelinated and travel rom the autonom ic ganglia to the e ector organ, utilizing acetylcholine as the neurotransm itter at the synapse with the m uscarinic receptor

Postganglionic f bers are unm yelinated and travel rom the autonom ic ganglia to the e ector organ, typically utilizing norepinephrine * as the neurotransm itter at the synapse with the α or β receptor

*Main exception to this is in the adrenal gland, where chromaf n cells secrete epinephrine and norepinephrine into the blood.

FUNCTIONS OF THE AUTONOMIC NERVOUS SYSTEM Parasympathetic

Sympathetic

Responsible or preserving and restoring energy

Responsible or preparing the body or em ergency situations

Discharges ocally, not as a com plete system

Discharges as a com plete system

Activated in response to the specif c body unction that needs to be adjusted (peristalsis, pupillary accom m odation)

Activated in response to stress ul situations (helps to increase cardiac output, get blood to m uscles, and decrease blood ow to the skin and viscera)

AUTO NO MICS O F THE HEAD AND NECK 547

20

OVERVIEW OF THE AUTONOMIC NERVOUS SYSTEM • Divisions and Functions

Inputs to autonomic preganglionic neurons of sympathetic and parasympathetic nervous systems: Limbic forebrain structures Some cortical regions Hypothalamic regions Brainstem centers and nuclei Sensory inputs Nucleus of Edinger-Westphal

Inputs to autonomic preganglionic neurons Preganglionic sympathetic Postganglionic sympathetic Preganglionic parasympathetic Postganglionic parasympathetic

Pupillary constrictor m. Ciliary m. Lacrimal glands Glands of nasal mucosa Salivary glands

Submandibular gland Sublingual gland Parotid gland

Smooth m., cardiac m., secretory glands in heart, lung, viscera, GI tract to descending colon

Ciliary ganglion Pterygopalatine ganglion O culomotor (III) n. Submandibular ganglion

Facial (VII) n.

Glossopharyngeal (IX) n. O tic ganglion Vagus (X) n. Lateral horn (intermediolateral cell column)

Intramural ganglia

Spinal n. To vascular smooth muscle in skin and muscles, arrector White ramus pili mm., sweat glands in limbs communicans Adrenal Secretion of medulla Splanchnic n. epinephrine and norepinephrine into blood To cardiac m., smooth m., Collateral secretory glands, metabolic cells ganglia (liver, fat), cells of immune system Smooth m., secretory glands in lower GI tract, pelvic viscera

Intramural ganglia

Ventral root Gray ramus communicans

Inferior salivatory nucleus Dorsal motor (autonomic) nucleus of X

Thoracic spinal cord (T1-L2)

Sympathetic chain ganglia Intermediate gray Ventral root

Pelvic nn.

Figu re 20-3

548

Superior salivatory nucleus

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

Sacral spinal cord (S2-S4)

OVERVIEW OF THE AUTONOMIC NERVOUS SYSTEM • Divisions and Functions

CENTRAL NERVO US SYSTEM

20

PERIPHERAL NERVO US SYSTEM Ciliary Pupillary constrictor m. ganglion Ciliary m.

Parasympathetics Cranial n. III Nucleus of Edinger-Westphal

Pterygopalatine Lacrimal glands ganglion Nasal mucosal glands Superior salivatory nucleus

Cranial n. VII

Submandibular ganglion

O tic ganglion Inferior salivatory nucleus

Submandibular gland Sublingual gland

Parotid gland

Cranial n. IX

Pupillary dilator m. Sympathetics

Superior cervical ganglion

T1-T2 Intermediolateral cell column Sweat glands and vascular smooth muscle in head and neck

Figu re 20-4

AUTO NO MICS O F THE HEAD AND NECK 549

20

OVERVIEW OF THE AUTONOMIC NERVOUS SYSTEM • Divisions and Functions

CENTRAL NERVO US SYSTEM

PERIPHERAL NERVO US SYSTEM

Lower motor neurons

C

N

Skeletal muscle

C

N

Sympathetic chain ganglion

Collateral ganglion

Sympathetics T1-L2

or A

or C

N

A

Target tissue Adrenal C

N

Epinephrine Norepinephrine

Chromaffin cell Intramural ganglion

Parasympathetics (cranial and sacral)

C

N

C

M

Target tissue Synapses

Receptors

A Adrenergic

or

Alpha or beta adrenergic

C Cholinergic

N M

Nicotinic Muscarinic

Figu re 20-5

550

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

SYMPATHETICS OF THE HEAD AND NECK • General Anatomic Pathway Type of Neuron

Name of Cell Body

Characteristics of Cell Body

Preganglionic f bers

Interm ediolateral horn nucleus

Collection o nerve cell bodies located in the lateral horn nucleus o the spinal cord between spinal segm ents T1 and T3 (and possibly T4)

Fibers arise rom the interm ediolateral horn nuclei rom T1 to T3 (or T4) Travel through the ventral root o the spinal cord to the spinal n. Enter the sym pathetic chain via a white ram us com m unicans Once in the sym pathetic chain, the preganglionic f bers will ascend and synapse with postganglionic f bers in the various sym pathetic chain ganglia A m ajority o the preganglionic f bers will synapse with postganglionic f bers in the superior cervical ganglion, located at the base o the skull

Postganglionic f bers

Superior cervical ganglion* (this is where a m ajority o postganglionic sym pathetic f bers to the head and neck begin)

Collection o nerve cell bodies located in the sym pathetic chain The location o the nerve cell body or a m ajority o the postganglionic neurons to the head and neck is the superior cervical ganglion The locations o the cell bodies or other postganglionic sym pathetics include the m iddle and in erior cervical ganglia

Postganglionic f bers arise in their respective sym pathetic chain ganglia (e.g., superior cervical, m iddle cervical, in erior cervical ganglia) Som e o the postganglionic f bers that travel to the periphery (e.g., skin o the neck, blood vessels) will rejoin the spinal nerves in the cervical region via a gray ram us com m unicans, to be distributed along the path o the peripheral nerves ollowing the path with blood vessels A m ajority o the postganglionic f bers join the m ajor blood vessels o the head (nam ely, the internal carotid a. and the external carotid a. and its branches) to ollow the vessel until reaching their f nal e ector organ (e.g., dilator pupillae m . o the eye)

20

Course of Neuron

*Location of the cell body for the postganglionic is variable and depends on the course of this neuron.

AUTO NO MICS O F THE HEAD AND NECK 551

20

SYMPATHETICS OF THE HEAD AND NECK • General Anatomic Pathway

Paro tid glan d

Glo sso p h aryn geal n erve (IX) Med u lla o b lo n gata

In tern al caro tid n erve Vagu s n erve (X)

Laryn x Trach ea Bro n ch i Lu n gs

Heart Cervical symp ath etic gan glia

Striated mu scle

Sweat glan d s W h ite ramu s co mmu n ican s

Gray ramu s co mmu n ican s

Th o racic p art o f sp in al co rd

Celiac gan glio n

Perip h eral arteries

Su p erio r mesen teric gan glio n

Up p er lu mb ar p art o f sp in al co rd (L1 -2 [3 ])

Hair fo llicles

Visceral arteries Gastro in testin al tract

Su p raren al glan d

In ferio r mesen teric gan glio n Pelvic sp lan ch n ic n erves

Sacral p art o f sp in al co rd

Urin ary b lad d er Ureth ra Pro state

C Cho linergic synapses A Adrenergic synapses

Sympathetic fibers

Presynaptic

Parasympathetic fibers

Po stsynaptic So matic fibers Antidro mic co nductio n

Figu re 20-6

552

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

Presynaptic Po stsynaptic

AUTONOMIC PATHWAYS • Parasympathetics of Cranial Nerve III With Corresponding Sympathetics

20

ANATOMIC PATHWAY FOR PARASYMPATHETICS OF THE EYE Type of Neuron

Name of Cell Body

Characteristics of Cell Body

Course of Neuron

Preganglionic neuron

EdingerWestphal nucleus

A collection o nerve cell bodies located in the m idbrain The Edinger-Westphal nucleus is ound m edial to the oculom otor nucleus and lateral to the cerebral aqueduct

Fibers arise rom the EdingerWestphal nucleus in the m idbrain rom the oculom otor n. Oculom otor n. passes anteriorly on the lateral wall o the cavernous sinus im m ediately superior to the trochlear n. Im m ediately be ore entering the orbit, the nerve divides into superior and in erior divisions o the oculom otor Both the superior and the in erior divisions o the oculom otor enter the orbit through the superior orbital f ssure Preganglionic parasym pathetic f bers travel in the in erior division A sm all parasym pathetic root passes rom the in erior division o the oculom otor to the ciliary ganglion, carrying the preganglionic parasym pathetic f bers

Postganglionic neuron

Ciliary ganglion

Located anterior to the optic oram en between the optic n. and the lateral rectus m . 3 roots connect to the ciliary ganglion: • Sensory root rom the ophthalm ic division o the trigem inal n., which carries general sensation f bers to the eye via the short ciliary n. • Parasym pathetic root rom the in erior division o the oculom otor n., carrying preganglionic parasym pathetic f bers to the ganglion • Sym pathetic root, which arises rom the postganglionic sym pathetic f bers that were carried by the internal carotid a. The short ciliary nn., usually num bering about 8 total, arise rom the ciliary ganglion to enter the posterior portion o the eye Fibers rom all 3 roots pass through the ciliary ganglion and short ciliary nn. to enter the eye Only the parasym pathetic f bers synapse in the ciliary ganglion

Fibers arise in the ciliary ganglion ollowing a synapse with the preganglionic parasym pathetic f bers Travel through the short ciliary nn. to enter the eye’s posterior portion Innervate the: • Sphincter pupillae m .— constricts the pupil • Ciliary m .—changes the shape o the lens during accom m odation

AUTO NO MICS O F THE HEAD AND NECK 553

20

AUTONOMIC PATHWAYS • Parasympathetics of Cranial Nerve III With Corresponding Sympathetics ANATOMIC PATHWAY FOR SYMPATHETICS OF THE EYE

554

Type of Neuron

Name of Cell Body

Characteristics of Cell Body

Preganglionic neuron

Interm ediolateral horn nucleus

Collection o nerve cell bodies located in the lateral horn nucleus o the spinal cord between spinal segm ents T1 and T3 (and possibly T4)

Fibers arise rom the interm ediolateral horn nuclei rom T1 to T3 (or T4) Travel through the ventral root o the spinal cord to the spinal n. Enter the sym pathetic chain via a white ram us com m unicans Once in the sym pathetic chain, the preganglionic f bers or the eye will ascend and synapse with postganglionic f bers in the superior cervical ganglion

Postganglionic neuron

Superior cervical ganglion

Collection o nerve cell bodies located in the superior cervical ganglion, which is located at the base o the skull

Fibers arise in the superior cervical ganglion Postganglionic f bers will orm the internal carotid nerve, which travels along the internal carotid a., orm ing the internal carotid plexus As the internal carotid a. nears the orbit, the postganglionic f bers branch rom the internal carotid plexus and ollow various structures that connect to the eye, such as the ophthalm ic a. and its branches, the long ciliary nn. that arise rom the ophthalm ic division o the trigem inal n., and the short ciliary nn. a ter traveling through the sym pathetic root that com m unicates with the ciliary ganglion. In the eye, the postganglionic f bers innervate the eye’s dilator pupillae m.

Course of Neuron

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

AUTONOMIC PATHWAYS • Parasympathetics of Cranial Nerve III With Corresponding Sympathetics

20

Ciliary ganglion Short ciliary nerves Sensory root of ciliary ganglion Sympathetic root of ciliary ganglion O culomotor nucleus Accessory oculomotor (Edinger-Westphal) Frontal nerve (cut) nucleus (parasympathetic) Lacrimal nerve (cut) Nasociliary nerve Oculomotor nerve (III) O phthalmic nerve (V1 )

Ciliary muscle Dilator muscle of pupil

Inferior division of oculomotor nerve

Sphincter muscle of pupil Efferent fibers Afferent fibers Sympathetic fibers Parasympathetic fibers

Parasympathetic root of ciliary ganglion

Figu re 20-7

AUTO NO MICS O F THE HEAD AND NECK 555

20

AUTONOMIC PATHWAYS • Parasympathetics of Cranial Nerve III With Corresponding Sympathetics

Sphincter muscle of pupil Short ciliary nerves

Dilator muscle of pupil

O culomotor (parasympathetic) root of ciliary ganglion

Accessory oculomotor (Edinger-Westphal) nucleus (parasympathetic)

Ciliary ganglion

Ciliary muscle

Superior colliculus Lateral geniculate body

?

? O ptic nerve (II)

O phthalmic nerve (V1 )

Nasociliary nerve Long ciliary nerve

Trigeminal ganglion

Nasociliary (sensory) root of ciliary ganglion

Internal carotid plexus

Sympathetic root of ciliary ganglion O phthalmic artery

Tympanic plexus

Tectospinal tract Thoracic part of spinal cord

Internal carotid artery

Superior cervical sympathetic ganglion 1st thoracic sympathetic trunk ganglion Gray ramus communicans Presynaptic Postsynaptic

Sympathetic fibers

Presynaptic Postsynaptic

Parasympathetic fibers

White ramus communicans T1 spinal nerve

Afferent fibers Visual pathway Descending pathway

Figu re 20-8

556

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

Presynaptic sympathetic cell bodies in intermediolateral nucleus (lateral horn) of gray matter

AUTONOMIC PATHWAYS • Parasympathetics of Cranial Nerve VII With Corresponding Sympathetics

20

ANATOMIC PATHWAY FOR PARASYMPATHETICS OF THE LACRIMAL, NASAL, PALATINE, PHARYNGEAL, SUBMANDIBULAR, AND SUBLINGUAL GLANDS Name of Cell Body

Characteristics of Cell Body

Preganglionic neuron

Superior salivatory nucleus

A collection o nerve cell bodies located in the pons Travel through the nervus interm edius o the acial n. into the internal acoustic m eatus In the acial canal, the acial n. gives rise to 2 parasym pathetic branches: • Greater petrosal n. • Chorda tym pani n.

Gre ate r Pe tro s al Ne rve Exits along the hiatus or the greater petrosal n. toward the oram en lacerum , where it joins the deep petrosal n. (sym pathetics) to orm the nerve o the pterygoid canal (vidian n.) Vidian n. passes through the pterygoid canal and enters the pterygopalatine ossa, where it joins with the pterygopalatine ganglion Cho rda Tympani Ne rve Exits the petrotym panic f ssure to enter the in ratem poral ossa, where it joins the lingual n. Preganglionic f bers travel with the lingual n. into the oor o the oral cavity, where it joins with the subm andibular ganglion

Postganglionic neuron

Pterygopalatine ganglion

A collection o nerve cell bodies located in the pterygopalatine ossa Postganglionic parasym pathetic f bers that arise in the pterygopalatine ganglion are distributed to the ophthalm ic and m axillary divisions o the trigem inal n. to the: • Lacrim al gland • Nasal glands • Palatine glands • Pharyngeal glands • Paranasal sinus glands

Ophthalmic and Maxillary Divis io n Dis tributio n Postganglionic f bers travel along the zygom atic branch o the m axillary division or a short distance to enter the orbit A short com m unicating branch joins the lacrim al n. o the ophthalm ic division o the trigem inal n. These f bers innervate: • Lacrim al gland to cause the secretion o tears Maxillary Divis io n Dis tributio n Postganglionic f bers travel along the m axillary division o the trigem inal n. to be distributed along its branches that are located in the nasal cavity, oral cavity, and pharynx (e.g., nasopalatine, greater palatine) These f bers innervate: • Nasal glands • Palatine glands • Pharyngeal glands • Paranasal sinus glands

Subm andibular ganglion

A collection o nerve cell bodies that is located in the oral cavity It is suspended rom the lingual n. at the posterior border o the m ylohyoid m . im m ediately superior to the deep portion o the subm andibular gland

Postganglionic parasym pathetic f bers arise in the subm andibular ganglion and are distributed to the: • Subm andibular gland • Sublingual gland

Type of Neuron

Course of Neuron

AUTO NO MICS O F THE HEAD AND NECK 557

20

AUTONOMIC PATHWAYS • Parasympathetics of Cranial Nerve VII With Corresponding Sympathetics

Trigeminal ganglion Deep petrosal nerve Greater petrosal nerve Chorda tympani nerve Trigeminal nerve (V) Facial nerve (VII) (intermediate nerve) Superior salivatory nucleus

O phthalmic nerve (V1 ) Mandibular nerve (V3 ) O tic ganglion Lingual nerve Maxillary nerve (V2 ) Nerve (vidian) of pterygoid canal Pterygopalatine ganglion Lacrimal gland

Descending palatine nerves Posterior nasal nerves

Pharyngeal nerve Maxillary artery Internal carotid nerve

Palatine nerves

Glossopharyngeal nerve (IX) Superior cervical sympathetic ganglion Sympathetic trunk

Greater Lesser

T1 and T2 spinal nerves Thoracic spinal cord

Submandibular ganglion

Dorsal root Sublingual gland White

Submandibular gland Facial artery

Gray

Rami communicantes

Lingual artery

Internal carotid artery

External carotid artery and plexus Common carotid artery

Ventral root

Sympathetic presynaptic cell bodies in intermediolateral nucleus (lateral horn) of gray matter

Sympathetic presynaptic fibers Sympathetic postsynaptic fibers Parasympathetic presynaptic fibers Parasympathetic postsynaptic fibers

Figu re 20-9

558

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AUTONOMIC PATHWAYS • Parasympathetics of Cranial Nerve VII With Corresponding Sympathetics

20

ANATOMIC PATHWAY FOR SYMPATHETICS OF THE LACRIMAL, NASAL, PALATINE, PHARYNGEAL, SUBMANDIBULAR, AND SUBLINGUAL GLANDS Type of Neuron

Name of Cell Body

Characteristics of Cell Body

Course of Neuron

Preganglionic neuron

Interm ediolateral horn nucleus

Collection o nerve cell bodies located in the lateral horn nucleus o the spinal cord between spinal segm ents T1 and T3 (and possibly T4)

Fibers arise rom the interm ediolateral horn nuclei rom T1 to T3 (or T4) Travel through the ventral root o the spinal cord to the spinal nerve Enter the sym pathetic chain via a white ram us com m unicans Once in the sym pathetic chain, the preganglionic f bers or the eye will ascend and synapse with postganglionic f bers in the superior cervical ganglion

Postganglionic neuron

Superior cervical ganglion

Collection o nerve cell bodies located in the superior cervical ganglion, which is located at the base o the skull Postganglionic sym pathetic f bers ollow the internal carotid or external carotid a. to pass near their respective e ector organs: • Nasal cavity • Paranasal sinuses • Palate • Lacrim al gland • Subm andibular gland • Sublingual gland

Nas al Cavity, Paranas al Sinus e s , and Palate • Postganglionic sym pathetic f bers ollow both the internal and external carotid aa. • Postganglionic f bers will orm the internal carotid nerve, which travels along the internal carotid a. orm ing the internal carotid plexus • Postganglionic sym pathetic f bers rom the internal carotid plexus branch in the region o the oram en lacerum to orm the deep petrosal n. • The deep petrosal n. joins the greater petrosal n. (parasym pathetics) to orm the nerve o the pterygoid canal (vidian n.) • Postganglionic sym pathetic f bers travel along the branches o the m axillary division o the trigem inal n. associated with the pterygopalatine ganglion to be distributed along its branches in the nasal cavity, paranasal sinuses, and palate • Postganglionic sym pathetic f bers rom the external carotid branch and ollow the m axillary a. • These f bers travel along the branches o the m axillary a. to be distributed along the nasal cavity, paranasal sinuses, and palate Lacrimal Gland • Postganglionic sym pathetic f bers ollow the internal carotid a. • Postganglionic sym pathetic f bers rom the internal carotid plexus branch o in the region o the oram en lacerum to orm the deep petrosal nerve • The deep petrosal n. joins the greater petrosal n. (parasym pathetics) to orm the nerve o the pterygoid canal (vidian n.) • Postganglionic f bers travel along the zygom atic branch o the m axillary division or a short distance to enter the orbit • A short com m unicating branch joins the lacrim al n. o the ophthalm ic division o the trigem inal n. • These f bers are distributed to the lacrim al gland Submandibular and Sublingual Glands • Postganglionic sym pathetic f bers ollow the external carotid a. • Postganglionic sym pathetic f bers branch o the external carotid to ollow the arteries that supply the subm andibular and sublingual glands

AUTO NO MICS O F THE HEAD AND NECK 559

20

AUTONOMIC PATHWAYS • Parasympathetics of Cranial Nerve VII With Corresponding Sympathetics

Superior salivatory nucleus (parasympathetic) Facial nerve (VII) Geniculum Greater petrosal nerve (parasympathetic) Deep petrosal nerve (sympathetic) Nerve (vidian) of pterygoid canal Maxillary nerve (V2 ) entering foramen rotundum Pterygopalatine ganglion in pterygopalatine fossa Lateral and medial posterior superior nasal branches in pterygopalatine fossa Infraorbital nerve Posterior superior and inferior lateral nasal nerves (cut ends)

Tympanic cavity

Medulla oblongata Spinal cord Sympathetic trunk

Internal carotid nerve Internal carotid artery

Greater and lesser palatine nerves

Superior cervical ganglion

Posterior superior alveolar nerves

Maxillary sinus

T1 T2 T3

Presynaptic sympathetic cell bodies in intermediolateral nucleus (lateral horn) of gray matter

Figu re 20-10

56 0 NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

Nasopalatine nerve

Postsynaptic fibers to vessels (sympathetic) and glands (parasympathetic) of nasal cavity, maxillary sinus, and palate Presynaptic parasympathetic fibers Postsynaptic parasympathetic fibers Presynaptic sympathetic fibers Postsynaptic sympathetic fibers

AUTONOMIC PATHWAYS • Parasympathetics of Cranial Nerve VII With Corresponding Sympathetics

Greater petrosal nerve

Trigeminal nerve (V)

Sensory root Motor root Ganglion

Internal carotid artery and plexus

Deep petrosal nerve Nerve (vidian) of pterygoid canal O culomotor nerve (III) Maxillary nerve (V2 )

Nasociliary nerve Sensory Sympathetic Parasympathetic

O phthalmic nerve (V1 )

20

Roots of ciliary ganglion

Ciliary ganglion Long ciliary nerve

Facial nerve (VII)

Short ciliary nerves

Vestibulocochlear nerve (VIII) Glossopharyngeal nerve (IX) Vagus nerve (X) Mandibular nerve (V3 ) O tic ganglion Internal carotid nerve Chorda tympani nerve

Pterygopalatine ganglion

Superior cervical sympathetic ganglion

Internal carotid artery and plexus Submandibular ganglion

Pharyngeal plexus Cervical sympathetic trunk

Maxillary artery and plexus External carotid artery and plexus

Middle meningeal artery and plexus Facial artery and plexus

Common carotid artery and plexus

Figu re 20-11

AUTO NO MICS O F THE HEAD AND NECK 561

20

AUTONOMIC PATHWAYS • Parasympathetics of Cranial Nerve IX With Corresponding Sympathetics ANATOMIC PATHWAY FOR PARASYMPATHETICS OF THE PAROTID GLAND Type of Neuron

Name of Cell Body

Characteristics of Cell Body

Preganglionic neuron

In erior salivatory nucleus

A collection o nerve cell bodies located in the m edulla

Preganglionic parasym pathetic f bers arise rom the in erior salivatory nucleus in the m edulla Travel through the glossopharyngeal n. and exit the jugular oram en Gives rise to the tym panic branch o IX, which reenters the skull via the tym panic canaliculus The tym panic branch o IX orm s the tym panic plexus along the prom ontory o the ear The plexus re- orm s as the lesser petrosal n., which typically exits the oram en ovale to enter the in ratem poral ossa Lesser petrosal n. joins the otic ganglion

Postganglionic neuron

Otic ganglion

A collection o nerve cell bodies located in erior to the oram en ovale m edial to the m andibular division o the trigem inal n.

Postganglionic parasym pathetic f bers arise in the otic ganglion These f bers travel to the auriculotem poral branch o the trigem inal n. Auriculotem poral n. travels to the parotid gland Postganglionic parasym pathetic f bers innervate the: • Parotid gland

Course of Neuron

ANATOMIC PATHWAY FOR SYMPATHETICS OF THE PAROTID GLAND

562

Type of Neuron

Name of Cell Body

Characteristics of the Cell Body

Preganglionic neuron

Interm ediolateral horn nucleus

Collection o nerve cell bodies located in the lateral horn nucleus o the spinal cord between spinal segm ents T1 and T3 (and possibly T4)

Fibers arise rom the interm ediolateral horn nuclei rom T1 to T3 (or T4) Travel through the ventral root o the spinal cord to the spinal n. Enter the sym pathetic chain via a white ram us com m unicans Once in the sym pathetic chain, the preganglionic f bers or the eye will ascend and synapse with postganglionic f bers in the superior cervical ganglion

Postganglionic neuron

Superior cervical ganglion

Collection o nerve cell bodies located in the superior cervical ganglion, which is located at the base o the skull

Fibers arise in the superior cervical ganglion Postganglionic f bers will ollow the external carotid a. Branches rom the external carotid a. ollow the arteries that supply the parotid gland

Course of the Neuron

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AUTONOMIC PATHWAYS • Parasympathetics of Cranial Nerve IX With Corresponding Sympathetics

20

Trigeminal ganglion

Mandibular nerve (V3 )

Lesser petrosal nerve

O tic ganglion

Chorda tympani nerve O phthalmic nerve (V1 )

Trigeminal nerve (V)

Maxillary nerve (V2 )

Facial nerve (VII) Glossopharyngeal nerve (IX)

Auriculotemporal nerve

Inferior salivatory nucleus

Superficial temporal artery

Pons

Parotid gland Maxillary artery Medulla oblongata Tympanic plexus Inferior alveolar nerve

Tympanic nerve (Jacobson) Inferior ganglion (IX)

Lingual nerve

Superior cervical sympathetic ganglion Sympathetic trunk T1 and T2 spinal nerves Thoracic spinal cord

External carotid artery

Dorsal root Internal carotid artery

Common carotid artery White

Gray

Rami communicantes Sympathetic presynaptic fibers Sympathetic postsynaptic fibers Parasympathetic presynaptic fibers Parasympathetic postsynaptic fibers

Ventral root

Sympathetic presynaptic cell bodies in intermediolateral nucleus (lateral horn) of gray matter

Figu re 20-12

AUTO NO MICS O F THE HEAD AND NECK 563

20

AUTONOMIC PATHWAYS • Parasympathetics of Cranial Nerve IX With Corresponding Sympathetics

Tympanic nerve (Jacobson) Tympanic cavity and plexus

Inferior salivatory nucleus

Efferent fibers Afferent fibers Parasympathetic fibers

Lesser petrosal nerve

Caroticotympanic nerve (from internal carotid plexus)

Pterygopalatine ganglion Mandibular nerve (V3 ) O tic ganglion Auriculotemporal nerve Parotid gland

Stylopharyngeus muscle (and branch from glossopharyngeal nerve)

Glossopharyngeal nerve (IX) Jugular foramen

Superior and Inferior ganglia of Glossopharyngeal nerve Taste and somatic sensation: posterior 1 ⁄ of tongue 3

Vagus nerve (X) Superior cervical sympathetic ganglion Sympathetic trunk

Internal carotid artery Carotid sinus Carotid body Common carotid artery External carotid artery

Figu re 20-13

564

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AUTONOMIC PATHWAYS • Cranial Nerve X

20

ANATOMIC PATHWAY FOR PARASYMPATHETICS OF THE VAGUS NERVE* Characteristics of Cell Body

Type of Neuron

Name of Cell Body

Course of Neuron

Preganglionic neuron

Dorsal m otor nucleus

A collection o nerve cell bodies located in the m edulla

Preganglionic f bers arise rom the dorsal m otor nucleus o the vagus in the m edulla* Travel through the vagus n. and exit the jugular oram en Various branches connect to intram ural ganglia in the thorax and derivatives o both the oregut and m idgut o the abdom en

Postganglionic neuron

Intram ural ganglion

A collection o nerve cell bodies located within the walls o the individual organ

Postganglionic f bers arise in the intram ural ganglia These f bers travel to the various e ector organs: • Cardiac m uscle • Sm ooth m uscle • Glands

*The vagus n. arises in the brainstem but provides parasympathetic innervation to the thorax and greater part of the abdomen, rather than the head and neck. The sympathetics that follow the vagus n. to the thorax and greater part of the abdomen, as well as the sympathetics that follow the parasympathetic pelvic splanchnic nerves, arise from the various paravertebral and prevertebral ganglia associated with the sympathetic chain.

Posterior nucleus of vagus nerve (parasympathetic and visceral afferent)

Vagus nerve (X) Jugular foramen Superior ganglion of vagus nerve Inferior ganglion of vagus nerve

Superior cervical cardiac branch of vagus nerve Inferior cervical cardiac branch of vagus nerve Thoracic cardiac branch of vagus nerve Pulmonary plexus Cardiac plexus Esophageal plexus Gastric branches of anterior vagal trunk (branches from posterior trunk behind stomach) Vagal branches (parasympathetic motor, secretomotor and afferent fibers) accompany superior mesenteric artery and its branches usually as far as left colic (splenic) flexure Small intestine Efferent fibers Afferent fibers Parasympathetic fibers

Figu re 20-14

AUTO NO MICS O F THE HEAD AND NECK 565

20

CLINICAL CORRELATE • Horner’s Syndrome • •

• • •

Resu lts from in ju ry or u n d u e stim u lu s to th e sym p ath etic n erves of th e h ead an d n eck Cau ses m ay in clu d e: • Stroke • Neck trau m a • Carotid artery in ju ry • Pan coast tu m or • Clu ster h eadach es Ph arm acologic tests can h elp localize th e affected p art of th e sym p ath etic p ath way Treatm en t d ep en d s on th e cau se (e.g., rem oval of a tu m or) Clin ical m an ifestation s in clu de: • Miosis (con striction of p u p il) • Ptosis (d roop in g of eyelid ) • An h id rosis (d ecreased sweatin g)

Horner’s syndrome; wasting, pain, paresthesias and paresis of arm and hand

Horner syndrome Right-sided Horner syndrome

Normal left eye

Ptosis Miosis Central or Preganglionic lesion

Postganglionic lesion

Cocaine drops

Cocaine drops

N o effect

Dilation

Hydroxyamphetamine drops

Dilation

Dilation

Phenylephrine drops

N o effect

N o effect

N o effect

Hydroxyamphetamine drops

N o effect

Dilation

Phenylephrine drops

Dilation

Figu re 20-15

566

Dilation

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

N o effect

CHAPTER 21

INTRAORAL INJECTIONS

Overview and Topographic Anatomy

56 8

Mandibular Injections

569

Maxillary Injections

578

Supplemental Injections

587

21

OVERVIEW AND TOPOGRAPHIC ANATOMY • General Information • • • • •

In traoral in jection s p rovide ad eq u ate p ain con trol or variou s den tal p rocedu res Man y tech n iq u es h ave been develop ed All req u ire d etailed u n d erstan din g o h ead an d n eck an atom y to m axim ize likelih ood o p rop er adm in istration an d to m in im ize com p lication s In jection s sh ou ld n ot be p er orm ed in areas o in ection or in f am m ation Th e ap p lication o top ical an esth etic to th e site o in jection will h elp lessen th e p ain cau sed by in sertion o th e n eed le

CLASSIFICATION

•

•

Field blocks: Local an esth etic is p laced n ear larger term in al n erve bran ch es (located at th e ap ex o th e tooth ) in stead o by th e term in al n erve en d in gs (a eld block will typ ically a ect th e area arou n d 1 or 2 teeth —d en tal p u lp an d associated so t tissu e) Nerve blocks: Local an esth etic is p laced n ear th e m ain n erve tru n k (su ch as with th e in erior alveolar n erve block)

COMMON BLOCKS

•

•

Man dibu lar • In erior alveolar n erve • Lon g bu ccal n erve • Men tal n erve • Gow-Gates • Akin osi Maxillary • Posterior su p erior alveolar n erve • Nasop alatin e n erve • Greater p alatin e n erve • In raorbital n erve • Maxillary d ivision

Figu re 21-1

56 8 NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

MANDIBULAR INJECTIONS • Innervation and Osteology Landmarks

21

MANDIBLE: GENERAL CONSIDERATIONS AND LANDMARKS

• • • • •

Th e stron gest an d largest facial bon e Com p osed of 2 p ieces of th ick cortical bon e: a lin gu al p late an d a bu ccal p late Teeth are con tain ed in th e h orsesh oe-sh ap ed bod y Ram u s exten d s su p eriorly from th e an gle of th e m an d ible Th e coron oid n otch is th e con cavity on th e an terior p ortion of th e ram u s u sed to estim ate th e h eigh t of th e m an d ibu lar foram en , wh ich also is located at th e h eigh t of th e occlu sal p lan e

ASSOCIATED NERVES

• • •

In ferior alveolar n erve en ters th e m an d ible at th e m an d ibu lar foram en Lin gu al n erve en ters th e oral cavity p assin g again st th e lin gu al tu berosity Bu ccal n erve lies on th e bu ccal sh elf

Head Pterygoid fovea

Condylar process Coronoid process Mandibular notch Mylohyoid groove

Neck Lingula Mandibular foramen

O blique line Submandibular fossa Mylohyoid line Sublingual fossa Interalveolar septa

Ramus Alveolar part (crest) Mental foramen Mental protuberance Mental tubercle Base of mandible

Angle

Body Head Coronoid process Neck Mandibular notch Pterygoid fovea Mylohyoid line

Mandible of adult: anterolateral superior view

Condylar process Lingula Mandibular foramen Mylohyoid groove

Lingula (covering the opening of the mandibular foramen)

Ramus Chorda tympani Inferior nerve

Mental spines

Angle y Submandibular Bo d fossa Sublingual fossa Digastric fossa

Mandible of adult: left posterior view

Lingual nerve Buccal nerve

Mental nerve

Mylohyoid nerve

Condyle

Coronoid process

Buccal shelf Mental foramen

Figu re 21-2

INTRAO RAL INJECTIO NS

569

21

MANDIBULAR INJECTIONS • Inferior Alveolar Nerve Block OVERVIEW • This block is im portant to m aster, because clinically acceptable m andibular anesthesia is m ore dif cult to achieve than m axillary anesthesia owing to the thickness of the cortical bone • Requires anesthetic deposition in the pterygom andibular space at the region of the m andibular foram en lateral to the sphenom andibular ligam ent • Requires proper needle penetration and correct needle angulation in the pterygom andibular space • Properly perform ed, it anesthetizes 2 nerves: • Inferior alveolar nerve (and its branches—the incisive and m ental nerves) • Lingual nerve • Areas anesthetized: • All m andibular teeth (inferior alveolar nerve) • Epithelium of the anterior 2/ 3 of the tongue (lingual nerve) • All lingual gingiva and lingual m ucosa (lingual nerve) • All buccal gingiva and m ucosa from the prem olars to the m idline (m ental nerve) • Skin of the lower lip (m ental nerve)

GENERAL METHODOLOGY—STEPS • Insert the needle into the m ucosa between the deepest portion of the coronoid notch (which should represent the vertical height of the m andibular foram en) and just lateral to the pterygom andibular raphe • Orient the needle from the contralateral prem olars and advance it along the occlusal plane of the m andible • The needle contacts the m andible after entering 20 to 25 m m (if bone is contacted im m ediately on penetration into the m ucosa, then the tem poral crest has been contacted; the needle should be reoriented to allow insertion to the proper depth) • Withdraw the needle slightly and perform aspiration to determ ine whether the needle is in a blood vessel (inferior alveolar vessels) • After obtaining a negative result on aspiration (no blood observed in the syringe), slowly inject the anesthetic into the pterygom andibular space • If the result of aspiration is positive, readjust the needle position and perform aspiration again before injecting into the pterygom andibular space

CONSIDERATIONS • In children, the m andibular foram en is located closer to the posterior border of the m andible until m ore bone is added with age • In edentulous patients, the alveolar bone is lost; thus, the deepest part of the coronoid notch is lower than norm al, which could lead the clinician to aim the needle too low • In class II m alocclusion, when the m andible is hypoplastic, the m andibular foram en is typically located m ore inferior than the clinician m ay think • In class III m alocclusion, when the m andible is hyperplastic, the m andibular foram en is typically located m ore superior than the clinician m ay think • A transient, dental procedure–induced Bell’s palsy can result if the needle is placed too far posteriorly in the parotid bed and anesthetic is introduced close to the facial nerve

570

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MANDIBULAR INJECTIONS • Inferior Alveolar Nerve Block

21

Chorda tympani nerve Inferior alveolar nerve

Buccal nerve

Masseteric nerve Inferior alveolar nerve

Incisive nerve

Mental nerve

Area anesthetized with an inferior alveolar nerve block Pterygomandibular raphe Medial pterygoid Inferior alveolar n., a., and v. Lingual nerve Needle in pterygomandibular space Buccal nerve Buccinator

Pterygomandibular raphe Buccal nerve

Sphenomandibular ligament

Buccinator

Inferior alveolar nerve Stylomandibular ligament Genioglossus Geniohyoid

Medial pterygoid Lingual nerve Mylohyoid muscle and nerve Anterior digastric

Thumb is placed in coronoid notch Pterygomandibular raphe

Figu re 21-3

INTRAO RAL INJECTIO NS

571

21

MANDIBULAR INJECTIONS • Long Buccal Nerve Block OVERVIEW • A branch of the m andibular division of the trigem inal nerve, the long buccal nerve is not anesthetized in an inferior alveolar injection • This block anesthetizes all buccal gingiva opposite the m andibular m olars, including the retrom olar trigone

GENERAL METHODOLOGY—STEPS • Insert the needle into the m ucosa posterior to the last m olar in the m andibular arch on the buccal side (the needle will be inserted a very short distance—about 2 m m ) • Perform aspiration; after obtaining a negative result, inject the anesthetic

CONSIDERATIONS • A hem atom a is rare with this block • This injection seldom fails

Condyle Coronoid process

Lingula Chorda (covering tympani the opening Inferior nerve of the mandibular Mylohyoid nerve foramen)

Lingual nerve Buccal nerve Needle on buccal shelf

Buccal shelf Mental foramen Area anesthetized by a long buccal injection

Pterygomandibular raphe

Mental nerve

Medial pterygoid Inferior alveolar n., a., and v. Lingual nerve Buccal nerve Needle penetrating the mucosa Buccinator

Figu re 21-4

572

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MANDIBULAR INJECTIONS • Mental Nerve Block

21

OVERVIEW • A branch of the inferior alveolar nerve within the m andibular canal • Areas anesthetized: • All buccal gingiva and m ucosa from the prem olars to the m idline (m ental nerve) • Skin of the lower lip (m ental nerve)

GENERAL METHODOLOGY—STEPS • Locate the m ental foram en by m eans of palpation • Insert the needle into the m ucosa at the m ucobuccal fold at the location of the m ental foram en (norm ally around the 2nd m andibular prem olar) (the needle will be inserted a short distance in the direction of the m ental foram en) • Perform aspiration; after obtaining a negative result, slowly inject the anesthetic

CONSIDERATIONS • • • •

X-ray im aging can help the clinician locate the m ental foram en if palpation does not do so This block seldom fails to achieve excellent dental anesthesia Often not effective for surgical procedures Risk of dam aging the nerve if the needle drops into the m ental foram en

Area anesthetized by a nerve injection Chorda tympani nerve

Buccal nerve

Masseteric nerve

Inferior alveolar nerve

Mental nerve Mental block

Incisive nerve

Figu re 21-5

INTRAO RAL INJECTIO NS

573

21

MANDIBULAR INJECTIONS • Gow-Gates Block OVERVIEW • A variation of the inferior alveolar nerve block, it anesthetizes the following nerves: • Inferior alveolar nerve (and its branches, the m ental and incisive nerves) • Mylohyoid nerve • Lingual nerve • Long buccal nerve • Auriculotem poral nerve • Low positive aspiration rate relative to that for the standard inferior alveolar nerve block injection • When the injection is properly adm inistered, the needle contacts the neck of the m andibular condyle • Areas anesthetized: • All m andibular teeth (inferior alveolar nerve) • Epithelium of the anterior 2/ 3 of the tongue (lingual nerve) • All lingual gingiva and lingual m ucosa (lingual nerve) • All buccal gingiva and m ucosa (long buccal and m ental nerves) • Skin of the lower lip (m ental nerve) • Skin along the tem ple, anterior to the ear, and posterior part of the cheek (auriculotem poral and buccal nerves)

GENERAL METHODOLOGY—STEPS • The m outh is opened as wide as possible • Insert the needle high into the m ucosa at the level of the 2nd m axillary m olar just distal to the m esiolingual cusp • Use the intertragic notch as an extraoral landm ark to help reach the neck of the m andibular condyle • Advance the needle in a plane from the corner of the m outh to the intertragic notch from the contralateral prem olars (this position varies in accordance with individual are of the m andible) until it contacts the condylar neck • Withdraw the needle slightly and perform aspiration to observe whether the needle is in a blood vessel • After obtaining a negative result on aspiration, slowly inject the anesthetic • Have the patient keep the m outh open for a few m inutes after injection to allow the anesthetic to diffuse around the nerves

CONSIDERATIONS • Useful for m ultiple procedures on m andibular teeth and buccal soft tissue • Few com plications • Works well for a bi d inferior alveolar nerve

574

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

MANDIBULAR INJECTIONS • Gow-Gates Block

21

Corner of mouth

Area anesthetized by a Gow-Gates injection

Condyle Intertragic notch

Chorda tympani nerve

Buccal nerve Masseteric nerve

Inferior alveolar nerve

Incisive nerve

Figu re 21-6

INTRAO RAL INJECTIO NS

575

21

MANDIBULAR INJECTIONS • Akinosi Block OVERVIEW • A closed-m outh approach for the m andibular nerve block, it anesthetizes the following nerves: • Inferior alveolar nerve (and its branches, the m ental and incisive nerves) • Mylohyoid nerve • Lingual nerve • Useful when m andibular depression (opening) is lim ited, such as with trism us • Considered a “blind” injection • Areas anesthetized: • All m andibular teeth (inferior alveolar nerve) • Epithelium of the anterior 2/ 3 of the tongue (lingual nerve) • All lingual gingiva and lingual m ucosa (lingual nerve) • All buccal gingiva and m ucosa from the prem olars to the m idline (m ental nerve) • Skin of the lower lip (m ental nerve)

