Trigeminal Nerve Anatomy

Department of Oral & Maxillofacial
Surgery
NARSINHBHAI PATEL DENTAL COLLEGE AND HOSPITAL VISNAGAR
Guided By :
Dr. Arvind Agarwal , HOD and
Professor
Dr.Anil Mannagutti , Professor
Dr.Shreedevi Bhoi
Presented by: Dr. Harsh Patel
1st 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
-Mylohyoid

NUCLEI

TRIGEMINAL NUCLEI
o 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.

SENSORY NUCLEI :
1.Mesencephalic
nucleus
- Cell body of Pseudounipolar
neuron
- 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 ROOT
GENERAL 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 meningeal
artery.

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 supercilliary
muscles
 Lies beneath frontalis
muscle
 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.

5. 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

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 meningeal
artery and provides sensory innervation to cranial dura
matter.

IN PTERIGOPALATINE FOSSA:
1. Ganglionic branches-
Arises as 2trunks.Trunks join to form single root within
pterygopalatine ganglion.
Gives Orital branches,Palatine branches,Pharyngeal
branches,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 inferior
conchae, posterior ethmiodal sinus and posterior
portion of nasal septum. It also includes Nasopalatine
branch.
-It passes across roof of nasal cavity downwards and
forwards lying between mucosa and periosteum of
nasal septum.
-Reaches to floor of nasal cavity n give branch to
anterior part of nasal septum and floor of nasal cavity.
-Enters Incisive canal and enters oral cavity through
insicive foramen
-It provides sensation to palatal mucosa of premaxilla
region.

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 zygomatic
bone
-Supplies skin on
prominence of cheek
B. Zygomaticotemporal
nerve
-Appears in infratemporal
region thru foramen in
zygomatic bone
-Supplies skin of temporal
region after peircing temporal
fascia 2 cm above zygoma
-Gives communicating branch
to lacrimal N suppling
parasymp. Secretomotor
fibres 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- gasserian
ganglion a
a small ant. Division
exit through foramen ovale in greater wing of sphenoid
from trunk which remain 2-3 mm undivided in infratemporal
fossa
travels between lat. Pterygoid and Otic ganglion laterally and
tensor palatine medially anteriorly to med. Meningeal A.
large post. division

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 of
mandible and sphenomandibular ligament superior to 1st part
of maxillary art.
Lies behind the TMJ close to the parotid
Ascends behind superficial temporal vessels and then in
temporal 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 pterygomandibular
raphe 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 branches
in orbit,
non synapsing
sensory for orbit
2.Pterygopalatine Ganglion: connected to maxillary nerve in infratemporal
fossa
sensory to orbital septum, orbicularis and nasal cavity, max sinus, palate,
nasopharynx.
3. Otic Ganglion: betwn trunk of mandibular n and tensor palatini, nerve to
med pterygoid passes thru but does not synapse in the ganglion.
4.Submandibular Ganglion: related to lingual n, rests on hypoglossus
supplies post gang. Parasym secretomotor fibres to submandibular and
sublingual 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 nerve
1- 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 thrombophlebitis
actinomycosis
rhinocerebellar mucormycosis
aspergillosis
tolosa hunt syndrome
neoplasms
vascular 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 throughly
about 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

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