Trigeminal Nerve Anatomy

Department of Oral & Maxillofacial Surgery

NARSINHBHAI PATEL DENTAL COLLEGE AND HOSPITAL VISNAGAR

Guided By :

Dr. Arvind Agarwal , HOD and ProfessorDr.Anil Mannagutti , ProfessorDr.Shreedevi Bhoi

Presented by: Dr. Harsh Patel1st year PG

1/20/2015 Oral And Maxillofacial Surgery 1

Contents: Introduction

Trigeminal Nuclei

Functional Components

Course & Distribution

Trigeminal Ganglion

Divisions of Trigeminal Nerve

Clinical Examination of V Nerve

Applied Anatomy

Summary

References


INTRODUCTION The largest cranial nerve

It is mixed nerve ( sensory and motor )

Sensory to – Skin of face

-Mucosa of cranial viscera

-Except base of tongue and pharynx

Motor to –Muscles of Mastication

-Tensor ville palatini,Tensor tympany

-Anterior belly of digastric

-Mylohyoid1/20/2015 Oral And Maxillofacial Surgery 3

NUCLEI


TRIGEMINAL NUCLEIo A cranial nerve nucleus is a collection

of neurons (gray matter) in the brain stem that is associated with one or more cranial nerves.

o Axons carrying information to and from the cranial nerves form a synapse first at these nuclei.

o Lesions occurring at these nuclei can lead to effects resembling those seen by the severing of nerve(s) they are associated with.


http://en.wikipedia.org/wiki/Neuron

http://en.wikipedia.org/wiki/Gray_matter

http://en.wikipedia.org/wiki/Brain_stem

http://en.wikipedia.org/wiki/Cranial_nerves

http://en.wikipedia.org/wiki/Axon

http://en.wikipedia.org/wiki/Synapse

http://en.wikipedia.org/wiki/Nucleus_(neuroanatomy)

SENSORY NUCLEI :

1.Mesencephalic nucleus

- Cell body of Pseudounipolarneuron

- Relay proprioception from muscles of mastication,

Extra ocular Muscles, Facial muscles.

Situated in Midbrain just latetral to Aqueduct.


2.Principal sensory nucleus-

Lies in Pons lateral to Motor nucleus

Relays touch sensation


3.Spinal nucleus- Extends from caudal end of principal sensory Nucles

in pons to 2nd or 3rd spinal

segment

It relys Pain and Temperature


MOTOR NUCLEUS : Innervates muscles of mastication and tensor

tympani and tensor palatini

Derived from first branchial arch.

Located in pons medial to principle sensory nucleus.


FUNCTIONAL COMPONENTS

Sensory Root

Motor Root


SENSORY ROOTGENERAL SOMATIC AFFERENTS- Face, Scalp, Teeth, Gingiva, Oral, Nasal,

Cavities, Para nasal sinus, Conjunctiva and Cornea.

Pain, temp, light touch touch, pressure proprioception

Trigeminal gang. Bypasses trigem gang.

sensory root.


Spinal nuc. Principal sen nuc. Mesencephalic

CNS

MOTOR NUCLEUS

MOTOR ROOT

MANDIBULAR NERVE

Muscles of mastication Tensor tympani

Masseter Tensor palatini

Lateral & Medial Pterygoids

Temporalis

CNS


MOTOR ROOT

COURSE & DISTRIBUTION

Both motor and sensory root are attached ventrally to junction

of pons and middle cerebellar peduncle with motor root lying

ventromedially to the sensory root.

Pass anteriorly in middle cranial fossa to lie below tentorium

cerebelli in cavum trigeminale, here motor root lies inferior

to sensory root.


Sensory root connected to postromedial concave

border of the trigeminal ganglion.

Convex antrolatateral margin of the ganglion gives

attachment to the 3 div. Of the trigeminal nerve.


Motor root turns further inferior with sensory component of

V3 to emerge out of foramen Ovale as Mandibular

nerve.

Ophthalmic and Maxillary division emerges through

Superior orbital fissure and foramen Rotundum

respectively.


GANGLION


THE TRIGEMINAL GANGLION

SEMILUNAR OR GASSERIAN GANGLION.

Cresentric in shape with convexity anterolaterally.

Contains cell bodies of pseudounipolar neurons.

LOCATION: lies in a bony fossa at apex of the petrous

temporal bone on floor of middle cranial fossa, just lateral

to posterior part of lateral wall of the cavernous sinus.