GENERAL METHODOLOGY—STEPS • Have the patient close the m outh • Insert the needle into the m ucosa between the m edial border of the m andibular ram us and the m axillary tuberosity at the level of the cervical m argin of the m axillary m olars • Advance the needle parallel to the m axillary occlusal plane • Once the needle is advanced approxim ately 23 to 25 m m , it should be located in the m iddle of the pterygom andibular space near the inferior alveolar and lingual nerves (Note: no bone will be contacted) • After a negative result on aspiration, slowly inject the anesthetic

CONSIDERATIONS • Often used in patients with a lim ited ability to open the m outh and when intraoral landm arks for a standard inferior alveolar nerve block are dif cult to view • A transient, dental procedure–induced Bell’s palsy can result if the needle is placed too far posteriorly in the parotid bed and anesthetic is introduced close to the facial nerve • Good for patients with a strong gag ref ex or m acroglossia

Figu re 21-7

576

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

MANDIBULAR INJECTIONS • Akinosi Block

21

Chorda tympani nerve

Area anesthetized by an Akinosi injection

Inferior alveolar nerve Buccal nerve

Mental nerve Incisive nerve

Masseteric nerve Inferior alveolar nerve

Pterygomandibular raphe Medial pterygoid Inferior alveolar n., a., and v. Lingual nerve Buccal nerve

Buccinator

Figu re 21-8

INTRAO RAL INJECTIO NS

577

21

MAXILLARY INJECTIONS • Innervation and Osteology Landmarks MAXILLA: GENERAL CONSIDERATIONS

• •

1 of th e largest facial bon es Porou s bon e, wh ich aid s in ach ievin g an esth esia of th e m axillary teeth

TEETH

• •

Con tain ed in th e alveolar bon e Maxillary teeth are su p p lied by th e an terior, m idd le, an d p osterior su p erior alveolar n erves (in som e p atien ts, th e m id dle su p erior alveolar n erve m ay n ot be p resen t)

HARD PALATE

• •

Com p osed of th e p alatal p rocess of th e m axilla an d th e h orizon tal p late of th e p alatin e Su p p lied by th e n asop alatin e an d greater p alatin e n erves

Inferior palpebral nerve Infraorbital nerve External nasal nerve Superior labial nerve

Nasopalatine nerve

Greater palatine nerve

Lesser palatine nerve

Soft palate

Figu re 21-9

578

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

MAXILLARY INJECTIONS • Innervation and Osteology Landmarks

21

Foramen ovale Foramen spinosum Spine of sphenoid bone

Sphenopalatine foramen Pterygopalatine fossa Choanae (posterior nares) Lateral plate Medial plate Tuberosity of maxilla Infratemporal fossa

of pterygoid process

Hamulus Pyramidal process of palatine bone

Alveolar process of maxilla

Infraorbital nerve Maxillary nerve

Middle superior alveolar nerve

Posterior superior alveolar nerve

Anterior superior alveolar nerve

Figu re 21-10

INTRAO RAL INJECTIO NS

579

21

MAXILLARY INJECTIONS • Posterior Superior Alveolar Nerve Block OVERVIEW • A frequently used block • The injection is in the infratem poral fossa • Areas anesthetized: • All m axillary m olars, with the possible exception of the m esiobuccal root of the 1st m axillary m olar • Buccal gingiva opposite the teeth

GENERAL METHODOLOGY—STEPS • With the m outh open, the patient is instructed to deviate the m andible toward the sam e side as the injection, to produce m ore work space for the clinician • Insert the needle into the m ucosa at the m ucobuccal fold just superior to the m axillary 2nd m olar, between the m edial border of the ram us of the m andible and the m axillary tuberosity • In a single m otion, the needle needs to be advanced approxim ately 15 m m in the following x-y-z plane at the sam e tim e, to reach the posterior superior alveolar nerve along the posterior surface of the m axilla: • Medially at a 45-degree angle to the m axillary occlusal plane • Superiorly at a 45-degree angle to the m axillary occlusal plane • Posteriorly at a 45-degree angle to the m axillary occlusal plane • Perform aspiration owing to the close proxim ity of the pterygoid plexus • After obtaining a negative result on aspiration, slowly inject the anesthetic

CONSIDERATIONS • Signi cant potential for form ation of a hem atom a involving the pterygoid plexus • Short needles are preferred, to reduce the risk of hem atom a • Frequent occurrence of a positive result on aspiration

May not always anesthetize the mesiobuccal root of the 1st maxillary molar

Area anesthetized by a posterior superior alveolar injection May not always anesthetize the mesiobuccal root of the 1st maxillary molar

Area anesthetized by a posterior superior alveolar injection

Figu re 21-11

58 0 NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

MAXILLARY INJECTIONS • Nasopalatine Nerve Block

21

OVERVIEW • Considered the m ost painful of dental injections • Because of the sensitivity of the area, pressure anesthesia (e.g., using a cotton swab applicator) is helpful at the site of injection • Areas anesthetized: • The area’s palatal gingiva and m ucosa from the m axillary canine on the right to the m axillary canine on the left side of the m axilla • Both the right and left nasopalatine nerves, because they exit onto the hard palate in close proxim ity • Oral m ucosa in this region is tightly adherent to the hard palate; thus deposition of anesthetic in the area has less space to diffuse

GENERAL METHODOLOGY—STEPS • Use a cotton swab applicator to apply pressure to the injection site • Insert the needle into the palatal m ucosa lateral to the incisive papilla • Deposit a sm all am ount of anesthetic to help lessen the traum a; the vasoconstrictor norepinephrine then causes the area’s soft tissue to blanch • Advance the needle until it contacts the hard palate • Withdraw the needle slightly and perform aspiration • After obtaining a negative result on aspiration, very slowly inject the anesthetic

CONSIDERATIONS • Pressure anesthesia is bene cial to help lessen the pain • Because the tissue is so dense and is attached to the bone, this block requires a slow injection • For surgical procedures, the nasopalatine nerve block often does not provide profound palatal anesthesia, so the initial injection should be followed by in ltration of the palatal gingiva of the surgical site for best effect

Nasopalatine nerve

Area anesthetized by a nasopalatine injection Greater palatine nerve

Figu re 21-12

INTRAO RAL INJECTIO NS

581

21

MAXILLARY INJECTIONS • Great Palatine Nerve Block OVERVIEW • Another com m only used block to anesthetize areas of the hard palate • Not as traum atic for the patient as the nasopalatine nerve block • Because of the sensitivity of the area, pressure anesthesia (e.g., using a cotton swab applicator) is helpful at the site of injection • Areas anesthetized: • Palatal gingiva and m ucosa in the area from the m axillary 1st prem olar (anteriorly) to the posterior portion of the hard palate to the m idline

GENERAL METHODOLOGY—STEPS • Locate the greater palatine foram en by using a cotton swab applicator to press down on the tissue in the region of the 1st m axillary m olar, m oving posteriorly until the swab dips into the tissue (usually posterior to the 2nd m axillary m olar) • Use a cotton swab applicator to apply pressure to the injection site • Insert the needle and inject a sm all am ount of anesthetic to lessen patient discom fort; the tissue of the area will begin to blanch from the effects of the anesthetic agent • Advance the needle until it contacts the hard palate • Withdraw the needle slightly and perform aspiration • After obtaining a negative result on aspiration, slowly inject the anesthetic

CONSIDERATIONS • The clinician should be able to feel the needle contact bone; otherwise, the needle could be too posterior in the soft palate • For surgical procedures, the greater palatine nerve block often does not provide profound palatal anesthesia, so the initial injection should be followed by in ltration of the palatal gingiva of the surgical site for best effect

Nasopalatine nerve Greater palatine nerve

Area anesthetized by a greater palatine injection

Lesser palatine nerve

Figu re 21-13

582

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

MAXILLARY INJECTIONS • Middle Superior Alveolar Nerve Block

21

OVERVIEW • The m iddle superior alveolar nerve is reported to be present in about 30% of all people • Areas anesthetized: • All m axillary prem olars and possibly the m esiobuccal root of the 1st m axillary m olar • Buccal gingiva opposite the teeth

GENERAL METHODOLOGY—STEPS • Insert the needle into the m ucosa at the m ucobuccal fold just superior to the area of the m axillary 2nd prem olar • Advance the needle until the tip is superior to the apex of the m axillary 2nd prem olar for m axim um anesthesia • After obtaining a negative result on aspiration, slowly inject the anesthetic

CONSIDERATIONS • Local in ltrations are a com m on substitute for this block • This area is som ewhat avascular, and hem atom a form ation is rare

Maxillary nerve

Anterior superior alveolar nerve

Posterior superior alveolar nerve Infraorbital nerve Middle superior alveolar nerve

Area anesthetized by a middle superior alveolar injection

Area anesthetized by a middle superior alveolar injection

Figu re 21-14

INTRAO RAL INJECTIO NS

583

21

MAXILLARY INJECTIONS • Infraorbital/Anterior Superior Alveolar Nerve Block OVERVIEW • Less frequently used because of associated risk of injury to the patient’s eye • This block anesthetizes the following nerves: • Anterior superior alveolar nerve • Middle superior alveolar nerve (when present) • Infraorbital nerve • Areas anesthetized: • All m axillary teeth from the central incisor to the prem olars, with the possible inclusion of the m esiobuccal root of the 1st m axillary m olar • Buccal gingiva opposite these teeth • Lateral aspect of nose, lower eyelid, and upper lip

GENERAL METHODOLOGY—STEPS • Locate the infraorbital foram en by m eans of palpation • Insert the needle into the m ucosa at the m ucobuccal fold in the area superior to the 1st m axillary prem olar • Advance the needle parallel to the long axis of the tooth until it contacts the bone of the infraorbital foram en • After obtaining a negative result on aspiration, slowly inject the anesthetic

CONSIDERATIONS • No signi cant potential for a hem atom a • Useful when pulpal anesthesia cannot be achieved in a local in ltration because of dense bone or when anesthesia is required on m ultiple teeth that would require m ore than 1 injection • Also useful for dealing with infected teeth/ abscess

Area anesthetized by an anterior superior injection

Inferior palpebral nerve Infraorbital nerve External nasal nerve Superior labial nerve

Figu re 21-15

584

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MAXILLARY INJECTIONS • Maxillary Division Block

21

OVERVIEW • • • •

An excellent technique to achieve hem im axillary anesthesia Anesthetizes all of the branches of the m axillary division of the trigem inal nerve Useful in extensive quadrant procedures and surgery With blocking of the entire division, the following nerves are anesthetized: • Posterior superior alveolar nerve • Middle superior alveolar nerve • Anterior superior alveolar nerve • Nasopalatine nerve • Greater palatine nerve • Infraorbital nerve • Areas anesthetized: • All m axillary teeth • All buccal gingiva • All palatal gingiva and m ucosa • Lateral aspect of nose, lower eyelid, and upper lip

GENERAL METHODOLOGY—STEPS • Go al: to deposit the anesthetic in the pterygopalatine fossa using its eventual connection with the greater palatine foram en • Locate the greater palatine foram en by using a cotton swab applicator to press in the region of the 1st m axillary m olar, m oving posteriorly until the swab dips into the tissue (usually posterior to the 2nd m axillary m olar) • Use a cotton swab applicator to apply pressure to the injection site • Insert the needle into the m ucosa and inject a sm all am ount of anesthetic to lessen patient discom fort; the tissue will begin to blanch as a result of effects of the anesthetic agent • Insert the needle further and locate the greater palatine foram en with the needle • Once the foram en is located, insert the needle and advance it approxim ately 28 to 30 m m ; at this location, the needle should be in the pterygopalatine fossa • During the passage, if any bony resistance is m et, the needle m ay be rotated to aid insertion (Note: under no circum stances should the needle be forced) • After obtaining a negative result on aspiration, slowly inject the anesthetic

CONSIDERATIONS • The needle should never be forced into the greater palatine foram en, because occasionally the canal is not vertical, so that forced entry will fracture the bone • Because the orbit is located superior to the pterygopalatine fossa, if the needle is placed too far superiorly, the anesthetic can be deposited in this region, affecting the eye • Because the palatine vessels also are contents of the canal, care m ust be taken to prevent hem atom a • Also useful for dealing with infected teeth/ abscess

INTRAO RAL INJECTIO NS

585

21

MAXILLARY INJECTIONS • Maxillary Division Block

Area anesthetized by a maxillary division injection

Area anesthetized by a maxillary division injection

Nasopalatine nerve

Greater palatine nerve

Soft palate Lesser palatine nerve

Figu re 21-16

58 6 NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

SUPPLEMENTAL INJECTIONS • General Considerations and Landmarks • • •

•

•

21

Ach ievin g adeq u ate p u lp al an esth esia in th e m an d ible can be ch allen gin g for a variety of reason s As a resu lt, a series of su p p lem en tal in jection tech n iq u es are available for u se wh en stan d ard tech n iq u es h ave failed Ad dition ally, th ere are occasion s in wh ich m an dibu lar m olars in op p osite q u ad ran ts req u ire treatm en t, an d p erform in g an in ferior alveolar n erve block in both q u ad ran ts wou ld p rod u ce p rofou n d soft tissu e sen sory an esth esia, wh ich th e p atien t wou ld n d very u n com fortable Th ere are 4 su p p lem en tal in jection s in com m on u se: • Period on tal ligam en t (PDL) in jection —excellen t for p u lp al an esth esia of th e m an d ible on sp eci c teeth • In trasep tal in jection —u sefu l for p eriod on tal su rgery • In traosseou s in jection —req u ires a h ole in th e in tersep tal bon e, so m an y clin ician s p refer sp ecialized d elivery system s for th is tech n iq u e • In trap u lp al in jection —u sefu l for en d od on tic treatm en t, bu t p ain fu l on in itiation of th e in jection On ly th e PDL in jection is d iscu ssed in th is ch ap ter, becau se of its overall ease of u se an d ap p lication in gen eral d en tistry

INTRAO RAL INJECTIO NS

587

21

SUPPLEMENTAL INJECTIONS • Periodontal Ligament (PDL) Injection OVERVIEW • • • • •

The PDL injection allows the clinician to achieve pulpal anesthesia of a single tooth An excellent choice when treatm ent of speci c teeth in both m andibular quadrants is required Less soft tissue anesthesia is present Can use traditional syringe or special syringes Areas anesthetized: • Pulpal and apical tissue • Soft tissue and bone of injection site

GENERAL METHODOLOGY—STEPS • Insert the needle interproxim ally along the vertical axis of the tooth • Because each root needs to be anesthetized, the needle can be inserted: • Single-root tooth—on m esial o r distal root • Multi-root tooth—on m esial and distal roots • Advance the needle until the tip is at the level of the gingival sulcus—the needle will resist further insertion • Very slowly inject the anesthetic

CONSIDERATIONS • The root of each tooth m ust be anesthetized • There is no positive aspiration with this injection • Dif cult to reach 2nd and 3rd m andibular m olars with this technique

Figu re 21-17

58 8 NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

CHAPTER 22

INTRODUCTION TO THE UPPER LIMB, BACK, THORAX, AND ABDOMEN

Overview and Topographic Anatomy

59 0

Osteology

592

Muscles

6 02

Contents of the Thorax

616

Contents of the Abdomen

623

Contents of the Pelvis

634

Vascular Supply

636

Nerve Supply

649

22

OVERVIEW AND TOPOGRAPHIC ANATOMY • General Information UPPER LIMB

•

• • •

Th e u p p er lim b is th e region of th e bod y com p osed of th e: • Pectoral gird le • Brach iu m (arm ) • An tebrach iu m (forearm ) • Carp u s, m etacarp u s, p h alan ges (wrist an d h an d) It is a very m obile stru ctu re th at allows m an ip u lation of objects All m otor an d sen sory in n ervation is d erived from th e brach ial p lexu s, wh ich arises from th e ven tral ram i of C5 to T1 It is a freq u en t site of trau m atic in ju ry

BACK AND THORAX

•

Th e th oracic cavity is d ivided in to: • 2 p leu ral cavities • Med iastin u m

ANTEROLATERAL ABDOMINAL WALL

•

Layers of th e an terolateral abd om in al wall: • Skin • Su p er cial fascia • Fatty su p er cial layer (Cam p er’s) • Mem bran ou s su p er cial layer (Scarp a’s) • Extern al obliq u e • In tern al obliq u e • Tran sversu s abd om in is • Tran sversalis fascia • Extrap eriton eal fat • Parietal p eriton eu m

ABDOMEN

•

•

Part of th e tru n k th at lies between th e th orax an d th e p elvis, con tain in g: • Periton eal cavity • Gastroin testin al (GI) organ s • Liver an d biliary system • Ad ren al glan d s • Pan creas • Kidn eys an d u p p er p art of u reters • Nerves an d blood vessels Divid ed in to bod y p lan es: • Xip h istern al—T9 • Tran sp yloric—L1 • Su bcostal—L3 • Su p racristal—L4 • Tran stu bercu lar—L5 • In tersp in ou s—S2

59 0 NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

OVERVIEW AND TOPOGRAPHIC ANATOMY • General Information

Transpyloric plane Subcostal plane

22

T12 L1 L2 L3

Intertubercular plane Interspinous plane

L5

Rectus sheath Linea alba External oblique muscle

Muscular part Camper’s (fatty) layer, Scarpa’s (membranous) layer of subcutaneous tissue of abdomen (turned back)

Aponeurotic part

Figu re 22-1

INTRO DUCTIO N TO THE UP P ER LIMB, BACK, THO RAX, AND ABDO MEN

591

22

OSTEOLOGY • Upper Limb BONES OF THE PECTORAL GIRDLE Clavicle • Is convex anteriorly at the sternal end (m edial 2/ 3) and concave anteriorly at the acrom ial end (lateral 1/ 3) • Provides for the attachm ent of 4 m uscles: • Pectoralis m ajor • Deltoid • Trapezius • Sternocleidom astoid • Transm its force from the upper lim b to the axial skeleton • Is paired • Is frequently fractured

Scapula • Is at and triangular in shape • Is paired • Has num erous parts: • Costal surface—provides attachm ent for subscapularis • Spine—provides attachm ent for trapezius and deltoid • Acrom ion—provides attachm ent for trapezius and deltoid and articulates with clavicle • Glenoid cavity—articulates with the head of the hum erus • Supraglenoid tubercle—provides attachm ent for the long head of the biceps brachii • Infraglenoid tubercle—provides attachm ent for the long head of the triceps brachii • Scapular notch—is crossed superiorly by the transverse scapular ligam ent; suprascapular n. passes inferior to ligam ent while suprascapular vv. pass superior to ligam ent • Coracoid process—provides attachm ent for pectoralis m inor, short head of biceps brachii, and coracobrachialis

Superior surface Po s

Acromial end

Acromion

An t e

Acromial facet

Inferior surface

Clavicle te ri

or

or An te ri

rio r

Supraglenoid tubercle Coracoid process

o Po ste ri

Sternal end Superior border

Sternal facet

Superior angle

Acromion Coracoid process

Suprascapular notch Neck

Suprascapular notch

Medial border Subscapular fossa

Glenoid cavity of scapula

r

Infraglenoid tubercle

Superior border Superior angle

Supraspinous fossa Spine Neck

Scapula

Lateral border Infraspinous fossa Inferior angle Medial border Lateral border Inferior angle

Figu re 22-2

592

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

Infraglenoid tubercle

OSTEOLOGY • Upper Limb

22

BONES OF THE UPPER LIMB Humerus • • • •

Articulates with the scapula, ulna, and radius Longest bone of the upper lim b Has 8 centers of ossi cation Has 16 m ajor parts: • Head—sm ooth surface that articulates with the glenoid cavity of the scapula • Anatom ic neck—oblique passing groove that provides attachm ent for the articular capsule • Greater tubercle—provides attachm ent for 3 rotator cuff m uscles: supraspinatus, infraspinatus, and teres m inor • Lesser tubercle—provides attachm ent for 1 rotator cuff m uscle: subscapularis • Intertubercular groove—between greater and lesser tubercles; long head of the biceps brachii located in groove • Surgical neck—axillary nerve and posterior hum eral circum ex a. and v. lie in contact with m edial portion of surgical neck • Radial groove—posterior surface of hum erus where radial n. and profunda brachii a. and v. are located • Deltoid tuberosity—provides attachm ent of deltoid • Capitulum —rounded distal end of the lateral hum erus that provides articulation with the radius (head) • Trochlea—pulley-shaped distal end of the m edial hum erus that provides articulation with the ulna (trochlear notch) • Olecranon fossa—depression on posterior hum erus superior to trochlea; provides area for olecranon process of ulna to occupy during extension of antebrachium • Coronoid fossa—depression on anterior hum erus superior to trochlea that provides area for coronoid process to occupy during exion of antebrachium • Radial fossa—depression on anterior hum erus superior to capitulum that provides area for radius (head) during exion of antebrachium • Supracondylar ridges—sharp elevations of bone on lateral portion of distal hum erus that provides attachm ent of brachial fascia • Medial epicondyle—elevation at distal part of m edial supracondylar ridge; ulnar n. and superior ulnar collateral a. and v. are located posterior • Lateral epicondyle—elevation at distal part of lateral supracondylar ridge

Radius • • • • •

Articulates with capitulum of hum erus superiorly Articulates with scaphoid and lunate inferiorly Is shorter than ulna Is frequently fractured at distal end (Colles’ fracture) Has 3 m ajor anatom ic structures: • Head—proxim al end of radius; provides articulation with capitulum of hum erus • Radial tuberosity—provides attachm ent for biceps brachii • Styloid process—provides attachm ent for brachioradialis

Ulna • Articulates with trochlea of hum erus • Has 6 m ajor anatom ic structures: • Olecranon—proxim al portion of ulna; provides attachm ent for triceps brachii • Coronoid process—provides attachm ent for brachialis • Trochlear notch—depression for articulation with trochlea of hum erus • Radial notch—depressed area for radius (head) • Head—distal portion of ulna • Styloid process—projects posterior and m edial

INTRO DUCTIO N TO THE UP P ER LIMB, BACK, THO RAX, AND ABDO MEN

593

22

OSTEOLOGY • Upper Limb

Anterior view

Posterior view

Anatomic neck Greater tubercle

Greater tubercle

Head of humerus

Lesser tubercle

Anatomic neck

Surgical neck Intertubercular sulcus

Surgical neck

Head of humerus

Deltoid tuberosity

Deltoid tuberosity Radial groove Humerus

Medial supracondylar ridge Lateral supracondylar ridge

Medial supracondylar ridge Medial epicondyle

Lateral supracondylar ridge Lateral epicondyle

Lateral epicondyle

Medial epicondyle Right radius and ulna in supination: anterior view

Right radius and ulna in pronation: anterior view O lecranon

Head

Trochlear notch Coronoid process Radial notch of ulna

Neck Ulnar tuberosity Radial tuberosity Radius

Ulna

Radius

Anterior surface Anterior surface Anterior border Anterior border Interosseous border

Ulna Lateral surface Posterior border Posterior surface

Interosseous membrane Interosseous border

Interosseous membrane Groove for extensor pollicis longus muscle

Dorsal (Lister’s) tubercle

Styloid process of ulna Styloid process

Styloid process

Figu re 22-3

594

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

OSTEOLOGY • Upper Limb

22

BONES OF THE CARPUS, METACARPUS, AND PHALANGES • The wrist (carpus) com prises 2 rows of sm all bones: • Proxim al row (lateral to m edial): • Scaphoid—frequently fractured • Lunate • Triquetrum • Pisiform • Distal row (lateral to m edial): • Trapezium • Trapezoid • Capitate • Ham ate • There are 5 m etacarpal bones that articulate with the distal row of carpal bones • There are 14 phalanges • Fingers 2–5 have a total of 3 phalanges per digit (1 proxim al, 1 m iddle, 1 distal) • Finger 1 (thum b) has a total of 2 phalanges (1 proxim al and 1 distal) Right hand: anterior (palmar) view

Head Distal Tuberosity phalanges Shafts Base Middle Head Shafts phalanges Base Proximal Head phalanges Shafts Base Metacarpal Head Shafts bones Base

5

4

3

2 1

Hook of hamate and hamate Capitate Pisiform Triquetrum Lunate

Trapezoid Right hand: posterior (dorsal) view

Sesamoid bones

Anterior (palmar) view

Tubercle and Trapezium

Tubercle and Scaphoid

Hamate Pisiform

Triquetrum

Trapezium

Lunate

Trapezoid

Shafts of distal phalanges

Capitate Scaphoid

Shafts middle phalanges Shafts proximal phalanges 2

3

4

Radius Ulna

Shafts of metacarpal bones

5

1 Triquetrum

Trapezium

Hamate

Trapezoid Scaphoid

Capitate

Lunate

Figu re 22-4 INTRO DUCTIO N TO THE UP P ER LIMB, BACK, THO RAX, AND ABDO MEN

595

22

OSTEOLOGY • Back BONES OF BACK Overview • Vertebral colum n includes 33 vertebrae: • 7 cervical • 12 thoracic • 5 lum bar • 5 sacral—fuse to form sacrum • 4 coccygeal—fuse to form coccyx • Functions include: • Support of body weight • Maintenance of posture • Allowing locom otion • Protection of spinal cord and spinal roots • Im portant vertebral levels: • T2—suprasternal • T3—spine of scapula • T7—inferior angle of the scapula • T9—xiphoid process • L1—transpyloric plane • L3—subcostal plane • L4—supracristal plane • L5—transtubercular plane • S2—interspinous plane

Parts of the Typical Vertebra • • • • • • • • •

596

Body Vertebral arch Pedicles Superior and inferior articulating facets Transverse process Lam ina Spinous process Superior and inferior vertebral notches Intervertebral foram en

Types of Vertebra

Characteristics

Cervical

7 in num ber (C1–C7) C1 is the atlas (has no body or spinous process) C2 is the axis (has dens) C3–C6 have sm all bodies and spinous processes C7 has long spinous process

Thoracic

12 in num ber (T1–T12) Costal facets on body and transverse process Long spinous processes Heart-shaped body

Lum bar

5 in num ber (L1–L5) Thick body No costal facets

Sacral

5 in num ber (S1–S5) Fused to form sacrum 4 pairs of sacral foram ina Sacral hiatus

Coccygeal

3–5 in num ber (typically 4) Fused to form coccyx Mainly provides m uscle and ligam ent attachm ent

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

OSTEOLOGY • Back

Left lateral view

22

L2 vertebra: superior view

Atlas (C1)

Vertebral body

Axis (C2) Cervical curvature

Vertebral foramen

Pedicle C7 T1

Transverse process

Superior articular process Mammillary process Lamina Thoracic curvature

Spinous process

Anterior inferior view

T12 L1

Ala (wing) Promontory Lumbar curvature

Anterior (pelvic) sacral foramina

L5

Sacral curvature

Sacrum (S1–5)

Apex of sacrum Transverse process of coccyx Coccyx

Coccyx Pelvic surface T6 vertebra: superior view

T6 vertebra: lateral view

Vertebral foramen

Body

Superior vertebral notch (forms lower margin of intervertebral foramen)

Superior costal facet

Superior costal facet Body

Lamina Superior articular facet

Pedicle Transverse costal facet

Pedicle Transverse costal facet

Spinous process

Superior articular process and facet

Inferior costal facet Inferior vertebral notch

Transverse process Inferior articular process

Spinous process

Figu re 22-5

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OSTEOLOGY • Thorax BONES OF THORAX Overview • Landm arks include: • Midclavicular line—vertical line passing through the m idpoint of the clavicle • Midaxillary line—vertical line passing through the m idpoint of the axilla • Scapular line—vertical line passing through the inferior angle of scapula • Suprasternal notch—T2 • Sternal angle—T4 • The thoracic apertures: • Superior thoracic aperture • Boundaries • Body of T1 vertebra • 1st pair of ribs and cartilages • Manubrium (superior portion) • Major contents • Trachea • Esophagus • Great vessels and nerves • Thoracic duct • Lungs • Inferior thoracic aperture • Boundaries • Body of T12 vertebra • 12th pair of ribs • Costal m argins • Xiphoid process

Sternum Parts

Characteristics

Manubrium

Superior part of sternum Quadrangular in shape Superior border is known as jugular notch or suprasternal notch (vertebral level T2) Articulates with: • Clavicle • 1st costal cartilage • 2nd costal cartilage • Body of sternum

Body

Longest part of sternum Articulates with 2nd through 7th ribs Articulates with: • Manubrium at m anubriosternal joint (vertebral level T4) • Xiphoid process (vertebral level T9)

Xiphoid process

Cartilaginous process, which ossi es

Ribs

598

Type

Characteristics

Vertebrosternal

Ribs 1–7 Known as “true ribs” because they articulate with the sternum through the costal cartilage Articulate with the sternum through the costal cartilage

Vertebrochondral

Ribs 8–10 Known as “false ribs” because they do not possess a direct articulation to the sternum These ribs articulate to a com m on cartilaginous connection to the sternum

Vertebral

Ribs 11 and 12 Most com m only known as “ oating ribs” They also are “false ribs” because they do not possess a direct articulation to the sternum Do not articulate with the sternum and end in the posterior abdom inal wall

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

OSTEOLOGY • Thorax

22

Anterior view Jugular notch Manubrium 1

Angle Body

2

Sternum

Xiphoid process

3 4 5 6

True ribs (1–7) Costal cartilages

11

7 8

False ribs (8–12)

12

9 10

Floating ribs (11 and 12) Posterior view

Head

Rib

Neck

1 2

Tubercle

3 4

Angle Body

5 6 7 True ribs (1–7)

8 9 10

False ribs (8–12)

11 Floating ribs (11 and 12)

12 6th rib: posterior view Tubercle

Neck

Head Superior Articular facets for vertebral Inferior body

Angle

Articular facet for transverse process of vertebra

Costal groove

Figu re 22-6

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OSTEOLOGY • Abdomen BONES OF ABDOMEN AND PELVIS Overview • The 5 lum bar vertebra are in the abdom en • Bones of the pelvis com prised of 3 structures: • Sacrum • Coccyx • Os coxae (hip bone) • Ilium • Ischium • Pubis • The pelvis is the inferior portion of abdom en providing a connection of the spinal colum n to the fem ur • Multiple functions: • Bear weight • Allow locom otion • Maintain posture • Provide for m uscle and ligam ent attachm ent • Has a pelvic cavity that is divided by the pelvic brim into: • False pelvis—superior to pelvic brim and contains inferior portion of abdom inal cavity • True pelvis—inferior to pelvic brim and contains the: • Bladder • Term inal colon and rectum • Som e reproductive and accessory reproductive organs: • Prostate • Sem inal vesicles • Vas deferens • Uterus with uterine tubes and ovary • Vagina

Os Coxae Part

Characteristics

Ilium

Largest part of the hip bone Com prises the: • Ala (wing) • Body Provides m uscle and ligam ent attachm ents

Ischium

Most posterior and inferior portion of the hip bone Com prise the: • Body • Superior ischial ram us • Inferior ischial ram us Provides m uscle and ligam ent attachm ents

Pubis

Most anterior portion of the hip bone Com prises the: • Superior pubic ram us • Inferior pubic ram us Provides m uscle and ligam ent attachm ent Right and left hip bones articulate at the pubic sym physis

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OSTEOLOGY • Abdomen

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Anterior view Iliac fossa

O uter lip of iliac crest Iliac tubercle of iliac crest Sacral promontory Anterior superior iliac spine Anterior inferior iliac spine Ischial spine Coccyx Superior pubic ramus

Ischiopubic ramus Pubic tubercle

Pubic symphysis

Tuberculum of iliac crest

Anterior superior iliac spine

Anterior inferior iliac spine

Acetabulum

Superior pubic ramus

Greater sciatic notch Body of ilium

Pubic tubercle

Ischial spine Lesser sciatic notch

Inferior pubic ramus

Body of ischium Ischial tuberosity

Ilium Ischium Pubis Ramus of ischium

Figu re 22-7

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MUSCLES • Upper Limb MUSCLES OF PECTORAL REGION Muscle

Origin

Insertion

Action(s)

Nerve Supply

Pectoralis m ajor

Clavicular head • Clavicle (m edial 1/ 2) Sternocostal head • Anterior surface of sternum • Upper 6 costal cartilages

Lateral lip of intertubercular groove

Flexion of hum erus Adduction of hum erus Medial rotation of hum erus

Medial pectoral n. Lateral pectoral n.

Pectoralis m inor

Ribs 3–5

Coracoid process

Protraction of scapula Aids in stabilization of scapula

Medial pectoral n.

Serratus anterior

Ribs 1–8

Medial border of scapula

Protraction of scapula Rotates the scapula Aids in stabilization of the scapula

Long thoracic n.

Subclavius

1st rib and 1st costal cartilage

Inferior surface of clavicle

Aids in depressing lateral part of clavicle

Subclavius n.

Perforating branches of internal thoracic artery and anterior cutaneous branches of intercostal nerves

Lateral thoracic artery

Pectoralis major muscle Lateral cutaneous branches of intercostal nerves and posterior intercostal arteries

Cephalic vein

Latissimus dorsi muscle Serratus anterior muscle

Long thoracic nerve and lateral thoracic artery

Thoracoacromial artery Cephalic vein Pectoralis major muscle (cut) Intercostobrachial nerve Pectoralis minor muscle Long thoracic nerve and lateral thoracic artery Lateral cutaneous branches of intercostal nerves and posterior intercostal arteries

Figu re 22-8

6 02 NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

Long thoracic nerve

MUSCLES • Upper Limb

22

MUSCLES OF SHOULDER Muscle

Origin

Insertion

Actions

Nerve Supply

Deltoid

• Lateral 1/ 3 of clavicle • Acrom ion • Spine of scapula

Deltoid tuberosity

Abduction of hum erus Anterior bers aid in exion of hum erus and m edial rotation of hum erus Posterior bers aid in extension of hum erus and lateral rotation of hum erus

Axillary n.

Teres m ajor

Inferior angle of posterior scapula

Medial lip of intertubercular groove

Adduction of hum erus Medial rotation of hum erus

Lower subscapular n.

Supraspinatus

Supraspinous fossa

Greater tubercle (superior facet)

Abduction of hum erus (1st 10–15 degrees) Aids in holding hum erus in glenoid cavity

Suprascapular n.

Infraspinatus

Infraspinous fossa

Greater tubercle (m iddle facet)

Lateral rotation of hum erus Aids in holding hum erus in glenoid cavity Aids in adduction

Suprascapular n.

Teres m inor

Lateral border of scapula

Greater tubercle (inferior facet)

Lateral rotation of hum erus Aids in holding hum erus in glenoid cavity Aids in adduction

Axillary n.

Subscapularis

Subscapular fossa

Lesser tubercle

Medial rotation of hum erus Aids in holding hum erus in glenoid cavity Aids in adduction

Upper subscapular n. Lower subscapular n.

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MUSCLES • Upper Limb

Axillary nerve

Deltoid

Subscapularis muscle

Superior transverse scapular ligament and suprascapular notch

Suprascapular artery and nerve

Infraspinatus tendon (reflected) Supraspinatus muscle (cut)

Deltoid muscle (reflected) Teres minor muscle

Spine of scapula

Quadrangular space transmitting axillary nerve and posterior circumflex humeral artery

Infraspinatus muscle (cut)

Profunda brachii (deep brachial) artery

Triangular space with circumflex scapular artery deep to space

Radial nerve Lateral head and Long head of triceps brachii muscle

Teres major muscle

Figu re 22-9

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MUSCLES • Upper Limb

22

MUSCLES OF BRACHIUM Flexor Compartment Muscle

Origin

Insertion

Action(s)

Nerve Supply

Biceps brachii

Long head • Supraglenoid tubercle Short head • Coracoid process

Radial tuberosity of radius

Flexion of antebrachium Supination of antebrachium Aids in exion of brachium

Musculocutaneous n.

Brachialis

Anterior surface of distal portion of hum erus

• Coronoid process of ulna • Ulnar tuberosity

Flexion of antebrachium

Musculocutaneous n.

Coracobrachialis

Coracoid process

Middle 1/ 3 of m edial hum erus

Flexion of brachium Adduction of brachium

Musculocutaneous n.

Extensor Compartment Triceps brachii

Long head • Infraglenoid tubercle Lateral head • Superior to radial groove Medial head • Inferior to radial groove

Olecranon of ulna

Extension of antebrachium Long head aids in slight adduction of brachium

Radial n.

Anconeus

Lateral epicondyle of hum erus

Olecranon of ulna

Extension of antebrachium

Radial n.

Superficial layer

Deep layer

Deep layer

Anterior circumflex humeral artery

Radial nerve

Biceps Long head brachii Short head muscle

Long head of triceps brachii muscle

Brachialis muscle

Lateral head of triceps brachii muscle (cut) Medial head of triceps brachii muscle Tuberosity of ulna

Biceps brachii tendon Bicipital aponeurosis

Figu re 22-10

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MUSCLES • Upper Limb MUSCLES OF FLEXOR SURFACE OF ANTEBRACHIUM Superf cial Group Muscle

Origin

Insertion

Action(s)

Nerve Supply

Pronator teres

Medial epicondyle of hum erus Coronoid process of ulna

Lateral surface of radius (m iddle portion)

Pronation of antebrachium Weak exion of antebrachium

Median n.

Flexor carpi radialis

Medial epicondyle of hum erus

Base of 2nd and 3rd m etacarpal

Flexion of antebrachium (little) Flexion of wrist Abduction of wrist

Median n.

Palm aris longus

Medial epicondyle of hum erus

Palm ar aponeurosis

Weak exion of antebrachium Flexion of wrist

Median n.

Flexor carpi ulnaris

Medial epicondyle of hum erus Posterior ulna

Pisiform Ham ate (hook) Base of 5th m etacarpal

Weak exion of antebrachium Flexion of wrist Adducton of wrist

Ulnar n.

Weak exion of antebrachium Flexion of hand Flexion of proxim al interphalangeal joints of digits 2–5

Median n.

Intermediate Group Flexor digitorum super cialis

Medial epicondyle of hum erus Coronoid process Radius (oblique line)

Middle phalanges of digits 2–5

Deep Group Flexor digitorum profundus

Anterior and m edial surface of ulna Interosseous m em brane

Base of distal phalanges of digits 2–5

Flexion of hand Flexion of distal interphalangeal joints of digits 2–5

Anterior interosseous of the m edian n. (lateral 1/ 2) Ulnar n. (m edial 1/ 2)

Flexor pollicis longus

Anterior surface of radius Interosseous m em brane

Base of distal phalanx of thum b

Flexion of thum b

Anterior interosseous of the m edian n.

Pronator quadratus

Anterior surface of distal ulna

Anterior surface of distal radius

Pronation of antebrachium

Anterior interosseous of the m edian n.

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MUSCLES • Upper Limb

22

Medial epicondyle of humerus

Common flexor tendon Pronator teres muscle Flexor carpi radialis muscle Palmaris longus muscle Flexor carpi ulnaris muscle Flexor pollicis longus muscle and tendon Radial artery Median nerve

Flexor digitorum superficialis muscle Palmaris longus tendon Ulnar artery and nerve Flexor digitorum superficialis tendons

Pronator teres muscle (hum eral head cut and reflected) Medial epicondyle of humerus Flexor carpi radialis, palmaris longus, flexor digitorum superficialis (humeroulnar head), and flexor carpi ulnaris muscles (cut) Pronator teres muscle (ulnar head) (cut) Median nerve (cut) Flexor digitorum profundus muscle Flexor digitorum superficialis muscle (radial head) (cut) Flexor pollicis longus muscle and tendon (cut) Ulnar nerve and dorsal branch Pronator quadratus muscle Flexor carpi ulnaris tendon (cut) Radial artery and superficial palmar branch Flexor pollicis longus tendon (cut) Flexor carpi radialis tendon (cut)

Figu re 22-11

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MUSCLES • Upper Limb MUSCLES OF EXTENSOR SURFACE OF ANTEBRACHIUM Muscle

Origin

Insertion

Action(s)

Nerve Supply

Brachioradialis

Lateral supracondylar ridge of hum erus

Styloid process of distal radius

Flexion of antebrachium

Radial n.

Extensor carpi radialis longus

Lateral epicondyle of hum erus

Base of 2nd m etacarpal

Extension of wrist Abduction of wrist Weakly aids in exion of forearm

Radial n.

Extensor carpi radialis brevis

Base of 3rd m etacarpal

Extension of wrist Abduction of wrist Weakly aids in exion of forearm

Deep radial n.

Extensor digitorum

Joints extensor expansion of digits 2–5

Extension of wrist Extension of digits 2–5

Posterior interosseous n. from the radial n.

Extensor digiti m inim i

Joins extensor expansion of the extensor digitorum tendon of proxim al phalanx 5th digit

Extension of 5th digit (little nger)

Posterior interosseous n. from the radial n.

Extensor carpi ulnaris

Lateral epicondyle of hum erus Posterior ulna

Base of 5th m etacarpal

Extension of wrist Adduction of wrist

Posterior interosseous n. from the radial n.

Supinator

Lateral epicondyle of hum erus Ulna

Radial tubercle Oblique line of radius

Supination

Deep radial n.

Extensor indicis

Posterior ulna Joins extensor expansion of the Interosseous m em brane extensor digitorum of index nger (2nd digit)

Extension of index nger (2nd digit)

Posterior interosseous n. from the radial n.

Abductor pollicis longus

Lateral posterior ulna Base of 1st m etacarpal (lateral Interosseous m em brane side) Posterior radius

Abducts 1st digit Adducts wrist

Posterior interosseous n. from the radial n.