COVERINGS: covered by dural pouch = MECKLES CAVE or CAVUM TRIGEMINALE.

cave lined by pia and arachnoid thus the

ganglion is bathed in CSF.

ARTERIAL SUPPLY: Ganglionic branches of Internal Carotid Artery, middle meningeal artery and accessory meningealartery.


RELATIONS:SUPERIORLY: *superior petrosal sinus

*free margin of tentorium cerebelli

INFERIORLY: *motor root

*greater petrosal nerve

*petrous apex

*foramen lacerum

MEDIALLY: *posterior part of lateral wall of cavernous sinus

*Internal Carotid Artery with its sympathetic plexus

LATERALLY: *uncus of temporal lobe

*middle meningeal artery and vein

*nervous spinosum


DIVISIONS OF TRIGEMINAL NERVE

1. Ophthalmic nerve

2. Maxillary nerve

3. Mandibular nerve


OPTHALMIC NERRVE


OPHTHALMIC NERVE Smallest division.

Sensory only

Supplies : eyeballs, conjunctiva, lacrimal gland, mucosa of

nose and paranasal sinus, skin of forehead eyelid and

nose


Course:

3 branches in ant part of cavernous sinus

superior orbital fissure

lat wall cavernous sinus

orbit

lacrimal, nasocilliary, frontal

emerges from trigeminal ganglion


LACRIMAL NERVE

Smallest

Passes into orbit through lateral compartment of the

Superior orbital fissure outside the tendinous ring.

Receives communicating branch from Trochlear nerve

branch of Opthalmic


Receives branch from Zygomaticotemporal nerve branch

of maxillary

Sensory to lateral conjunctiva, Upper Lid, lacrimal gland

Post synaptic parasympathetic fibers from pterigopalatine

ganglion to lacrimal gland (parasym secretomotor).


FRONTAL NERVE

Largest

Enters orbit through lateral part of superior orbital fissure

outside tendinous ring

Passes forward between roof of orbit and Levator Palpebral

Superioris

Supratrochlear Nerve

Divides midway into :

Supraorbital Nerve


SUPRATROCHLEAR N SUPRAORBITAL N

Smaller nerve

Medial branch

Receives communication branches from infratrochlear nerve

Curves around superomedial margin of orbit

Larger nerve

lateral branch

Passes through supraorbital notch

Divides in medial and lateral branches.


supplies: median conjunctiva, Upper Lid and lower part of forehead

Lies between frontalis and corrugator supercilliarymuscles

Lies beneath frontalismuscle

Supplies: conjunctiva,

scalp upto vertex , mucous membrane of frontal sinus


NASOCILLIARY NERVE

Purely Sensory

Passes through middle part of superior orbital fissure within the tendenious ring .

Runs along medial wall of orbit between Superior Oblique and Medial Rectus

Divides into Anterior Ethmoidal and External Nasal

5 branches in orbit.


1. Short Clliary Nerves: Fibers reaches eyeball and also

contains fibers from Cilliary Ganglion

2. Long Cilliary Nerves : 2 or 3in no. supply to Iris and

Cornea.

3. Post Ethmoidal Nerve: passes through posterior

ethmoidal foramen to supply the Ethmoid and Sphenoid

PNS.

4. Infratrochlear Nerve: appears on face above med angle

the eye. Supplies to skin of lacrimal sac and caruncle.


l5. Anterior Ethmoidal Nerve:

larger terminal branch

Course: anterior ethmoidal foramen and canal

into anterior cranial fossa on sup surf of cribriform plate

Through slit lat to crista galli into nasal cavity

Med internal nasal branch lat internal nasal branch

Supplies ant nasal septum supplies ant part lat nasal

cavity emerges as

external nasal nerve to

skin of ala,vestibule,and

tip of nose 1/20/2015 Oral And Maxillofacial Surgery 46

MAXILLARY NERVE


MAXILLARY NERVE Second division of trigeminal nerve

Pure sensory Supplies derivatives of maxillary process and frontonasal

process


Course:


Trigeminal ganglion-> Middle cranial fossa

Lateral wall of cavernous sinus

Foramen rotundum

Pterigopalatine fossa

In groove on posterior surface of maxilla

Through inferior orbital fissure into orbit as INFRA ORBITAL N

Through infraorbital foramen on face

After leaving foramen rotundum it moves anteriorly in

the uppermost part of pterygopalatine fossa.