Extensor pollicis longus

Posterior ulna Base of distal phalanx Extension of distal Posterior of 1st digit phalanx of 1st digit interosseous n. Interosseous m em brane from the radial n. Helps extend and abduct wrist

Extensor pollicis brevis

Posterior ulna Base of proxim al phalanx of 1st digit Interosseous m em brane Posterior radius

Extensor carpi radialis longus Extensor carpi radialis brevis Extensor carpi ulnaris Abductor pollicis longus Extensor indicis Extensor pollicis brevis Extensor pollicis longus Extensor digitorum and extensor digiti minimi tendons (cut)

Extend and abduct 1st digit

Lateral epicondyle Common extensor tendon Extensor digitorum and extensor digiti minimi (cut aw ay) Anconeus Interosseous muscle membrane Flexor carpi ulnaris muscle Radius Extensor carpi Ulna ulnaris muscle Extensor retinaculum (compartments numbered) Dorsal branch of ulnar nerve Extensor carpi ulnaris tendon Extensor digiti minimi tendon Extensor digitorum tendons Extensor indicis tendon 5th metacarpal bone

3 21 65 4

Figu re 22-12

6 0 8 NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

Posterior interosseous n. from the radial n.

Triceps brachii tendon Brachioradialis muscle Extensor carpi radialis longus muscle Common extensor tendon Extensor carpi radialis brevis muscle Extensor digitorum muscle Extensor digiti minimi muscle Abductor pollicis longus muscle Extensor pollicis brevis muscle Extensor pollicis longus tendon Extensor carpi radialis brevis tendon Extensor carpi radialis longus tendon Abductor pollicis longus tendon Extensor pollicis brevis tendon Extensor pollicis longus tendon

MUSCLES • Upper Limb

22

MUSCLES OF THE HAND Muscle(s)

Origin

Insertion

Action(s)

Abductor pollicis Flexor retinaculum brevis Tubercle of scaphoid Tubercle of trapezium

Base of proxim al phalanx of thum b (radial side)

Abduction of Recurrent thum b branch of m edian n. Aids in opposition of thum b Aids in extension of thum b

Opponens pollicis

1st m etacarpal (radial side)

Opposition of thum b

Base of proxim al phalanx of thum b (radial side)

Flexion of thum b at m etacarpophalangeal joint

Flexor retinaculum Tubercle of trapezium

Flexor pollicis brevis

Nerve Supply

Abductor digiti m inim i

Flexor retinaculum Pisiform

Base of proxim al phalanx of 5th digit

Abduction of 5th digit (little nger)

Opponens digiti m inim i

Flexor retinaculum Ham ulus of ham ate

Shaft of 5th m etacarpal

Flexion of 5th m etacarpal Laterally rotate 5th m etacarpal

Flexor digiti m inim i brevis

Flexor retinaculum Ham ulus of ham ate

Base of proxim al phalanx of 5th digit

Flexion of m etacarpophalangeal joint of 5th digit

Palm aris brevis

Flexor retinaculum Palm ar aponeurosis

Skin of palm

Raises hypothenar em inence

Super cial branch of ulnar n.

Base of proxim al phalanx of thum b

Adduction of thum b

Deep branch of ulnar n.

Adductor pollicis • Capitate, 2nd and 3rd m etacarpals • Oblique head • Shaft of 3rd • Transverse m etacarpal head

Deep branch of ulnar n.

Lum brical • 1st and 2nd are unipennate • 3rd and 4th are bipennate

1st and 2nd—radial side Extensor expansion of exor digitorum profundus tendons of m iddle index and ngers 3rd—side of exor digitorum profundus tendons of m iddle and ring ngers 4th—side of exor digitorum profundus tendons of ring and little ngers

Flexion of proxim al • Median n. for phalanx 1st and 2nd lum bricals Extension of m iddle and distal • Deep branch phalanges of ulnar n. for 3rd and 4th lum bricals

Dorsal interosseous (bipennate)

1st—radial side of 2nd m etacarpal; ulnar side of 1st m etacarpal 2nd—radial side of 3rd m etacarpal; ulnar side of 2nd m etacarpal 3rd—radial side of 4th m etacarpal; ulnar side of 3rd m etacarpal 4th—radial side of 5th m etacarpal; ulnar side of 4th m etacarpal

1st—radial side of 2nd proxim al phalanx; extensor expansion 2nd—radial side of 3rd proxim al phalanx; extensor expansion 3rd—ulnar side of 3rd proxim al phalanx; expansion extensor 4th—ulnar side of 4th proxim al phalanx; extensor expansion

Abduction of ngers from the m iddle nger Aid in exion of m etacarpophalangeal joint Aid in extension of interphalangeal joints

Palm ar interosseous (unipennate)

1st—ulnar side of 2nd m etacarpal 2nd—radial side of 4th m etacarpal 3rd—radial side of 5th m etacarpal

1st—ulnar side of proxim al phalanx of 2nd digit 2nd—radial side of proxim al phalanx of 4th digit 3rd—radial side of proxim al phalanx of 5th digit

Adduction of ngers toward the m iddle nger Aid in exion of m etacarpophalangeal joint Aid in extension of interphalangeal joints

Deep branch of ulnar n.

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MUSCLES • Upper Limb

O pponens digiti minimi muscle

Flexor digitorum superficialis tendons (cut) 3rd and 4th lumbrical muscles (bipennate)

Adductor pollicis muscle Abductor pollicis brevis muscle (cut) Flexor pollicis brevis muscle O pponens pollicis muscle

Flexor digiti minimi brevis muscle (cut) Abductor digiti minimi muscle (cut)

1st and 2nd lumbrical muscles (unipennate) Flexor digitorum profundus tendons Note: Flexor digitorum superficialis and profundus tendons encased in synovial sheaths are bound to phalanges by fibrous digital sheaths made up of alternating strong annular (A) and weaker cruciform (C) parts (pulleys).

Deep palmar branch of ulnar artery and deep branch of ulnar nerve

Posterior (dorsal) view

Dorsal interosseous muscles (bipennate)

Anterior (palmar) view Lumbrical muscles (reflected) 1st dorsal interosseous muscle

1

2

3

Branches of median nerve to thenar muscles and to 1st and 2nd lumbrical muscles Median nerve Ulnar nerve Anterior (palmar) view

3

4

2

1

Abductor digiti minimi muscle

Abductor pollicis brevis muscle

Deep transverse metacarpal ligaments Palmar interosseous muscles (unipennate)

Note: Arrow s indicate action of muscles.

Insertion of extensor tendon to base of middle phalanx

Finger in extension: lateral (radial) view Extensor expansion (hood) Long extensor tendon

Insertion of extensor tendon to base of distal phalanx

Flexor digitorum Interosseous muscles profundus tendon Flexor digitorum Lumbrical muscle superficialis tendon Note: Black arrow s indicate pull of long extensor tendon; red arrow s indicate pull of interosseous and lumbrical muscles.

Figu re 22-13

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MUSCLES • Back

22

OVERVIEW OF MUSCLES OF BACK Extrinsic

Intrinsic

Others

Super cial

Connect upper lim b to trunk

Interm ediate

Super cial respiratory m uscles such as serratus posterior

Super cial

Splenius m uscles

Interm ediate

• Spinalis • Spinalis thoracis • Spinalis cervicis • Spinalis capitis • Longissim us • Longissim us thoracis • Longissim us cervicis • Longissim us capitis • Iliocostalis • Iliocostalis lum borum • Iliocostalis thoracis • Iliocostalis cervicis

Deep (transversospinal)

• Sem ispinalis • Sem ispinalis thoracis • Sem ispinalis cervicis • Sem ispinalis capitis • Multi dus • Rotatores (long and short)

• Interspinales • Intertransversarii

MAJOR EXTRINSIC MUSCLES OF THE BACK Muscle

Origin

Insertion

Action(s)

Nerve Supply

Trapezius

External occipital protuberance, ligam entum nuchae, spinous processes of C7-T12

Lateral 1/ 3 of clavicle, acrom ion, and spine of scapula

Elevates pectoral girdle Retracts pectoral girdle Depresses pectoral girdle Rotates scapula

Spinal accessory n.

Latissim us dorsi

Spinous processes of T7–12, thoracolum bar fascia, iliac crest, inferior 3–4 ribs

Floor of intertubercular groove

Extends hum erus Adducts hum erus Medial rotates hum erus

Thoracodorsal n.

Levator scapulae

Transverse processes of C1–4

Superior angle of scapula

Elevates scapula

Dorsal scapular n.

Rhom boid m ajor

Spinous processes of T2–5

Medial border of scapula below the spine of the scapula

Retracts scapula Helps rotate scapula

Rhom boid m inor

Ligam entum nuchae, spinous processes of C7–T1

Medial border at the level of the spine of the scapula

Retracts scapula Helps rotate scapula

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MUSCLES • Back

Trapezius muscle (reflected) Trapezius muscle

Accessory nerve (XI)

Deltoid muscle

Transverse cervical artery and vein

Levator scapulae muscle Rhomboid minor muscle Posterior cutaneous branches (from lateral branches of dorsal rami of T7–12 spinal nerves)

Rhomboid major muscle Latissimus dorsi muscle

External oblique muscle Thoracolumbar fascia

Iliac crest

Intermediate layers Superior nuchal line of skull

Splenius capitis and splenius cervicis muscles

Longissimus capitis muscle Semispinalis capitis muscle (cut)

Serratus posterior superior muscle

Spinalis cervicis muscle Longissimus cervicis muscle

Iliocostalis muscle

Iliocostalis cervicis muscle

Erector spinae Longissimus muscle muscle

Iliocostalis thoracis muscle

Spinalis muscle

Spinalis thoracis muscle Longissimus thoracis muscle

Serratus posterior inferior muscle

Iliocostalis lumborum muscle

Figu re 22-14

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MUSCLES • Thorax Muscle(s)

Origin

Insertion

Action(s)

Nerve Supply

External intercostals

Inferior border of ribs

Upper border of ribs

Extend from tubercles to angles of ribs and aid in respiration by elevating ribs for inspiration

Intercostal n. in intercostal space

Internal intercostals

Inferior border of ribs

Upper border of ribs

Extend from sternum to cartilages and aid in respiration by depressing ribs for exhalation

Intercostal n. in intercostal space

Transversus thoracis

Posterior body of sternum and xiphoid

Inferior border of costal cartilages of ribs 2–6

Depresses ribs

Intercostal n. in intercostal space

Innerm ost intercostal

Inferior border of ribs

Upper border of ribs

Aids in respiration by depressing ribs for exhalation

Intercostal n. in intercostal space

Subcostal

Near angle of rib in lower thorax

2 or 3 ribs inferior

Helps raise ribs

Intercostal n. in intercostal space

Anterior scalene muscle Subclavian artery and vein Brachiocephalic vein Phrenic nerve and pericardiacophrenic artery and vein

22

Common carotid artery Inferior thyroid artery Vertebral artery Brachiocephalic trunk Subclavian artery and vein Brachiocephalic vein Internal thoracic artery and vein Anterior intercostal arteries and veins and intercostal nerve

Internal thoracic artery and vein Anterior intercostal arteries and veins and intercostal nerve

Innermost intercostal muscles Internal intercostal muscles Transversus thoracis muscle

Internal thoracic artery and veins Diaphragm

Musculophrenic artery and vein

Transversus abdominis muscle

Superior epigastric artery and veins Internal intercostal membrane deep to external intercostal muscle

Posterior intercostal artery Internal intercostal membrane

Intercostal nerve (ventral ramus of thoracic spinal nerve) Innermost intercostal muscle Internal intercostal muscle

Innermost intercostal muscle Right posterior intercostal arteries (cut)

Internal intercostal muscle External intercostal muscle

External intercostal muscle Transversus thoracis muscle

Internal thoracic artery Superior epigastric artery

Anterior intercostal arteries

Figu re 22-15 INTRO DUCTIO N TO THE UP P ER LIMB, BACK, THO RAX, AND ABDO MEN

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614

MUSCLES • Abdomen Muscle

Origin

Insertion

Action(s)

Nerve Supply

External oblique

Ribs 5–12

Muscular • Anterior 1/ 2 of iliac crest Aponeurotic • Xiphoid process • Linea alba • Pubic sym physis, crest, and tubercle • Anterior superior iliac spine

Com presses abdom en Flexes abdom en Rotates trunk to contralateral side

Ventral ram i of T7–12

Internal oblique

Thoracolum bar fascia, anterior 2/ 3 of iliac crest, lateral 2/ 3 of inguinal ligam ent

Muscular • Ribs 10–12 Aponeurotic • Above arcuate line—splits to form rectus sheath • Anterior rectus sheath • Posterior rectus sheath • Below arcuate line • Form s conjoint tendon • Anterior rectus sheath

Com presses abdom en Flexes abdom en Rotates trunk to ipsilateral side

Ventral ram i of T7–L1

Transversus abdom inis

Thoracolum bar fascia, anterior 2/ 3 of iliac crest, lateral 1/ 3 of inguinal ligam ent, lower 6 costal cartilages

Aponeurotic Ab ove arcuate line: • Form s posterior rectus sheath Below arcuate line: • Form s conjoint tendon • Anterior rectus sheath

Com presses abdom en

Rectus abdom inis

Pubic sym physis, crest and tubercle

Costal cartilages of ribs 5, 6, and 7

Com presses abdom en Flexes abdom en

Ventral ram i of T7–T12

Diaphragm

Sternal portion • Xiphoid process Costal portion • Costal cartilages and ribs 7–12 Lum bar portion • Lateral arcuate ligam ent • Medial arcuate ligam ent • Crura • Right crus—L1–3 • Left crus—L1 and 2

Central tendon

Contraction causes central tendon to depress, creating a negative pressure in the thoracic cavity, thus causing inhalation

Phrenic n. (C3–5)

Psoas m ajor

Transverse processes of L1–5 Sides of bodies of T12–L5

Lesser trochanter of fem ur

Flexes fem ur Aids in exing spine Aids in lateral exion

Ventral ram i of L2 and L3

Iliacus

Iliac fossa

Lesser trochanter of fem ur

Flexes fem ur

Fem oral n.

Quadratus lum borum

Iliac crest

12th rib Transverse processes of L1–4

Lateral exion

Ventral ram i of T12–L4

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

MUSCLES • Abdomen

22

Anterior layer of rectus sheath (cut) Linea alba Anterior layer of rectus sheath

Superior epigastric vessels Rectus abdominis muscle

Transversus abdominis muscle (cut)

External oblique aponeurosis (cut)

Transversalis fascia (opened on left)

Internal oblique aponeurosis (cut) Internal oblique muscle (cut) Transversus abdominis muscle Posterior layer of rectus sheath Arcuate line

Extraperitoneal fascia (areolar tissue)

Inferior epigastric vessels

Inguinal ligament (Poupart’s)

Caval opening Diaphragm Central tendon of diaphragm

Esophagus and vagal trunks Left crus of diaphragm

Right crus of diaphragm

Median arcuate ligament

Aorta and thoracic duct

Lateral arcuate ligament

Medial arcuate ligament

Q uadratus lumborum muscle

Psoas minor muscle

Transversus abdominis muscle Internal oblique muscle

Psoas major muscle

External oblique muscle Iliacus muscle

Piriformis muscle

Inguinal ligament (Poupart’s)

Coccygeus (ischiococcygeus) muscle

Section above arcuate line Anterior layer of rectus sheath Rectus abdominis muscle Aponeurosis of external oblique muscle Falciform ligament Linea Aponeurosis of internal oblique muscle Skin alba Aponeurosis of transversus abdominis muscle

Internal oblique muscle External oblique muscle

Peritoneum

Transversus abdominis muscle

Posterior layer of rectus sheath Subcutaneous tissue (fatty layer) Transversalis fascia Extraperitoneal fascia Aponeurosis of internal oblique muscle splits to form anterior and posterior layers of rectus sheath. Aponeurosis of external oblique muscle joins anterior layer of sheath; aponeurosis of transversus abdominis muscle joins posterior layer. Anterior and posterior layers of rectus sheath unite medially to form linea alba.

Figu re 22-16

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CONTENTS OF THE THORAX • Pleural Cavity • •

•

•

•

•

•

Th ere are 2 p leu ral cavities Th e con ten ts of each cavity con sist of a 2-layered p leu ral sac th at secretes a th in layer of serou s u id • Visceral layer—lin es th e lu n g an d ssu res • Parietal layer—lin es th e wall of th e cavity • Costal—lin es th e cavity alon g th e ribs • Med iastin al—lin es th e cavity alon g th e m ed iastin u m • Diap h ragm atic—lin es th e cavity alon g th e diap h ragm • Cervical (cu p u la)—lin es th e cavity form in g a d om e in th e ribs op p osite th e ap ex of th e lu n g Pleu ral re ection s—abru p t lin es wh ere th e p arietal p leu ra fold s back or ch an ges d irection • Vertebral (p osterior)—wh ere costal p leu ra is con tin u ou s with th e m ed iastin al p leu ra at th e vertebral colu m n • Costal (in ferior)—wh ere costal p leu ra is con tin u ou s with d iap h ragm atic p leu ra • Stern al (an terior)—h ere costal p leu ra is con tin u ou s with th e m ed iastin al p leu ra p osterior to stern u m Bou n daries • An terior m id lin e—6th rib (righ t), 4th rib (left) • Mid clavicu lar lin e—8th rib • Mid axillary lin e—10th rib • Scap u lar lin e—12th rib In ferior bord er of lu n gs in q u iet resp iration • An terior m id lin e—6th rib (righ t), 4th rib (left) • Mid clavicu lar lin e—6th rib • Mid axillary lin e—8th rib • Scap u lar lin e—10th rib Pleu ral recesses—p oten tial sp aces in th e p leu ral cavity wh ere p arts of th e p arietal p leu ra con tact on e an oth er d u rin g q u iet resp iration • Costom ed iastin al—p oten tial sp ace wh ere costal an d m ed iastin al p leu rae com e togeth er • Costod iap h ragm atic—p oten tial sp ace wh ere costal an d d iap h ragm atic p leu rae com e togeth er Pu lm on ary ligam en t—a fold created wh ere th e m ed iastin al p leu ral layers at th e root of th e lu n g com e togeth er an d exten d in feriorly

Costal part of parietal pleura

Mediastinal part of parietal pleura Mediastinal part of parietal pleura

Diaphragmatic part of parietal pleura (cut)

Horizontal fissure of right lung (often incomplete)

O blique fissure of right lung Costodiaphragmatic recess of pleural cavity

Figu re 22-17

616

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

Anterior view Cardiac notch of left lung

O blique fissure of left lung Costodiaphragmatic recess of pleural cavity

CONTENTS OF THE THORAX • Lungs Surface anatom y

• • • • •

Lobes

• Right lung • Superior • Middle • Inferior • Left lung • Superior • Inferior

Air conduction system

• Prim ary bronchus—travels to lung • Right bronchus—m ore vertical, wider in diam eter, shorter • Left bronchus—less vertical, narrower in diam eter, longer • Secondary bronchus—travels to lobes • Tertiary bronchus—travels to bronchopulm onary segm ent

Fissures

• Oblique • Right lung—separates superior and m iddle lobes from inferior lobe • Left lung—separates superior and inferior lobes • Horizontal—between superior and m iddle lobes of right lung beginning at oblique ssure and paralleling the 4th rib anteriorly

Borders

• Anterior • Posterior • Inferior

Structures located on the root of the lung

• • • • •

Apex—extends 1 inch into neck Base—concave area that is located on the convexity of the diaphragm Costal—large convex area that conform s to the thoracic cavity Mediastinal—area in contact with the m ediastinal pleura Hilus—area where the structures that m ake the root of the lung enter and exit

Pulm onary vv. Bronchus Bronchial vv. Pulm onary plexus Lym phatics

Groove for subclavian artery Groove for brachiocephalic vein Groove for 1st rib Groove for superior vena cava Superior lobe

22

Right lung Area for trachea Area for esophagus Groove for azygos vein O blique fissure

Horizontal fissure Cardiac impression Middle lobe O blique fissure

Groove for esophagus Inferior lobe

Left lung

Groove for subclavian artery Groove for left brachiocephalic vein Groove for 1st rib

Area for trachea and esophagus

Diaphragmatic surface Groove for inferior vena cava

O blique fissure Groove for arch of aorta

Superior lobe Cardiac impression Inferior lobe

Cardiac notch

Groove for descending aorta

O blique fissure

Groove for esophagus Lingula

Figu re 22-18 INTRO DUCTIO N TO THE UP P ER LIMB, BACK, THO RAX, AND ABDO MEN

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22

CONTENTS OF THE THORAX • Mediastinum • •

Region in th e m id dle of th e th orax between th e 2 p leu ral sacs Su bd ivid ed in to su p erior an d in ferior SUPERIOR MEDIASTINUM Borders include: • Superior-Superior thoracic aperture • Inferior-Horizontal plane at level of sternal angle (T4) • Anterior-Manubrium • Posterior-Bodies of T1–T4 vertebra • Lateral-Pleura

Major Contents Vessels

• • • •

Superior vena cava Brachiocephalic vv. Arch of the aorta: brachiocephalic a., left com m on carotid a., left subclavian a. Thoracic duct

Nerves

• • • •

Phrenic n. Vagus n. Left recurrent laryngeal n. Plexus: • Cardiac plexus branches (parasym pathetic and sym pathetic branches) • Pulm onary plexus branches (parasym pathetic and sym pathetic branches)

Viscera

• Esophagus • Trachea • Thym us (rem nants)

Right common carotid artery Right vagus nerve (X) Phrenic nerve External jugular vein Right subclavian artery and vein Brachiocephalic trunk Right brachiocephalic vein Phrenic nerve and pericardiacophrenic artery and vein (cut)

Trachea

Left common carotid artery Left vagus nerve (X) Phrenic nerve (cut) Thoracic duct Left subclavian artery and vein Arch of aorta Vagus nerve (X) Left recurrent laryngeal nerve Ligamentum arteriosum

Superior vena cava

Thymus

Figu re 22-19

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NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

CONTENTS OF THE THORAX • Mediastinum

22

INFERIOR MEDIASTINUM Anterior Mediastinum Borders

• From lower border of superior m ediastinum (T4) to diaphragm (T9) • Body of sternum and transversus thoracis to brous pericardium

Contents

• No m ajor structures • Rem nants of the thym us • Lym ph nodes

Middle Mediastinum Borders

• From lower border of superior m ediastinum (T4) to diaphragm (T9/ T10) • Anterior and posterior borders are the brous pericardium

Contents

• Heart and pericardium • Vessels (roots of the great vessels): • Ascending aorta • Pulm onary trunk (with origins of pulm onary arteries) • Superior vena cava • Pericardiacophrenic vv. • Phrenic

Posterior Mediastinum Borders

• Lower border of superior m ediastinum (T4) to diaphragm (T12) • Fibrous pericardium to vertebral colum n

Contents

• Esophagus • Thoracic aorta (and branches): • Posterior intercostal aa. • Bronchial aa. • Esophageal aa. • Azygos venous system • Hem iazygos and accessory hem iazygos • Thoracic duct • Cisterna chyli • Vagus • Esophageal plexus • Sym pathetic trunk • Greater splanchnic n. (T5–9) • Lesser splanchnic n. (T10–11) • Least splanchnic n. (T12) Left lateral view Esophagus Left vagus nerve (X) Thoracic duct Left superior intercostal vein Left brachiocephalic vein Arch of aorta Left recurrent laryngeal nerve Left internal thoracic artery Left pulmonary artery Accessory hemiazygos vein Posterior intercostal vein Ligamentum arteriosum and artery and intercostal nerve Right lateral view Left phrenic nerve and Right superior Esophagus pericardiacophrenic Trachea intercostal vein artery and vein Right vagus nerve (X) Sympathetic trunk Right and left brachiocephalic veins Left pulmonary veins Superior vena cava Right internal Esophagus and esophageal thoracic artery plexus (covered by mediastinal Phrenic nerve and part of parietal pleura) pericardiacophrenic artery and vein Left main bronchus and bronchial artery Right pulmonary Thoracic (descending) aorta artery Greater thoracic splanchnic nerve Right main bronchus Sympathetic trunk and bronchial artery Gray and white rami communicantes Right pulmonary veins Inferior vena cava Posterior intercostal vein and artery and intercostal nerve (covered by mediastinal part of parietal Gray and white rami communicantes pleura) Greater thoracic splanchnic nerve Azygos vein Diaphragm (covered by diaEsophagus and esophageal plexus phragmatic part of parietal pleura)

Figu re 22-20 INTRO DUCTIO N TO THE UP P ER LIMB, BACK, THO RAX, AND ABDO MEN

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22

CONTENTS OF THE THORAX • Heart PERICARDIUM • A double-walled broserous sac that encloses the heart and the roots of the great vessels • Subdivided into: • Fibrous pericardium —outer layer • Serous pericardium —secretes serous uid • Parietal pericardium —lines wall of pericardium • Visceral pericardium —lines the heart

SURFACES OF THE HEART Inferior or diaphragm atic surface

• Shape—concave • Position—lower border of T8, T9 • Form ed by: • Largely left ventricle, som e right ventricle

Posterior surface

• Shape—quadrilateral • Position—opposite 5th to 8th thoracic vertebrae • Form ed by: • Largely left atrium , som e right atrium

Anterior or sternocostal surface

• Shape— attened • Position—posterior to sternum and costal cartilages 3–6 • Form ed by: • Atrial region—largely right atrium and left auricle • Ventricular region—largely right ventricle, som e left ventricle

Right surface

• Shape—convex • Position—just lateral to the right border of the sternum • Form ed by: • Right atrium

Left surface

• Shape—convex • Position—1/ 2 inch to left of m anubriosternal junction to apex • Form ed by: • Largely left ventricle, som e left auricle

Left auricle (atrial appendage) Left atrium Right atrium Left ventricle Right ventricle

Arch of aorta Right pulmonary artery

Left pulmonary artery

Right auricle (atrial appendage) Superior vena cava Right superior pulmonary vein

Left auricle (atrial appendage)

Right atrium

Left superior pulmonary vein Sulcus terminalis

Left atrium

Right inferior pulmonary vein

Left inferior pulmonary vein O blique vein of left atrium (of Marshall)

Inferior vena cava

Coronary sinus

Right ventricle

Left ventricle

Figu re 22-21

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NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

CONTENTS OF THE THORAX • Heart

22

CHAMBERS OF THE HEART Right atrium

• • • • •

Pectinate m uscle Fossa ovalis Coronary sinus opening Superior and inferior vena cava opening Valves of the coronary sinus and inferior vena cava

Right ventricle

• • • • • •

Lea ets of the tricuspid valve Trabeculae carneae Papillary m uscles (anterior, posterior, and septal) Chordae tendineae Septom arginal trabeculae Conus arteriosus (infundibulum )

Left atrium

• Pectinate m uscle in the auricle

Left ventricle

• • • • •

Lea ets of the bicuspid (m itral) valve Trabeculae carneae Papillary m uscles (anterior and posterior) Chordae tendineae Mem branous part of the interventricular septum

VALVES OF THE HEART • Atrioventricular—close during systole to prevent the back ow of blood into the atrium • Tricuspid—between right atrium and right ventricle • Bicuspid (m itral)—between left atrium and left ventricle • Sem ilunar—close during diastole to prevent the back ow of blood into the ventricles • Pulm onary—between pulm onary artery and right ventricle • Aortic—between aorta and left ventricle

Right auricle (atrial appendage) Crista terminalis Interatrial septum Limbus of fossa ovalis Pectinate muscles O pening of coronary sinus

Left auricle (atrial appendage) Left atrium Anterior cusp of mitral valve

Posterior cusp Anterior cusp Fossa ovalis

Valve (thebesian) of coronary sinus Valve (eustachian) of inferior vena cava

Posterior semilunar (noncoronary) cusp

Left semilunar cusp

O penings of coronary arteries Right auricle (atrial appendage) Left semilunar cusp Right semilunar cusp Supraventricular crest Conus arteriosus Right anterior papillary muscle (cut)

Right atrium Interventricular part

Septomarginal trabecula (moderator band)

Anterior cusp (retracted) Septal cusp Posterior cusp Right ventricle Right anterior papillary muscle (cut) Right posterior papillary muscle Left Muscular part of interventricular septum ventricle Left posterior papillary muscle Left anterior papillary muscle Left ventricle

Right ventricle Septal (medial) papillary muscle

Plane of section

Figu re 22-22 INTRO DUCTIO N TO THE UP P ER LIMB, BACK, THO RAX, AND ABDO MEN

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CONTENTS OF THE THORAX • Heart CORONARY CIRCULATION OF THE HEART Arterial supply

• Right coronary • Major branches include: • Conus a. • Marginal • Sinus nodal a. • Posterior interventricular a. • Atrioventricular nodal a. • Left coronary • Major branches include: • Anterior interventricular a. • Diagonal a. • Circum ex a. • Marginal a.

Venous supply

• Cardiac veins • Coronary sinus • Great cardiac v. • Middle cardiac v. • Posterior vein of the left ventricle • Oblique vein of the left atrium • Sm all cardiac v. • Anterior cardiac v. • Venae cordis m inim ae

Sternocostal surface Sinuatrial (SA) nodal branch

Left coronary artery

Atrial branch of right coronary artery

Circumflex branch of left coronary artery

Right coronary artery

Great cardiac vein

Anterior cardiac veins

Anterior interventricular branch (left anterior descending) of left coronary artery

Small cardiac vein Diaphragmatic surface

Right (acute) marginal branch of right coronary artery

Sinuatrial (SA) nodal branch

Circumflex branch of left coronary artery Left marginal branch Posterior interventricular branch (posterior descending) of right coronary artery Right coronary artery Right marginal branch

Figu re 22-23

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NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

CONTENTS OF THE ABDOMEN • Stomach

Cardiac notch (incisure) Fundus of stomach

Duodenum Pylorus

Cardiac part of stomach er

Body of stomach

r

c

u

rv

a

t

u

Angular notch (incisure)

P y l o ri c a n tru m

re

Cardiac orifice

u

at

rv

c

u

Cardiac zone

te

r

Pyl c a n o ric al st Pylo o m ri a c c p a rt h of

e

• • •

ss

•

e

• •

Part of th e foregu t Th ere are 4 an atom ic p arts of th e stom ach : • Card ia—wh ere esop h agu s en ters th e stom ach • Fu n du s—created by th e su p erior p ortion of th e greater cu rvatu re • Bod y—p rim ary cen tral area • Pyloru s—in ferior p ortion th at con tin u es to n arrow u n til reach in g th e p yloric sp h in cter Th e m u cosal lin in g of th e stom ach h as raised elevation s kn own as gastric rugae Th ere are 2 m ajor cu rvatu res: • Greater cu rvatu re—p rovid es attach m en t for som e rem n an ts of th e d orsal m esogastriu m : • Gastrop h ren ic • Gastrosp len ic • Greater om en tu m • Lesser cu rvatu re—p rovid es attach m en t for rem n an ts of th e ven tral m esogastriu m : • Lesser om en tu m • Hep atogastric p ortion (h ep atod u oden al p ortion d oes n ot attach to th e stom ach ) Th ere are 2 sp h in cters associated with th e stom ach : • Esop h ageal—n ot an an atom ic sp h in cter • Pyloric—h as a th ick m u scu lar sp h in cter Receives exten sive au ton om ic n erve su p p ly Is su p p lied by bran ch es of th e celiac artery Releases p ep sin an d h yd roch loric acid to aid in d igestion

L

• •

22

G

a re

Gastric folds (rugae) Superior (1st) part of duodenum (ampulla, or duodenal cap)

Pylorus

Gastric and fundic zones Pyloric zone

Figu re 22-24 INTRO DUCTIO N TO THE UP P ER LIMB, BACK, THO RAX, AND ABDO MEN

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CONTENTS OF THE ABDOMEN • Duodenum •

• •

• • • • •

Is th e 1st of th e 3 p arts of th e sm all in testin e: • Du oden u m • Jeju n u m • Ileu m Part of th e foregu t an d m id gu t Th ere are 4 an atom ic p arts of th e d u oden u m : • 1st p art—in trap eriton eal, p art of foregu t • 2n d p art—retrop eriton eal, p art of foregu t • Min or d u oden al p ap illa—wh ere accessory p an creatic d u ct (if p resen t) d rain s • Major d u od en al p ap illa—wh ere p an creas, liver, an d gallblad d er d rain • 3rd p art—retrop eriton eal, p art of m id gu t • 4th p art—retrop eriton eal, p art of m id gu t Th e m u cosal lin in g of th e du od en u m h as raised elevation s kn own as plicae circulares Receives exten sive au ton om ic n erve su p p ly Is su p p lied by bran ch es of th e celiac an d su p erior m esen teric arteries Is th e p ortion of th e sm all in testin e wh ere th e m ajority of ch em ical d igestion occu rs A m ajor h istologic featu re is th e p resen ce of m u cu s-secretin g glan d s—Bru n n er’s glan d s

Superior (1st) part Descending (2nd) part Inferior (horizontal, or 3rd) part Ascending (4th) part

Duodenum

(Common) bile duct Minor duodenal papilla (inconstant) Descending (2nd) part Accessory pancreatic duct (of Santorini) Main pancreatic duct (of Wirsung) Major duodenal papilla (of Vater) Head of pancreas Inferior (horizontal, or 3rd) part

Figu re 22-25

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NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

Ascending (4th) part

CONTENTS OF THE ABDOMEN • Jejunum and Ileum •

• • • • • •

22

Are th e n al 2 of th e 3 p arts of th e sm all in testin e: • Du oden u m • Jeju n u m • Ileu m Part of th e m idgu t In trap eriton eal Su sp en ded by th e m esen tery p rop er Th e m u cosal lin in g h as raised elevation s kn own as plicae circulares Receive exten sive au ton om ic n erve su p p ly Su p p lied by bran ch es of th e su p erior m esen teric artery

JEJUNUM

• • • •

Is abou t 7 to 8 feet in len gth Has scattered lym p h atic n odu les an d very few Bru n n er’s glan d s Has p rom in en t p licae circu lares Vascu lar su p p ly h as large p rom in en t arterial arcades term in atin g with lon g vasa recta

ILEUM

• • • • • •

Is abou t 6 to 12 feet in len gth Has exten sive Peyer’s p atch es (lym p h atic n odu les) Has fewer p licae circu lares th an th e jeju n u m Vascu lar su p p ly h as large sm aller layers of arterial arcades term in atin g with sh ort, com p act vasa recta En d s in th e large in testin e at th e ileocecal valve Is th e em bryologic con n ection to th e u m bilicu s via th e vitellin e d u ct; a Meckel’s d iverticu lu m is a rem n an t of th e d u ct in th e ad u lt

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CONTENTS OF THE ABDOMEN • Jejunum and Ileum

Jejunum Mesentery Anastomotic loop (arcade) of jejunal arteries Straight arteries (arteriae rectae) Serosa (visceral peritoneum) Longitudinal muscle layer

Barium radiograph of jejunum

Circular muscle layer Submucosa Mucosa Circular folds (valves of Kerckring) Solitary lymphoid nodule

Ileum Mesentery Anastomotic loops (arcades) of ileal arteries Straight arteries (arteriae rectae) Serosa (visceral peritoneum) Longitudinal muscle layer Barium radiograph of ileum

Circular muscle layer Submucosa Mucosa Circular folds Solitary lymphoid nodules Aggregate lymphoid nodules (Peyer’s patches)

Figu re 22-26

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NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

CONTENTS OF THE ABDOMEN • Large Intestine •

•

• • • • • •

22

Is divid ed in to: • Cecu m with ap p en d ix • Ascen d in g colon • Tran sverse colon • Descen d in g colon • Sigm oid colon • Rectu m Has th e followin g ch aracteristic featu res: • Taen iae coli—3 sep arate ban d s of lon gitu d in al m u scle • Hau stra—p ou ch -like ap p earan ce cau sed by th e con traction of th e taen iae coli • Ep ip loic ap p en d ages—sm all p ou ch es of fat alon g th e p eriton eu m Part of th e m idgu t an d h in d gu t Is in trap eriton eal an d retrop eriton eal Th e m u cosal lin in g h as raised elevation s kn own as plicae sem ilunares Receives exten sive au ton om ic n erve su p p ly Is su p p lied by bran ch es of th e su p erior m esen teric an d in ferior m esen teric arteries Major fu n ction is th e absorp tion of water from th e in d igestible waste an d exp u lsion from th e bod y

CECUM

• • • •

Is in trap eriton eal Con n ects ileu m to th e large in testin e at th e ileocecal valve Blin d p ou ch Ap p en d ix is a sm all (typ ically arou n d 4 in ch es) blin d tu bu lar in trap eriton eal stru ctu re con n ected to th e cecu m

ASCENDING COLON

• • •

Is retrop eriton eal Begin s at ileocecal valve an d ascen d s Makes a colic im p ression on th e liver an d m akes a sh arp tu rn to th e left side of th e bod y, kn own as th e righ t colic (h ep atic) exu re, before con tin u in g as th e tran sverse colon

TRANSVERSE COLON

• • •

Is in trap eriton eal, su sp en d ed by th e tran sverse m esocolon Lon gest p ortion of th e large in testin e At th e area of th e sp leen , m akes a sh arp tu rn to travel in feriorly, kn own as th e left colic (sp len ic) exu re, before con tin u in g as th e descen d in g colon

DESCENDING COLON

• • • •

Is retrop eriton eal Descen d s u n til it en d s at th e sigm oid colon Term in al p ortion of th e d escen din g colon is often called th e iliac colon becau se it lies in th e iliac fossa Typ ically is sm aller in d iam eter th an th e ascen d in g colon

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CONTENTS OF THE ABDOMEN • Large Intestine SIGMOID COLON

• • •

Is in trap eriton eal, su sp en d ed by th e sigm oid m esocolon Begin s at th e level of th e p elvic brim Travels toward th e m idlin e, wh ere it en d s at th e rectu m

RECTUM

• • • •

Begin s as in trap eriton eal, bu t is retrop eriton eal u n til it p asses th rou gh th e p elvic oor Is abou t 4 to 5 in ch es in len gth Does n ot h ave taen iae coli, becau se th e sep arate ban d s m erge to form a com p lete ban d of lon gitu d in al m u scle at th e rectu m En d s at th e an u s

Right colic (hepatic) flexure

Transverse colon

Left colic (splenic) flexure

O mental (epiploic) appendices Haustra O mental taenia (exposed by hook) Ascending colon

Free taenia Semilunar folds Ileum

Ileal orifice

Cecum Vermiform appendix Rectum Sigmoid colon Rectosigmoid junction (taeniae spread out and unite to form longitudinal muscle layer)

External anal sphincter muscle Free taenia

Free taenia

Mesocolic taenia O mental taenia

Terminal part of ileum Ileocecal lips: labial form of ileal orifice (as seen commonly postmortem and occasionally in vivo) O rifice of vermiform appendix Free taenia Vermiform appendix

Figu re 22-27

628

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

CONTENTS OF THE ABDOMEN • Liver •

•

• • •

• • •

•

22

Large, m u ltifu n ction al organ , with roles in clu d in g: • Detoxi cation • Glycogen storage • Prod u ction of h orm on es • Syn th esis of p lasm a p rotein s • Prod u ction of bile Divid ed in to 4 an atom ic lobes: • Righ t—largest lobe • Cau d ate—located between ssu re for th e ligam en tu m ven osu m an d th e in ferior ven a cava • Qu ad rate—located between ssu re for th e ligam en tu m teres h ep atis (rou n d ligam en t of th e liver) an d th e gallbladd er • Left— atten ed lobe Is fu rth er su bdivid ed in to fu n ction al segm en ts based on th e vascu lar su p p ly Is com p letely covered by visceral p eriton eu m excep t an area wh ere th e liver con n ects with th e d iap h ragm , kn own as th e bare area Th e p orta h ep atis is th e cen tral p ortion of th e liver, wh ere th e followin g stru ctu res en ter an d exit: • Hep atic p ortal vein —p rovid es 75% of th e blood to th e liver • Prop er h ep atic artery—p rovid es 25% of th e blood to th e liver • Com m on bile du ct Is in trap eriton eal Is su p p lied by bran ch es of th e celiac artery All rem n an ts of th e ven tral m esen tery attach to th e liver: • Falciform ligam en t • Coron ary ligam en t • Trian gu lar ligam en t • Lesser om en tu m • Hep atogastric ligam en t • Hep atod u oden al ligam en t Th e liver is su bject to d evelop m en t of n u m erou s p ath ologic con d ition s, in clu d in g: • Hep atitis • Cirrh osis • Can cer

Visceral surface Q uadrate lobe Round ligament of liver Fissure for ligamentum teres

Gallbladder

Porta hepatis Cystic duct Common hepatic duct Common bile duct

Caudate lobe

Hepatic portal vein Right triangular ligament

Fissure for ligamentum venosum

Proper hepatic artery Caudate process

Left triangular ligament

Bare area Inferior vena cava

Hepatic veins

Coronary ligament

Figu re 22-28

INTRO DUCTIO N TO THE UP P ER LIMB, BACK, THO RAX, AND ABDO MEN

629

22

CONTENTS OF THE ABDOMEN • Pancreas •

•

• •

•

• •

Th e p an creas fu n ction s as 2 typ es of glan d s: • En d ocrin e—islets of Lan gerh an s p rodu cin g h orm on es • Exocrin e—com p ou n d tu bu loalveolar p an creatic acin i p rod u cin g d igestive en zym es Com p rises 4 m ajor p arts: • Head—located in th e C or cu rve form ed by th e d u od en u m ; is retrop eriton eal • Un cin ate p rocess—an exten sion of th e h ead crossed by th e su p erior m esen teric vein s • Neck—con stricted p ortion of p an creas con n ectin g th e h ead to th e bod y; is retrop eriton eal • Bod y—largest p art of th e p an creas sep arated from th e stom ach by th e om en tal bu rsa; is retrop eriton eal • Tail—exten ds in to th e lien oren al ligam en t with th e sp len ic vein s to th e sp leen Is p art of th e foregu t Develop s as 2 sep arate ou tgrowth s from th e 2n d p art of th e d u od en u m : • Ven tral p an creatic bu d —an ou tgrowth of th e h ep atic bu d • Develop s in to th e h ead an d n eck of th e p an creas • Dorsal p an creatic bu d —a d irect ou tgrowth of th e 2n d p art of th e d u oden u m • Develop s in to th e body an d tail of th e p an creas Drain s in to th e 2n d p art of th e d u od en u m • Main p an creatic du ct—d rain s in to th e m ajor du od en al p ap illa by join in g th e com m on bile d u ct, form in g th e h ep atop an creatic am p u lla • Accessory p an creatic d u ct—d rain s in to th e m in or du od en al p ap illa (if p resen t an d p aten t) Is su p p lied by bran ch es of th e celiac an d su p erior m esen teric arteries Receives exten sive au ton om ic n erve su p p ly

Abdominal aorta

Duodenum

Tail Pancreas Body Neck

Head

Superior mesenteric artery and vein Pancreatic duct (of Wirsung) Accessory pancreatic duct (of Santorini)

Figu re 22-29

630

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

CONTENTS OF THE ABDOMEN • Gallbladder and Duct System

22

GALLBLADDER

• • • • •

• •

Sm all in trap eriton eal organ Is p art of th e foregu t Stores an d con cen trates bile, wh ich em u lsi es fat d u rin g d igestion Is located in a fossa on th e liver wh ere th e lin ea sem ilu n aris attach es to th e rib cage at th e 9th costal cartilage Divid ed in to 3 p arts: • Fu n du s • Bod y • Neck Is su p p lied by bran ch es of th e celiac artery Receives exten sive au ton om ic n erve su p p ly

DUCT SYSTEM

• •

Th e cystic du ct join s th e com m on h ep atic du ct to form th e com m on bile d u ct Th e com m on bile d u ct join s th e m ain p an creatic du ct with in th e su bstan ce of th e p an creas to form th e h ep atop an creatic am p u lla, wh ich p asses th rou gh th e wall of th e 2n d p art of th e d u od en u m in to th e m ajor d u od en al p ap illa

Right and left hepatic ducts Common hepatic duct Cystic duct (Common) bile duct

Hepatic ducts

Cystic duct

Right Left

Spiral Smooth fold part Common hepatic duct

(Common) bile duct

Gallbladder

Head of pancreas Descending (2nd) part of duodenum Hepatopancreatic ampulla (of Vater)

Pancreatic duct

Major duodenal papilla (of Vater)

Figu re 22-30

INTRO DUCTIO N TO THE UP P ER LIMB, BACK, THO RAX, AND ABDO MEN

631

22

CONTENTS OF THE ABDOMEN • Spleen • • •

• • •

•

A lym p h atic organ on th e left sid e of th e bod y d ivid ed in to: • Red p u lp • W h ite p u lp Is in trap eriton eal Major fu n ction s in clu d e: • Storage of red blood cells • Filtration of red blood cells • Rem oval of old red blood cells • Storage of m on ocytes Is n ot a d erivative of th e foregu t, alth ou gh it receives its arterial su p p ly from bran ch es of th e celiac artery Is located between th e 9th an d 11th ribs, p arallelin g th e 10th rib Has con tact with 4 organ s: • Stom ach • Large in testin e • Left kid n ey • Tail of p an creas Is su sp en d ed by dorsal m esen tery of th e foregu t: • Lien oren al—con tain s tail of th e p an creas an d sp len ic vein s • Gastrosp len ic—con tain s sh ort gastric an d left gastroep ip loic vein s

Visceral surface Gastrosplenic ligament Diaphragmatic surface

Short gastric vessels

Gastric impression

Renal impression

Hilum

Splenorenal (lienorenal) ligament Splenic artery Left gastro-omental (gastroepiploic) vessels Splenic vein Colic impression Spleen in situ Short gastric vessels in gastrosplenic ligament Stomach (cut)

Spleen

Left kidney Tail of pancreas

Splenic artery and vein

Transverse colon Splenorenal (lienorenal) ligament

Figu re 22-31

632

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

CONTENTS OF THE ABDOMEN • Kidney, Ureter, and Suprarenal Gland

22

KIDNEY

• • •

• • • • • • • •

Paired organ s Is retrop eriton eal Has m u ltip le fu n ction s, with roles in clu din g: • Filtration of blood • Regu lation of electrolytes • Regu lation of blood p ressu re • Prod u ction of h orm on es Nep h ron is th e fu n ction al u n it Located between T12 an d L3, with h ilu m at L1 Left kid n ey is sligh tly larger th an th e righ t kidn ey Righ t kid n ey is sligh tly in ferior to th e left kid n ey owin g to p resen ce of th e liver Su rrou n ded by a tou gh cap su le Divid ed in to: • Cortex • Med u lla Receives arterial su p p ly from ren al vein s Receives exten sive au ton om ic n erve su p p ly

URETER

• • • •

Is retrop eriton eal Carries u rin e from kidn ey to th e blad der Begin s at h ilu m , or L1, an d travels in ferior to th e bladd er Com m on sites of kid n ey ston es in clu de: • Uterop elvic ju n ction • Crossin g iliac vein s on p elvis • Ju n ction with bladd er

SUPRARENAL GLAND

• • •

•

Also kn own as adrenal gland Paired glan ds of en d ocrin e typ e Divid ed in to: • Cortex—resp on sible for p rod u ction of m in eralocorticoid s, glu cocorticoid s, an d an d rogen s • Med u lla—resp on sible for catech olam in es via sym p ath etic resp on se (“ igh t or igh t”) Receives th reefold arterial su p p ly: • Su p erior su p raren al—from in ferior p h ren ic artery • Mid dle su p raren al—from aorta • In ferior su p raren al—from ren al artery Left suprarenal gland

Right suprarenal gland

Celiac trunk Left kidney Left renal artery and vein

Right kidney Right renal artery and vein

Superior mesenteric artery (cut) Right ureter

Figu re 22-32 INTRO DUCTIO N TO THE UP P ER LIMB, BACK, THO RAX, AND ABDO MEN

633

22

CONTENTS OF THE PELVIS • Male • • • • •

Bladd er Prostate Sem in al vesicle Du ctu s d eferen s Rectu m Paramedian (sagittal) dissection Ductus (vas) deferens

External iliac vessels

Urinary bladder and fascia Ureter (cut)

Peritoneum

Seminal vesicle

Rectus abdominis muscle

Rectovesical pouch

Anterior layer of rectus sheath

Rectum

Transversalis fascia

Rectoprostatic (Denonvilliers) fascia

Umbilical prevesical fascia Subcutaneous tissue

Fatty (Camper) membrane (Scarpa)

Prostate (covered by fascia) Pelvic diaphragm (levator ani muscle)

Superior pubic ramus (cut)

Ischiopubic ramus (cut)

Fundiform ligament of penis

Deep transverse perineal muscle

Suspensory ligament of penis Deep dorsal vein of penis

Perineal body

Corpus cavernosum

External anal Deep sphincter Superficial muscle Subcutaneous Deep perineal (investing or Gallaudet) fascia

Deep (Buck) fascia of penis Corpus spongiosum Superficial (dartos) fascia of penis and scrotum Septum of scrotum

Superficial perineal (Colles) fascia (inferior fascia of superficial perineal space) Superficial (dartos) fascia of scrotum

Testis

Areolar tissue and vesical venous plexus in retropubic (prevesical) space

External spermatic fascia

Urachus

Median (sagittal) section Vesical fascia Rectovesical pouch Rectum

Apex Fundus Urinary bladder Body Trigone Neck Pubic symphysis Fundiform ligament of penis

Seminal vesicle Prostate Rectoprostatic (Denonvilliers) fascia

Suspensory ligament of penis Inferior (arcuate) pubic ligament

Sphincter urethrae muscle

Transverse perineal ligament (anterior thickening of perineal membrane)

Bulbourethral (Cowper) gland

Perineal membrane Corpus cavernosum

Perineal body

Corpus spongiosum

Bulbospongiosus muscle Deep perineal (investing or Gallaudet) fascia

Superficial (dartos) fascia of penis and scrotum

Superficial perineal (Colles) fascia

Deep (Buck) fascia of penis

Buck fascia

Superficial perineal space Prepuce Glans penis and external urethral meatus

Septum of scrotum Navicular fossa

Figu re 22-33

634

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

CONTENTS OF THE PELVIS • Female • • • •

22

Bladd er Uteru s (an d u terin e tu be) an d vagin a Ovary Rectu m Paramedian (sagittal) dissection Ureter

Uterine (fallopian) tube

Vesicouterine pouch

O vary

Rectouterine pouch (of Douglas)

Ligament of ovary Peritoneum (cut edge) Round ligament of uterus

Rectum

Broad ligament (cut) Superior pubic ramus (cut)

Ureter

Body of clitoris

Pelvic diaphragm (levator ani muscle)

Ischiocavernosus muscle

Vagina

Labia minora Labium majus Inferior pubic ramus (cut)

External anal sphincter muscle Urinary bladder Deep transverse perineal muscle (cut)

Median (sagittal) section Suspensory ligament of ovary Uterine (fallopian) tube O vary

Sacral promontory Vesicouterine pouch Uterosacral ligament Ureter Rectouterine pouch (of Douglas)

External iliac vessels

Cervix of uterus

Ligament of ovary

Posterior part of vaginal fornix

Body of uterus Round ligament of uterus (ligamentum teres)

Anterior part of vaginal fornix

Fundus of uterus Urinary bladder

Rectum

Pubic symphysis

Vagina

Urethra

Levator ani muscle

Sphincter urethrae Crus of clitoris Deep dorsal vein of clitoris Labium majus External urethral orifice Labium minus Vaginal orifice Superficial transverse perineal muscle

Anal canal External anal sphincter muscle

Anus Perineal membrane Deep transverse perineal muscle

Figu re 22-34

INTRO DUCTIO N TO THE UP P ER LIMB, BACK, THO RAX, AND ABDO MEN

635

22

VASCULAR SUPPLY • Upper Limb ARTERIAL SUPPLY OF THE AXILLA

• • •

•

Axillary artery—d ivid ed in to 3 p arts based on its relation sh ip to th e p ectoralis m in or: 1st p art • Su p erior th oracic—su p p lies 1st 2 in tercostal sp aces 2n d p art • Th oracoacrom ial • Pectoral • Acrom ial • Deltoid—accom p an ies cep h alic vein • Clavicular • Lateral th oracic—follows in ferior border of p ectoralis m in or to th orax 3rd p art • Su bscap u lar • Scapular circum f ex—located in trian gu lar sp ace • Thoracodorsal—p asses with th oracod orsal n erve to latissim u s d orsi • Posterior h u m eral circu m ex—travels in q u adran gu lar sp ace with axillary n erve • An terior h u m eral circu m ex

Anterior view Transverse cervical artery Thyrocervical trunk

Suprascapular artery

Subclavian artery Dorsal scapular artery

1

Anterior circumflex humeral artery Posterior circumflex humeral artery

2

Superior thoracic artery Thoracoacromial artery

3

Subscapular artery Circumflex scapular artery 1, 2, 3 indicate 1st, 2nd, and 3rd parts of axillary artery

Brachial artery Thoracodorsal artery Lateral thoracic artery

Figu re 22-35

636

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

VASCULAR SUPPLY • Upper Limb

22

ARTERIAL SUPPLY OF THE BRACHIUM • Brachial artery—begins at inferior border of teres m ajor • Profunda brachii • Middle collateral • Radial collateral • Supraduodenal ulnar collateral—passes with ulnar nerve posterior to m edial epicondyle • Inferior ulnar collateral • Muscular branches

ARTERIAL SUPPLY OF THE ANTEBRACHIUM • Brachial artery—divides into: • Radial • Radial recurrent • Palm ar carpal branch • Superf cial palm ar branch • Ulnar • Anterior ulnar recurrent • Posterior ulnar recurrent • Com m on interosseous • Palm ar carpal branch

Brachium

Thoracoacromial artery Axillary artery

Superior thoracic artery

Anterior circumflex humeral artery

Lateral thoracic artery

Posterior circumflex humeral artery

Subscapular artery

Brachial artery Profunda brachii (deep brachial) artery

Radial collateral artery Middle collateral artery Radial recurrent artery

Antebrachium

Brachial artery

Circumflex scapular artery Thoracodorsal artery Level of lower margin of teres major muscle is landmark for name change from axillary to brachial artery

Ulnar artery Radial artery

Common interosseous artery Superior ulnar collateral artery Inferior ulnar collateral artery Anterior interosseous artery Ulnar artery Anterior ulnar recurrent artery Posterior ulnar recurrent artery Recurrent interosseous artery Common interosseous artery Posterior interosseous artery Anterior interosseous artery Radial artery Ulnar artery Superficial palmar branch of radial artery

Figu re 22-36

INTRO DUCTIO N TO THE UP P ER LIMB, BACK, THO RAX, AND ABDO MEN

637

22

VASCULAR SUPPLY • Upper Limb CARPUS, METACARPUS, AND PHALANGES Ulnar

• • • •

Dorsal carp al bran ch Deep bran ch of th e u ln ar Palm ar carp al bran ch Su p er cial p alm ar arch • Com m on p alm ar d igital • Prop er p alm ar d igital

Ra dia l

• • •

Prin cep s p ollicis Rad ialis in d icis Deep p alm ar arch

Palmar digital arteries Common palmar digital arteries Palmar metacarpal arteries Radialis indicis artery Digital arteries and nerves of thumb Princeps pollicis artery Deep palmar branch of ulnar artery and deep branch of ulnar nerve

Deep palmar (arterial) arch and deep branch of ulnar nerve Superficial palmar branch of radial artery

Palmar carpal branches of radial and ulnar arteries

Radial artery

Ulnar artery and nerve Posterior (dorsal) view Dorsal branches of palmar digital branches of ulnar nerve and of palmar digital arteries to dorsum of middle and distal phalanges of 5th and ulnar ½ of 4th fingers

Dorsal metacarpal arteries

Dorsal digital arteries

Dorsal carpal (arterial) arch Dorsal carpal branch of ulnar artery Radial artery in anatomic snuffbox

Figu re 22-37

638

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

VASCULAR SUPPLY • Upper Limb

22

VEINS

2 typ es of vein s: • Su p er cial—lie in su p er cial fascia • Cep h alic • Basilic • Deep (h ave eith er): • Sin gle sim ilar-sized vein followin g th e artery of th e u p p er lim b (e.g., su bclavian vein or axillary vein ) • Ven a com itan s—accom p an yin g vein • A p airin g of vein s with both su rrou n din g th e artery • Typ ically, an y vein s th at are d istal to th e axillary vein is a ven a com itan s (e.g., brach ial vein s, u ln ar vein s, an d rad ial vein s), wh ich are p aired arou n d th e artery of th e sam e n am e

Anterior view

Cephalic vein

Basilic vein

Median cubital vein

Basilic vein

Figu re 22-38

INTRO DUCTIO N TO THE UP P ER LIMB, BACK, THO RAX, AND ABDO MEN

639

22

VASCULAR SUPPLY • Thorax ARTERIAL SUPPLY OF THE THORAX Thoracic Wall

•

•

In tern al th oracic—arises from su bclavian artery • Pericard iacop h ren ic (d oes n ot su p p ly wall) • Term in ates as: • Mu scu lop h ren ic • Su p erior ep igastric In tercostal arteries • Posterior in tercostal • 2 (Costocervical tru n k) • 9 (Th oracic aorta) • 1 Su bcostal (th oracic aorta) • An terior in tercostal • 6 (In tern al th oracic) • 3 (Mu scu lop h ren ic)

Visceral Contents

• •

•

Esop h agu s (in Th orax) • Esop h ageal (th oracic aorta) Lu n gs • Bron ch ial • Righ t (3rd p osterior in tercostal artery) • 2 left (th oracic aorta) Diap h ragm • Su p erior p h ren ic (th oracic aorta) • Pericard iacop h ren ic (in tern al th oracic) • Mu scu lop h ren ic (in tern al th oracic) • In ferior p h ren ic (abd om in al aorta)

VEINS

•

640

Azygos system • Posterior in tercostal vein s • Esop h ageal vein s • Bron ch ial vein s • Righ t sid e of th orax • Right suprem e intercostal vein • Right superior intercostal vein • Left side of th orax • Left suprem e intercostal vein • Left superior intercostal vein • Accessory hem iazygos vein • Hem iazygos vein

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

VASCULAR SUPPLY • Thorax Internal view

22

Common carotid artery

Anterior scalene muscle

Inferior thyroid artery

Subclavian artery and vein

Vertebral artery

Brachiocephalic vein

Brachiocephalic trunk Subclavian artery and vein Brachiocephalic vein

Phrenic nerve and pericardiacophrenic artery and vein

Internal thoracic artery and vein

Internal thoracic artery and vein

Anterior intercostal arteries and veins and intercostal nerve

Anterior intercostal arteries and veins and intercostal nerve

Internal intercostal muscles Innermost intercostal muscles Transversus thoracis muscle

Diaphragm

Musculophrenic artery and vein

Transversus abdominis muscle

Superior epigastric artery and veins

Internal thoracic artery and veins

Esophageal branch of Inferior thyroid artery Subclavian artery Arch of aorta Esophageal branch of right bronchial artery Inferior left bronchial artery and esophageal branch

Esophageal branches of thoracic aorta

Esophageal branch of left gastric artery

Common variations: Esophageal branches may originate from left inferior phrenic artery and/or directly from celiac trunk. Branches to abdominal esophagus may also come from splenic or short gastric arteries.

Figu re 22-39

INTRO DUCTIO N TO THE UP P ER LIMB, BACK, THO RAX, AND ABDO MEN

641

22

VASCULAR SUPPLY • Abdomen UNPAIRED VISCERAL ARTERIES CELIAC ARTERY (ARTERY OF THE FOREGUT)—ARISES AT T12 • Left gastric • Com m on hepatic • Proper hepatic • Right gastric • Left hepatic • Right hepatic • Cystic • Gastroduodenal • Supraduodenal • Right gastroepiploic • Anterior and posterior superior pancreaticoduodenal • Splenic • Pancreatic branches • Short gastric • Left gastroepiploic

Celiac trunk Left hepatic artery Right hepatic artery

Left gastric artery Splenic artery Esophageal branch of left gastric artery Short gastric arteries

Cystic artery

Proper hepatic artery Right gastric artery Supraduodenal artery

Splenic branches of splenic artery Left gastro-omental (gastroepiploic) artery

Posterior superior, Anterior superior pancreaticoduodenal arteries

Common hepatic artery Right gastro-omental (gastroepiploic) artery Gastroduodenal artery

Anterior superior pancreaticoduodenal artery Posterior superior pancreaticoduodenal (retroduodenal) artery Posterior inferior pancreaticoduodenal artery (phantom) Anterior inferior pancreaticoduodenal artery Inferior (common) pancreaticoduodenal artery Superior mesenteric artery

Figu re 22-40

642

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

VASCULAR SUPPLY • Abdomen

22

SUPERIOR MESENTERIC ARTERY (ARTERY OF THE MIDGUT)—ARISES AT L1 • Anterior and posterior inferior pancreaticoduodenal • Jejunal m esenteric • Arterial arcades and vasa recta • Ileal m esenteric • Arterial arcades and vasa recta • Ileocolic • Appendicular • Right colic • Middle colic

INFERIOR MESENTERIC ARTERY (ARTERY OF THE HINDGUT)—ARISES AT L3 • Left colic • Sigm oid • Superior rectal

Inferior pancreaticoduodenal arteries

(Common portion) Posterior Anterior

Superior mesenteric artery and vein Middle colic artery (cut) Right colic artery

Straight arteries (arteriae rectae)

Ileocolic artery

Inferior mesenteric artery Left colic artery

Sigmoid arteries

Jejunal and ileal (intestinal) arteries Anastomotic loops (arcades)

Superior rectal artery

Figu re 22-41

INTRO DUCTIO N TO THE UP P ER LIMB, BACK, THO RAX, AND ABDO MEN

643

22

VASCULAR SUPPLY • Abdomen PAIRED VISCERAL AND PARIETAL ARTERIES

•

•

Paired visceral bran ch es—p aired bran ch es su p p lyin g organ s • Ren al—arises at L2 • Gon ad al—arises between L2 an d L3 • Testicu lar • Ovarian • Su p raren al • Su p erior—arises from th e in ferior p h ren ic • Mid dle—arises from th e aorta • In ferior—arises from th e ren al Paired p arietal (bod y wall) bran ch es—p aired bran ch es su p p lyin g th e wall • In ferior p h ren ic • Lu m bar—4 arise from th e aorta

Inferior phrenic arteries

Superior suprarenal arteries

Celiac trunk

Middle suprarenal artery Superior mesenteric artery

Middle suprarenal artery

Inferior suprarenal artery

Right renal artery

Left renal artery

Psoas major muscle (cut) Subcostal artery

Testicular (ovarian) arteries

1st to 4th right lumbar arteries

Inferior mesenteric artery

Common iliac arteries

Median sacral artery

5th lumbar artery Internal iliac artery Testicular (ovarian) artery External iliac artery

Inferior epigastric artery Inferior epigastric artery

Medial umbilical ligament (occluded part of umbilical artery)

Femoral artery

Anterior abdominal wall (turned down) Inferior vena cava Right and left inferior phrenic arteries

Esophagus Left inferior phrenic vein

Celiac trunk Right superior suprarenal arteries

Left superior suprarenal arteries Left middle suprarenal artery

Right middle suprarenal artery

Left suprarenal vein

Right suprarenal vein Left inferior suprarenal artery

Right inferior suprarenal artery

Left renal artery and vein

Right renal artery and vein

Left 2nd lumbar vein and communication to ascending lumbar vein

Ureteric branch of right renal artery

Superior mesenteric artery (cut)

Right testicular (ovarian) artery and vein

Left testicular (ovarian) artery and vein

Abdominal aorta Inferior vena cava

Inferior mesenteric artery

Figu re 22-42

644

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

VASCULAR SUPPLY • Abdomen

22

VENOUS SUPPLY OF THE VISCERA

• • • • • • •

Vein s th at drain th e abd om in al viscera closely follow th e celiac, su p erior m esen teric, an d in ferior m esen teric arteries Th ese vein s even tu ally d rain in to th e h ep atic p ortal vein , wh ich p asses in to th e liver, allowin g it to clear th e blood of an y wastes an d to store n u trien ts Th e h ep atic p ortal vein is form ed by th e: • Su p erior m esen teric vein • Sp len ic vein After p assin g th rou gh th e liver, th e blood retu rn s in to th e system ic system via h ep atic vein s in to th e in ferior ven a cava Becau se th e vein s in th is region lack valves, th ey take th e p ath of least resistan ce If th ere is an obstru ction in th e p ath of th e h ep atic p ortal vein , th e blood will attem p t to retu rn toward th e h eart by byp assin g th e block an d u sin g th e an astom osis between th e p ortal system an d th e system ic system (ven a cava) Th ere are 4 m ajor collaterals between th e p ortal an d system ic system s: • Esop h ageal • Parau m bilical • Rectal • Retrop eriton eal

Umbilicus Falciform ligament and round ligament of liver Paraumbilical veins

Esophageal veins Blood from superior mesenteric vein Blood from splenic, gastric, and inferior mesenteric veins Mixture of above 2

1 2

Caval tributaries

Right gastric vein Hepatic portal vein

2

Posterior, Anterior superior pancreaticoduodenal veins

Short gastric veins

4

Left gastro-omental (gastro-omental) vein

4

Superior mesenteric vein Posterior, Anterior inferior pancreaticoduodenal 4 veins

4

4 4

Splenic vein Right gastro-omental (gastroepiploic) vein

4

Middle colic vein Right colic vein

Left gastric vein

1

4

Inferior mesenteric vein Left colic vein Sigmoid veins

4

4

Ileocolic vein Anterior, Posterior cecal veins

Left and right superior rectal veins 4

Appendicular vein Portacaval anastomoses 1 Esophageal 3 Rectal 2 Paraumbilical 4 Retroperitoneal

3

Middle rectal veins Levator ani muscle Inferior rectal veins

Figu re 22-43

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645

22

VASCULAR SUPPLY • Abdomen HEPATIC PORTAL VEIN

•

•

646

Min or d irect tribu taries in clu d e: • Cystic vein • Righ t gastric vein • Left gastric vein • Esop h ageal vein s • Posterior su p erior p an creaticod u od en al vein Major tribu taries in clu de: • Su p erior m esen teric vein • Righ t gastroep ip loic vein • An terior su p erior p an creaticod u oden al vein • An terior in ferior p an creaticodu od en al vein • Posterior in ferior p an creaticod u od en al vein • Mid dle colic vein • Jeju n al m esen teric vein s • Ven ou s an astom otic loop s • Vasa recta • Ileal m esen teric vein s • Ven ou s an astom otic loop s • Vasa recta • Ileocolic vein • Righ t colic vein • Sp len ic vein • Pan creatic bran ch es • Sh ort gastric vein • Left gastroep ip loic vein • In ferior m esen teric—som etim es join s to form h ep atic p ortal vein • Left colic vein • Sigm oid vein s • Su p erior rectal vein

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

VASCULAR SUPPLY • Abdomen

22

VENOUS SUPPLY OF THE POSTERIOR ABDOMINAL WALL

• •

Vein s of th e p osterior abdom in al wall drain in to th e in ferior ven a cava Tribu taries in clu de: • Hep atic vein s • Righ t h ep atic vein • Mid dle h ep atic vein • Left h ep atic vein • In ferior p h ren ic vein • Su p raren al vein • Ren al vein • Left gon ad al vein • Testicu lar • Ovarian • Righ t gon ad al vein • Testicu lar • Ovarian • Su bcostal vein • Lu m bar vein s

Inferior phrenic veins

Hepatic veins Left suprarenal veins and anastomosis with inferior phrenic vein

Right renal vein

Left renal vein

Psoas major muscle (cut)

O varian (testicular) veins

Subcostal vein 1st to 4th right lumbar veins

Ascending lumbar veins

Common iliac vein

Common iliac vein

O varian (testicular) veins and ureter (cut)

Internal iliac vein

Median sacral vein

External iliac vein

Inferior epigastric vein Inferior epigastric vein (cut) Femoral vein Great saphenous vein Anterior abdominal wall (turned down)

Figu re 22-44

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647

22

VASCULAR SUPPLY • Pelvis ARTERIAL SUPPLY OF THE PELVIS

• •

Extern al iliac • In ferior ep igastric • Deep circu m ex iliac In tern al iliac • Posterior d ivision • Iliolu m bar • Lateral sacral • Su p erior glu teal • An terior d ivision • Um bilical • Su p erior vesical • Obtu rator • Uterin e (in fem ale) • Vagin al (in fem ale) • In ferior vesical • Mid dle rectal • In tern al p u d en dal • In ferior glu teal

Right paramedian section: lateral view O bturator artery Umbilical artery (patent part) Superior gluteal artery Uterine artery Middle rectal artery Piriformis muscle Internal pudendal artery Inferior gluteal artery (Ischio-)coccygeus muscle Vaginal artery Inferior vesical artery Superior vesical arteries Internal pudendal artery Inferior rectal artery Medial umbilical ligament (occluded distal part of umbilical artery)

Abdominal aorta Inferior vena cava Right common iliac artery Left common iliac artery Ureters External iliac artery (cut) Internal iliac artery Posterior division Anterior division

O bturator canal O bturator internus muscle Levator ani muscle Inferior vena cava

Abdominal aorta Common iliac vessels Median sacral vessels External iliac vessels (cut) Internal iliac vessels Iliolumbar artery Superior gluteal artery Lateral sacral artery O bturator artery

Deep circumflex iliac vessels Inferior epigastric vessels

Umbilical artery

Right obturator vessels

Inferior gluteal artery

Left paramedian section: lateral view

Figu re 22-45

648

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

NERVE SUPPLY • Upper Limb • • •

• •

•

22

Altern atin g join in g an d bran ch in g of n erves to reorgan ize th e term in al bran ch es, with con tribu tion s from m u ltip le sp in al cord levels Origin from ven tral ram i of 5th to 8th cervical an d 1st th oracic sp in al n erves Gen eral organ ization is: • 5 ven tral ram i • 3 tru n ks • 6 division s • 3 cord s • 6 bran ch es Nerves to m u scles on ven tral an d d orsal su rfaces of u p p er lim b are derived from an terior an d p osterior d ivision s, resp ectively Location an d arterial relation s: • Ram i an d tru n ks—p osterior trian gle of n eck; su bclavian artery • Division s—beh in d clavicle; su bclavian artery an d 1st p art of axillary artery • Cord s—axilla; 2n d p art of axillary artery • Bran ch es—axilla; 3rd p art of axillary artery Key lan d m ark of M form ed by m ed ial an d lateral cord s an d term in al bran ch es

Note: Usual composition shown. Prefixed plexus has large C4 contribution but lacks T1. Postfixed plexus lacks C5 but has T2 contribution.

r io r te s an sio n rio r 3 vi te di po s o ns 3 visi di 3

c

ntral e s) e v ( s t rv Dorsal scapular 5 ro o pinal ne s f o nerve (C5) ks rami n u 3 tr Dorsal ramus To phrenic Suprascapular nerve C5 nerve (C5, 6) To subclavius nerve (C5, 6) C6 e Sup

ds r o

Lateral pectoral nerve (C5, 6, 7)

al in e s rm c h Te ran b

Musculocutaneous nerve (C5, 6, 7) Axillary nerve (C5, 6) Radial nerve (C5, 6, 7, 8, T1) Median nerve (C5, 6, 7, 8, T1) Ulnar nerve (C7, 8, T1) Inconstant contribution

t La

rio r

C7

d Mid

le

io er f In

al er

C8 r

T1

r rio e t s Po

Contribution from T2 (postfixed) l dia Me

To longus colli and scalene muscles (C5, 6, 7, 8) 1st intercostal nerve Long thoracic nerve (C5, 6, 7) Medial pectoral nerve (C8, T1) Medial brachial cutaneous nerve (T1) Medial antebrachial cutaneous nerve (C8, T1) Upper subscapular nerve (C5, 6) Thoracodorsal (middle subscapular) nerve (C6, 7, 8) Lower subscapular nerve (C5, 6)

Figu re 22-46

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649

22

NERVE SUPPLY • Upper Limb BRACHIAL PLEXUS Nerve

Source

Comments

Dorsal scapular (C5)

Ventral ram i

Passes posteriorly to lie along the m edial border of the scapula Innervates the: • Levator scapulae • Rhom boid m ajor • Rhom boid m inor

Long thoracic (C5, C6, C7)

Ventral ram i

Passes inferiorly along the serratus anterior Innervates the serratus anterior

Muscular branches

Ventral ram i

Supplies the scalenes and longus colli

Subclavius (C5, C6)

Upper trunk

Innervates the subclavius

Suprascapular (C5, C6)

Upper trunk

Innervates the: • Supraspinatus • Infraspinatus

Lateral pectoral (C5, C6, C7)

Lateral cord

Innervates the clavicular head of the pectoralis m ajor

Musculocutaneous (C5, C6, C7)

Lateral cord

Passes into the coracobrachialis to enter the exor com partm ent of the brachium After passing through the coracobrachialis, it travels distally in the brachium between the biceps brachii and the brachialis Innervates the: • Coracobrachialis • Biceps brachii • Brachialis Term inates as the lateral cutaneous nerve of the antebrachium upon exiting the distal com partm ent

Median (C5, C6, C7) from lateral head (C8, T1) from m edial head

Lateral and m edial cord

Brachium: Has no m otor or sensory branches in the arm Ante brachium: No sensory branches in antebrachium Innervates: • Pronator teres • Flexor carpi radialis longus • Palm aris longus • Flexor digitorum super cialis Has 1 m ajor m otor branch innervating the deep exor m uscles: • Flexor pollicis longus • Flexor digitorum profundus • Pronator quadratus Carpus , Me tacarpus , and Phalange s : Sensory branches: • Palm ar cutaneous branch—lateral portion of palm • Com m on palm ar digital branches—lateral portion of palm • Proper palm ar digital branches—palm ar surface of 1st, 2nd, and 3rd digits and lateral 1/ 2 of 4th digit Motor branches: Recurrent branch of m edian n. • Opponens pollicis • Abductor pollicis brevis • Flexor pollicis brevis Motor branches to 1st and 2nd lum bricals

Medial brachial cutaneous (T1)

Medial cord

Provides sensory innervation to the m edial aspect of the superior portion of the brachium Continued on next page

650

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

NERVE SUPPLY • Upper Limb

22

BRACHIAL PLEXUS—cont’d Nerve

Source

Comments

Medial antebrachial cutaneous (C8, T1)

Medial cord

Provides sensory innervation to the m edial aspect of the inferior portion of the brachium

Medial pectoral (C8, T1)

Medial cord

Innervates: • Pectoralis m inor • Sternal head of pectoralis m ajor

Ulnar (C7, C8, T1)

Medial cord

Brachium: Has no m otor or sensory branches in the arm Ante brachium: Has no sensory branches in the antebrachium Innervates: • Flexor carpi ulnaris • Flexor digitorum profundus (m edial 1/ 2) Carpus , Me tacarpus , and Phalange s : Sensory branches: • Dorsal cutaneous n.—posterior surface of m edial portion of m anus • Dorsal digital branches—dorsal aspect of 5th digit and m edial 1/ 2 of 4th digit • Palm ar cutaneous n.—m edial aspect of palm • Com m on palm ar cutaneous branches—distal portion of m edial aspect of palm • Proper palm ar digital branches—palm ar surface of 5th digit and m edial 1/ 2 of 4th digit Motor branches: Super cial ulnar n. • Palm aris brevis Deep ulnar n. • Abductor digiti m inim i • Flexor digiti m inim i brevis • Opponens digiti m inim i • Adductor pollicis • Dorsal interosseous • Palm ar interosseous • 3rd and 4th lum brical

Upper subscapular (C5, C6)

Posterior cord

Innervates the upper portion of the subscapularis

Thoracodorsal (C6, C7, C8)

Posterior cord

Innervates the latissim us dorsi

Lower subscapular (C5, C6)

Posterior cord

Innervates: • Lower portion of the subscapularis • Teres m ajor

Axillary (C5, C6)

Posterior cord

Innervates: • Deltoid • Teres m inor Has a sensory branch on the lateral aspect of the superior portion of the brachium : • Superior lateral cutaneous branch

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651

22

NERVE SUPPLY • Upper Limb BRACHIAL PLEXUS Nerve

Source

Comments

Radial (C5, C6, C7, C8, T1)

Posterior cord

Brachium: Innervates the: • Triceps brachii • Anconeus Has 2 sensory branches: • Inferior lateral cutaneous n.—sensory on lateral aspect of inferior brachium • Posterior cutaneous n.—sensory on posterior surface of brachium Ante brachium: Has 1 sensory branch: • Posterior cutaneous n. of the antebrachium Innervates the: • Brachioradialis • Extensor carpi radialis longus Divides into: • Super cial radial n. (sensory in m anus) • Deep radial n. (m otor in antebrachium ) Deep radial innervates: • Extensor carpi radialis brevis • Supinator Deep radial passes through the supinator to the posterior surface, becom ing the posterior interosseus The posterior interosseus innervates: • Extensor digitorum • Extensor carpi ulnaris • Extensor indicis • Extensor digiti m inim i • Extensor pollicis longus • Abductor pollicis longus • Extensor pollicis brevis Carpus , Me tacarpus , and Phalange s : Sensory branches: • Super cial radial nerve—dorsal aspect of m anus • Dorsal digital branches—dorsal aspect of 1st digit There are no m otor branches in the m anus

Anterior (palmar) view Supraclavicular nerves (from cervical plexus - C3, 4) Axillary nerve Superior lateral brachial cutaneous nerve (C5, 6) Radial nerve Inferior lateral brachial cutaneous nerve (C5, 6) Lateral antebrachial cutaneous nerve (C5, 6 [7]) (terminal part of musculocutaneous nerve) Radial nerve Superficial branch (C6–8) Median nerve Palmar branch and Palmar digital branches (C6–8)

Posterior (dorsal) view Supraclavicular nerves (from cervical plexus - C3, 4)

Intercostobrachial nerve (T2) and medial brachial cutaneous nerve (C8, T1, 2) Medial antebrachial cutaneous nerve (C8, T1) Ulnar nerve (C8, T1) Palmar branch Palmar digital branches

Dorsal branch and dorsal digital branches Palmar digital branches

Figu re 22-47

652

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

Axillary nerve Superior lateral brachial cutaneous nerve (C5, 6) Radial nerve Posterior brachial cutaneous nerve (C5–8) Inferior lateral cutaneous nerve Posterior antebrachial cutaneous nerve (C[5], 6–8) Lateral antebrachial cutaneous nerve (C5, 6[7]) (terminal part of musculocutaneous nerve) Radial nerve Superficial branch and dorsal digital branches (C6–8) Median nerve Palmar digital branches

NERVE SUPPLY • Posterior Abdominal Wall

22

NERVES

• • • •

• •

Su bcostal—T12 Ilioh yp ogastric—L1 Ilioin gu in al—L1 Lateral fem oral cu tan eou s n erve—L2, L3 • Gen itofem oral—L1, L2 • Gen ital bran ch —crem aster • Fem oral bran ch —sen sory on th igh Fem oral—L2, L3, L4 Obtu rator—L2, L3, L4

Iliohypogastric nerve (L1)

Genitofemoral nerve (L1, 2)

Subcostal nerve (T12) Subcostal nerve (T12)

Ilioinguinal nerve (L1)

Iliohypogastric nerve (L1) Ilioinguinal nerve (L1) Genitofemoral nerve (L1, 2) Lateral femoral cutaneous nerve (L2, 3) Lumbosacral trunks (L4, 5) O bturator nerves Accessory obturator nerve (L3, 4) (occasional)

Lateral femoral cutaneous nerve (L2, 3)

Femoral nerve Lumbosacral plexus (L4–S4)

Femoral nerve (L2–L4) Anterior femoral cutaneous branch (L2, 3)

Anterior cutaneous branch of iliohypogastric nerve (L1) Anterior scrotal (labial) branches of ilioinguinal nerve (L1) Genital branch of genitofemoral nerve (L1, 2) Femoral branches

Figu re 22-48

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653

This pa ge inte ntiona lly le ft bla nk

APPENDIX A

LYMPHATICS

•

Th e lym p h atic system is a m ajor p art o th e body’s im m u n e system th at u n ction s to: • Collect, lter, an d retu rn excess in terstitial f u id to th e ven ou s system • Absorb at an d at-solu ble vitam in s ( rom th e villi o th e sm all in testin e) • Help de en d again st m icroorgan ism s

PARTS OF THE LYMPHATIC SYSTEM Lymph

• • • • • • • •

Lym p h is a clear f u id th at com es rom excess tissu e f u id Flu id s p ass ou t o cap illaries at th e arterial en d an d bath e cells Osm otic p ressu re aids in th e retu rn o th e f u id in to th e ven ou s en d o th e cap illary Excess in terstitial f u id (con tain in g waste an d m icroorgan ism s su ch as bacteria) en ters th e lym p h atic cap illaries an d is n ow called lym p h Th e lym p h is th en ltered th rou gh lym p h n od es an d retu rn ed to th e ven ou s system Lym p h con tain s p len ti u l lym p h ocytes an d oth er wh ite blood cells Lym p h rom th e villi o th e sm all in testin e also absorbs at an d at-solu ble vitam in s Th e absorbed at m akes th e lym p h rom th is area h ave a m ilky color, an d it is n ow called ch yle

Lymphatic Vessels

• • •

Lym p h atic vessels carry lym p h in on ly 1 direction —away rom th e tissu es Lym p h atic cap illaries are located th rou gh ou t th e tissu e sp aces with in th e card iovascu lar cap illary bed s Lym p h atic cap illaries are com p osed o overlap p in g en d oth elial cells, wh ich orm a 1-way valve allowin g th e excess in terstitial tissu e f u id to en ter th e lym p h atic cap illary, bu t n ot lym p h , wh ich th en m u st travel in th e vessel away rom th e tissu e

Lymph Nodes

• • •

Lym p h atic vessels are con n ected to lym p h n od es an d lter th e lym p h Becau se lym p h atic vessels are 1-way, lym p h en ters th e lym p h n od e th rou gh a eren t lym p h vessels, wh ere it is ltered In add ition to its ltration u n ction , th e lym p h n ode h as a rich su p p ly o lym p h ocytes an d oth er wh ite blood cells th at h elp p rovide an im m u n e resp on se to ( oreign ) m icroorgan ism s

Lymphatic Ducts

• •

Lym p h atic vessels con tin u e to take lym p h toward th e h eart to join th e ven ou s system at an area o low p ressu re Th ere are 2 con n ection s in to th e ven ou s system at th e ju n ction o th e in tern al ju gu lar vein an d th e su bclavian vein : • Righ t lym p h atic d u ct—carries lym p h rom righ t arm , righ t th orax, an d righ t sid e o h ead • Th oracic d u ct—carries lym p h rom rem ain d er o th e bod y

LYMPHATICS • General Overview Tonsils

• • •

Ton sils are lym p h atic tissu e th at are associated with th e im m u n e fu n ction s th at d efen d th e bod y Ton sils are p art of th e m u cosa-associated lym p h atic tissu e (MALT) system of lym p h oid tissu e Th ere are 4 sets of ton sils, togeth er kn own as Wald eyer’s rin g, located in th e n asop h aryn x an d orop h aryn x th at gu ard again st foreign m icroorgan ism s: • Ph aryn geal ton sils (aden oids) • Tu bal ton sils (very sm all, located at en tran ce of au d itory tu be in n asop h aryn x) • Palatin e ton sils (between p alatoglossal an d p alatop h aryn geal fold s) • Lin gu al ton sils (on p osterior 1/ 3 of th e ton gu e)

OTHER LYMPHOID ORGANS

• •

Th ym u s Sp leen

Lymphatics of upper limb

Tonsils Thoracic duct

Cervical lymph nodes

Right lymphatic duct Thymus gland Mediastinal lymph nodes Axillary lymph nodes

Thoracic duct

Lymph nodes of mammary gland Cisterna chyli

Spleen Lumbar lymph nodes

Lymphoid nodules of intestine

Iliac lymph nodes Inguinal lymph nodes

Bone marrow Drainage of right lymphatic duct

Drainage of thoracic duct Lymphatics of lower limb

Figu re A-1

656

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

LYMPHATICS • Lymphatics of the Head and Neck •

•

• •

Th ere are m u ltip le ways to classi y lym p h atics o th e h ead an d n eck; on e way is to divid e lym p h n odes in to: • Su p erf cial n od es • Deep n odes Th is classif cation resu lts in 4 typ es o lym p h n odes: • Su p erf cial lym p h n od es o th e h ead • Deep lym p h n od es o th e h ead • Su p erf cial lym p h n od es o th e n eck • Deep lym p h n od es o th e n eck • Up p er d eep cervical • Lower d eep cervical A ter bein g f ltered by lym p h n od es (p rim ary n od e), th e lym p h will con n ect to an oth er lym p h n od e an d be f ltered again (secon dary n od e) Even tu ally, all lym p h will drain in to th e in erior grou p o deep cervical lym p h n od es wh ere th ey join th e ju gu lar lym p h tru n ks, wh ich even tu ally create th e righ t lym p h atic d u ct (on th e righ t sid e) an d th e th oracic d u ct (on th e le t sid e), wh ich em p ties in to th e ven ou s system at th e ju n ction o th e in tern al ju gu lar vein an d th e brach iocep h alic vein SUPERFICIAL LYMPH NODES OF THE HEAD Node