As it passes through pterygopalatine fossa it also gives

branches to sphnopalatine ganglion, posterior superior

alveolar nerve and zygomatic branches.


It then moves laterally and moves in a groove on

posterior surface of maxilla.

Then enters orbit through infra orbital fissure and

moves through infra orbital groove where it is called as

Infraorbital nerve and emerges on face from infra

orbital foramen.


BRANCHES

IN MIDDLE CRANIAL FOSSA:

- Meningeal branch:Travels along the middle meningealartery and provides sensory innervation to cranial duramatter.


IN PTERIGOPALATINE FOSSA:

1. Ganglionic branches-

Arises as 2trunks.Trunks join to form single root within pterygopalatine ganglion.

Gives Orital branches,Palatine branches,Pharyngealbranches,Nasal branches

Gives postganglionic secretomotor fibers to lacrimal gland via zygomaticotemporal and lacrimal.


2.Orbital branch: Supplies periosteum of orbit

3.Nasal branch: Supplies to mucosa of superior and inferiorconchae, posterior ethmiodal sinus and posteriorportion of nasal septum. It also includes Nasopalatinebranch.

-It passes across roof of nasal cavity downwards andforwards lying between mucosa and periosteum ofnasal septum.

-Reaches to floor of nasal cavity n give branch toanterior part of nasal septum and floor of nasal cavity.

-Enters Incisive canal and enters oral cavity throughinsicive foramen

-It provides sensation to palatal mucosa of premaxillaregion.


4. Palatine branch: Arise as greater palatine (anterior) and lesser

palatine (middle and posterior)

-Greater palatine nerve descends through pterygopalatine canal

from the ganglion and emerges from greater palatine foramen of

hard palate.

-Then moves anteriorly between mucoperiostem and hard palate

upto 1st premolar supplying sensory innervation to palatal soft

tissue and bone. Then communicates with nasopalatine

-Middle palatine and posterior palatine emerges from lesser

palatine foramen and supply soft palate and tonsilar region

respectively.


5. Pharyngeal branch: It leaves the posterior part of

pterygopalatine ganglion and passes through the

phryngeal canal

It is distributed to the mucous mambreane of the nasal

part of pharynx, posterior to eustachian tube.


POST. SUPERIOR ALVEOLAR NERVE

-It arises from the main trunk of maxillary nerve in the

petrygopalatine fossa just before the nerve enters the inferior

orbital canal

- Usually arises as 2 trunks.

- Passes downwards and crosses the pterygoplatine fossa reaching

infratemporal surface of maxilla.

- 1st trunk continues downwards on posterior surface of maxilla

and provide sensory innervation to buccal gingiva in maxillary

molar region and adjacent facial mucosal surface


-2nd trunk enters maxila through PSA canal to travel to

posterolateral wall of maxillary sinus providing sensory

innervation to sinus mucosa. Continuing downwards this

also provides sensory innervation to alveoli, PDL, pulp of

molar tooth.


Zygomatic nerve :

A. Zygomaticofacial nerve

-Appears on face through foramen in the zygomaticbone

-Supplies skin on prominence of cheek

B. Zygomaticotemporalnerve

-Appears in infratemporalregion thru foramen in zygomatic bone

-Supplies skin of temporal region after peircing temporal fascia 2 cm above zygoma

-Gives communicating branch to lacrimal N supplingparasymp. Secretomotorfibres to lacrimal gland.


It enters orbit through infra orbital fissure.

IN THE INFRAORBITAL CANAL

1.Middle superior alveolar nerve:

runs along lat wall of maxilla

Participates in superor dental plexus

Supplies premolars.

2. Anterior superior alveolar nerve:

Runs in canal in ant wall of maxilla=canalii sinosus

#Dental branches # nasal branches

Joins sup dental plexus lat wallof inf meatus to

to supply canines opening of max sinus.


3. FACIAL BRANCHES:

1.Palpebral nerves-pierces Orbicularis Occuli and supplies skin of lower lid.

2.Nasal branches-supplies skin of lat wall nose and mobile part of septum.

3. Superior labial nerve- forms infraorbital plexus

supplies skin and mm of upper lip, cheek and labial glands.


MANDIBULAR NERVE


MANDIBULAR NERVE Largest

Mixed

Nerve of 1st branchial arch

Motor root- from motor nucleus in pons

sensory root- gasserianganglion a

a small ant. Division

exit through foramen ovale in greater wing of sphenoid

from trunk which remain 2-3 mm undivided in infratemporalfossa

travels between lat. Pterygoid and Otic ganglion laterally and tensor palatine medially anteriorly to med. Meningeal A.

large post. division1/20/2015 Oral And Maxillofacial Surgery 71

Branches Trunk (undivided)

Nervous Spinosus

Nerve to medial Pterygoid

Anterior Division Massetric Nerve.

Deep temporal Nerve.

Nerve to lateral Pterygoid

Buccal Nerve.

Posterior Division Auriculo Temporal Nerve

Inferior. Alveolar Nerve

Lingual Nerve.


Branches from trunk Before dividing into anterior and posterior division it gives 2 branches

during its 2-3mm path

1.Nervous spinosus or Meningeal branch of Mandibular nerve

It reenters cranial cavity through foramen spinosus along with middle

meningial artery

Supply Dura matter of middle cranial fossa and mastoid air sinus

2.Nerve to mededial Pterygoid

Supplies medial pterygoid

Through Otic ganglion without interruption to

Tensor tympani

Tensor palatini


Branches from the anterior division

The anterior division is significantly smaller than posterior.

After dividing from the main trunk. It runs anteriorly and below

the lateral pterygoid muscle to over its upper border. After this

the nerve is buccal nerve. reach its external surface of muscle by

either passing through two heads or winding

1.Nerve to lateral pterygoid: It enters the deep surface of the

muscle. It may arise as independent branch or may arise in

common with buccal nerve.


2.Massetric nerve- Emerges at the upper border of the lateral

pterygoid just in front of TMJ. Passes laterally through mandibular

notch along with massetric vessels, and enters the deep surface of

masseter, also suppliesTMJ

3.Buccal nerve-is the only sensory branch of ant div. travels betwn 2

heads of lat pterygoid and emerges in cheek at ant border of masseter.

Supplies skin and mucous membrane of cheek.

4.Deep temporal nerve-There are anterior and posterior deep

temporal nerves. Passes between skull, and enters deep surface of the

temporalis. Anterior is often a branch of buccal nerve and the posterior

may arise in common with massetric nerve.


Branches Of Posterior Division


1.Auriculotemporal nerve-Arises from 2 roots which run backwards and encircle the

middle meningeal artery and form single trunk

The trunk passes posterior to lateral pterygoid between neck ofmandible and sphenomandibular ligament superior to 1st partof maxillary art.

Lies behind the TMJ close to the parotid

Ascends behind superficial temporal vessels and then intemporal region divides into superficial temporal branches.


Branches Of Auriculotemporal Nerve

Auricular branches- supply tragus, upper part of aurical,roof of external auditory meatus, anterosuperior part of tympanic membrane

Superficial temporal branches-supply skin of temple

It also supply sensory and secretomotor to parotid.

Articular branches-supply the TMJ.


2. Inferior alveolar nerve:• Is mixed nerve

• Runs vertically downwards medial to lateral ptrygoid and

lateroposterior to lingual nerve. Then moves between the

sphenomandibular ligament and medial surface of mandibular

ramus

• Enters mandible through mandibular foramen to run in a bony

canal below the teeth


Branches:1.Mylohyoid: Arises just before the nerve enters mandibular foramen.It pierces the

sphenomandibular ligament along with mylohyoid muscle and runs in the mylohyoid

goove. Supplies to mylohyoid muscle and anterior belly of digastric. It is also sensory to

skin on inferior and anterior surface surfaces of mental protuberence. It may provide

sensory innervation to mandibular incisors. There is also evidence that mylohyoid supply

to mesial root of mandibular frist molar.

2.Branches to lower teeth and gums.

3.Mental nerve : It exits canal and divides into three branches innervating skin of chin and

skin and mucous membrane of the lower lip.

4.Incisive nerve : It remains within the canal and form plexus that innervates pulpal tissue of

first premolar canine and incisors through dental branches.


3.Lingual nerve: lies anterior to inferior alveolar n between lateral

pterygoid and tensor palatini

receives chorda tympani (SVA)

Emerges from inferior border of lateral pterygoid to lie between ramus and medial pterygoid in peterygomandibular space

moves downwards and forwards deep to pterygomandibularraphe between origins of supirior constrictor and mylohyoid

Reach to side of base of tongue 1 cm below and behind 3rd

molar just below mucous membrane of lateral lingual sulcus



-Then proceeds anteriorly across the muscles of tongue ,looping

medially and downwards to submandibular duct to deep surface of

submandibular gland where it break in terminal branches

-Sensory to anterior 2/3 of tonge along with special sensation also

sensory to floor of mouth and gingiva on lingual side of mandible.