Location

Structure(s) Drained

Facial

Along cheek

Superf cial ace Cheek

Parotid (superf cial nodes)

Along superf cial lobe o parotid gland and anterior to the ear

Upper parts o ace Lateral parts o ace Anterior scalp Lateral scalp External ear (anterior portion)

Mastoid

Along m astoid process superf cial to the attachm ent o the sternocleidom astoid

Lateral scalp External ear (posterior portion)

Occipital

Along the apex o the posterior triangle where the trapezius and sternocleidom astoid converge near the superior nuchal line

Posterior scalp Upper neck

Subm ental

Between anterior bellies o the digastric in Subm ental triangle

Tip o tongue Medial portion o in erior lip Mandibular incisors and associated gingiva Anterior oor o the m outh Chin

Subm andibular

In erior to m andible between anterior and posterior digastrics in the Subm andibular triangle

Superior lip Lateral portion o lower lip Cheek Hard palate So t palate Teeth and associated gingiva (except m andibular incisors) Tongue (anterior 2/ 3—except the tip and central 1/ 3) Floor o the m outh Sublingual gland Subm andibular gland Nose and nasal vestibule Nasal cavity (anterior portion) Medial eyelids Frontal sinus Anterior and m iddle ethm oid sinus Maxillary sinus Subm ental nodes

LYMP HATICS

657

LYMPHATICS • Lymphatics of the Head and Neck SUPERFICIAL LYMPH NODES OF THE NECK Node

Location

Structure(s) Drained

Posterior cervical Along external jugular vein Skin o angle o m andible nodes External ear (in erior portion) Parotid region Anterior cervical nodes

Along pretracheal ascia with anterior triangle

Skin o anterior neck in erior to the hyoid

DEEP LYMPH NODES OF THE HEAD Node

Location

Structure(s) Drained

Parotid (deep)

Deep in parotid gland

Tym panic cavity Parotid gland Auditory tube External acoustic m eatus (portion)

Retropharyngeal

Posterior to superior constrictor at the base o the skull im m ediately anterior to the atlas

Sphenoid sinus Posterior ethm oid sinus Nasal cavity (m ajority) So t palate Nasopharynx Auditory tube Oropharynx Pharyngeal tonsils Tubal tonsils

DEEP LYMPH NODES OF THE NECK

658

Node

Location

Structure(s) Drained

Upper deep cervical nodes

Along superior portion o the internal jugular vein superior to the om ohyoid

Occipital nodes Mastoid nodes Parotid nodes (superf cial and deep) Subm andibular nodes Superf cial cervical nodes Retropharyngeal nodes Palatine tonsil

Jugulodigastric node (subset o upper deep cervical nodes)

Along lower portion o the Tongue (posterior 1/ 3) internal jugular vein Palatine tonsil Occasionally m andibular m olars

Juxtavisceral nodes (includes: Prelaryngeal Pretracheal Paratracheal)

Midline nodes located along anatom ic area or which they are nam ed

Larynx Thyroid gland Trachea Esophagus

In erior deep cervical nodes

Along in erior portion o internal jugular vein near the interm ediate tendon o the om ohyoid

Upper deep cervical nodes Jugulodigastric nodes Tongue (anterior 2/ 3—except tip and lateral m argin) Superf cial cervical nodes Transverse cervical nodes

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

LYMPHATICS • Lymphatics of the Head and Neck

Superficial parotid nodes (deep parotid nodes deep to and within parotid gland)

Subparotid node Facial nodes Nasolabial Buccinator

O ccipital nodes Mastoid nodes Sternocleidomastoid nodes Superior lateral superficial cervical (external jugular) node Accessory nerve (XI)

Mandibular nodes Submandibular nodes

Jugulodigastric node

Submental nodes

Posterior lateral superficial cervical (spinal accessory) nodes

Suprahyoid node Superior deep lateral cervical (internal jugular) nodes

Intercalated node Inferior deep lateral cervical (scalene) node

Superior thyroid nodes Jugulo-omohyoid node

Thoracic duct

Anterior deep cervical (pretracheal and thyroid) nodes (deep to infrahyoid muscles)

Transverse cervical chain of nodes

Anterior superficial cervical nodes (anterior jugular nodes) Jugular trunk Supraclavicular nodes Subclavian trunk and node

Figu re A-2

LYMP HATICS 659

LYMPHATICS • Lymphatics of the Head and Neck

Accessory nerve (XI) Hypoglossal nerve (XII) Rectus capitis anterior muscle (cut)

Pharyngobasilar fascia Retropharyngeal nodes Internal jugular vein Digastric muscle (posterior belly) Sternocleidomastoid muscle Intercalated node Jugulodigastric node

Deep lateral cervical (internal jugular) nodes Jugulo-omohyoid node Apical collecting vessels Central collecting vessels Marginal collecting vessels Basal collecting vessels Communication to opposite side

Lymphatic drainage of pharynx: posterior view

Lymphatic drainage of tongue

Submental node Submandibular node Jugulodigastric node Deep lateral cervical (internal jugular) nodes Jugulo-omohyoid node

Figu re A-3

66 0 NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

APPENDIX B

QUESTIONS AND ANSWERS

CHAPTER 1 DEVELOPMENT OF THE HEAD AND NECK 1. All  of  th e  followin g  are  stru ctu res  d erived  from   n eu ral  crest  except: A.  In cu s B. An terior  ligam en t  of  th e  m alleu s C.  Th yroid   cartilage D.  Lesser  corn u   of  th e  h yoid E. Styloid   p rocess 2. W h at  ad u lt  stru ctu re  arises  from   th e  1st  p h aryn geal  p ou ch ? A.  Tym p an ic  cavity B. Th ym u s C.  Su p erior  p arath yroid   glan d D.  Ultim obran ch ial  bod y E. Ton sillar  fossa 3. All  of  th e  followin g  cran ial  n erves  p rovide  gen eral  som atic  afferen t  (GSA) bers  to  th e  ep ith eliu m   of  th e  ton gu e  except: A.  Glossop h aryn geal B. Facial C.  Vagu s D.  Trigem in al E. C  an d   D

CHAPTER 2 OSTEOLOGY

N S W E R

6. A  h orizon tal  fractu re  of  th e  m id face  exten d in g  from   th e  lateral  m argin   of  th e  p iriform   ap ertu re  to  th e  p terygoid   p lates  su p erior  to  th e  ap ices  of  th e  teeth   is  term ed : A.  Le  Fort  I B. Le  Fort  II C.  Le  Fort  III D.  Jefferson E. Han gm an ’s

S

5. Th e  an terior  tym p an ic  artery  p asses  th rou gh   th e: A.  Tym p an ic  can alicu lu s B. Ju gu lar  foram en C.  Hiatu s  for  th e  greater  p etrosal  n erve D.  Foram en   ovale E. Petrotym p an ic ssu re

A

4. Th e  op h th alm ic  artery  p asses  th rou gh   th e: A.  Op tic  can al B. In ferior  orbital ssu re C.  Su p erior  orbital ssu re D.  Con d ylar  can al E. Sp h en op alatin e  foram en

A E A B A C

6 5 4 3 2 1

Qu ESTiONS AND ANSw ERS

CHAPTER 3 BASiC NEu ROANATOMY AND CRANiAL NERVES 7. W h ich   of  th e  followin g  is  a  collection   of  n erve  cell  bod ies  located  in   th e  p erip h eral  n ervou s  system ? A.  Su p erior  salivatory  n u cleu s B. Ocu lom otor  n u cleu s C.  Tractu s  solitariu s D.  Trigem in al  gan glion E. Trigem in oth alam ic  tract 8. W h ich   of  th e  followin g  is  resp on sible  for  p rop riocep tion   of  th e  trigem in al  n erve? A.  Prin cip al  sen sory  n u cleu s  of  V B. Motor  n u cleu s  of  V C.  Sp in al  n u cleu s  of  V D.  Nu cleu s  am bigu u s E. Mesen cep h alic  n u cleu s  of  V 9. W h ich   of  th e  followin g  fu n ction al  colu m n s  is  resp on sible  for  in n ervatin g  bran ch ial  arch   m u scles? A.  GSE B. SVE C.  GVE D.  SSA E. SVA

CHAPTER 4 THE NECK 10.  W h ich   of  th e  followin g  m u scles  is  a  bou n d ary  for  th e  carotid  an d   su bm an dibu lar  trian gles? A.  An terior  d igastric B. Posterior  d igastric C.  Su p erior  belly  of  th e  om oh yoid D.  In ferior  belly  of  th e  om oh yoid E. Stern ocleidom astoid 11.  W h ich   of  th e  followin g  m u scles  is  in n ervated  by  th e  ven tral  ram i  of  C1? A.  An terior  d igastric B. Styloh yoid C.  Myloh yoid D.  Th yroh yoid E. Hyoglossu s 12.  W h ich   vessel  is  th e  origin   of  th e  su bm en tal  artery? A.  Lin gu al B. Facial C.  Maxillary D.  Su p erior  laryn geal E. Ascen d in g  p h aryn geal

A

N

S

WE

R

S

13.  All  of  th e  followin g  cross  th e  stern ocleid om astoid   except: A.  Extern al  ju gu lar  vein B. Great  au ricu lar  n erve C.  In vestin g  layer  of  d eep   cervical  fascia D.  Su p rascap u lar  n erve D 31 E. Tran sverse  cervical  n erve B D B B E D

21 11 01 9 8 7

662

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Qu est io n s a n d a n sw er s

CHa Pt er 5 s Ca LP a n d Mu s CLes o F Fa Cia L eXPr ess io n 14.  All  o   th e ollowin g  statem en ts  regard in g acial  an atom y  are  correct  except: A.  Th e  skin   is  attach ed   to  th e  u n d erlyin g  bon e  by  retain in g  ligam en ts  wh ich   are  in   con stan t  location s  on   th e ace B. Th e  su p erf cial ascia  o   th e ace  h as  varyin g  am ou n ts  o   ad ip ose  tissu e C.  Th e  su p erf cial  m u scu lar  ap on eu rotic  system   (SMAS)  is  d eep   to  th e  su p erf cial  ascia  an d   p rovid es  a  su rgical  p lan e or  su rgery  o   th e ace D.  Th e  m u scles  o  acial  exp ression   are  also  called   m im etic  m u scles E. Th ere  is  d eep  ascia  alon g  th e ace 15.  W h ich   o   th e ollowin g  m u scles  d ep resses  th e  corn ers  o   th e  m ou th   in   an   in erior  an d   lateral  d irection ? A.  Dep ressor  labii  in erioris B. Men talis C.  Dep ressor  an gu li  oris D.  Risoriu s E. Orbicu laris  oris 16.  W h ich   o   th e ollowin g  m u scles  d oes  not  con n ect  th e  su p erf cial  vein s  o   th e  ace  to  th e  d eep   vein s  o   th e ace  in   th e  “d an ger  area  o   th e ace”? A.  Su p erior  op h th alm ic  vein B. Deep  acial  vein C.  Tran sverse acial  vein D.  In raorbital  vein E. In erior  op h th alm ic  vein 17.  W h ich   bran ch (es)  o   th e acial  n erve  is/ are  resp on sible or  in n ervatin g  th e  orbicu laris  ocu li? A.  Tem p oral  on ly B. Zygom atic  on ly C.  Tem p oral  an d   zygom atic D.  Bu ccal  on ly E. Zygom atic  an d   bu ccal

CHa Pt er 6 Pa r o t id Fo ssa a n d GLa n d

Q u e s t io n s a n d a n s w e r s

N S W E R

20.  All  o   th e ollowin g  statem en ts  con cern in g  th e  p arotid   glan d   are  correct  except: A.  Th e  p arotid   glan d   is  th e  largest  salivary  glan d B. Th e  p arotid   glan d   is  resp on sible or  80%  o   th e  saliva orm ed  by  th e  salivary  glan d s C.  Th e  p arotid   glan d   is  en tirely  serou s  in   secretion D.  Th e  extern al  carotid   artery  p asses  with in   th e  su bstan ce  o   th e  p arotid   glan d E. Th e  retrom an dibu lar  vein   p asses  with in   th e  su bstan ce  o   th e  p arotid   glan d

S

19.  Th e  com m on  acial  vein   is orm ed   by  th e  join in g  o   wh ich   2  vein s? A.  Posterior  d ivision   o   th e  retrom an d ibu lar  vein   an d   th e  p osterior  au ricu lar  vein s B. An terior  an d   p osterior  division s  o   th e  retrom an d ibu lar  vein C.  An terior  d ivision   o   th e  retrom an d ibu lar  vein   an d   th e acial  vein D.  Su p erf cial  tem p oral  an d   tran sverse acial  vein s E. Su p erf cial  tem p oral  an d   m axillary  vein s

A

18.  All  o   th e ollowin g  statem en ts  con cern in g  th e  p arotid   glan d   are  correct  except: A.  Th e  p arotid   glan d   receives  p arasym p ath etic  in n ervation  rom   th e  glossop h aryn geal  n erve B. Th e  p arotid   glan d   en ters  th e  oral  cavity  op p osite  th e  2n d  m axillary  p rem olar C.  Th e  d eep   lobe  lies  ad jacen t  to  th e  lateral  p h aryn geal  sp ace D.  Abou t  25%  o   th e  p arotid   glan d   is  retrom an d ibu lar E. Most  tu m ors  o   th e  p arotid  glan d   are  ben ign

B C B C C C e

663

02 91 81 71 61 51 41

Qu ESTiONS AND ANSw ERS

CHAPTER 7 TEMPORAL AND iNFRATEMPORAL FOSSAE 21.  Th e  au ricu lotem p oral  n erve  wrap s  arou n d   wh ich   artery? A.  Posterior  d eep   tem p oral  artery B. In ferior  alveolar  artery C.  Mid d le  m en in geal  artery D.  Masseteric  artery E. An terior  tym p an ic  artery 22.  W h ich   of  th e  followin g  arteries  located   in   th e  in fratem p oral  fossa  arises  from   th e  3rd   p art  of  th e  m axillary  artery? A.  Posterior  su p erior  alveolar  artery B. Mid dle  m en in geal  artery C.  Descen d in g  p alatin e  artery D.  Artery  of  th e  p terygoid   can al E. Bu ccal  artery 23.  All  of  th e  followin g  are  bran ch es  of  th e  p osterior  d ivision   of  th e  trigem in al  n erve  with in   th e  in fratem p oral  fossa  except: A.  Au ricu lotem p oral  n erve B. Myloh yoid   n erve C.  Lin gu al  n erve D.  In ferior  alveolar  n erve E. Masseteric  n erve

CHAPTER 8 Mu SCLES OF MASTiCATiON 24.  Th e  p arotid   d u ct  crosses  su p er cial  to  th e: A.  Tem p oralis B. Masseter C.  Med ial  p terygoid D.  Ten sor  veli  p alatin i E. Lateral  p terygoid 25.  W h ich   m u scle  attach es  alon g  th e  m ed ial  su rface  of  th e  ram u s  an d   an gle  of  th e  m an d ible? A.  Lateral  p terygoid B. Tem p oralis C.  Ten sor  veli  p alatin i D.  Med ial  p terygoid E. Masseter

CHAPTER 9 TEMPOROMANDiBu LAR JOiNT

A

N

S

WE

R

S

26.  Th e  an terior  bou n d ary  of  th e  glen oid  fossa  is  th e: A.  Articu lar  em in en ce B. Postglen oid   tu bercle C.  Tym p an ic  p late D.  Petrotym p an ic ssu re E. Sq u am otym p an ic ssu re

D A D B E A C

72 62 52 42 32 22 12

664

27.  W h ich   of  th e  followin g  sen sory  n erves  of  th e  tem p orom an d ibu lar  join t  arise  from   th e  p osterior  d ivision   of  th e  trigem in al  n erve? A.  Posterior  d eep   tem p oral  n erve B. An terior  d eep   tem p oral  n erve C.  Lin gu al  n erve D.  Au ricu lotem p oral  n erve E. Masseteric  n erve

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

Qu ESTiONS AND ANSw ERS 28.  W h ich   ligam en t  attach es  to  th e  lin gu la? A.  Stylom an d ibu lar  ligam en t B. Tem p orom an d ibu lar  ligam en t C.  Sp h en om an d ibu lar  ligam en t D.  Med ial  collateral  ligam en t E. Lateral  collateral  ligam en t

CHAPTER 10 PTERYGOPALATiNE FOSSA 29.  All  of  th e  followin g  h ave  a  d irect  com m u n ication   with   th e  p terygop alatin e  fossa  via  an   op en in g  on   th e  fossa  except: A.  In fratem p oral  fossa B. Oral  cavity C.  Mid d le  cran ial  fossa D.  Nasop h aryn x E. Tem p oral  fossa 30.  Th e  in ferior  orbital ssu re  com m u n icates  th e  p terygop alatin e  fossa  with   th e: A.  Mid d le  cran ial  fossa B. Orbit C.  In fratem p oral  fossa D.  Nasal  cavity E. Nasop h aryn x

CHAPTER 11 NOSE AND NASAL CAViTY 31.  All  of  th e  followin g  arteries  con tribu te  to  Kiesselbach ’s  p lexu s  except: A.  Sp h en op alatin e B. Greater  p alatin e C.  Posterior  eth m oid D.  An terior  eth m oid E. Sep tal  bran ch   from   th e  su p erior  labial  artery 32.  Th e  sp h en op alatin e  foram en   com m u n icates  th e  n asal  cavity  with   th e: A.  Mid d le  cran ial  fossa B. Pterygop alatin e  fossa C.  In fratem p oral  fossa D.  Orop h aryn x E. Maxillary  sin u s

CHAPTER 12 PARANASAL SiNu SES 33.  Th e  n asolacrim al  d u ct  d rain s  in to  th e: A.  Sp h en oeth m oid   recess B. Su p erior  m eatu s C.  Mid d le  m eatu s D.  Hiatu s  sem ilu n aris E. In ferior  m eatu s

S

R

E

W

S

N

A

34.  W h ich   p aran asal  sin u s  is  m ost  p ron e  to  sin u sitis? A.  An terior  eth m oid B. Posterior  eth m oid C.  Maxillary D.  Fron tal E. Sp h en oid

C E B C B E C Q UESTIO NS AND ANSWERS

665

43 33 23 13 03 92 82

Qu est io n s a n d a n sw er s

CHa Pt er 13 o r a L Ca Vit Y 35.  Th e  d ep ressed   area  located  between   th e  base  of  th e  n ose  an d   th e  verm ilion   bord er  of  th e  u p p er  lip   is  kn own   as  th e: A.  Ph iltru m B. Vestibu le C.  Labial  com m issu re D.  Retrom olar  region E. Mu cobu ccal  fold 36.  W h at  stru ctu re  drain s  in to  th e  su blin gu al  p ap illa? A.  Su blin gu al  glan d B. Parotid  glan d C.  Bu ccal  glan d D.  Palatal  glan d E. Su bm an d ibu lar  glan d

CHa Pt er 14 t o n Gu e 37.  Th e  taste  bu ds  in n ervated   by  th e  glossop h aryn geal  n erve  are  associated  with   wh ich   p ap illa? A.  Su bm an d ibu lar B. Foliate C.  Fu n giform D.  Filiform E. Circu m vallate 38.  W h at  stru ctu re  lies  deep   to  th e  h yoglossu s? A.  Lin gu al  n erve B. Lin gu al  artery C.  Hyp oglossal  n erve D.  Su bm an d ibu lar  d u ct E. Su blin gu al  glan d

CHa Pt er 15 PHa r Yn X 39.  Th e  su p erior  bou n d ary  of  th e  orop h aryn x  is  th e: A.  Ep iglottis B. Palatoglossal  fold C.  Palatop h aryn geal  fold D.  Nasop h aryn x E. Laryn gop h aryn x

S

40.  Th e  an terior  bou n d ary  of  th e  orop h aryn x  is  th e: A.  Palatoglossal  fold B. Palatop h aryn geal  fold C.  Ep iglottis D.  In ferior  bord er  of  th e  cricoid E. Soft  p alate

A

N

S

WE

R

CHa Pt er 16 La r Yn X

C a d B e e a

14 04 93 83 73 63 53

666

41.  Th e  d ep ression   in   th e  m u cosa  between   th e  p h aryn geal  p ortion   of  th e  ton gu e  an d   th e  an terior  bord er  of  th e  ep iglottis  is  kn own   as  th e: A.  Piriform   recess B. Ph aryn geal  recess C.  Vallecu la D.  Vestibu le E. Ton sillar  sin u s

NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

Qu ESTiONS AND ANSw ERS 42.  Th e  m u cosa  coverin g  th e  p osterior  su rface  of  th e  ep iglottis  is: A.  Pseu d ostrati ed   colu m n ar  ep ith eliu m   with   cilia B. Strati ed   sq u am ou s  ep ith eliu m C.  Strati ed   sq u am ou s  n on keratin ized   ep ith eliu m D.  Sim p le  colu m n ar  ep ith eliu m E. Sim p le  sq u am ou s  ep ith eliu m

CHAPTER 17 CERViCAL FASCiA 43.  Th e  su p erior  bou n d ary  of  th e  can in e  fascial  sp ace  is  th e: A.  Levator  an gu li  oris B. Levator  labii  su p erioris C.  Zygom aticu s  m ajor D.  Nasalis E. Proceru s

CHAPTER 18 EAR 44.  Th e  roof  of  th e  m id dle  ear  is  th e: A.  Tym p an ic  can alicu lu s B. Au ditory  tu be C.  Facial  can al D.  Tegm en   tym p an i E. Mastoid   an tru m

CHAPTER 19 EYE AND ORBiT 45.  Th e  p igm en ted   vascu lar  layer  between   th e  sclera  an d   th e  retin a  is  th e: A.  Ch oroid B. Ciliary  bod y C.  Iris D.  Aq u eou s  h u m or E. Posterior  ch am ber

CHAPTER 20 Au TONOMiCS OF THE HEAD AND NECK 46.  All  of  th e  followin g  cran ial  n erves  are  resp on sible  for  p arasym p ath etic  activity  except: A.  Ocu lom otor B. Trigem in al C.  Facial D.  Glossop h aryn geal E. Vagu s

S

R

E

W

S

N

A

47.  Th e  greater  p etrosal  n erve  con tain s: A.  Pregan glion ic  p arasym p ath etic bers B. Postgan glion ic  p arasym p ath etic bers C.  Pregan glion ic  sym p ath etic bers D.  Postgan glion ic  sym p ath etic bers E. Taste bers  to  th e  an terior  2/ 3  of  th e  ton gu e

CHAPTER 21 iNTRAORAL iNJECTiONS 48.  All  of  th e  followin g  areas  are  an esth etized  in   a  m axillary  division   block  except: A.  All  m axillary  teeth B. All  m axillary  bu ccal  gin giva C.  All  m axillary  p alatal  gin giva D.  Up p er  lip E. Lower  lip

Q UESTIO NS AND ANSWERS

E A B A D B A

667

84 74 64 54 44 34 24

Qu ESTiONS AND ANSw ERS

CHAPTER 22 iNTRODu CTiON TO THE u PPER LiMB, BACK, THORAX, AND ABDOMEN 49.  Th e  layer  of  p arietal  p leu ra  th at  lin es  th e  cavity  alon g  th e  ribs  is  th e: A.  Cervical B. Costal C.  Diap h ragm atic D.  Med iastin al E. Visceral

A

N

S

WE

R

S

50.  Th e  sep tom argin al  trabecu lae  is  located   in   th e: A.  Righ t  atriu m B. Righ t  ven tricle C.  Left  atriu m D.  Left  ven tricle E. Fossa  ovalis

B 05 B 94

66 8 NETTER’S HEAD AND NECK ANATO MY FO R DENTISTRY

In d ex

Page n u m bers followed by “f ” in d icate

gu res.

A Abd om en . See also Abdom in al wall. arterial su p p ly to, 642–644, 642f–644f bon es of, 600, 601f du oden u m in , 624, 624f gallblad d er an d d u ct system in , 631, 631f gen eral in form ation abou t, 590, 591f ileu m in , 625, 626f jeju n u m in , 625, 626f kidn eys in , 633, 633f large in testin e in , 627–628, 628f liver in , 629, 629f m u scles of, 614, 615f p an creas in , 630, 630f sp leen in , 632, 632f stom ach in , 623–633, 623f su p raren al glan ds in , 633, 633f u reters in , 633, 633f ven ou s d rain age from , 645, 645f Abd om in al wall an terolateral, 590, 591f p osterior n erve su p p ly to, 653, 653f ven ou s d rain age from , 647, 647f Abd u cen s (VI) n erve eye an d orbit in n ervation by, 525, 526f bers an d fu n ction al colu m n typ e of, 80, 80f p alsy, 538 in p erip h eral n ervou s system , 74, 74f Abd u ctor digiti m in im i m u scle, 609, 610f Abd u ctor p ollicis brevis m u scle, 609, 610f Abd u ctor p ollicis lon gu s m u scle, 608f Abscesses, 480, 480f Accessory m en in geal artery, 216–220, 217f Accessory (XI) n erve carotid trian gle an d , 116, 117f bers an d fu n ction al colu m n typ e of, 102, 102f lesion s affectin g, 104, 104f n eck in n ervation by, 139, 660f n eck m u scles an d , 126 in p erip h eral n ervou s system , 74, 74f p osterior trian gle an d , 120, 121f Acetylch olin e, 544 Acu te otitis extern a, 506, 506f Acu te otitis m ed ia, 507, 507f

Acu te sin u sitis, 333, 333f–334f Acyclovir, 392 Ad am ’s ap p le, 449 Ad en ocarcin om a of p arotid glan d, 202, 202f Ad en oid s, 393, 428, 429f Ad en om a of p arotid glan d , 202 Ad ren al glan d s, 633, 633f Afferen t gen eral or sp ecial fu n ction al colu m n s of cran ial n erves, 75, 75f Akin osi n erve block, 576, 576f–577f Ala of n ose, 278f Alar, deep layer of d eep fascia an d , 108 Alar bran ch es of facial artery, 280–282 Alar cartilage, 279f, 288f Alar fascia, 468f, 469–470 Alar brofatty tissu e, 279f Alar ligam en t, 59–60, 60f Allergic rh in itis, 307–308, 307f Alveolar p rocess of m an d ible, 44 of m axilla, 26, 43f Am acrin e cell, 520f Am etrop ias, 542, 542f Am p u lla of sem icircu lar can als, 491 An atom ic crown , 359, 359f An atom ic root, 359, 359f An con eu s m u scle, 605 An eu rysm s cavern ou s sin u s syn drom e an d, 185, 185f cerebral, cau sin g op h th alm op legia, 538 An gu lar artery, 170f, 172, 172f, 174f An gu lar tract of Eisler, 189 An gu lar vein from eye an d orbit, 530–532, 533f from face, 170f, 175, 176f from n ose, 280–282, 282f An kyloglossia, 420–423, 420f An kylosis of TMJ, 255, 255f ANS. See Au ton om ic n ervou s system (ANS). An sa cervicalis carotid trian gle an d , 116, 117f in frah yoid m u scles an d, 127 m u scu lar trian gle an d, 118, 119f n eck in n ervation by, 144, 145f–146f om oh yoid m u scle an d , 126 p osterior trian gle an d, 121f

In d e x

669

In d ex An tebrach iu m arterial su p p ly of, 637, 637f m u scles of, 607f–608f sen sory in n ervation by, 650–652 An terior au ricu lar artery, 170f An terior au ricu lar m u scle, 168, 169f An terior cervical lym p h n od es, 657–658, 659f An terior ciliary artery, 530–532 An terior cran ial fossa, 26, 287 An terior d eep tem p oral artery to in fratem p oral fossa, 216–220, 217f to m asticatory m u scles, 234, 235f to tem p oral fossa, 210–211, 210f An terior d eep tem p oral n erve, 212, 213f An terior d eep tem p oral vein , 210–211, 236 An terior d igastric m u scle, 113, 115f An terior d ivision of an terior d eep tem p oral bran ch of m an dibu lar n erve, cou rse of in fratem p oral fossa, 220–226, 222f–223f m asticatory m u scles, 231, 232f, 237, 238f tem p oral fossa, 212 An terior d ivision of bu ccal bran ch es of m an d ibu lar n erve, cou rse of face, 180f in fratem p oral fossa, 220–226, 222f–223f p arotid bed , 191f An terior d ivision of lateral p terygoid bran ch of m an d ibu lar n erve, 220–226, 222f An terior d ivision of m ed ial p terygoid bran ch of m an d ibu lar n erve, 220–226, 222f An terior d ivision of p osterior d eep tem p oral bran ch of m an dibu lar n erve, cou rse of in fratem p oral fossa, 220–226, 222f–223f m asticatory m u scles, 237, 238f tem p oral fossa, 212 tem p orom an d ibu lar join t, 250 An terior d ivision of th e retrom an d ibu lar vein , 192–193 An terior eth m oidal artery to eth m oid sin u ses, 322, 322f to eye an d orbit, 530–532, 531f to fron tal sin u ses, 317, 317f to n asal cavity, 291–294, 292f–293f An terior eth m oidal foram en an terior view, 50, 50f in orbit, 512 in su p erior view of cran ial base, 51, 53f An terior eth m oidal n erve cou rse of eth m oid sin u ses, 323–324, 323f eye an d orbit, 521–529, 523f in tern al an d extern al n asal bran ch es of, 295f, 298f–299f in n asociliary bran ch of trigem in al n erve op h th alm ic d ivision , 86f An terior ju gu lar vein , 118, 135, 138f, 291–294 An terior m allear fold , 487, 490f An terior n ares, 278f An terior n asal sp in e, 279f An terior scalen e m u scle, 128, 128f An terior su p erior alveolar artery, 326, 326f, 371, 371f

670

An terior su p erior alveolar n erve cou rse of, 89f m axillary sin u s, 327, 327f teeth , 374 in traoral in jection s an d , 578 n asal bran ch of, 298f An terior su p erior alveolar n erve block, 584, 584f An terior su p erior alveolar vein , 372 An terior trian gle gen eral in form ation abou t, 111, 111f–112f su bd ivision s of carotid , 116, 117f m u scu lar, 109f, 111, 118, 119f su bm an d ibu lar, 114, 115f su bm en tal, 113–118, 113f An terior tym p an ic artery to extern al ear, 499, 500f to in fratem p oral fossa, 216–220, 217f–218f to m idd le ear, 501, 502f to tem p orom an d ibu lar join t, 248, 248f An terior wall of m id dle ear, 489 An terolateral abd om in al wall, 590, 591f An tih elix of au ricle, 487 An titragu s, 487, 488f An trostom y, 337 An tru m of High m ore. See Maxillary sin u s. Ap ex of n ose, 278 Ap ex of root of tooth , 359 Ap ex p rocess of aryten oid cartilage, 451, 451f Ap ical foram in a, 359f Ap ical ligam en t of d en s, 59–60, 60f Ap on eu rosis, 156, 156f, 158f Ap p en d ix, 627, 628f Arach n oid foveae, 28 Arth ritis of TMJ, 255, 255f Articu lar d isc, 242–246, 242f p erforation s of, 251–255, 251f Articu lar em in en ce, 243–246 Articu lar tu bercle, 243–246 Aryep iglottic fold , 427f, 429f, 442f–443f Aryep iglottic m u scle, 456–457, 456f Aryten oid cartilages, 433f, 448, 448f, 451, 451f, 453f Ascen d in g colon , 627, 628f Ascen d in g p alatin e artery to oral cavity oor, 368–371, 370f to p alate, 368–371, 369f to p h aryn x, 435, 437f Ascen d in g p h aryn geal artery carotid trian gle an d , 116, 117f to n eck, 130, 134f to p alate, 368–371, 369f to p h aryn x, 435, 437f ton gu e an d, 416 Astigm atism , 542, 542f Astrocytes, 67, 67f Atlan toaxial join t, m ajor in tern al ligam en ts for, 60f Atlan to-occip ital m em bran e, 58, 58f, 122 Atlas (C1) as cervical vertebrae, 56, 56f Jefferson fractu re of, 64, 64f rotary su blu xation of, torticollis an d , 149f su boccip ital trian gle an d , 122, 122f

n e TTe R’S He Ad An d n e CK An ATO MY FO R d e n TISTRY

In d ex Atriu m of n ose, 278 Atrop h y of ton gu e, 105f, 421, 421f Au ricle, 487, 488f Au ricu lar bran ch of vagu s (X) n erve, 139, 495, 496f Au ricu lar grou p of m u scles of facial exp ression , 168, 169f Au ricu lar m u scle, 168 Au ricu lar tu bercle (of Darwin ), 488f Au ricu lotem p oral n erve, 159, 160f, 180f, 195–197, 195f extern al ear an d , 495, 496f in fratem p oral fossa an d , 220–226 tem p oral fossa an d , 159, 160f, 180f, 195–197, 195f, 212, 213f tem p orom an d ibu lar join t an d , 250, 250f Au ton om ic n ervou s system (ANS), 72. See also Parasym p ath etic n ervou s system ; Sym p ath etic n ervou s system . clin ical correlate for, 566, 566f d ivision s of, 544, 547–548 fu n ction s of, 547–548, 548f–550f gen eral in form ation abou t, 544, 545f–546f salivary glan d s in , 384–386, 385f, 387f two-n eu ron ch ain system of, 544 vagu s n erve in , 565, 565f Axillary artery, 636, 636f Axillary n erve, 651, 652f Axis (C2), 56, 56f, 64, 64f fractu res of, 64, 64f Axon s, 66, 66f Azygos system , 640

B Back bon es of, 596, 597f m u scles of, 611, 612f Bacterial in fection s, 199, 203 Basilar m em bran e, 486f, 493f Beclard ’s trian gle, 114 Bell’s p alsy, 94, 199–205, 200f, 570, 576 Bicep s brach ii m u scle, 605, 605f Bilam in ar zon e, 243–246, 245f Bip olar n eu ron s, 66, 66f Bitem p oral h em ian op sia, 78 Black h airy ton gu e, 400, 401f Blad d er, u rin ary fem ale, 635, 635f m ale, 634, 634f Blep h arop lasty, 166 Blin d sp ot, 516 Bon es, 25–64 abd om in al, 600, 601f articu lation s of, 27–28, 27f back, 596, 597f cervical vertebrae m ajor extern al ligam en ts of, 58, 58f m ajor in tern al ligam en ts of, 59–60, 60f p arts an d ch aracteristics of, 56, 56f–57f derived from p h aryn geal arch es, 6f facial, 154, 155f fractu res of, 61–64, 61f–64f gen eral in form ation abou t, 26

Bon es (Continued) in traoral in jection s an d m an d ibu lar, 569, 569f m axillary, 578, 578f–579f q u estion s/ an swers abou t, 656 sku ll. See Sku ll. th oracic, 598, 599f u p p er lim b, 592–595, 592f, 594f–595f Botox in jection s, 166 Brach ial artery, 637, 637f Brach ial p lexu s n eck in n ervation by, 146, 146f p osterior trian gle an d , 120, 121f in root of n eck, 125 u p p er lim b in n ervation by, 650–652, 652f Brach ialis m u scle, 605, 605f Brach iocep h alic vein from n eck, 135 in root of n eck, 125 Brach iorad ialis m u scle, 608f Brach iu m , 605, 605f, 650 arterial su p p ly of, 637, 637f sen sory in n ervation by, 652 Brain , 68f–69f, 69 Brain stem , 69 Bu ccal artery to face, 172, 172f to in fratem p oral fossa, 216–220, 217f to lip s an d ch eeks, 344–345, 344f to m asticatory m u scles, 234, 235f Bu ccal bran ch es of facial n erve, 164, 166, 188, 188f, 190, 346, 346f Bu ccal bran ch es of m an d ibu lar n erve, 347, 347f Bu ccal fascial sp ace, 473, 476f Bu ccal n erve, 180f, 182, 220–226, 569, 571f–572f Bu ccal su rface of teeth , 357, 358f Bu ccal vein , 175, 236, 344–345, 345f Bu ccin ator lym p h n od es, 659f Bu ccin ator m u scle, 346, 346f ch eeks an d , 343 facial exp ression an d, 164, 165f lon g bu ccal n erve block an d, 572f m astication an d , 230f, 232f–233f, 239 oral cavity oor an d, 356f p h aryn geal m u scles an d , 433f–434f soft p alate an d , 353f Bu ccop h aryn geal fascia, 426, 426f, 433f, 468f, 469–470, 476f

C C cells, 123 Cald well-Lu c p roced u re, 337, 337f Cam p er’s layer of abdom in al wall, 590, 591f Can in e fascial sp ace, 473 Can in es (cu sp ids), 358f, 360–367, 361f, 364f, 396f–397f Cap su le of in n er ear, 492f of p arotid glan d , 189, 202 of tem p orom an d ibu lar join t, 243–246, 247f–248f, 250f Carbam azep in e, 183

In d e x

671

In d ex Carcin om as p arotid glan d, 202, 202f sq u am ou s cell, 422, 422f Cardiac vagal bran ch es of vagu s n erve, 139 Caries, 389, 389f Caroticotym p an ic bran ch of in tern al carotid artery, 501, 502f Carotid arteries. See Com m on carotid arteries; Extern al carotid artery; In tern al carotid artery. Carotid can al in su p erior view of cran ial base, 51, 53f tem p oral bon e an d , 32, 33f Carotid sh eath , 108, 469–470, 470f, 477–478, 478f Carotid trian gle, 111, 116, 117f Carp al bon es, 595, 595f Carp u s, 638, 638f Cartilage d erived from p h aryn geal arch es, 5, 6f, 11f Cartilagin ou s n eu rocran iu m , 10, 12, 12f Cavern ou s sin u s eye an d orbit d rain ed by, 530–532, 533f face drain ed by, 176f sp h en oid bon e an d , 34 sp h en oid al sin u s an d , 329, 329f Cavern ou s sin u s syn d rom e, 185, 185f Cecu m , 627, 628f Celiac artery, 642–643, 642f Cellu litis, 333, 477–479 Cem en tu m , 359, 359f Cen tral in cisors, 358f, 360–367, 361f, 365f, 397f Cen tral n ervou s system , 549f brain an d , 68f–69f, 69 gen eral in form ation abou t, 68, 68f sp in al cord an d , 70, 70f–71f Cen tral retin al artery, 515f, 530–532, 531f Cen tral retin al vein , 515f Cen tral su lcu s (of Rolan do), 68f, 69 Cerebellu m , 69, 69f Cerebral an eu rysm s, 538 Cerebral cortex, 68f, 69 Cerebral n erves. See Cran ial n erves. Cerebru m , 68f, 69 Cervical bran ch of facial n erve, 168, 182, 190, 191f Cervical em p h ysem a, 481, 481f Cervical en largem en t of sp in al cord , 70, 70f Cervical fascia clin ical correlates for, 479–481, 479f–481f d eep . See Deep cervical fascia. fascial sp aces of, 471–478, 472f in frah yoid , 477–478, 478f su p rah yoid , 473–475, 476f traversin g len gth of n eck, 477–478, 478f gen eral in form ation abou t, 466, 466f–467f su p er cial, 466, 468, 468f Cervical lin e of tooth , 359 Cervical lym p h n od es, 657–658, 659f Cervical p lexu s facial in n ervation by, 177, 177f, 181f n eck in n ervation by, 142, 143f, 144, 145f p osterior trian gle an d , 120 scalp in n ervation by, 159, 160f