Branches of lingual nerve and its communications:

1.Chorda tympani

2.Communications with submandibular ganglion

3.Hypoglossal nerve


Ganglia Associated With The Trigeminal Nerve

1.Cilliary Ganglion: connected with nasocilliary nerve by ganglionic branchesin orbit,non synapsingsensory for orbit

2.Pterygopalatine Ganglion: connected to maxillary nerve in infratemporalfossasensory to orbital septum, orbicularis and nasal cavity, max sinus, palate,nasopharynx.

3. Otic Ganglion: betwn trunk of mandibular n and tensor palatini, nerve tomed pterygoid passes thru but does not synapse in the ganglion.

4.Submandibular Ganglion: related to lingual n, rests on hypoglossussupplies post gang. Parasym secretomotor fibres to submandibular andsublingual gland.


CUTANEOUS DISTRIBUTION OF TRIGEMINAL NERVE

Each half of face is supplied by 13 cut N

1motor and 12 sensory

Of 12 sensory : 11 are from trigeminal N

1 is c2 greater auricular N

Branches of trigeminal N

5 from ophthalmic: lacrimal

supraorbital

supratrocheal

infratrochlear

external nasal


3 from maxillary N: infra orbital N

zygomaticofacial N

zygomaticotemporal N

3 from mandibular N: buccal N

auriculotemporal N

mental N

DIVISIONAL SUPPLY:

From lat canthus to vertex- ophthalmic N

From angle of mouth to vertex- mandibular N

Between the two areas-maxillary N


Examination of trigeminal nerve


Examination of trigeminal nerve1- Sensation Function

2- Motor Function

3- Corneal reflex

4- Test jaw jerk


Sensation function

use sterile sharp item on forehead, cheek, and jaw

If any abnormality present we test the thermal

sensation and light touch


Corneal reflex

a clean piece of cotton wool and ask the patient to

look away gently touch the cornea with the cotton wool and the patient will blink.


Test jaw jerk

Doctor finger on tip of jaw, grip patellar hammer

halfway up shaft and tap finger lightly usually nothing

happens, or just a slight closure.


APPLIED ANATOMY


1. Trigeminal Neuralgia – Tic Douloureux

• Sudden, usually unilateral severe, brief, stabbing

lancinating, recurring pain in the distribution of one or

more branches of the 5th Nerve


2. TRIGEMINAL NEUROPATHY

• sensory loss of face or weakness of the jaw muscles

• causes- sjogren syndrome

• herpes zoster, leprosy

• meningioma,schwanomma


4. HERPES ZOSTER OPHTHALMICUS:

Recurrent neurocutaneous inf. In opth. Div. of trigeminal

dermatome, most freq. affecting nasociliary branch

HHV3 / vericella zoster

Gasserian ganglion

ophthalmic nerve

Supraorbital N. Infraorbital N.

Supratrochlear N.

Infratrochlear N.

Nasal N.


5. Cavernous sinus syndrome

• Cavernous sinus syndrome• Multiple cranial neuropathies• Exophthalmos, ocular motor defects, sensory loss in V1

and / or V2.• Pupils may be spared or involved.

causes: bacterial thrombophlebitisactinomycosisrhinocerebellar mucormycosisaspergillosistolosa hunt syndromeneoplasmsvascular lesions


6.Gradenigos syndrome

Petrous bone osteitis due to otitis media

Characterized by I/L trigeminal N palsy (Va, Vb)

retro orbital pain

I/L sixth N palsy.


Conclusion Since Trigeminal nerve is mixed nerve, suplies mainly

head and neck region. Hence as a Oral and Maxillofacial surgeon one should know throughlyabout itracranial and extracranial course and distribution of Trigeminal nerve,to diagnose the pathologies associated with Trigeminal nerveand for appropriate treatment.


Refrences:

Greys anatomy

Snells anatomy

Head and Neck Anatomy-BD Chourasia

Textbook of Local Anesthesia-Stenly F Malamed


THANK YOU


Trigeminal Nerve Anatomy

Health & Medicine

Transcript of Trigeminal Nerve Anatomy