672

Cervical sp in al n erves, 70, 70f Cervical vertebrae fractu res of, 64, 64f m ajor ligam en ts of extern al, 58, 58f in tern al, 59–60, 60f p arts an d ch aracteristics of, 56, 56f–57f Ch eeks. See also Face. arterial su p p ly to, 344–345, 344f d evelop m en t of, 13 as oral cavity bou n d ary, 354, 354f sen sory in n ervation of, 347, 347f stru ctu ral featu res of, 164, 343 ven ou s d rain age from , 344–345, 345f Ch ild ren , in ferior alveolar n erve block in , 570 Ch oan ae (p osterior n ares), 286, 286f Ch orda tym p an i bran ch of facial n erve, cou rse of in fratem p oral fossa, 214, 220–226, 223f, 225f–226f oral cavity oor, 377–378, 378f salivary glan d s, 386 su blin gu al glan ds an d , 557 ton gu e, 410–412, 413f Ch orda tym p an i n erve, 488f, 489, 490f, 571f Ch oroid , 515f, 516, 520f Ch rom osom e 22, DiGeorge syn d rom e an d , 22 Ch ron ic sin u sitis, 333, 333f–334f Ciliary body, 515f, 516, 520f Ciliary gan glion , 4 ch aracteristics of, 553 n erve roots con n ected to, 528f n erve su p p ly to n asal cavity an d , 299f in orbit, 520f, 523f Ciliary m u scle, 80, 81f Ciliary p rocesses, 515f Cin gu lu m , 359 Circu lar esop h ageal m u scle, 427f, 433f Circu m vallate p ap illae, 402 Class II m alocclu sion , in ferior alveolar n erve block in , 570 Class III m alocclu sion , in ferior alveolar n erve block in , 570 Clavicle, 120, 592, 592f Cleft lip an d p alate, 23, 23f–24f Clin ical crown , 359 Clin ical root, 359 Clivu s, 34, 35f Closed an gle glau com a, 539 Coccygeal sp in al n erves, 70, 70f, 73f Coccyx, 596, 597f Coch lea, 486f–487f, 491 Coch lear d u ct, 491, 492f–493f Coch lear n erve, 498, 498f Collateral ligam en ts, 243–246, 247f Com m issu re of lip s, 278f, 343, 343f Com m on carotid arteries, 116, 125, 134f, 158f, 170f. See also Extern al carotid artery; In tern al carotid artery. Com m on facial vein , 135, 137f–138f Com m on ten din ou s rin g, 517, 518f Com m u n icatin g vein s, 176f Com p lete cleft of lip an d p alate, 23, 24f Com p ressor n aris m u scle, 166

n e TTe R’S He Ad An d n e CK An ATO MY FO R d e n TISTRY

In d ex Con ch a bu llosa, 308f Con ch ae, n asal of au ricle, 487, 488f in facial skeleton , 155f in ferior, 27–28, 41, 41f, 289, 289f–290f, 308f–309f on lateral walls, 286f m idd le, 289, 289f–290f, 308f–309f as n asal cavity bou n d ary, 287, 288f stru ctu res d rain ed by, 289, 289f–290f su p erior, 289, 289f, 309f Con d ylar can al, 51, 53f Con d ylar p rocess, 44, 45f, 214 Con e of ligh t, 488f Con es, retin al, 72–73, 78, 520f Con n ective tissu e of th e scalp , 156, 156f, 159 stru ctu res, d erived from p h aryn geal arch es, 5 Con u s elasticu s, 454, 455f Con u s m edu llaris, 70f Coracobrach ialis m u scle, 605 Corn icu late cartilage, 448, 448f, 453, 453f Corn icu late tu bercle, 427f Coron oid n otch , 570, 571f Coron oid p rocess, 44, 45f Corru gator su p ercilii m u scle, 166, 167f Corti, sp iral organ of, 96, 96f, 493f Costocervical artery, 130, 131f Cran ial n erves. See also Neu roan atom y. I (olfactory). See Olfactory (I) n erves. II (op tic). See Op tic (II) n erve. III (ocu lom otor). See Ocu lom otor (III) n erve. IV (troch lear). See Troch lear (IV) n erve. V (trigem in al). See Trigem in al (V) n erve. VI (abdu cen s). See Abd u cen s (VI) n erve. VII (facial). See Facial (VII) n erve. VIII (vestibu lococh lear). See Vestibu lococh lear (VIII) n erve. IX (glossop h aryn geal). See Glossop h aryn geal (IX) n erve. X (vagu s), see vagu s (X) n erve XI (accessory). See Accessory (XI) n erve. XII (h yp oglossal). See Hyp oglossal (XII) n erve. clin ical correlates for, 104–105, 104f–105f derived from p h aryn geal arch es, 4–5, 4f fu n ction al com p on en ts (colu m n s) of, 75, 75f gen eral in form ation abou t, 74, 74f orbit in n ervation by, 519, 520f–521f, 521–529, 523f–524f p erip h eral n ervou s system an d , 72 q u estion s/ an swers abou t, 655–656 sp in al n erves an d , 73f Cran ial p art of accessory n erve, 414 Cran iosacral bers, 547–548 Cran iu m , 26 Cretin ism , 150 Cribriform p late of eth m oid bon e, 38, 39f, 77f foram in a of, 51, 53f as n asal cavity bou n d ary, 287, 287f n erve su p p ly to n asal cavity an d , 299f

Cricoaryten oid join t, 451, 454 Cricoid cartilage of laryn x, 448, 448f, 450, 450f p h aryn x an d, 433f Cricop h aryn geal p ortion of in ferior con strictor m u scle, 442, 442f–443f Cricop h aryn geu s m u scle, 427f, 433f–434f Cricoth yroid join t, 449–450, 449f–450f, 454 Cricoth yroid ligam en t, 449f Cricoth yroid m em bran e, 462–464, 462f Cricoth yroid m u scles, 456–457, 456f–457f Cricoth yrotom y, 462–464, 462f Cricotrach eal ligam en t, 454 Crista galli, 38, 308f Cristae of sem icircu lar can als, 96, 96f–97f Crown of tooth , 359, 359f Cru ciate ligam en t, 59–60, 60f Cru ra of an tih elix, 488f Cru s h elix, 487, 491 Cru x of h elix, 488f Cu n eiform cartilage, 448, 453, 453f Cu n eiform tu bercle, 427f Cu sp id s. See Can in es (cu sp ids). Cu sp s, 359, 359f Cytop lasm , 66

D Dan ger sp ace, 477–478, 478f Deep au ricu lar artery to extern al ear, 499, 500f to in fratem p oral fossa, 216–220, 217f–218f to tem p orom an d ibu lar join t, 248, 248f Deep cervical artery, 130, 131f Deep cervical fascia. See also Carotid sh eath . carotid trian gle an d , 116 deep layer of, 108, 109f, 469–470 gen eral in form ation abou t, 466, 466f–467f in vestin g layer of. See Su p er cial layer of deep cervical fascia. m idd le layer of, 108, 469–470 su p er cial layer of. See Su p er cial layer of deep cervical fascia. Deep facial vein , 176f, 282f in fratem p oral fossa an d , 216–220, 219f Deep lateral cervical lym p h n odes, 657–658 Deep layer of deep cervical fascia, 108, 109f, 469–470 Deep lin gu al artery, 342f, 404f, 416, 417f Deep lin gu al n erves, 342f Deep lin gu al vein s, 342f, 404 Deep lym p h n od es, 657–658, 659f Deep p etrosal n erve, 301, 302f Deep tem p oral arteries, 172f, 210–211, 210f, 216–220, 217f to m asticatory m u scles, 234, 235f Deep tem p oral n erves, 212, 213f Deep tem p oral vein s, 210–211, 236 Deglu tition m astication an d , 230, 239, 240f p rocess of, 442, 442f–443f soft p alate an d , 351 Deltoid m u scle, 603, 604f Den d rites, 66, 66f

In d e x

673

In d ex Den s ap ical ligam en t of, 59–60, 60f of axis, 56, 56f Den tal caries, 204, 389, 389f Den tal im p lan ts, 338–339, 338f–339f Den tal n otation system s, 360 Den tin , 359, 359f Den toalveolar abscesses, 480, 480f Dep ressor an gu li oris m u scle, 164, 165f Dep ressor labii in ferioris m u scle, 164, 165f Dep ressor sep ti (n asi) m u scle, 166, 167f Descen d in g colon , 627, 628f Descen d in g p alatin e artery, 261f, 262–264, 263f Descen d in g p alatin e vein , 262–264 Deviated sep tu m , 306, 306f, 308f Diabetic retin op ath y, 541, 541f Diap h ragm , 614, 615f, 641f Dien cep h alon , 69 Digastric fossa, 44, 45f Digastric m u scle p arotid glan d an d , 188–189 p h aryn geal m u scles an d , 434f su bd ivid in g trian gles by, 126, 126f in su p rah yoid region , 111, 127 Digastric trian gle. See Su bm an dibu lar trian gle. DiGeorge syn drom e, 22, 22f Digestion , m astication an d , 239, 240f Dilator n aris m u scle, 166 Dip lop ia, 80 Discrim in ative tou ch (sen sation ), 82, 92f, 410–412 Dislocation s, m an dibu lar, 252, 252f Distal su rface of teeth , 357, 358f Dorsal in terosseu s m u scles, 609, 610f Dorsal lin gu al arteries, 416, 417f Dorsal m otor n u cleu s, 565 Dorsal n asal artery to eye an d orbit, 530–532, 531f to face, 172f to n ose, 280–282, 281f Dorsal ram i scalp in n ervation by, 159, 160f sen sory in n ervation of n eck by, 142, 143f Dorsal scap u lar artery, 120, 121f, 130, 131f Dorsal scap u lar n erve, 120, 650 Dorsu m of n ose, 278 Dorsu m sellae, 34, 35f Dry m ou th , 204, 204f Du ct system of abdom en , 631, 631f Du ctu s d eferen s, 634, 634f Du ctu s reu n ien s, 492f Du oden u m , 624, 624f Dyston ia, 148

E Ears arterial su p p ly to extern al, 499, 500f in n er, 503, 503f m id dle, 501, 502f clin ical correlates for, 506–508, 506f–508f gen eral in form ation abou t, 484, 485f–486f glossop h aryn geal n erve to, 98, 99f

674

Ears (Continued) m u scles of, 494, 494f sen sory in n ervation of extern al, 495, 496f in n er, 498, 498f m idd le, 497, 497f stru ctu res an d bou n d aries of extern al, 487, 487f–488f in n er, 491, 492f–493f m idd le, 489, 489f–490f ven ou s d rain age from , 504, 505f Ectoderm , 2, 4 Ectop ic th yroid , 19, 19f Edem a, p eriorbital, 185, 185f Eden tu lou s p atien ts, 570 Edin ger-Westp h al n u cleu s ch aracteristics of, 553 GVE bers an d , 80, 80f–81f p arasym p ath etics of th e eye an d, 527, 528f Em bryon ic d evelop m en t clin ical correlates for, 19–23, 19f–24f of face, 13, 13f–14f gen eral in form ation abou t, 2, 2f–3f of p alate, 15, 15f–16f of p h aryn geal arch es, 2, 4–5, 4f an om alies of, 20–22, 20f–22f d erivatives of, 5, 6f of p h aryn geal clefts, 7–9 of p h aryn geal m em bran es, 7–8, 7f of p h aryn geal p ou ch es, 4, 7–9, 7f–9f an om alies of, 19, 19f of sku ll, 10–12, 11f–12f of th yroid glan d , 18, 18f of ton gu e, 17, 17f Em issary vein s, 291–294 En am el, tooth , 359, 359f En d oderm , 2, 3f, 4 En d olym p h atic d u ct, 491, 492f En d olym p h atic sac, 492f En d oscop ic sin u s su rgery, fu n ction al, 340, 340f Ep icran iu s m u scle, 167f Ep iglottic vallecu la, 428, 442, 442f–443f Ep iglottis cartilage, 448, 448f, 452, 452f laryn gop h aryn x an d, 429, 429f swallowin g an d, 442, 442f–443f ton gu e an d, 409f Ep istaxis, 304–308, 305f Ep ith alam u s, 69 Ep itym p an ic recess, 489, 490f Eryth rop lasia of ton gu e, 422 Esop h agu s, 118, 125 Eth m oid bon e an atom y of, 38, 39f in facial skeleton , 155f n asal cavity an d , 287, 287f–288f orbital p late of, 513f p aran asal sin u ses an d, 315f stru ctu res articu latin g with , 27–28, 27f Eth m oid bu lla, 38 Eth m oid labyrin th , 38

n e TTe R’S He Ad An d n e CK An ATO MY FO R d e n TISTRY

In d ex Eth m oid sin u ses arterial su p p ly to, 322, 322f Caldwell-Lu c p roced u re in , 337, 337f con ch ae an d , 289 drain age of, 315 featu res of, 313, 313f–314f gen eral in form ation abou t, 320, 320f–321f im agin g of, 324f n asal cavity an d, 287 n erve su p p ly to, 323–324, 323f sin u sitis in , 333 Eth m oid al bran ch es of ven ou s p lexu s, 291–294 Exop h th alm os, 185 Exten sor carp i rad ialis brevis m u scle, 608f Exten sor carp i rad ialis lon gu s m u scle, 608f Exten sor carp i u ln aris m u scle, 608f Exten sor d igiti m in im i m u scle, 608f Exten sor d igitoru m m u scle, 608f Exten sor in d icis m u scle, 608f Exten sor p ollicis brevis m u scle, 608f Exten sor p ollicis lon gu s m u scle, 608f Extern al acou stic m eatu s, 487, 487f–488f. See also Extern al ears. p arotid glan d an d , 189, 487, 487f–488f Extern al carotid artery bran ch es of, to ear, 503f carotid trian gle an d , 116, 117f to extern al ear, 499, 500f to face, 158f, 170, 170f, 172, 172f to m asticatory m u scles, 234 to n eck, 130, 134f to n ose, 279f, 281f to p arotid bed , 190, 191f–192f, 192–193 to scalp , 157, 158f to ton gu e, 416, 418f Extern al ears arterial su p p ly to, 499, 500f clin ical correlate for, 506, 506f gen eral in form ation abou t, 484 sen sory in n ervation of, 495, 496f stru ctu res of, 487, 487f–488f ven ou s d rain age from , 504, 505f Extern al in tercostal m u scle, 613, 613f Extern al ju gu lar vein s, 120, 121f, 135, 137f–138f Extern al laryn geal n erve, 116, 440, 460, 461f Extern al n asal artery, 174f, 280–282, 281f, 530–532 Extern al n asal n erve, 86f, 178, 283–286, 284f Extern al obliq u e m u scle, 590, 591f, 614, 615f Extraocu lar m u scle testin g, 537, 537f Eyeballs, 79f Eyes. See also Orbit. an atom y of, 510, 510f–511f clin ical correlates for, 537–539, 537f, 539f–542f, 541–542 com p on en ts of, 514, 514f–515f, 516 gen eral in form ation abou t, 510, 510f m u scles of, 517, 518f–519f p arasym p ath etics of, 527, 528f, 553–554, 555f–556f sym p ath etics of, 528f, 553–554

F Face. See also Ch eeks; Facial exp ression , m u scles of; Lip s; Scalp . adu lt stru ctu res of, 13 arterial su p p ly to, 158f, 170, 170f, 279f extern al carotid artery an d bran ch es in , 158f, 170, 170f, 172, 172f op h th alm ic artery an d bran ch es in , 177–178, 177f, 179f bon es of, 154, 155f clin ical correlates for, 182f, 183–185, 184f–185f em bryotic d evelop m en t of, 13f–14f fascia of, 466 gen eral in form ation abou t, 13, 154, 155f m axilla an d , 42 n erve su p p ly to cervical p lexu s in , 177, 177f, 181f gen eral in form ation abou t, 177–182, 177f m an dibu lar division of trigem in al n erve in , 177, 177f, 179f–180f m axillary d ivision of trigem in al n erve in , 177, 177f, 179f m otor in n ervation in , 182 op h th alm ic d ivision of trigem in al n erve in , 177–178, 177f, 179f sen sory in n ervation in , 178, 179f–181f ven ou s d rain age from , 175, 175f com m u n icatin g vein s, 176f deep vein s, 176f su p er cial vein s, 175, 175f–176f Facial artery carotid trian gle an d , 116 to face, 170f, 172, 172f, 174f, 176f to lip s an d ch eeks, 344–345, 344f to n asal cavity, 291–294, 293f, 302f to n eck, 130, 134f to n ose, 279f, 280–282 to oral cavity oor, 368–371, 370f to p alate, 368–371, 369f su bm an dibu lar trian gle an d , 114, 115f Facial exp ression , m u scles of au ricu lar grou p , 168, 169f gen eral in form ation abou t, 154, 161–169, 161f–162f n asal grou p , 166, 167f n eck grou p , 168, 169f oral grou p , 164, 165f orbital grou p , 166, 167f q u estion s/ an swers abou t, 655 scalp grou p , 168, 169f Facial lym p h n od es, 657–658, 659f Facial (VII) n erve Bell’s p alsy an d , 199–205, 200f bu ccal bran ch es of, 164, 166, 188, 188f, 190, 346, 346f cervical bran ch of, 168, 182, 190, 191f ch ord a tym p an i bran ch of, 214, 220–226, 223f, 225f–226f cou rse of face, 182 m idd le ear, 497, 497f n asal cavity, 303f oral cavity, 346, 346f

In d e x

675

In d ex Facial (VII) n erve (Continued) digastric m u scle an d , 126–127 bers an d fu n ction al colu m n typ es of, 94, 95f m an d ibu lar bran ch of, 164, 182, 190, 191f, 346, 346f as m id dle ear bou n dary, 490f p arasym p ath etics of, with corresp on din g sym p ath etics, 557–559, 558f, 560f–561f with in p arotid bed , 189f, 190, 191f p arotid glan d an d , 188 in p erip h eral n ervou s system , 73f–74f, 74 p h aryn geal arch es an d , 4–5 salivary glan d in n ervation by, 381–382 sen sory facial in n ervation by, 154, 177–182, 177f, 347, 347f styloh yoid m u scle an d , 127 tem p oral bran ch es of. See Tem p oral bran ch es of facial n erve. ton gu e in n ervated by, 411f zygom atic bran ch es of, 164, 166, 188, 188f, 190, 191f Facial su rface of teeth , 357, 358f Facial vein from eye an d orbit, 530–532, 533f from face, 170f, 175, 175f–176f from n eck, 135, 137f from n ose, 280–282, 282f su bm an d ibu lar trian gle an d , 114, 115f Farsigh ted n ess, 542, 542f Fascial sp aces, 471–478, 472f in frah yoid , 477–478, 478f su p rah yoid , 473–475, 476f traversin g len gth of n eck, 477–478, 478f Fem ale p elvis, 635, 635f Field blocks, 568 Filiform p ap illae, 402, 403f Fim briated fold , 342f, 404f Fissu red ton gu e, 400, 401f Fistu las cavern ou s sin u s syn d rom e an d, 185, 185f of p arotid glan d , 205, 205f Flexor carp i radialis m u scle, 607f Flexor carp i u ln aris m u scle, 607f Flexor d igiti m in im i brevis m u scle, 609, 610f Flexor digitoru m p rofu n du s m u scle, 607f Flexor digitoru m su p er cialis m u scle, 607f Flexor p ollicis brevis m u scle, 609, 610f Flexor p ollicis lon gu s m u scle, 607f Floor of oral cavity, 355, 356f arterial su p p ly to, 368–371, 370f of m idd le ear, 489 sen sory in n ervation of, 377–378, 378f ven ou s d rain age from , 372 Fold of Passavan t, 351 Foliate p ap illae, 402, 410f Fon tan elles, 11–12 Foram en cecu m in su p erior view of cran ial base, 51, 53f of ton gu e, 402, 403f, 409f Foram en laceru m , 51, 53f Foram en m agn u m , 30, 51, 53f

676

Foram en ovale in cran ial base, 51, 53f sp h en oid bon e an d , 34, 35f Foram en rotu n d u m p terygoid can al an d, 273f–274f p terygop alatin e fossa an d , 259, 260f–261f sp h en oid bon e an d , 34, 35f in su p erior view of cran ial base, 51, 53f Foram en sp in osu m in cran ial base, 51, 53f sp h en oid bon e an d , 34, 35f Foram en tran sversariu m , 56, 56f Ford yce sp ots, 343 Fovea cen tralis, 516 Fractu res of cervical vertebrae, 64, 64f Le Fort, 62, 62f m an d ibu lar, 63, 63f zygom atic, 61–64, 61f Fren u la labial, 343 lin gu al, 355 Frey’s syn d rom e, 201, 201f Fron tal bon e an atom y of, 28, 28f in facial skeleton , 155f orbital m argin an d , 512, 513f root of n ose an d, 278, 279f stru ctu res articu latin g with , 27–28, 27f tem p oral fossa an d , 209f Fron tal lobe, 68f Fron tal n erve, 521–529, 523f Fron tal p rocess, 26, 43f Fron tal sin u ses arterial su p p ly to, 317, 317f con ch ae an d , 289, 289f drain age of, 315 featu res of, 313, 313f–314f gen eral in form ation abou t, 316, 316f im agin g of, 319f n asal cavity an d , 287, 287f–288f n erve su p p ly to, 318, 318f sin u sitis in , 333 su rgical obliteration of, 336–340, 336f Fron talis m u scle, 168 Fu n ction al en d oscop ic sin u s su rgery, 340, 340f Fu n du scop y, 539f Fu n giform p ap illae, 402, 403f

G Galea ap on eu rosis, 156, 156f, 160f, 168 Gallblad d er, 631, 631f Gan glion , 66 Gen eral fu n ction al colu m n s of cran ial n erves, 75 Gen eral som atic afferen t (GSA) fu n ction . See GSA (gen eral som atic afferen t) fu n ction . Gen icu late gan glion , 200f Gen icu lu m of facial n erve, 486f, 490f Gen ioglossu s m u scle h yp oglossal n erve p aralysis an d , 105 h yp oglossal n erve to, 103, 103f oral cavity oor an d, 356f ton gu e an d, 406, 407f

n e TTe R’S He Ad An d n e CK An ATO MY FO R d e n TISTRY

In d ex Gen ioh yoid fascia, 468 Gen ioh yoid m u scle oral cavity oor an d, 355, 356 in su p rah yoid region , 111, 111 , 127, 127 Geograp h ic ton gu e, 400, 401 Gin giva Akin osi block an d , 576 Gow-Gates block an d , 574 greater p alatin e n erve block an d , 582 in ferior alveolar n erve block an d , 570 lon g bu ccal n erve block an d, 572 m axillary d ivision n erve block an d , 585 m en tal block an d , 573 m id dle su p erior alveolar n erve block an d , 583 n asop alatin e n erve block an d , 581 p osterior su p erior alveolar n erve block an d , 580 teeth an d , 359 , 388, 388 Gin gival groove, 359 Gin givitis, 388, 388 Glau com a, 539, 539 –540 Glen oid fossa, 243–246 Glossitis, xerostom ia an d , 204 Glossoep iglottic fold s, 402, 403 , 405 Glossop h aryn geal (IX) n erve, 139, 141 cou rse of oor of oral cavity, 377–378, 378 p alate, 379, 380 p h aryn x, 439, 441 ton gu e, 410–412, 411 , 413 bers an d fu n ction al colu m n typ es of, 98, 99 p arasym p ath etics of, with corresp on din g sym p ath etics, 562, 563 –564 in p erip h eral n ervou s system , 73 –74 , 74 p h aryn geal arch es an d , 4–5 salivary glan d in n ervation by, 381–382 Glycop yrrolate, 201 Golgi ap p aratu s, 66, 66 Gow-Gates n erve block, 574, 575 Graves’ d isease, 151 Gray m atter of sp in al cord , 70, 70 Great au ricu lar n erve, cou rse of extern al ear, 495, 496 face, 181 n eck, 142, 143 p arotid bed , 195–197, 195 –196 scalp , 160 Greater occip ital n erve, 122, 142, 159, 160 Greater p alatin e arteries to n asal cavity, 291–294, 293 to p alate, 368–371, 369 to p terygop alatin e fossa, 261 , 263 Greater p alatin e can al, 259, 273 –274 Greater p alatin e foram en h ard p alate an d , 349, 350 im agin g of, 395 n asal cavity an d , 288 Greater p alatin e n erve cou rse of, 89 eth m oid sin u ses, 323–324 n ose, 285 , 298 , 303

Greater p alatin e n erve (Continued) p alate, 379, 380 p terygop alatin e fossa, 261 , 265–271, 266 in traoral in jection s an d , 578, 578 p terygop alatin e gan glion an d, 265–271, 268 , 272 Greater p alatin e n erve block, 582, 582 Greater p alatin e vein , 372 Greater p etrosal n erve, p arasym p ath etics associated with , 557 for lacrim al glan d , 535 for n asal cavity, 300, 302 –303 for p terygop alatin e fossa, 265–271, 270 for salivary glan ds, 386, 387 Greater p etrosal n erve groove, 486 Greater win g of sp h en oid bon e an atom y of, 34, 35 in fratem p oral fossa an d , 214, 214 orbital su rface of, 513 tem p oral fossa an d , 209, 209 GSA (gen eral som atic afferen t) fu n ction ch aracteristics of, 75 facial n erve an d, 94 glossop h aryn geal n erve an d , 98, 139 ton gu e an d, 410–412 trigem in al n erve an d, 82, 82 vagu s n erve an d , 100 GSE, 75, 80, 103, 103 GVA, 75 facial n erve an d, 94 glossop h aryn geal n erve an d , 98 vagu s n erve an d , 100 GVE, 75, 80 facial n erve an d, 94 glossop h aryn geal n erve an d , 98 vagu s n erve an d , 100 Gyri, 68 , 69

H Haem ophilus inf uenzae, 507 Hair cells, in n er an d ou ter, 493 Hairy leu kop lakia of ton gu e, 423, 423 Hairy ton gu e, 400, 401 Han d arterial su p p ly to, 638, 638 m u scles of, 609, 610 Han gm an ’s fractu re, 64, 64 Hard p alate, 342, 349, 350 n erve blocks to, 578, 582 Hash im oto’s th yroid itis, 150 Head an d n eck. See also Neck. develop m en t of. See also Em bryon ic develop m en t. overview of, 2, 2 p h aryn geal arch es, 4–5, 4 q u estion s/ an swers abou t, 656–658 lym p h atics of, 657–658, 659 p arasym p ath etic p ath ways of cran ial n erve III with corresp on d in g sym p ath etics, 553–554, 555 –556 cran ial n erve IX with corresp on d in g sym p ath etics, 562, 563 –564

In d e x

677

In d ex Head an d n eck (Continued) cran ial n erve VII with corresp on din g sym p ath etics, 557–559, 558f, 560f–561f cran ial n erve X with corresp on din g sym p ath etics, 565, 565f sym p ath etics of, 551, 552f Heart, 620–622, 620f–622f Helicotrem a, 492f Helix of au ricle, 487, 488f Hem ian op sia, h om on ym ou s or bilateral, 78 Hep atic p ortal vein , 645–646 Herpes sim p lex viru s (HSV-1), 199, 392, 392f Hiatu s for greater p etrosal n erve, 51, 53f Hiatu s for lesser p etrosal n erve, 51, 53f Hiatu s sem ilu n aris, 38, 39f Hip bon e, 600, 601f HIV (h u m an im m u n od e cien cy viru s) in fection , 203 Hom on ym ou s h em ian op sia, 78 Horizon tal cell, 520f Horizon tal p late of p alatin e bon e, 41, 41f, 43f Horn er’s syn drom e, 566, 566f HSV-1. See Herp es sim p lex viru s (HSV-1). Hu m an im m u n ode cien cy viru s (HIV) in fection , 203 Hu m eru s, 593, 594f Hyoep iglottic ligam en t, 454 Hyoglossu s m u scle, 406, 407f, 434f Hyoid bon e fascial sp aces an d , 471 in n eck, 110f an terior trian gle an d , 111, 111f su bm an d ibu lar trian gle an d , 115f su bm en tal trian gle an d, 113 in oral cavity, 356f p h aryn x an d , 433f swallowin g an d , 442, 442f–443f Hyp eracu sis in Bell’s p alsy, 200f Hyp erop ia, 542, 542f Hyp erth yroid ism , 151, 151f Hyp oglossal can al in lateral p ortion of occip ital bon e, 30, 31f in su p erior view of cran ial base, 51, 53f Hyp oglossal (XII) n erve, 139, 141f, 660f carotid trian gle an d , 116, 117f bers an d fu n ction al colu m n typ e of, 103, 103f in frah yoid m u scle an d , 127 lesion s affectin g, 105, 105f p aralysis of, 421, 421f in p erip h eral n ervou s system , 74, 74f su bm an d ibu lar trian gle an d , 114, 115f ton gu e in n ervation by, 414, 415f Hyp oglossu s m u scle, 115f, 356f Hyp op h yseal fossa, 34, 35f Hyp oth alam u s, 69 Hyp oth yroid ism , 150, 150f

I Ileu m , 625, 626f Iliacu s m u scle, 614, 615f Iliocostalis cervicis m u scle, 611, 612f

678

Iliocostalis lu m boru m m u scle, 611, 612f Iliocostalis th oracis m u scle, 611, 612f Iliu m , 600, 601f In cisal su rface of teeth , 357, 358f In cisive artery, 371, 371f In cisive can al, 299f In cisive foram en , 15, 349 In cisive fossa, 350f, 395f In cisive n erve, 375 In cisive p ap illa, 349, 350f In cisors in cu s, 488f, 489, 490f m an d ibu lar, 360–367, 365f m axillary, 360–367, 361f In fection s abscesses, 480, 480f Bell’s p alsy an d , 199 fascial sp aces an d, 471 in in frah yoid region , 477–478, 478f in su p rah yoid region , 473–475, 476f traversin g len gth of n eck, 477–478, 478f Lu d wig’s an gin a, 479–481, 479f of p aran asal sin u ses, 312f, 335f p arotitis an d , 203 sin u sitis, 333–340, 333f–334f In ferior alveolar artery, 216–220, 217f, 371, 371f In ferior alveolar n erve, 574, 575f–577f, 576 in fratem p oral fossa an d , 220–226, 222f–223f teeth an d , 375 In ferior alveolar n erve block, 570, 571f, 587 im p rop er ad m in istration of, tem p orary Bell’s p alsy from , 199 In ferior alveolar vein , 372, 372f In ferior cervical gan glion , 147 In ferior com p artm en t of tem p orom an dibu lar join t, 242f, 243–246, 247f In ferior con strictor m u scle, 407f, 427f, 430, 431f, 434f carotid trian gle an d , 116 In ferior d eep cervical lym p h n od es, 657–658, 659f In ferior d ivision of th e ocu lom otor n erve, 525, 526f In ferior h orn of th yroid cartilage, 449, 449f In ferior labial artery, 172, 172f, 344–345, 344f In ferior labial vein , 175, 176f, 344–345, 345f In ferior lam in a of TMJ, 242f, 243–246 In ferior laryn geal arteries, 458, 458f In ferior laryn geal n erve, 461f In ferior laryn geal vein , 459 In ferior lateral p alp ebral artery, 531f In ferior lon gitu d in al ban d, 59–60 In ferior lon gitu d in al m u scle, 408, 409f In ferior m ed iastin u m , 619, 619f In ferior m esen teric artery, 643, 643f In ferior n asal con ch ae, 27–28, 41, 41f, 289, 289f–290f, 308f–309f In ferior n asal m eatu s, 289, 289f–290f, 315 In ferior obliq u e m u scle, 517, 518f–519f In ferior op h th alm ic vein from eye an d orbit, 530–532 from face, 176f

n e TTe R’S He Ad An d n e CK An ATO MY FO R d e n TISTRY

In d ex In ferior op h th alm ic vein (Continued) from n ose, 280–282 from p terygop alatin e fossa, 262–264, 264f In ferior orbital ssu re an terior view, 50, 50f as orbital op en in g, 512 p terygop alatin e fossa an d , 259, 260f In ferior p alp ebral artery, 530–532 In ferior p h aryn geal con strictor m u scle of p h aryn x, 407f, 427f, 430, 431f, 434f In ferior rectu s m u scle, 517, 518f–519f In ferior salivatory n u cleu s, p arasym p ath etics of p arotid glan d an d , 384–386, 385f an atom ic p ath way for, 195–197, 220–226, 227f, 562, 563f–564f In ferior tem p oral lin e, 209, 209f In ferior th yroid artery, 130 to p h aryn x, 435, 437f th yroid glan d an d, 123, 124f In ferior th yroid vein , 118, 123, 124f, 125, 135, 137f In ferior tu bercle of th yroid cartilage, 449 In ferior tym p an ic artery, 501, 502f In ferior wall of orbit, 512–513 In frah yoid fascia, 469–470 In frah yoid fascial sp aces, 471, 477–478, 478f In frah yoid m u scles, 127 In frah yoid region of n eck, 111 In fraorbital artery to eye an d orbit, 524, 524f to face, 170f, 172, 172f, 174f to p terygop alatin e fossa, 262–264, 263f In fraorbital can al, m axillary division n erve bran ch es with in , 89f In fraorbital ssu re, 273f–274f In fraorbital foram en , 50, 50f In fraorbital groove an d can al, 512 In fraorbital n erve cou rse of eye an d orbit, 524, 524f face, 179f lip s an d ch eeks, 344–345, 344f m axillary sin u s, 327, 327f n asal cavity, 303f n ose, 283–286, 284f p terygop alatin e fossa, 265–271, 266f teeth , 374 p terygop alatin e fossa an d , 261f In fraorbital n erve block, 584, 584f In fraorbital vein , 170f, 176f, 262–264, 530–532 In frasp in atu s m u scle, 603, 604f In fratem p oral fascial sp ace, 473 In fratem p oral fossa an atom y of, 208, 208f arterial su p p ly to, 216–220, 217f–218f bord erin g stru ctu res of, 214, 214f–215f m axilla an d , 26 n ervou s stru ctu res of, 220–226, 222f–223f, 225f–227f p terygop alatin e fossa an d , 258, 258f, 260f q u estion s/ an swers abou t, 655 ven ou s d rain age from , 216–220, 219f In fratroch lear artery, 530–532, 531f

In fratroch lear n erve cou rse of eye an d orbit, 521–529 face, 178, 179f n ose, 283–286, 284f, 299f In jection s in traoral. See In traoral in jection s. in traosseou s, 587 in trap u lp al, 587 in trasep tal, 587 p eriod on tal ligam en t, 587–588, 588f In n er ears arterial su p p ly to, 503, 503f gen eral in form ation abou t, 484 sen sory in n ervation of, 498, 498f stru ctu res of, 491, 492f–493f ven ou s d rain age from , 504 In n er h air cells, 486f In n er h orizon tal p art of lateral ligam en ts, 243–246 In n er lim itin g m em bran e, 520f In n erm ost in tercostal m u scle, 613, 613f In su la, 68f, 69 In tercalated lym p h n od es, 659f–660f In term axillary segm en t, 15 In term axillary su tu re, 279f, 395f In term ed iolateral h orn n u cleu s, ch aracteristics of for eye, 528f, 553–554 gen eral, 551 for lacrim al, su bm an d ibu lar, an d su blin gu al glan d, 557–559 for n asal cavity, 300, 557–559 for p arotid glan d , 195–197, 562 for p terygop alatin e fossa, 265–271 In tern al acou stic m eatu s. See also In n er ears. in su p erior view of cran ial base, 51, 53f in tem p oral bon es, 32 In tern al au d itory m eatu s, 200f In tern al bran ch of su p erior laryn geal n erve, 378f, 433f In tern al carotid artery caroticotym p an ic bran ch of, 501, 502f carotid trian gle an d , 116, 117f to face, 158f, 170, 170f as m id dle ear bou n dary, 490f to n eck, 130, 134f to n ose, 279f, 302f In tern al in tercostal m u scle, 613, 613f In tern al ju gu lar lym p h n od es, 660f In tern al ju gu lar vein s carotid trian gle an d , 116, 117f from n eck, 135, 137f–138f p h aryn geal p lexu s an d, 438f in root of n eck, 125 su bm an d ibu lar trian gle an d , 115f In tern al laryn geal n erve, cou rse of oor of oral cavity, 377–378, 378f laryn x, 460, 460f–461f ton gu e, 410–412 In tern al n asal n erve, 283–286, 284f In tern al obliq u e m u scle, 614, 615f In tern al su p erior laryn geal n erve, 433f In tersp in ou s p lan e, 590, 591f

In d e x

679

In d ex In tertragic n otch , 487 In tracran ial au ditory m eatu s, 200f In tram u ral gan glion , 565 In traoral in jection s gen eral in form ation abou t, 568, 568f m an d ibu lar, 568–576 Akin osi, 576, 576f–577f Gow-Gates, 574, 575f in ferior alveolar, 570, 571f, 587 lan d m arks for, 569, 569f lon g bu ccal, 572, 572f m en tal, 573, 573f m axillary, 568 an terior su p erior alveolar, 584, 584f gen eral in form ation abou t, 578, 578f greater p alatin e, 582, 582f in fraorbital, 584, 584f lan d m arks for, 578, 578f–579f m axillary d ivision , 585, 586f m id dle su p erior alveolar, 583, 583f n asop alatin e, 581, 581f p osterior su p erior alveolar, 580, 580f In traosseou s in jection s, 587 In trap u lp al in jection s, 587 In trasep tal in jection s, 587 In vestin g layer of deep cervical fascia of n eck, 468f, 469–470, 470f p arotid glan d an d , 189, 189f p osterior trian gle an d , 120 stern ocleidom astoid m u scle an d , 108 trap eziu s m u scle an d, 108, 109f Iris, 514f–515f, 516 Isch iu m , 600, 601f

J Jefferson fractu re, 64, 64f Jeju n u m , 625, 626f Ju gu lar foram en , 30, 51 Ju gu lar fossa, 32, 33f, 490f, 494f Ju gu lar vein s. See An terior ju gu lar vein ; Extern al ju gu lar vein s; In tern al ju gu lar vein s. Ju gu lod igastric lym p h n odes, 657–658, 659f–660f Ju gu lo-om oh yoid lym p h n odes, 659f–660f Ju xtavisceral lym p h n od es, 657–658

K Keratin ized strati ed sq u am ou s ep ith eliu m , 278 Kid n eys, 633, 633f Kiesselbach ’s p lexu s, 291

L Labial su rface of teeth , 357, 358f Labiom en tal groove, 343, 343f Labyrin th in e artery, 503, 503f Labyrin th in e vein , 504 Lacrim al ap p aratu s, 534–535, 534f, 536f Lacrim al artery, 292f, 530–532, 531f Lacrim al bon es an atom y of, 36, 36f in facial skeleton , 155f n asal cavity an d , 287

Lacrim al bon es (Continued) orbit walls an d , 513f stru ctu res articu latin g with , 27–28, 27f Lacrim al can alicu li, 290f, 534, 534f Lacrim al caru n cle, 290f, 534f Lacrim al fossa, 36 Lacrim al glan d s GVE bers of facial n erve an d , 94 in lacrim al ap p aratu s, 534, 534f orbital an d p alp ebral p arts of, 290f p arasym p ath etics of, 535, 536f, 557–559, 558f sym p ath etics of an atom ic p ath way for, 536f, 559, 560f–561f traversin g p terygop alatin e fossa, 265–271 Lacrim al n erve cou rse of, 89f eye an d orbit, 521–529, 523f face, 178, 179f n asal cavity, 299f Lacrim al p art of orbicu laris ocu li m u scle, 166 Lacrim al sac, 290f, 534, 534f Lam in a p rop ria of gin giva, 359f Large in testin e, 627–628, 628f Laryn geal ad itu s, 442, 442f–443f Laryn geal n erve, 115f, 140 Laryn geal p rom in en ce, 449, 449f Laryn geal vein , 115f Laryn gitis, 463, 463f Laryn gop h aryn x, 429, 429f Laryn x an atom y of, 123, 124f, 446f–447f arterial su p p ly to, 458, 458f carotid trian gle an d , 116 cartilages of, 446f, 448, 448f aryten oid, 451, 451f cricoid, 450, 450f ep iglottis, 452, 452f m in or, 453, 453f th yroid , 449, 449f clin ical correlates for, 462–464, 462f–464f gen eral in form ation abou t, 446, 446f join ts, m em bran es, an d ligam en ts of, 454, 455f m otor an d sen sory bran ch es from vagu s n erve to, 460, 460f–461f m u scles of, 456–457, 456f–457f m u scu lar trian gle an d, 118 swallowin g an d, 442, 442f–443f ven ou s d rain age from , 459, 459f Lateral collateral ligam en t, 243–246, 247f Lateral cricoaryten oid m u scle, 456–457, 456f–457f Lateral cru s, 279f Lateral in cisors, 358f, 360–367, 361f, 365f im agin g of, 396f–397f Lateral ligam en ts, 243–246, 247f Lateral n asal artery, 172, 172f, 174f, 280–282, 281f Lateral n asal cartilage, 278, 279f Lateral n asal vein , 175 Lateral p alp ebral artery, 531f Lateral p ectoral n erve, 650

6 8 0 n e TTe R’S He Ad An d n e CK An ATO MY FO R d e n TISTRY

In d ex Lateral p h aryn geal fascial sp ace, 474 Lateral p late m esod erm , 2, 3f, 4 Lateral p terygoid m u scle in fratem p oral fossa an d , 214, 215f m astication an d , 230f, 231, 232f–233f, 239 in op en in g th e m an dible, 253, 254f p h aryn geal m u scles an d , 434f Lateral p terygoid n erve, 237, 238f Lateral rectu s m u scle, 517, 518f–519f Lateral sem icircu lar can al, 486f Lateral su lcu s (of Sylviu s), 69 Lateral th yroh yoid ligam en ts, 454 Lateral walls of m id d le ear, 489 of n asal cavity, 286 of orbit, 512–513 Latissim u s d orsi m u scle, 611, 612f Le Fort fractu res, 62, 62f Len s, 514f–515f, 516 Lesser occip ital n erve, 142, 159, 160f, 495, 496f Lesser p alatin e arteries to n asal cavity, 293f to n ose, 281f to p alate, 368–371, 369f to p h aryn x, 435 to p terygop alatin e fossa, 261f, 263f Lesser p alatin e foram en h ard p alate an d , 349, 350f im agin g of, 395f n asal cavity an d , 288f Lesser p alatin e n erve cou rse of, 89f n ose, 285f, 298f, 303f p alate, 379, 380f p terygop alatin e gan glion an d, 261f, 265–271, 266f, 268f, 272f Lesser p alatin e vein , 372 Lesser p etrosal n erve, 214, 220–226, 223f, 226f, 490f Lesser win g of sp h en oid bon e, 34, 35f, 513f Lesser’s trian gle, 114 Leu kop lakia, 422–423, 423f Levator an gu li oris m u scle, 164, 165f Levator labii su p erioris alaeq u e n asi m u scle, 164, 165f Levator labii su p erioris m u scle, 164, 165f Levator p alp ebrae su p erioris m u scle, 517, 518f–519f Levator scap u lae m u scle, 120, 121f, 611, 612f Levator veli p alatin i m u scle m astication an d , 233f p h aryn geal m u scles an d , 407f, 434f p h aryn gotym p an ic tu be an d, 353f, 432f, 490f in soft p alate, 351–352, 351f–353f Ligam en ta ava, 58, 58f Ligam en tu m n u ch ae, 58, 58f, 126 Ligh t tou ch (sen sation ), 92f Lin gu al artery carotid trian gle an d , 116, 117f to n eck, 130, 134f

Lin gu al artery (Continued) to oral cavity oor, 368–371, 370f su bm an d ibu lar trian gle an d , 114, 115f to ton gu e, 416, 417f–418f Lin gu al foram en , 27f, 51, 397f Lin gu al fren u lu m , 355, 356f, 404, 404f, 420–423, 420f Lin gu al m in or salivary glan d , 404f Lin gu al n erve cou rse of oor of oral cavity, 377–378, 378f ton gu e, 410–412, 413f Gow-Gates block an d , 574 in ferior alveolar n erve block an d, 570, 571f in fratem p oral fossa an d, 220–226, 222f in traoral in jection s an d , 569 as oral cavity oor bord er, 355, 356f su bm an d ibu lar trian gle an d , 114 Lin gu al su rface of teeth , 357, 358f Lin gu al ton sils, 393, 402, 403f, 405 Lin gu al vein carotid trian gle an d , 116 from n eck, 135, 137f from oral cavity, 372 su bm an d ibu lar trian gle an d , 114 from ton gu e, 419, 419f Lip s. See also Face. arterial su p p ly to, 344–345, 344f cleftin g of, 23, 23f–24f em bryotic d evelop m en t of, 13 fren u lu m of, 342f in fraorbital n erve block an d , 584 m axillary d ivision n erve block an d , 585 sen sory in n ervation of, 347, 347f stru ctu ral featu res of, 343, 343f ven ou s d rain age from , 344–345, 345f Liver, 629, 629f Lobu le of au ricle, 487, 488f Lon g bu ccal n erve, Gow-Gates block an d , 574 Lon g bu ccal n erve block, 572, 572f Lon g ciliary n erves, 86f Lon g th oracic n erve, 120, 650 Lon gissim u s cap itis m u scle, 611, 612f Lon gissim u s cervicis m u scle, 611, 612f Lon gissim u s th oracis m u scle, 611, 612f Lon gu s cap itis m u scle, 128, 128f Lon gu s colli m u scle, 128, 128f Loose areolar con n ective tissu e, 156, 156f Lower m otor n eu ron s, 550f Lower su bscap u lar n erve, 651 Lu d wig’s an gin a, 479–481, 479f Lu m bar sp in al n erves, 70, 70f Lu m bar sp lan ch n ic n erves, 73f Lu m bar vertebrae, 596, 597f Lu m bosacral en largem en t, of sp in al cord , 70, 70f Lu m brical m u scles, 609, 610f Lu n gs, 617, 617f Lym p h , 655, 657 Lym p h n od es, 655, 656f carotid trian gle an d , 116 typ es of, 657–658, 659f

In d e x

6 81

In d ex Lym p h atic d u cts, 655, 656f Lym p h atic system drain age, 657, 660f fu n ction s of, 655 p arts of, 655–658, 656f, 659f Lym p h atic vessels, 655 Lym p h osarcom a, 202f Lysosom es, 66, 66f

M Macroglossia, 576 Macu la lu tea, 516 Macu lae of u tricle an d saccu le, 96, 96f–97f Male p elvis, 634, 634f Malleu s, 489, 489f–490f Mam elon s, 360–367 Man d ible an atom y of, 44, 45f, 51, 51f dislocation of, 252, 252f in facial skeleton , 110f fractu res of, 63, 63f obliq u e lin e of, 434f op en in g th e, 253, 253f–254f stru ctu res articu latin g with , 27–28, 27f TMJ an d op en in g of, 251–255, 251f Man d ibu lar arch , 5, 357 Man d ibu lar bran ch of facial n erve, 164, 182, 190, 191f, 346, 346f Man d ibu lar con d yles, 243–246, 574 Man d ibu lar d ivision (V3 ) of trigem in al (V) n erve bran ch es with in , 91f cou rse of face, 177, 177f, 179f–180f in fratem p oral fossa, 214, 220–226, 222f–223f in m asticatory m u scles, 237, 238f, 239 scalp , 160f teeth , 375, 376f tem p oral fossa, 212, 212f–213f GSA bers an d , 82, 82f oral cavity in n ervation by, 373–379, 373f p h aryn geal arch es an d, 4 sen sory in n ervation of n eck by, 143f tem p oral fossa in n ervation by, 213f Man d ibu lar foram en , 27f, 51 Man d ibu lar in jection s, 568–576 Akin osi, 576, 576f–577f Gow-Gates, 574, 575f in ferior alveolar, 570, 571f, 587 lan d m arks for, 569, 569f lon g bu ccal, 572, 572f m en tal, 573, 573f Man d ibu lar lym p h n odes, 659f Man d ibu lar m u cosa, 570 Man d ibu lar p rocesses, 4–5, 11 Man d ibu lar ram u s, 189, 189f, 191f, 569, 569f Man d ibu lar teeth . See Teeth : m an d ibu lar. Man d ibu lar toru s, 390 Man u briu m , 125, 598, 599f Man u s, 638, 638f, 650–652 Margin al m an d ibu lar bran ch of facial n erve, 191f, 212f

Masseter m u scle m astication an d , 230f, 231, 232f, 239 p arotid glan d an d , 188–189 Masseteric artery, 216–220, 217f, 234, 235f Masseteric bran ch of m an d ibu lar n erve, 220–226, 223f, 231 Masseteric n erve, 235f, 237, 238f, 571f tem p orom an dibu lar join t an d , 250, 250f Masseteric vein , 236 Mastication , m u scles of an atom y of, 230–231, 230f, 232f–233f arterial su p p ly to, 234, 235f clin ical correlate for, 239, 240f m otor bran ch es of trigem in al n erve in , 237, 238f q u estion s/ an swers abou t, 656 ven ou s d rain age from , 236, 236f Masticator fascial sp ace, 475, 476f Mastoid air cells, 32 Mastoid an tru m , 489, 490f Mastoid foram en , 51, 53f Mastoid lym p h n od es, 657–658, 659f Mastoid itis, 508, 508f Maxillae an atom y of, 42, 42f–43f an terior n asal sp in e of, 279f in facial skeleton , 155f in fratem p oral fossa an d, 214, 214f–215f n asal cavity an d , 287, 288f orbital m argin an d , 512, 513f p alatin e p rocess of, 349, 350f p terygop alatin e fossa an d, 259 root of n ose an d , 278 stru ctu res articu latin g with , 27–28, 27f Maxillary arch , 357 Maxillary artery to extern al ear, 499, 500f to face, 172, 172f to in fratem p oral fossa, 214, 216–220, 217f–218f ligation of, for severe p osterior ep istaxis, 304, 305f to m asticatory m u scles, 231, 232f, 234, 235f to n asal cavity, 291–294, 293f to n ose, 280–282, 281f to p alate, 368–371, 369f to p arotid bed , 192–193, 192f to p terygop alatin e fossa, 261f, 262–264, 263f to teeth , 371, 371f Maxillary d ivision (V2 ) of trigem in al (V) n erve across p terygop alatin e fossa, 265–271, 270f bran ch es with in , 89f associated with p terygop alatin e gan glia, 265–271, 268f cou rse of eye an d orbit, 519, 524, 524f face, 177, 177f, 179f in fratem p oral fossa, 220–226, 222f m axillary sin u s, 327, 327f n asal cavity, 295, 295f, 300, 302f–303f n ose, 283–286, 284f–285f oral cavity, 373–379, 373f p alate, 379, 380f

6 82 n e TTe R’S He Ad An d n e CK An ATO MY FO R d e n TISTRY

In d ex Maxillary division (V2 ) of trigem in al (V) n erve (Continued) p terygop alatin e fossa, 265–271, 266f scalp , 159, 160f teeth , 374 GSA bers an d , 82, 82f n erve blocks to, 585, 586f p arasym p ath etics associated with , 557 p h aryn geal arch es an d , 4 Maxillary in jection s an terior su p erior alveolar, 584, 584f gen eral in form ation abou t, 578, 578f greater p alatin e, 582, 582f in fraorbital, 584, 584f lan d m arks for, 578, 578f–579f m axillary d ivision , 585, 586f m id dle su p erior alveolar, 583, 583f n asop alatin e, 581, 581f p osterior su p erior alveolar, 580, 580f Maxillary p rocesses, 4–5, 11 Maxillary p rom in en ce, 15 Maxillary sin u s arterial su p p ly to, 326, 326f bou n daries an d relation s of, 287 Caldwell-Lu c p roced u re in , 337, 337f con ch ae an d , 289, 289f drain age of, 315 featu res of, 313, 313f–314f gen eral in form ation abou t, 325–328, 325f im agin g of, 308f, 328f, 395f–396f n erve su p p ly to, 303f, 327, 327f sin u sitis in , 333, 334f Maxillary teeth . See Teeth : m axillary. Maxillary vein from ears, 504 from face, 176f from in fratem p oral fossa, 216–220, 219f from m asticatory m u scles, 236 from p arotid bed , 192–193 from p terygop alatin e fossa, 264f from tem p oral fossa, 210–211, 211f from tem p orom an dibu lar join t, 249, 249f Meckel’s cartilage, 44 Medial an tebrach ial cu tan eou s n erve, 651 Medial brach ial cu tan eou s n erve, 650 Medial collateral ligam en t, 243–246, 247f Medial cru s, 279f Medial p alp ebral artery, 530–532, 531f Medial p ectoral n erve, 651 Medial p terygoid m u scle in fratem p oral fossa an d, 214, 215f m astication an d , 230f, 231, 233f, 239 p arotid glan d an d , 189, 189f Medial p terygoid n erve, 220–226, 237, 238f Medial rectu s m u scle, 517, 518f–519f Medial wall of m idd le ear, 489 of orbit, 512–513 Median cricoth yroid ligam en t, 449f, 454 Median su lcu s, 402, 403f Median th yroh yoid ligam en t, 454 Mediastin u m , 618–619, 618f–619f Medu lla, 69 Medu lla oblon gata, 139

Mem bran ou s labyrin th , 96, 96f–97f, 491, 492f, 505f Mem bran ou s n eu rocran iu m , 10 Mem bran ou s su p er cial layer of abdom in al wall, 590, 591f Men in geal n erve, 89f, 220–226 Men in gitis, 333 Men tal artery, 172, 172f, 344–345, 344f, 371 Men tal bran ch of in ferior alveolar artery, 372 Men tal bran ch of in ferior alveolar n erve, 180f, 347f, 375 Men tal foram en , 27f, 44, 45f, 50–51, 50f, 573 Men tal n erve, 180f, 347, 347f, 571f, 573f teeth an d , 375 Men tal n erve block, 573, 573f Men tal p rotu beran ce, 343f Men tal vein , 175, 176f, 344–345, 345f Men talis m u scle, 164, 165f Mesial su rface of teeth , 357, 358f Mesod erm , 2, 3f Microglia, 67, 67f Microvascu lar decom p ression , 184f Midbrain , 69, 69f, 92f Midd le cervical gan glion , 147, 147f Midd le con strictor m u scle, 430, 432f–434f, 434 carotid trian gle an d , 116 Midd le cran ial fossa, 26, 89f Midd le ears, 488f arterial su p p ly to, 501, 502f clin ical correlate for, 507, 507f gen eral in form ation abou t, 484 sen sory in n ervation of, 497, 497f stru ctu res of, 489, 489f–490f ven ou s d rain age from , 504, 505f Midd le layer of deep cervical fascia, 108, 469–470 Midd le m en in geal artery, 216–220, 217f Midd le n asal con ch ae, 289, 289f–290f, 308f–309f Midd le n asal m eatu s an atom y of, 289, 289f drain age of, 315 eth m oid sin u ses an d , 320 fron tal sin u ses an d , 316 m axillary sin u s an d , 325 Midd le p h aryn geal con strictor m u scle, 430, 432f–434f, 434 Midd le scalen e m u scle, 128, 128f Midd le su p erior alveolar artery, 326, 326f, 371, 371f Midd le su p erior alveolar n erve cou rse of, 89f m axillary sin u s, 327, 327f n asal cavity, 299f teeth , 374 in traoral in jection s an d , 578, 579f Midd le su p erior alveolar n erve block, 583, 583f Midd le su p erior alveolar vein , 372 Midd le tem p oral artery, 210–211, 210f, 234, 235f Midd le tem p oral vein , 210–211, 211f, 236, 236f

In d e x

6 83

In d ex Mid d le th yroid vein , 116, 135, 137f Mid lin e groove of ton gu e, 403f Mid lin e sep tu m of ton gu e, 402 Mim etic m u scles, 154 Min or’s starch iod in e test, 201 Mitoch on dria, 66, 66f Mixed den tition , 357 Modiolu s of coch leas, 486f, 491 Molar glan d s, ch eeks an d, 343 Molars decidu ou s vs. p erm an en t, 358f im agin g of, 396f–397f m an d ibu lar, 367, 367f m axillary, 363, 363f p osterior su p erior alveolar n erve block an d , 580, 580f Mu cobu ccal fold , 343 Mu cocele, 391, 391f Mu cou s m em bran e of oral cavity oor, 355 Mü ller cell, 520f Mu ltip olar n eu ron s, 66, 66f Mu m p s, 203, 203f Mu scu lar bran ch of op h th alm ic artery, 530–532, 531f Mu scu lar p rocess of aryten oid cartilage, 451, 451f Mu scu lar trian gle, 109f, 111, 118, 119f Mu scu locu tan eou s n erve, 650 Mu scu loskeletal region of cervical fascia, 468f, 469–470 Mu scu lu s u vu lae, 351–352 Myd riasis, 80 Myloh yoid lin e, 44, 45f Myloh yoid m u scle oral cavity oor an d , 355, 356f su bm an d ibu lar trian gle an d , 114, 115f in su p rah yoid region , 111, 111f, 127, 127f Myloh yoid n erve, 114, 356f, 574, 576 in fratem p oral fossa an d , 220–226, 222f Myop ia, 542, 542f

N Nasal bon es an atom y of, 36, 36f an terolateral view, 279f in facial skeleton , 155f, 278, 278f n asal cavity an d , 287f–288f stru ctu res articu latin g with , 27–28, 27f Nasal bran ch of in fraorbital artery, 279f, 280–282 Nasal bran ch of in fraorbital n erve, 283–286, 284f–285f Nasal cavity an atom y of, 286–301, 286f, 315f arterial su p p ly to, 291–294, 292f–293f au ton om ics traversin g p terygop alatin e fossa an d , 265–271 bon es of, 315f bou n daries an d relation s of, 287, 287f–288f clin ical correlates for, 304–308, 305f–307f con ch ae of. See Con ch ae, n asal. gen eral in form ation abou t, 276, 276f–277f im agin g of, 308, 308f–309f m axilla an d , 26

Nasal cavity (Continued) p arasym p ath etics of, 300, 303f, 557–559, 558f sen sory in n ervation of, 295–301, 295f–296f, 298f–299f, 302f–303f sym p ath etics of, 300–301, 303f an atom ic p ath way for, 559, 560f–561f ven ou s d rain age from , 291–294, 294f Nasal grou p of m u scles of facial exp ression , 166, 167f Nasal p olyp , im agin g of, 309f Nasal sep tu m d eviated , 306, 306f, 308f eth m oid bon e an d, 38 n asal cavity an d, 286, 287f vom er an d , 40 Nasal sin u ses. See Paran asal sin u ses. Nasal ven ou s p lexu s, 286, 291–294, 294f Nasal vestibu le, 278f, 286f–287f Nasalis m u scle, 166, 167f, 174f Nasociliary bran ch of trigem in al n erve op h th alm ic d ivision , 86f, 178 Nasociliary n erve cou rse of, 323–324, 521–529, 523f op h th alm ic d ivision (V1) an d , 86f Nasofron tal vein , 170f Nasolabial groove, 343 Nasolabial lym p h n od es, 659f Nasolabial su lcu s, 278f, 343f Nasolacrim al can al, 512 Nasolacrim al d u ct drain age of, 315 im agin g of, 309f n asal cavity an d , 286, 289, 289f op en in g of, 288f–290f, 534f orbit an d, 512, 534 Nasop alatin e n erve cou rse of n asal cavity, 303f n ose, 285f, 298f–299f p alate, 379, 380f in traoral in jection s an d , 578 n asop alatin e n erve block an d , 581 p terygop alatin e fossa an d , 261f, 265–271 p terygop alatin e gan glion an d , 265–271, 268f Nasop alatin e n erve block, 581, 581f Nasop h aryn x, 428, 429f Nearsigh ted n ess, 542, 542f Neck, 107–151. See also Cervical vertebrae; Head an d n eck. arterial su p p ly to carotid , 130, 134f su bclavian , 130, 131f cervical p lexu s of, 144, 145f clin ical correlates for, 148, 148f–151f, 150–151 cran ial n erves of, 139, 141f deep fascia of, 469–470, 470f facial exp ression m u scles an d , 168, 169f fascial sp aces traversin g len gth of, 471, 477–478, 478f gen eral in form ation abou t, 108, 109f–110f in frah yoid m u scle of, 127 p revertebral m u scles of, 128, 128f

6 84 n e TTe R’S He Ad An d n e CK An ATO MY FO R d e n TISTRY

In d ex Neck (Continued) q u estion s/ an swers abou t, 655 root of, 125, 125f sen sory in n ervation of, 142, 143f su p er cial fascia of, 468, 468f su p rah yoid m u scle of, 127, 127f sym p ath etics in , 147, 147f trian gles of an terior, 111, 111f–113f, 113–118, 115f, 117f, 119f m u scles bord erin g, 126, 126f m u scles su bd ivid in g, 126, 126f p osterior, 120, 121f su boccip ital, 122, 122f, 129, 129f ven ou s d rain age from , 135, 137f–138f ven tral ram i n erves of, 146, 146f visceral con ten ts of, 123, 124f Neck tu m ors, voice effects from , 105, 105f Nerve blocks, 568. See also In traoral in jection s. Nervou s system cen tral brain an d , 68f–69f, 69 gen eral in form ation abou t, 68, 68f sp in al cord an d , 70, 70f–71f p erip h eral. See Perip h eral n ervou s system . Nervou s tissu e, 66–67, 66f–67f Neu ral crest, 2, 4–5, 12–13 Neu ral p late, 3f Neu rap raxia, facial n erve, 199 Neu roan atom y. See also Cran ial n erves; Nervou s system . n ervou s tissu e, 66–67, 66f–67f q u estion s/ an swers abou t, 655–656 Neu rocran iu m , 10, 12, 12f, 26 Neu roectod erm , 2 Neu roglia, 67, 67f Neu ron s, 66, 66f p ostgan glion ic. See Postgan glion ic n eu ron s. p regan glion ic. See Pregan glion ic n eu ron s. for trigem in al n erve sen sory system , 92f Neu rotu bu les, 66, 66f Nissl su bstan ce, 66, 66f Norep in ep h rin e, 544 Norm a basalis, 26, 49, 49f Norm a fron talis, 26, 46, 46f Norm a lateralis, 26, 48, 48f Norm a occip italis, 26, 46, 46f Norm a verticalis, 26, 47, 47f Nose. See also Nasal cavity. an atom y of, 278–279, 278f–279f, 315f arterial su p p ly to, 279–282, 279f, 281f clin ical correlates for, 304–308, 305f–307f em bryotic d evelop m en t of, 13, 13f–14f gen eral in form ation abou t, 276, 276f–277f im agin g of, 308, 308f–309f in fraorbital n erve block an d , 584 m axillary d ivision n erve block an d , 585 n erve su p p ly to, 283–286, 284f–285f ven ou s d rain age from , 280–282, 282f Nosebleed s, 279, 304–308, 305f Nostrils, 278f Nu cleu s, 66, 66f Nu cleu s solitariu s, 94, 98, 100

O Obliq u e aryten oid m u scles, 456–457 Obliq u e cricoaryten oid m u scle, 456–457, 456f Obliq u e h ead of ad d u ctor p ollicis m u scle, 609, 610f Obliq u e lin e m an d ibu lar, 434f of th yroid cartilage, 449, 449f Obliq u u s cap itis in ferior m u scle, 122, 122f, 129, 129f Obliq u u s cap itis su p erior m u scle, 122, 122f, 129, 129f Occip ital artery carotid trian gle an d , 116, 117f to n eck, 130, 134f p osterior trian gle an d , 120 to scalp , 157, 158f, 160f Occip ital bon e, 27–28, 30, 31f Occip ital con d yles, 30 Occip ital lobe, 68f, 69 Occip ital lym p h n od es, 657–658, 659f Occip ital trian gle, 120 Occip ital vein from n eck, 135, 137f p osterior trian gle an d , 120 from scalp , 158f Occip italis m u scle, 168, 169f Occlu sal su rface of teeth , 357, 358f Ocu lom otor (III) n erve as cran ial n erve, 73f eye an d orbit in n ervation by, 519, 520f, 525, 526f eye m u scles an d , 518f bers an d fu n ction al colu m n typ es of, 80, 80f–81f op h th alm op legia an d, 185f p alsy, 538 p arasym p ath etics of, with corresp on din g sym p ath etics, 553–554, 555f–556f in p erip h eral n ervou s system , 74, 74f Od on toid p rocess, 56, 56f fractu res of, 64, 64f Olfactory bu lb, 76f–77f, 296f, 299f Olfactory ep ith eliu m , 286, 296, 296f Olfactory m u cosa, 77f, 296f Olfactory (I) n erves n asal cavity in n ervation by, 285f, 295, 295f, 298f in p erip h eral n ervou s system , 74, 74f SVA an d , 76, 76f–77f Olfactory tract, 299f Oligod en d rocytes, 67, 67f Om oclavicu lar trian gle, 120 Om oh yoid m u scle in in frah yoid region , 111, 111f, 127 p osterior trian gle an d , 120 su bd ivid in g trian gles, 126, 126f Op en an gle glau com a, 539 Op h th alm ic artery to eth m oid sin u ses, 322 to eye, 528f, 530–532, 531f to face, 172f, 174f to fron tal sin u ses, 317, 317f to n asal cavity, 291–294, 292f

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In d ex Op h th alm ic artery (Continued) to n ose, 279–282 to sp h en oid sin u s, 330 Oph th alm ic d ivision (V1 ) of trigem in al (V) n erve bran ch es of, 85f–86f cou rse of eye an d orbit, 520f, 521–529, 523f, 535 face, 177–178, 177f, 179f n asal cavity, 295, 295f, 302f n ose, 283–286, 284f p terygop alatin e fossa, 265–271, 270f scalp , 159, 160f fron tal sin u ses in n ervation by, 316, 318, 318f GSA bers an d , 82f p arasym p ath etics associated with , 557 p h aryn geal arch es an d, 4f sen sory in n ervation of n eck by, 143f Op h th alm op legia, 185, 185f, 538 Op p on en s d igiti m in im m u scle, 609, 610f Op p on en s p ollicis m u scle, 609, 610f Op tic can al (foram en ) an terior view, 50, 50f as orbital op en in g, 512, 513f sp h en oid bon e an d , 34, 35f su p erior view, 51, 53f Op tic d isc, 515f, 516 Op tic (II) n erve eye an d orbit in n ervation by, 520f–521f, 521–529 in p erip h eral n ervou s system , 74, 74f SSA bers an d , 78, 79f Ora serrata, 515f, 520f Oral cavity bou n daries of gen eral in form ation abou t, 348, 348f in ferior ( oor), 355, 356f lateral (ch eeks), 354, 354f p osterosu p erior (soft p alate), 351–352, 351f–353f su p erior (h ard p alate), 349, 350f clin ical correlates for, 388–394, 388f–394f extern al featu res of arterial su p p ly to, 344–345, 344f lip s an d ch eeks, 343, 343f m u scles, 346, 346f sen sory in n ervation of, 347, 347f ven ou s d rain age from , 344–345, 345f oor of. See Floor of oral cavity. gen eral in form ation abou t, 342, 342f im agin g of, 395f–397f n asal cavity an d , 287, 287f p alate of. See Palate. salivary glan d s an d. See Salivary glan d s. sen sory in n ervation of, 373–379, 373f teeth in . See Teeth . ven ou s d rain age from , 372, 372f Oral grou p of m u scles of facial exp ression , 164, 165f Oral m u cosa, 343 Akin osi block an d , 576 Gow-Gates block an d , 574

Oral m u cosa (Continued) m axillary d ivision n erve block an d , 585 n asop alatin e n erve block an d , 581 Oral vestibu le, 342–343, 342f–343f Orbicu laris ciliaris of ciliary bod y, 515f Orbicu laris ocu li m u scle, 166, 167f Orbicu laris oris m u scle, 164, 165f, 230f, 232f, 343, 346, 346f Orbit arterial su p p ly to, 530–532, 531f bon es creatin g m argin s of, 513, 513f cran ial n erve su p p ly to, 519, 520f–521f, 521–529, 523f–524f extrin sic m u scle of, 517, 518f–519f eye, 514, 514f–515f, 516 gen eral in form ation abou t, 510, 510f lacrim al ap p aratu s of, 534–535, 534f, 536f lacrim al bon es an d , 36 m axilla an d , 26, 43f m axillary d ivision n erve block an d , 585 m otor in n ervation of, 519, 520f, 525, 526f n asal cavity an d , 287 op en in gs in , 512, 513f sen sory in n ervation of, 519, 520f–521f, 521–529, 523f–524f ven ou s d rain age from , 530–532, 533f walls of, 513, 513f zygom atic bon es an d, 37 Orbital bran ch of p terygop alatin e gan glion , 331, 331f Orbital grou p of m u scles of facial exp ression , 166, 167f Orbital p art of lacrim al glan d , 290f Orbital p art of orbicu laris ocu li m u scle, 166, 167f Organ of Corti, 96, 96f Orop h aryn x, 428, 429f Os coxae, 600, 601f Osseou s coch lea, 486f Osseou s labyrin th , 491 Osseou s sp iral lam in a, 486f Ossicles, 487f, 489f Osteoarth ritis of TMJ, 255, 255f Osteology. See Bon es. Osteom yelitis, 333, 335f, 336 Ostiu m , 316, 320, 325, 329, 428 Otalgia, 507 Otic gan glion , 4 ch aracteristics of, for p arotid glan d, 195–197, 226f, 384–386, 562 cou rse of, 220–226, 223f, 225f, 227f, 385f, 563f–564f GVE bers an d , 98, 99f to in fratem p oral fossa, 214 Otitis extern a, acu te, 506, 506f Otitis m ed ia, acu te, 507, 507f Ou ter h air cells, 486f Ovary, 635, 635f Oxyp h il cells, 123

P Pain facial n erve an d , 94 glossop h aryn geal n erve an d , 98

6 8 6 n e TTe R’S He Ad An d n e CK An ATO MY FO R d e n TISTRY

In d ex Pain (Continued) in m idd le ear, 507 n asop alatin e n erve block an d , 581 p arotitis an d , 203 ton gu e an d, 410–412 trigem in al n erve an d, 82, 92f trigem in al n eu ralgia an d, 182f, 183–185 vagu s n erve an d , 100 Palatal (p alatin e) glan d s, 350f, 351 p arasym p ath etics of, 557–559, 558f Palate arterial su p p ly to, 368–371, 369f cleftin g of, 23, 23f–24f em bryotic d evelop m en t of, 15, 15f–16f h ard , 342, 349, 350f n asal cavity an d , 287 sen sory in n ervation of, 379, 380f soft, 342, 342f, 351 sym p ath etics of, 559, 560f–561f ven ou s d rain age from , 372, 372f Palatin e ap on eu rosis, 406, 433f Palatin e bon es an atom y of, 41, 41f h orizon tal p rocess of, 349 n asal cavity an d , 287, 287f–288f orbital p rocess of, 513f p terygop alatin e fossa an d , 258f, 259 stru ctu res articu latin g with , 27–28 Palatin e can al, 259, 261f Palatin e (p alatal) glan d s, 349, 350f p arasym p ath etics of, 557–559, 558f Palatin e p rocess h ard p alate an d , 349, 350f im agin g of, 395f of m axilla, 26 n asal cavity an d , 287 Palatin e rap h e, 350f Palatin e ton sils h ard p alate an d , 350f in oral cavity, 342f orop h aryn x an d , 428 soft p alate an d , 351f ton gu e an d, 409f ton sillitis an d , 393 Palatin e toru s, 390, 390f Palatoglossal arch es, 342f, 351f, 402 Palatoglossal fold , 428 Palatoglossu s m u scles, 351–352, 351f, 406, 407f Palatop h aryn geal arch , 342f, 351f Palatop h aryn geal fold , 428 Palatop h aryn geu s m u scles oral cavity an d , 351–352, 351f–353f p h aryn x an d, 430, 433f swallowin g an d, 442, 442f–443f Palatop h aryn geu s sp h in cter, 433f Palatovagin al can al. See Ph aryn geal can al. Palm ar in terosseu s m u scles, 609, 610f Palm aris brevis m u scle, 609, 610f Palm aris lon gu s m u scle, 607f Palm er Nu m berin g System , 360 Palp ebral p art of lacrim al glan d , 290f Palp ebral p art of orbicu laris ocu li m u scle, 166, 167f

Pan creas, 630, 630f Pap illae, 402, 403f Parafollicu lar cells, 123 Param yxoviru s, 203 Paran asal sin u ses an atom y of, 315f clin ical correlates for, 333–340, 333f–340f drain age region s of, 315 eth m oid . See Eth m oid sin u ses. featu res of, 312f–314f, 313 fron tal. See Fron tal sin u ses. gen eral in form ation abou t, 312–313 im agin g of, 319f, 324f, 328f, 332f m axillary. See Maxillary sin u s. n asal cavity an d , 286 n erve su p p ly to, 303f sp h en oid. See Sp h en oid sin u s. Parasym p ath etic n ervou s system , 544, 547–548 cran ial n erve III with corresp on d in g sym p ath etics, 553–554, 555f–556f cran ial n erve IX with corresp on d in g sym p ath etics, 562, 563f–564f cran ial n erve VII with corresp on din g sym p ath etics, 557–559, 558f, 560f–561f cran ial n erve X with corresp on din g sym p ath etics, 565, 565f eyes an d , 527, 528f fu n ction s of, 547–548, 548f–550f lacrim al glan d an d , 535, 536f n asal cavity an d , 300, 303f p arotid bed in , 195–197, 198f p arotid glan d an d , 220–226, 227f, 384–386, 385f, 387f Parath yroid glan d s, 118, 123, 124f Parath yroid h orm on e, 123 Paratrach eal lym p h n od es, 657–658 Paraxial m esod erm , 2, 3f, 12 Parietal bon es, 27–29, 27f, 29f, 155f tem p oral fossa an d , 209f Parietal em issary vein , 170f Parietal lobe, 68f, 69 Parieto-occip ital su lcu s, 69 Parotid bed arterial su p p ly to, 192–193, 192f m ajor stru ctu res of, 190, 191f p arasym p ath etics of, 195–197 q u estion s/ an swers abou t, 655 recess of, 189, 189f sen sory n erves of, 195–197, 195f–196f sym p ath etics of, 195–197 ven ou s d rain age from , 192–193, 194f Parotid d u ct, 188, 190, 191f, 203f, 343, 381–382 Parotid fossa, 182 Parotid glan d bord ers an d stru ctu res of, 189, 189f clin ical correlates for, 199–205, 200f–205f featu res of, 190, 381–382 gen eral in form ation abou t, 188, 188f, 381, 381f glossop h aryn geal n erve to, 98 in ferior p ortion of, 114

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In d ex Parotid glan d (Continued) p arasym p ath etics of, 220–226, 227f, 384–386, 385f, 387f an atom ic p ath way for, 195–197, 562, 563f–564f as p arotid bed stru ctu re, 191f q u estion s/ an swers abou t, 655 su bm an d ibu lar trian gle an d , 115f sym p ath etics of, 195–197, 562, 563f–564f tu m ors of, 202, 202f, 205 Parotid glan d fascial sp ace, 475 Parotid lym p h n od es, 657–658, 659f Parotid p ap illa, 354, 354f Parotidectom y, 201 Parotitis, 203, 203f Pars accid a, 487, 488f Pars ten sa, 487, 488f, 490f Passavan t’s rid ge, 433f, 442, 442f–443f PDL in jection s. See Period on tal ligam en t (PDL) in jection s. Pectoral gird le, bon es of, 592–593, 592f Pectoral region m u scles, 602, 602f Pectoralis m ajor m u scle, 602, 602f Pectoralis m in or m u scle, 602, 602f Ped icles, 596, 597f Pelvic sp lan ch n ic n erves, 73f Pelvis, 597f, 600, 601f arterial su p p ly to, 648, 648f fem ale, 635, 635f m ale, 634, 634f Periap ical abscesses, 480, 480f Pericard iu m , 620 Pericoron itis, 480, 480f Pericran iu m , 156, 156f Period on tal abscesses, 480, 480f Period on tal ligam en t (PDL) in jection s, 587–588, 588f Period on tiu m , 359f Periorbita, 321f Periorbital ed em a, 185, 185f Perip h eral n ervou s system au ton om ic n ervou s system of. See Au ton om ic n ervou s system (ANS). cran ial n erves. See Cran ial n erves. fu n ction s of, 549f–550f gen eral in form ation abou t, 72, 72f sp in al n erves, 70, 70f, 72, 73f Periton sillar fascial sp ace, 475, 476f Perp en d icu lar p late of eth m oid bon e, 38, 39f, 40, 308f of p alatin e bon e, 41, 41f Petrotym p an ic ssu re, 32, 33f Petrou s p art of tem p oral bon e, 33f, 486f Ph aryn geal ap on eu rosis, 427f, 433f Ph aryn geal arch es abn orm alities related to, 20–22, 20f–22f cran ial n erves of, 4, 4f derivatives of, 5, 6f em bryotic d evelop m en t of, 2, 4 sku ll d evelop m en t from , 11 Ph aryn geal artery, 261f, 262–264, 435 Ph aryn geal bran ch of glossop h aryn geal (IX) n erve, 439, 441f

Ph aryn geal bran ch of vagu s (X) n erve, 139, 414, 439, 441f Ph aryn geal can al, 34, 35f, 259, 260f–261f Ph aryn geal clefts, 4, 7–9 Ph aryn geal con strictor m u scles, 434, 434f Ph aryn geal glan d s, p arasym p ath etics of, 557–559, 558f Ph aryn geal m em bran es, 7–8, 7f Ph aryn geal n erve, 261f, 265–271, 268f, 440 Ph aryn geal p lexu s p h aryn x in n ervation by, 439, 441f ton gu e in n ervation by, 414 ven ou s d rain age from oral cavity an d , 372 from p h aryn x, 438, 438f Ph aryn geal p ou ch es abn orm alities related to, 19, 19f em bryotic d evelop m en t of, 4, 7–9, 7f–9f Ph aryn geal rap h e, 427f, 433f Ph aryn geal recess, 286f, 428, 429f Ph aryn geal ton sil, 393, 428, 429f Ph aryn geal tu bercle, 30, 31f, 427f, 433f Ph aryn geal vein , 135, 262–264 Ph aryn geal ven ou s p lexu s, 216–220, 236 Ph aryn gitis, 444, 444f Ph aryn gobasilar fascia, 426, 427f Ph aryn goep iglottic fold , 427f Ph aryn gotym p an ic tu be cartilagin ou s p art of, 427f, 432f m id dle ear’s an terior wall an d, 489 n asal cavity an d , 286f p h aryn geal op en in g of, 429f soft p alate an d , 353f Ph aryn x arterial su p p ly to, 435, 436f–437f clin ical correlates for, 442, 442f–444f, 444 gen eral in form ation abou t, 426–427, 426f–427f lym p h atic d rain age of, 660f m u scles of, 430, 431f–433f p arasym p ath etics of, 557–559 p arts of, 428–429, 429f p oten tial ap ertu res in wall of, 434, 434f sen sory in n ervation of, 439–440, 441f trach ea an d , 123 ven ou s d rain age from , 438, 438f Ph iltru m , 13, 342f–343f, 343 Ph on ation , 123 Ph ren ic n erve in root of n eck, 125 ven tral ram i an d , 146, 146f Pierre Robin seq u en ce, 20–22, 20f Piriform ap ertu re, 286 Piriform fossa, 429f Piriform recess, 429 Pirogov’s trian gle, 114 Pitu itary glan d , 329, 329f Platysm a m u scle deep fascia an d , 470f facial exp ression an d , 168, 169f su p er cial fascia an d , 108, 109f, 468, 468f Pleom orp h ic aden om a of p arotid glan d, 202 Pleu ral cavity, 616, 616f Plica m briata, 355, 404

6 8 8 n e TTe R’S He Ad An d n e CK An ATO MY FO R d e n TISTRY

In d ex Pon s, 69, 69f, 92f Posterior au ricu lar artery to extern al ear, 499, 500f to in n er ear, 503, 503f to m idd le ear, 501 to p arotid bed, 192–193, 192f to scalp , 157, 158f Posterior au ricu lar m u scle, 168, 169f Posterior au ricu lar n erve, 182, 182f Posterior au ricu lar vein , 194f, 504 Posterior cervical lym p h n od es, 657–658, 659f Posterior ciliary arteries, 531f Posterior com m u n icatin g artery, 185f Posterior cricoaryten oid m u scle, 456–457, 456f–457f Posterior d eep tem p oral artery to in fratem p oral fossa, 216–220, 217f–218f to m asticatory m u scles, 234, 235f to tem p oral fossa, 210–211, 210f Posterior d eep tem p oral n erve, 212, 213f, 250, 250f Posterior d eep tem p oral vein , 210–211, 236 Posterior d igastric m u scle, 114, 116 Posterior d ivision of au ricu lotem p oral bran ch of m an d ibu lar n erve cou rse of extern al ear, 495, 496f face, 180f in fratem p oral fossa, 220–226, 222f–223f m asticatory m u scles, 231 p arotid bed , 192–193, 194f tem p oral fossa, 212, 213f tem p orom an dibu lar join t, 250, 250f Gow-Gates block an d , 574 Posterior d ivision of in ferior alveolar bran ch of m an d ibu lar n erve, 220–226, 222f–223f Posterior d ivision of lin gu al bran ch of m an d ibu lar n erve, 220–226, 222f–223f, 225f Posterior d ivision of m yloh yoid bran ch of m an d ibu lar n erve, 220–226, 222f Posterior d ivision of th e retrom an d ibu lar vein , 192–193 Posterior eth m oid al artery to eth m oid sin u ses, 322, 322f to eye an d orbit, 512, 530–532, 531f to n asal cavity, 291–294, 292f to sp h en oid sin u s, 330, 330f Posterior eth m oid al foram en , 50–51, 50f, 53f, 512 Posterior eth m oid al n erve cou rse of eth m oid sin u ses, 323–324, 323f eye an d orbit, 521–529, 523f sp h en oid sin u s, 331, 331f n asal bran ch es of, 295f, 299f in n asociliary bran ch of trigem in al n erve op h th alm ic division , 86f Posterior eth m oid al vein , 291–294, 294f Posterior in ferior n asal bran ch of th e greater p alatin e n erve, 89f, 298f Posterior lateral in ferior n asal n erve, 302f, 323–324

Posterior lateral n asal artery bran ch es, 322, 322f–323f, 330, 330f Posterior lateral n asal bran ch of sp h en op alatin e artery, 281f, 293f Posterior lateral sep tal bran ch of sp h en op alatin e artery, 281f, 293f Posterior lateral su p erior n asal n erve, cou rse of eth m oid sin u ses, 323–324, 323f n asal cavity, 298f, 302f Posterior lon gitu din al ligam en t, 59–60, 60f Posterior m allear fold , 487, 490f Posterior m edial su p erior n asal n erve, 298f Posterior n asal ap ertu res. See Ch oan ae (p osterior n ares). Posterior scalen e m u scle, 128, 128f Posterior su p erior alveolar artery to in fratem p oral fossa, 216–220, 217f to m axillary sin u s, 326, 326f to teeth , 371, 371f Posterior su p erior alveolar bran ch of m axillary n erve, cou rse of, 89f in fratem p oral fossa, 220–226, 223f p terygop alatin e fossa, 261f, 265–271, 266f Posterior su p erior alveolar n erve cou rse of m axillary sin u s, 327, 327f n asal cavity, 299f teeth , 374 in traoral in jection s an d , 578, 579f Posterior su p erior alveolar n erve block, 580, 580f Posterior su p erior alveolar vein , 262–264, 372, 372f Posterior su p erior n asal n erve, 298f, 302f p terygop alatin e fossa an d , 265–271 Posterior trian gle, 109f an atom y of, 120, 121f su p er cial fascia an d , 468f Posterior wall of m id d le ear, 489 Postgan glion ic n eu ron s au ton om ic n ervou s system , 544 cou rse of across p terygop alatin e fossa, 265–271 gen eral an atom ic p ath way, 551 glossop h aryn geal n erve corresp on d en ce, 562 m axillary d ivision d istribu tion , 265–271, 300, 386, 557 ocu lom otor n erve corresp on d en ce, 553–554 op h th alm ic an d m axillary division distribu tion , 386, 557 op h th alm ic d ivision distribu tion , 265–271 p arotid glan d, 195–197, 220–226, 227f, 384–386, 385f, 387f sym p ath etics of eye, 528f sym p ath etics of n asal cavity, 301 in p arasym p ath etic n ervou s system , 548f eyes an d , 527, 528f glossop h aryn geal n erve an d , 562, 563f–564f lacrim al glan d an d , 535, 536f

In d e x

6 89

In d ex Postgan glion ic n eu ron s (Continued) n asal cavity an d , 300–301 vagu s n erve an d , 565, 565f Postglen oid tu bercle, 243–246 Pou tin g, m u scles for, 164 Pregan glion ic n eu ron s au ton om ic n ervou s system , 544 cou rse of across p terygop alatin e fossa, 265–271 ch orda tym p an i n erve corresp on den ce, 557 gen eral an atom ic p ath way, 551 glossop h aryn geal n erve corresp on d en ce, 562, 563f–564f greater p etrosal n erve corresp on d en ce, 265–271, 535, 557 ocu lom otor n erve corresp on d en ce, 553–554 op h th alm ic an d m axillary division distribu tion , 386, 535 sym p ath etics of eye, 528f sym p ath etics of n asal cavity, 300 sym p ath etics of p arotid glan d, 195–197, 198f in p arasym p ath etic n ervou s system , 548f eyes an d , 527, 528f glossop h aryn geal n erve an d , 562, 563f–564f lacrim al glan d an d , 535, 536f n asal cavity an d , 300 p arotid glan d an d , 195–197, 198f, 220–226, 227f, 384–386, 385f, 387f vagu s n erve an d , 565, 565f Prelaryn geal lym p h n od es, 657–658 Prem olars, 358f im agin g of, 397f m an d ibu lar, 366, 366f m axillary, 362f n erve blocks to, 583 Pressu re. See Tou ch (sen sation ). Pretrach eal fascial sp ace, 477–478, 478f Pretrach eal layer of fascia, 469–470, 470f Pretrach eal lym p h n od es, 657–658 Prevertebral d eep layer of d eep fascia, 108, 468f, 469–470 Prevertebral fascial sp ace, 477–478, 478f Prevertebral m u scles, 128, 128f Prim ary cleft of lip an d p alate, 23, 24f Prim ary p alate, 15, 15f Proceru s m u scle, 166, 167f Prom on tory, 488f, 489, 490f, 494f Pron ator q u ad ratu s m u scle, 607f Pron ator teres m u scle, 607f Propriocep tion , 82, 92f Prostate, 634, 634f Pseudom onas aeruginosa, 506 Psoas m ajor m u scle, 614, 615f Pterion , 209f Pterygoid arteries, 216–220, 217f, 234, 235f Pterygoid can al artery of to p h aryn x, 435 to p terygop alatin e fossa, 261f, 262–264, 263f

Pterygoid can al (Continued) n erve of, to p terygop alatin e fossa, 261f, 265–271, 266f, 268f p terygop alatin e fossa an d , 259, 260f, 273f–274f sp h en oid bon e an d , 34, 35f vein of, from p terygop alatin e fossa, 262–264 Pterygoid fovea, 44, 45f Pterygoid h am u lu s, 34, 35f, 350f, 433f Pterygoid p lexu s ears d rain ed by, 504, 505f eye an d orbit d rain ed by, 530–532, 533f face d rain ed by, 175, 176f h em atom as in , p osterior su p erior alveolar n erve block an d , 580 in fratem p oral fossa d rain ed by, 214, 216–220, 219f m asticatory m u scles d rain ed by, 236, 236f n asal cavity drain ed by, 294f p terygop alatin e fossa d rain ed by, 262–264, 264f Pterygoid p rocesses, 34, 35f, 110f, 259 Pterygoid vein , 236 Pterygom an dibu lar fascial sp ace, 475, 571f Pterygom an dibu lar rap h e h ard p alate an d , 350f in ferior alveolar n erve block an d , 571f m an d ible an d , 44 p h aryn x an d , 407f, 434f soft p alate an d , 353f, 354 Pterygom axillary ssu re, 259, 261f Pterygop alatin e fossa arterial su p p ly to, 262–264, 263f bord erin g stru ctu res of, 259 gen eral in form ation abou t, 258, 258f im agin g of, 273f–274f m axillary d ivision n erve block an d , 585 m axillary d ivision n erve bran ch es associated with , 265–271, 266f n asal cavity an d, 286–287 n erve su p p ly to, 265–271, 266f, 268f, 270f, 272f op en in gs for, 259, 260f–261f p alatin e bon e an d , 41 p arasym p ath etics associated with , 265–271, 270f q u estion s/ an swers abou t, 657–658 sym p ath etics associated with , 265–271, 272f ven ou s d rain age from , 262–264, 264f Pterygop alatin e gan glion , 4 bran ch es of m axillary d ivision of trigem in al n erve an d , 89f, 265–271, 268f ch aracteristics of, 557 for n asal cavity, 298f, 302f for p terygop alatin e fossa, 303f for salivary glan ds, 386, 387f eth m oid sin u ses an d , 323–324 orbital bran ch of, 331, 331f p arasym p ath etics associated with , 265–271 p terygop alatin e fossa an d , 258, 265–271, 268f, 272f Ptosis, 80

69 0 n e TTe R’S He Ad An d n e CK An ATO MY FO R d e n TISTRY

In d ex Pu bis, 600, 601f Pu lp cavity, 359 Pyloru s of stom ach , 623, 623f Pyram id , m id d le ear’s p osterior wall an d , 489 Pyram id al p rocess, 41, 258f, 259

Q Qu ad ran gu lar m em bran e, 454 Qu ad ratu s lu m boru m m u scle, 614, 615f

R Radial artery, 637–638, 637f–638f Radial n erve, 652, 652f Radiu s, 593, 594f Ram i com m u n ican tes. See Dorsal ram i; Ven tral ram i. Rectu m , 627–628, 628f, 634, 634f Rectu s abd om in is m u scle, 614, 615f Rectu s cap itis lateralis m u scle, 128, 128f Rectu s cap itis p osterior m ajor m u scle, 122, 122f, 129, 129f Rectu s cap itis p osterior m in or m u scle, 122, 122f, 129, 129f Recu rren t laryn geal n erve (bran ch of vagu s) to laryn x, 460, 461f lesion s of, 464 to n eck, 139, 141f to p h aryn x, 440, 441f in root of n eck, 125 Reissn er’s m em bran e, 486f, 493f Ren al vein , 647, 647f Resp iratory ep ith eliu m , 276, 312 Retin a, 78, 79f, 515f, 516 Retin op ath y, diabetic, 541, 541f Retrodiscal p ad of TMJ, 242f, 243–246, 245f Retrom an dibu lar vein , 115f, 138f, 170f, 190, 192–193, 194f, 294f Retrom olar region , 343 Retrom olar trigon e, 572 Retrop h aryn geal fascial sp ace, 477–478, 478f Retrop h aryn geal lym p h n od es, 320, 657–658, 659f Retrop h aryn geal sp ace, 433f Rh eu m atoid arth ritis, 255 Rh in itis, 307–308, 307f Rh om boid m ajor m u scle, 611, 612f Rh om boid m in or m u scle, 611, 612f Rh ytid ectom y, 166 Ribosom es, 66, 66f Ribs, 125, 125f, 598, 599f Righ t lym p h atic du ct, 125 Rim a glottid is, 442, 456–457 Risoriu s m u scle, 164, 165f Robin u l. See Glycop yrrolate. Rod s, retin al, 72–73, 78, 520f Roof of m idd le ear, 489 Root can als of teeth , 359f, 396f Root of n eck, 125, 125f Root of ton gu e, 409f Roots of teeth , 359, 359f, 396f Rotation al m ovem en t in op en in g th e m an dible, 253, 253f–254f Rou n d win d ow (fen estra coch leae), 489, 490f, 492f–493f

S Saccu le, 491, 492f–493f Sacral sp in al n erves, 70, 70f Sacru m , 596, 597f Saliva, 188, 381 Salivary glan d s clin ical correlates for, 391, 391f, 394, 394f featu res of, 381–382, 383f gen eral in form ation abou t, 381–386, 381f, 383f oral cavity an d , 342, 342f, 356f p arasym p ath etics of, 384–386, 385f, 387f p arotid . See Parotid glan d . su blin gu al. See Su blin gu al glan d . su bm an d ibu lar. See Su bm an d ibu lar glan d . Salivation , m astication an d , 239, 240f, 381–382, 385f Salp in gop h aryn geal fold , 428, 429f Salp in gop h aryn geu s m u scle, 353f, 427f, 430, 431f, 433f Satellite cells, 67, 67f Scala tym p an i, 486f, 492f–493f Scala vestibu li, 486f, 492f–493f Scalen e m u scles in n eck, 109f, 128, 128f p osterior trian gle an d , 120, 121f Scalp arterial su p p ly to, 157, 158f gen eral in form ation abou t, 154 grou p of facial m u scles, 168, 169f q u estion s/ an swers abou t, 655 sen sory n erves of, 159, 160f ven ou s d rain age from , 157, 158f Scap h oid fossa, 487, 488f Scap u la, 592, 592f Scarp a’s layer of abdom in al wall, 590, 591f Sch lem m ’s can al, 515f Sch wan n cells, 67, 67f Sclera, 514f–515f, 516 Scleral ven ou s sin u s, 515f Secon d ary cleft of lip an d p alate, 23, 24f Secon d ary p alate, 15, 15f Sella tu rcica, 34, 35f Sem icircu lar can als cristae of, 96, 96f–97f as in n er ear bou n d aries, 491, 492f–493f Sem icircu lar d u cts, 491, 492f Sem in al vesicle, 634, 634f Sem isp in alis cap itis m u scle, 120, 611, 612f Sen sory root of ciliary gan glion , 86f, 521–529, 523f Sep tal artery, 280–282 Sep tal cartilage an atom y of, 279f bou n d aries an d relation s of, 287, 287f–288f im agin g of, 308f Sep tal d erm op lasty for recu rren t severe an terior ep istaxis, 304, 305f Sep tic th rom bosis in cavern ou s sin u s syn d rom e an d, 185, 185f Sep tu m . See Nasal sep tu m . Serratu s an terior m u scle, 602, 602f Sh ort ciliary n erves, 86f, 520f, 523f

In d e x

691

In d ex Sh ou ld er accessory n erve lesion s affectin g, 104, 104f m u scles of, 603, 604f Sialoceles of p arotid glan d, 205, 205f Sialolith iasis, 394, 394f Sialolith s, 204 Sigm oid colon , 627–628, 628f Sigm oid su lcu s, 28 Sin u s lift p rocedu re, 339, 339f Sin u ses. See Paran asal sin u ses. Sin u sitis, 333–340, 333f–334f Sjögren ’s syn d rom e, 203 Skin Akin osi block an d , 576 Gow-Gates block an d , 574 over th e scalp , 156, 156f, 158f Sku ll bon es of articu lation s of, 27–28, 27f division s of, 26 eth m oid bon e. See Eth m oid bon e. fractu res of, 61–64, 61f–62f fron tal bon e. See Fron tal bon e. in ferior n asal con ch ae, 27–28, 41, 41f, 289, 308f–309f lacrim al bon es. See Lacrim al bon es. m an d ible. See Man dible. m axillae. See Maxillae. n asal bon es. See Nasal bon es. occip ital bon e, 27–28, 30, 31f p alatin e bon es. See Palatin e bon es. p arietal bon es, 27–29, 27f, 29f, 155f sp h en oid bon e. See Sp h en oid bon e. tem p oral bon es. See Tem p oral bon es. vom er. See Vom er. zygom atic bon es. See Zygom atic bon es (zygom a). develop m en t of, 10–12, 11f–12f gen eral in form ation abou t, 10, 26 m ajor foram in a an d ssu res in an terior view, 50, 50f m an d ible, 51, 51f su p erior view of cran ial base, 51, 53f of n ewborn , 12f views an d su tu res n orm a basalis, 49, 49f n orm a fron talis, 46, 46f n orm a lateralis, 48, 48f n orm a occip italis, 46, 46f n orm a verticalis, 47, 47f SMAS (Su p er cial Mu scu lar Ap on eu rotic System ), 154, 188 Soft p alate m u scles of, 433f as oral cavity border, 351–352, 351f–353f as oral cavity bou n d ary, 342, 342f p h aryn x an d, 429f swallowin g an d, 442, 442f–443f Som atic gen eral or sp ecial fu n ction al colu m n s of cran ial n erves, 75 Som atic n ervou s system , 72, 72f Sp ecial visceral afferen t (SVA) fu n ction . See SVA (sp ecial visceral afferen t) fu n ction .

692

Sp h en oeth m oidal recess drain age of, 289, 315 n asal cavity an d , 288f–289f sp h en oidal sin u s an d , 329 Sp h en oid bon e an atom y of, 34, 35f in facial skeleton , 155f in fratem p oral fossa an d , 214, 214f–215f n asal cavity an d , 287, 287f–288f stru ctu res articu latin g with , 27–28, 27f tem p oral fossa an d , 209f Sp h en oid foram en , 51 Sp h en oid sin u s arterial su p p ly to, 330, 330f bou n daries an d relation s of, 287, 287f–288f con ch ae an d , 289, 289f drain age of, 315 featu res of, 313, 314f gen eral in form ation abou t, 329–331, 329f im agin g of, 308f, 324f, 332f n erve su p p ly to, 331, 331f sin u sitis in , 333 Sp h en om an d ibu lar ligam en t, 243–246, 247f Sp h en op alatin e artery to eth m oid sin u ses, 322, 322f to n asal cavity, 291–294, 293f to p alate, 368–371, 369f p osterior lateral n asal an d sep tal bran ch es of, 281f, 293f to p terygop alatin e fossa, 261f, 262–264, 263f to sp h en oid sin u s, 330, 330f Sp h en op alatin e foram en n asal cavity an d, 286, 288f p alatin e bon e an d , 41, 41f p terygop alatin e fossa an d , 258f, 259 d iagram of, 261f im agin g of, 273f–274f in fratem p oral fossa an d , 260f vascu lar su p p ly an d , 263f Sp h en op alatin e vein , 262–264, 291–294, 294f, 372 Sp in al cord , 70, 70f–71f Sp in al n erves, 70, 70f, 72, 73f Sp in al p art of sp in al accessory n erve, 140 Sp in alis cervicis m u scle, 611, 612f Sp in alis th oracis m u scle, 611, 612f Sp in ou s p rocesses, 56, 56f, 60f, 596, 597f Sp iral gan glion , 486f, 493f Sp iral lam in a, 493f Sp iral ligam en t, 486f, 493f Sp leen , 632, 632f Sp len iu s cap itis m u scle, 120, 611, 612f Sp len iu s cervicis m u scle, 611, 612f Sq u am ou s cell carcin om a, 422, 422f Sq u am ou s p ortion of fron tal bon e, 28 of occip ital bon e, 30 of tem p oral bon e, 32 tem p oral fossa an d , 209, 209f tem p orom an d ibu lar join t an d , 242–246 SSA (sp ecial som atic afferen t) fu n ction , 75, 78, 96 Stap ediu s m u scle, 94, 490f, 494, 494f

n e TTe R’S He Ad An d n e CK An ATO MY FO R d e n TISTRY

In d ex Stap es, 489, 490f, 492f Staphylococcus aureus, 506 Stellate gan glion , 147 Sten sen ’s d u ct. See Parotid d u ct. Stereocilia, 493f Stern ocleid om astoid lym p h n odes, 659f Stern ocleid om astoid m u scle accessory n erve to, 102, 102f lesion s affectin g, 104, 104f carotid trian gle an d , 116 in vestin g layer of deep cervical fascia arou n d, 108, 109f m u scu lar trian gle an d , 118 as n eck trian gles’ border, 126 p arotid glan d an d , 189, 189f p osterior trian gle an d , 120 torticollis an d , 148, 148f Stern oh yoid m u scle in in frah yoid region , 111, 112f, 127 m u scu lar trian gle an d , 118, 119f Stern oth yroid m u scle in in frah yoid region , 111, 127 m u scu lar trian gle an d , 118, 119f Stern u m , 598, 599f Stom ach , 623–633, 623f Stom atitis, viral, 393 Strap m u scles, 118 Strati ed sq u am ou s ep ith eliu m of ch eek, 354 n on keratin ized , 343, 404 oral cavity oor an d , 355 taste bu d s an d , 403f Streptococcus pneum oniae, 507 Strip p in g wave in swallowin g, 442, 442f–443f Styloglossu s m u scle n erve su p p ly to, 103, 103f p h aryn x an d , 407f, 434f ton gu e an d , 406, 407f Styloh yoid ligam en t, 407f, 434f Styloh yoid m u scle facial n erve an d , 94, 182 p arotid glan d an d , 188–189, 189f in su p rah yoid region , 111, 112f, 127 Styloid p rocess, 127, 214, 214f–215f Stylom an d ibu lar fascia, 189 Stylom an d ibu lar ligam en t, 243–246, 247f Stylom astoid foram en , 32, 33f, 182 Stylop h aryn geu s m u scle, 98, 353f, 430, 432f Su bclavian artery to n eck, 130, 131f p osterior trian gle an d , 120, 121f in root of n eck, 125, 125f Su bclavian lym p h n od es, 659f Su bclavian vein , 125, 135, 137f Su bclaviu s m u scle, 602, 602f Su bclaviu s n erve, 650 Su bcostal m u scle, 613 Su bcostal p lan e, 590, 591f Su blin gu al artery, 416, 417f Su blin gu al caru n cle, 342f, 381f, 404f Su blin gu al d u cts, 342f, 381f Su blin gu al fascial sp ace, 473 Su blin gu al fold , 342f, 381–382, 381f, 404f

Su blin gu al glan d facial n erve an d, 94, 95f featu res of, 381–382 gen eral in form ation abou t, 381, 381f oral cavity oor an d, 342f, 356f, 404f p arasym p ath etics of, 386, 387f, 557–559, 558f sym p ath etics of, an atom ic p ath way for, 559, 560f–561f Su blin gu al p ap illa, 355, 404 Su bm an d ibu lar d u ct oral cavity an d , 342f, 355, 356f salivary glan d s an d, 381–382, 381f ton gu e an d, 404f Su bm an d ibu lar fascial sp aces, 474 Su bm an d ibu lar gan glion , 4, 386, 387f, 557 Su bm an d ibu lar glan d facial n erve an d, 94, 95f featu res of, 381–382 gen eral in form ation abou t, 381, 381f oral cavity oor an d, 356f p arasym p ath etics of, 386, 387f, 557–559, 558f su bm an d ibu lar trian gle an d , 114 sym p ath etics of, an atom ic p ath way for, 559, 560f–561f Su bm an d ibu lar glan d fascial sp ace, 475 Su bm an d ibu lar lym p h n odes, 114, 316, 320, 325, 657–658, 659f Su bm an d ibu lar trian gle, 109f, 111, 114, 115f Su bm asseteric fascial sp ace, 475 Su bm axillary fascial sp ace, 473 Su bm en tal artery to face, 172f to oral cavity oor, 368–371, 370f su bm an d ibu lar trian gle an d , 114, 115f to ton gu e, 416, 418f Su bm en tal fascial sp ace, 474 Su bm en tal lym p h n odes, 657–658, 659f Su bm en tal trian gle, 109f, 111, 113–118, 113f Su bm en tal vein , 114, 115f, 372, 372f from ton gu e, 419, 419f Su boccip ital n erve, 122, 122f, 129, 160f Su boccip ital trian gle, 122, 122f, 129, 129f Su bp arotid lym p h n od es, 659f Su bscap u laris m u scle, 603, 604f Su bth alam u s, 69 Su cced an eou s teeth , 357 Su lci, 68f, 69 Su lcu s term in alis, 402 Su p er cial cervical fascia, 466, 468, 468f Su p er cial fascial sp ace, 477–478, 478f Su p er cial layer of deep cervical fascia, 469–470, 470f gen eral in form ation abou t, 466, 467f p arotid glan d an d , 189, 189f trap eziu s m u scle an d , 108, 109f Su p er cial lym p h n od es, 657–658, 659f Su p er cial Mu scu lar Ap on eu rotic System (SMAS), 154, 188 Su p er cial tem p oral artery to extern al ear, 499, 500f, 505f to face, 170, 170f, 172, 172f to p arotid bed, 192–193, 192f

In d e x

693

In d ex Sup er cial tem p oral artery (Continued) to scalp , 157, 158f to tem p oral fossa, 210–211, 210f to tem p orom an d ibu lar join t, 248, 248f Su p er cial tem p oral vein from ears, 504, 505f from face, 175 from p arotid bed , 192–193, 194f from scalp , 157, 158f from tem p oral fossa, 210–211, 211f from tem p orom an dibu lar join t, 249, 249f Su p er cial vein s, 175, 175f–176f Su p erior au ricu lar m u scle, 168, 169f Su p erior cervical gan glion , 147, 147f an atom ic p ath way for sym p ath etics of, 562, 563f–564f ch aracteristics of for eye, 528f, 553–554 gen eral, 551 for lacrim al, su bm an dibu lar, an d su blin gu al glan ds, 557–559 for n asal cavity, 301, 302f for p arotid glan d , 195–197, 198f, 562 for p terygop alatin e fossa, 265–271 Su p erior com p artm en t of tem p orom an d ibu lar join t, 242f, 243–246, 247f Su p erior con strictor m u scle, 430, 431f, 434, 434f Su p erior deep lateral cervical lym p h n odes, 659f Su p erior division of th e ocu lom otor n erve, 525, 526f Su p erior h orn of th yroid cartilage, 449 Su p erior labial artery to face, 172, 172f to lip s an d ch eeks, 344–345, 344f to n asal cavity, 291–294, 293f n asal sep tal bran ch of, 281f trau m a to sep tal bran ch of, 279 Su p erior labial bran ch of in fraorbital artery, 344–345, 344f Su p erior labial bran ch of in fraorbital n erve, 347, 347f Su p erior labial vein , 175, 176f n asal cavity an d , 282f, 291–294, 294f oral cavity an d , 344–345, 345f Su p erior lam in a of TMJ, 242f, 243–246 Su p erior laryn geal artery, 437f, 458, 458f Su p erior laryn geal n erve in tern al bran ch of, 433f to laryn x, 460, 461f vagu s n erve an d , 139, 141f Su p erior laryn geal vein , 459, 459f Su p erior lateral p alp ebral artery, 531f Su p erior ligam en t of m alleu s, 488f Su p erior lon gitu d in al ban d , 59–60, 60f Su p erior lon gitu d in al m u scle, 408, 409f Su p erior m acu lar arteriole an d ven u le, 515f Su p erior m ed iastin u m , 618, 618f Su p erior m esen teric artery, 643, 643f Su p erior n asal con ch ae, 289, 289f, 309f Su p erior n asal m eatu s, 289, 289f, 315, 320 Su p erior obliq u e m u scle, 517, 518f–519f Su p erior om oh yoid m u scle, 116, 118

694

Su p erior op h th alm ic vein from eye an d orbit, 530–532, 533f from face, 176f from n ose, 280–282, 282f Su p erior orbital ssu re, 50, 50f, 512 Su p erior p alp ebral artery, 530–532 Su p erior p etrosal sin u s, 504, 505f Su p erior p h aryn geal con strictor m u scle, 427f, 430, 432f–434f, 434 Su p erior rectu s m u scle, 517, 518f–519f Su p erior salivatory n u cleu s n asal cavity in n ervation an d , 300, 303f p arasym p ath etic n ervou s system an d , 386, 387f, 557, 558f in p terygop alatin e fossa, 265–271, 270f, 272f Su p erior tem p oral lin e, 209, 209f Su p erior th yroid artery carotid trian gle an d , 116 m u scu lar trian gle an d , 118 to n eck, 130, 134f to p h aryn x, 435 su p erior p arath yroid glan d s an d, 123, 124f th yroid glan d an d, 123, 124f Su p erior th yroid lym p h n od es, 659f Su p erior th yroid vein s carotid trian gle an d , 116 m u scu lar trian gle an d , 118 from n eck, 135, 137f–138f Su p erior tu bercle of th yroid cartilage, 449 Su p erior tym p an ic artery, 501, 502f Su p erior wall of orbit, 512–513 Su p in ator m u scle, 608f Su p raclavicu lar lym p h n od es, 659f Su p raclavicu lar n erves, 120, 142, 143f, 652f Su p rah yoid fascial sp aces, 471, 473–475, 476f Su p rah yoid lym p h n odes, 659f Su p rah yoid m u scles, 127, 127f Su p rah yoid region of n eck, 111 Su p raorbital artery to eye an d orbit, 530–532, 531f to face, 170f, 172f, 174f to fron tal sin u ses, 317, 317f to scalp , 157, 158f Su p raorbital foram en , 512 Su p raorbital n erve cou rse of eye an d orbit, 521–529 face, 178, 179f fron tal sin u ses, 318, 318f scalp , 159, 160f as fron tal bran ch of trigem in al n erve op h th alm ic division , 85f Su p raorbital vein from eye an d orbit, 530–532 from face, 170f, 175, 176f from scalp , 158f Su p raren al glan ds, 633, 633f Su p rascap u lar artery, 120, 121f, 130, 437f Su p rascap u lar n erve, 120, 650 Su p rascap u lar vein , 120, 135, 137f–138f Su p rasp in atu s m u scle, 603, 604f Su p rastern al sp ace, 468f, 470f

n e TTe R’S He Ad An d n e CK An ATO MY FO R d e n TISTRY

In d ex Su p ratroch lear artery to eye an d orbit, 530–532, 531f to face, 172f, 174f to scalp , 157, 158f Su p ratroch lear n erve cou rse of eye an d orbit, 521–529, 523f face, 178, 179f scalp , 159, 160f as fron tal bran ch of trigem in al n erve op h th alm ic d ivision , 85f Su p ratroch lear vein , 157, 158f, 175, 176f, 530–532, 533f Su p rem e in tercostal artery, 130, 131f Su sp en sory ligam en t, 520f Su sten tacu lar cells, 403f Su tu ral bon es, 26 Su tu res, views an d n orm a basalis, 49, 49f n orm a fron talis, 46, 46f n orm a lateralis, 48, 48f n orm a occip italis, 46, 46f n orm a verticalis, 47, 47f SVA (sp ecial visceral afferen t) fu n ction of cran ial n erves, 75 facial n erve an d, 94, 95f glossop h aryn geal n erve an d , 98 olfactory n erve an d, 76 ton gu e an d, 410–412 vagu s n erve an d , 100 SVE (sp ecial visceral efferen t) fu n ction accessory n erve an d , 102 of cran ial n erves, 75 facial n erve an d, 94 glossop h aryn geal n erve an d , 98 trigem in al n erve an d, 82f vagu s n erve an d , 100 Swallowin g m astication an d , 230, 239, 240f p rocess of, 442, 442f–443f Swim m er’s ear, 506, 506f Sym p ath etic n ervou s system , 544, 547–548 clin ical correlate for, 566, 566f eyes an d , 528f fu n ction s of, 547–548, 548f–550f gen eral an atom ic p ath way of, 551, 552f n asal cavity an d , 300–301, 303f p arotid bed in , 195–197, 198f T1-L2, 550f Sym p ath etic tru n k, 116, 125, 147, 147f Syn ovial u id , 243–246

T Taste (sen sation ), 98, 99f, 410–412 Taste bu d s, 402, 403f, 410f Tear form ation an d absorp tion , 534, 534f Tectorial m em bran e, 59–60, 60f, 486f, 493f Teeth an atom y of, 359, 359f arterial su p p ly to, 371, 371f decidu ou s vs. p erm an en t, 357–367, 358f den tal caries an d , 389, 389f den tal n otation system s for, 360 gen eral in form ation abou t, 357–367

Teeth (Continued) im agin g of, 395f–397f m an d ibu lar Akin osi block an d , 576 can in es (cu sp id s), 360–367, 364f Gow-Gates block an d , 574 in cisors, 360–367, 365f in ferior alveolar n erve block an d , 570, 571f in traoral in jection s an d , 569 m olars, 367, 367f p rem olars, 366, 366f sen sory in n ervation of, 375, 376f m axillary can in es (cu sp id s), 360–367, 361f im p lan ts of, 338–339, 338f–339f in cisors, 360–367, 361f in traoral in jection s an d , 578, 584 m axillary d ivision n erve block, 585 m olars, 363, 363f p erm an en t, 350f p rem olars, 362f sen sory in n ervation of, 374–375, 376f p erm an en t typ es of, 357, 358f, 360–367 su rfaces of, 357, 358f ven ou s d rain age from , 372 Tegm en tym p an i, 488f, 490f Tegretol. See Carbam azep in e. Tem p eratu re (sen sation ) facial n erve an d, 94 glossop h aryn geal n erve an d , 98 ton gu e an d, 410–412 trigem in al n erve an d, 82, 92f vagu s n erve an d , 100 Tem p oral bon es an atom y of, 32, 33f in facial skeleton , 155f in fratem p oral fossa an d, 214, 214f–215f p arotid glan d an d , 189, 189f stru ctu res articu latin g with , 27–28, 27f tem p oral fossa an d , 209, 209f Tem p oral bran ch es of facial n erve cou rse of, 166, 168, 182 with in p arotid bed , 190, 191f to tem p oral fossa, 212, 212f–213f Tem p oral fascial sp ace, 475 Tem p oral fossa an atom y of, 208, 208f arterial su p p ly to, 210–211, 210f bord erin g stru ctu res of, 209, 209f n erve su p p ly to, 212, 212f–213f q u estion s/ an swers abou t, 655 ven ou s d rain age from , 210–211, 211f Tem p oral lobe, 68f, 69 Tem p oralis m u scle in fratem p oral fossa an d, 214 m astication an d , 230f, 231, 232f, 239 Tem p orom an d ibu lar join t (TMJ) an atom ic featu res of, 243–246, 244f–245f, 247f arterial su p p ly to, 218f, 248, 248f clin ical correlates for, 251–255, 251f–255f dysfu n ction of, 242 gen eral in form ation abou t, 242, 242f

In d e x

695

In d ex Tem p orom an d ibu lar join t (TMJ) (Continued) q u estion s/ an swers abou t, 656 sen sory in n ervation of, 250, 250f ven ou s d rain age from , 249, 249f Tem p orom an dibu lar ligam en t, 243–246, 247f Ten sor tym p an i m u scle gen eral in form ation abou t, 494, 494f as m id dle ear bou n dary, 489, 490f in tym p an ic cavity, 488f Ten sor veli p alatin i m u scle extern al acou stic m eatu s an d , 488f m astication an d , 233f p h aryn geal m u scles an d , 433f–434f p h aryn gotym p an ic tu be an d , 353f, 432f of soft p alate, 351–352, 351f–353f ten d on of, 433f Teres m ajor m u scle, 603, 604f Teres m in or m u scle, 603, 604f Term in al su lcu s, 403f Th alam u s, 69, 69f Th ird occip ital n erve, 159, 160f Th oracic cavity, root of n eck an d , 125 Th oracic d u ct, 125, 659f Th oracic sp in al n erves, 70, 70f Th oracic vertebrae, 125, 596, 597f Th oracic wall, 640, 641f Th oracod orsal n erve, 651 Th oracolu m bar bers, 547–548 Th orax bon es of, 598, 599f gen eral in form ation abou t, 590 h eart in , 620–622, 620f–622f lu n gs in , 617, 617f m ediastin u m in , 618–619, 618f–619f m u scles of, 613, 613f p leu ral cavity in , 616, 616f vascu lar su p p ly of, 640, 641f Th rom bosis, cavern ou s sin u s syn d rom e an d , 185, 185f Th yroaryten oid m u scle, 456–457, 456f–457f Th yrocervical artery, 130, 131f Th yroep iglottic ligam en t, 452f, 454 Th yroep iglottic m u scle, 456–457, 456f Th yroh yoid m em bran e, 112f, 449, 449f, 454, 455f Th yroh yoid m u scle carotid trian gle an d , 116 in in frah yoid region , 111, 112f, 127 m u scu lar trian gle an d, 118, 119f Th yroid cartilage lam in a, 449, 449f Th yroid cartilage of laryn x, 433f, 448–449, 448f–449f Th yroid glan d an atom y of, 123, 124f–125f carotid trian gle an d , 116, 117f ectop ic, 19, 19f em bryotic d evelop m en t of, 18, 18f h yp erth yroid ism an d , 151, 151f h yp oth yroid ism an d , 150, 150f m u scu lar trian gle an d, 118, 119f Th yroid n otch , 449 Th yroid itis, 151 Th yrotoxicosis, 151 Th yroxin e, 123, 150

696

Tic d ou lou reu x, 182f, 183–185, 184f TMJ. See Tem p orom an d ibu lar join t (TMJ). Ton gu e, 355 Akin osi block an d , 576 arterial su p p ly to, 416, 417f–418f clin ical correlates for, 420–423, 420f–423f dorsal su rface stru ctu res of, 402–405, 403f em bryotic d evelop m en t of, 17, 17f gen eral in form ation abou t, 400, 400f–401f glossop h aryn geal n erve an d , 98, 99f Gow-Gates block an d , 574 h yp oglossal n erve lesion s affectin g, 105, 105f h yp oglossal n erve’s GSE bers an d , 103 lym p h atic drain age of, 660f m astication an d , 230f m otor in n ervation of, 414, 415f m u scles of, 17, 17f, 406, 407f, 408, 409f oral cavity an d , 342 oral cavity oor an d , 355, 356f as p art of lym p h atic system , 656, 656f sen sory in n ervation of, 410–412, 410f–411f, 413f ven ou s d rain age from , 419, 419f ven tral su rface stru ctu res of, 404, 404f Ton gu e-tie, 420–423, 420f Ton sillar artery, 435, 437f Ton sillitis, 393, 393f Torticollis, 148, 148f–149f Toru s, 390, 390f Toru s levatoriu s, 429f Toru s tu bariu s, 428, 429f Tou ch (sen sation ), 82, 92f, 410–412 Trach ea, 118, 125 Tractu s solitariu s, 94, 98, 100 Tragu s, 487, 488f Tran slation al m ovem en t in op en in g th e m an dible, 253, 253f–254f Tran sp yloric p lan e, 590, 591f Tran stu bercu lar p lan e, 590, 591f Tran sverse aryten oid m u scles, 456–457, 457f Tran sverse cervical artery, 120, 121f, 125, 125f, 130, 437f Tran sverse cervical ch ain of lym p h n odes, 659f Tran sverse cervical n erves, 142, 143f, 181f Tran sverse cervical vein , 120, 135, 137f–138f Tran sverse colon , 627, 628f Tran sverse cricoaryten oid m u scle, 456–457, 456f Tran sverse facial artery to face, 170f, 172, 172f, 174f to m asticatory m u scles, 234, 235f to n ose, 281f to p arotid bed , 192–193, 192f p arotid glan d an d , 188 Tran sverse facial vein from face, 170f, 175 from m asticatory m u scles, 236, 236f from p arotid bed , 192–193, 194f Tran sverse h ead of ad d u ctor p ollicis m u scle, 609, 610f Tran sverse ligam en t of atlas, 59–60, 60f Tran sverse m u scle of ton gu e, 408, 409f

n e TTe R’S He Ad An d n e CK An ATO MY FO R d e n TISTRY

In d ex Tran sverse p alatin e su tu re, im agin g of, 395f Tran sverse p rocesses, 56, 56f, 597f Tran sverse ru gae (p licae), 349 Tran sverse sin u s vein , 504 Tran sversu s abd om in is m u scle, 614, 615f Tran sversu s th oracis m u scle, 613, 613f Trap eziu s m u scle of back, 611, 612f in vestin g layer of deep cervical fascia arou n d, 108, 109f as n eck trian gles’ border, 126, 126f n erve su p p ly to, 102, 102f p osterior trian gle an d , 120 sp in al accessory n erve lesion s affectin g, 104, 104f Trau m a cavern ou s sin u s syn drom e an d , 185, 185f to sep tal bran ch of su p erior labial artery, 279 su rgical p rocedu res on fron tal sin u s du e to, 336, 336f Treach er Collin s syn d rom e, 21f Trian gles of th e n eck an terior carotid , 116, 117f gen eral in form ation abou t, 111, 111f–112f m u scu lar, 118, 119f su bm an d ibu lar, 114, 115f su bm en tal, 113–118, 113f m u scles borderin g, 126, 126f m u scles su bd ivid in g, 126, 126f p osterior, 109f, 120, 121f su boccip ital, 122, 122f, 129, 129f Trian gu lar fossa, 488f Tricep s brach ii m u scle, 605 Trigem in al (V) n erve digastric m u scle an d, 126–127 bers an d fu n ction al colu m n typ es of, 82f–83f in fraorbital can al bran ch es of, 89f m an dibu lar division (V3 ) of. See Man dibu lar division (V3 ) of trigem in al (V) n erve. m axillary d ivision (V2 ) of. See Maxillary division (V2 ) of trigem in al (V) n erve. m idd le cran ial fossa bran ch es of, 85f–86f, 89f m yloh yoid m u scle an d , 127 op h th alm ic d ivision (V1 ) of. See Op h th alm ic division (V1 ) of trigem in al (V) n erve. overview of, 82, 82f p ath ways of, 92f in p erip h eral n ervou s system , 74, 74f p h aryn geal arch es an d , 5 p rop riocep tion of, 92f to ton gu e, 411f Trigem in al n eu ralgia, 182f, 183–185, 184f Trigem in oth alam ic lem n iscu s, 98 Triiodoth yron in e, 123, 150 Trism u s, Akin osi block an d , 576 Triticeal cartilage, 453 Troch lear (IV) n erve eye an d orbit in n ervation by, 525, 526f eye m u scles an d , 518f

Troch lear (IV) n erve (Continued) bers an d fu n ction al colu m n typ e of, 80, 80f in p erip h eral n ervou s system , 74, 74f Tru e p elvis, 600 Tru e ribs, 598, 599f Tu bercle of su p erior lip , 278f, 343f Tu bercu losis, p arotitis an d , 203 Tym p an ic bran ch of glossop h aryn geal n erve, 495 Tym p an ic can alicu lu s, 32, 33f, 489 Tym p an ic cavity, 492f Tym p an ic cells, 490f Tym p an ic m em bran e, 487, 488f Tym p an ic n eu rectom y, 201 Tym p an ic p late, 243–246 Tym p an ic p lexu s, 488f, 490f, 497

U Uln a, 593, 594f Uln ar artery, 637–638, 637f–638f Uln ar n erve, 651 Um bo, 488f, 492f Un cin ate p rocess, 38, 39f, 288f, 308f Un ip olar n eu ron s, 66, 66f Un iversal Nu m berin g System , 360 Up p er d eep cervical lym p h n od es, 657–658, 659f Up p er lim bs arterial su p p ly to, 636–638, 636f–638f bon es of, 592–595, 592f, 594f–595f gen eral in form ation abou t, 590 m u scles of brach iu m , 605, 605f exten sor su rface of an tebrach iu m , 608f exor su rface of an tebrach iu m , 607f h an d , 609, 610f p ectoral region , 602, 602f sh ou ld er, 603, 604f n erve su p p ly to, 649–653, 649f, 652f ven ou s d rain age from , 639, 639f Up p er su bscap u lar n erve, 651 Ureters, 633, 633f Uteru s, 635, 635f Utricle, 491, 492f Utricu losaccu lar d u ct, 491 Uveal tract, 516 Uvu la, 342f, 427f Uvu lar m u scle, 334, 335t, 350f

V Vagin a, 635, 635f Vagu s (X) n erve, 139, 141f carotid trian gle an d , 116, 117f bers an d fu n ction al colu m n typ es of, 100, 101f in m astication , 240f p arasym p ath etics of, with corresp on d in g sym p ath etics, 565, 565f in p erip h eral n ervou s system , 73f–74f, 74 p h aryn geal arch es an d , 4–5 p h aryn geal bran ch of, 139, 414, 439, 441f in root of n eck, 125 ton gu e in n ervation by, 411f

In d e x

697

In d ex Vallate p ap illae, 402, 403f, 410f Ven tral ram i in frah yoid m u scle an d , 127 of n eck, 146, 146f p revertebral m u scles an d , 128 scalp an d , 159 sen sory in n ervation of face by, 181f of n eck by, 142, 144 of u p p er lim bs by, 650 Ven tral trigem in oth alam ic tract, 92f Verm ilion zon e, 343, 343f Vertebral arteries to n eck, 130, 131f in root of n eck, 125, 125f su boccip ital trian gle an d , 122, 122f Vertebral colu m n , 596, 597f Vertebral foram in a, 56, 56f, 597f Vertebral ribs, 598, 599f Vertebral vein s, 122, 125, 135 Vertebroch on dral ribs, 598, 599f Vertebrostern al ribs, 598, 599f Vertical m u scle of ton gu e, 408, 409f Vestibu lar aq u ed u ct, op en in g of, 51, 53f Vestibu lar fold , 343 Vestibu lar ligam en t, 454, 455f Vestibu lar m em bran e, 454, 486f, 493f Vestibu lar n erve, 486f, 498, 498f Vestibu le of in n er ear, 491, 492f of laryn x, 442, 442f–443f, 446 of n ose, 278, 286f–287f of oral cavity, 342–343, 342f–343f Vestibu lococh lear (VIII) n erve cou rse of, to in n er ear, 498, 498f bers an d fu n ction al colu m n typ es of, 96, 96f–97f, 486f in p erip h eral n ervou s system , 74, 74f Vibrissae, 278 Vid ian n erve of p terygoid can al n asal cavity an d , 302f–303f to p terygop alatin e fossa, 265–271, 266f p terygop alatin e gan glion an d, 265–271, 268f, 272f Viral in fection s, p arotitis an d, 203 Visceral gen eral or sp ecial fu n ction al colu m n s of cran ial n erves, 75 Visceral region of cervical fascia, 468f, 469–470 Viscerocran iu m , 10–11, 11f, 26 Vision , 519, 521–529, 521f Vocal cords, m u scles alterin g, 456–457 Vocal ligam en ts, 454, 455f, 457f Vocal p rocess of aryten oid cartilage, 451, 451f

698

Vocalis, 456–457 Voice, lesion s affectin g, 464, 464f Vom er an atom y of, 40, 40f in facial skeleton , 155f n asal cavity an d , 287, 287f, 308f stru ctu res articu latin g with , 27–28, 27f

W Wald eyer’s rin g, 393 Wallerian d egen eration , 199 W h arton ’s d u ct, 204f, 381–382 W h ite m atter of sp in al cord , 70, 70f W h ite ram u s com m u n ican s, 72f Worm ian bon es, 26 Wrist, arterial su p p ly to, 638, 638f Wryn eck, 148, 148f–149f

X Xerostom ia, 204, 204f Xip h oid p rocess, 598, 599f

Z Zon u lar bers, 515f Zygom atic arch , 32, 37, 37f, 209, 209f Zygom atic bon es (zygom a) an atom y of, 37, 37f fractu res of, 61–64, 61f orbital m argin an d , 512, 513f stru ctu res articu latin g with , 27–28, 27f tem p oral fossa an d , 209, 209f Zygom atic bran ch es of facial n erve, 164, 166, 188, 188f, 190, 191f Zygom atic foram en , 512 Zygom atic n erve, cou rse of, 89f eye an d orbit, 524, 524f face, 179f, 182 p terygop alatin e fossa, 261f, 265–271, 266f Zygom atic p rocess of fron tal bon e, 28 m axilla an d , 26, 43f in tem p oral bon es, 32, 33f tem p oral fossa an d , 209, 209f Zygom aticofacial artery, 170f, 174f Zygom aticofacial foram en , 50, 50f Zygom aticofacial n erve, 179f Zygom aticofacial vein , 170f Zygom aticoorbital artery, 170f Zygom aticoorbital vein , 170f Zygom aticotem p oral artery, 170f Zygom aticotem p oral n erve, 159, 160f, 179f Zygom aticotem p oral vein , 170f Zygom aticu s m ajor m u scle, 164, 165f Zygom aticu s m in or m u scle, 164, 165f

n e TTe R’S He Ad An d n e CK An ATO MY FO R d e n TISTRY

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