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1. TRIGEMINAL NERVE
The trigeminal nerve is so called because of its three main divisions i.e. the
Optalmic, Maxillary & Mandibular nerves. It is derived from the combination of
2 Latin words, tres meaning three+ geminus meaning twin i.e. three born
together (bilaterally)
It is the largest of the cranial nerves.
It is the fifth cranial nerve
It is a mixed nerve and is sensory to the greater part of the scalp, the
teeth, and the oral and nasal cavities. Motor supply is to the MOM.
Proprioceptive nerve fibres from the masticatory and extra-ocular muscles.
Various nuclei associated with the fifth nerve are situated within the pons.
They are:
Motor nucleus
Sensory nucleus
Mesencephalic nucleus
Spinal nucleus
THE TRIGEMINAL GANGLION:
The trigeminal nerve is continuous with the ventral surface of the
pons near its upper border by a large sensory and a small motor root. The
ganglion occupies a recess (Trigeminal or Meckel’s cave) in the dura mater in
front of the apex of the petrous temporal bone. It lies at depth of 4.5 –5 cm
from the lateral aspect of the head near the posterior part of the zygomatic
arch.
It is crescentic or semilunar in shape. Medially it is related to I.C.A &
cavernous sinus, inferiorly with the motor root and the greater petrosal nerve
& the apex of the petrous temporal bone and for.lacerum.
Blood supply to the ganglion is through the ganglionic branches of
the IC & the accesory meningeal artery which enters through the for.ovale.

2. MOTOR ROOT
It arises separately from the sensory root in the motor nucleus of pons. At the
semilunar ganglion it passes inferolaterally under the ganglion towards
for.ovale, through which it leaves the middle cranial fossa along with the
man.div. After it exits the skull, it unites with the sensory root and forms a
single nerve trunk. It supplies the following muscles:
1. Muscles of mastication
2. Mylohyoid
3. Ant belly of the diagastric
4. Tensor tympani
5. Tensor veli palatini
SENSORY ROOT
The fibres of the sensory root arise from the cells of the trigeminal ganglion.
The branches of the unipolar cells of the trigeminal ganglio are divided into
central and peripheral branches. The central branches leave the concave
surface to enter the pons. The peripheral branches are grouped to form the
ophthalmic and maxillary nerves and sensory part of the mandibular nerve.
OPTHALMIC NERVE
• It is the superior division of the V nerve & is the smallest.
• It is wholly sensory.
• It has 3 branches. All 3 of them pass through the sup. orbital fissure
into the orbit. They are;
1. Lacrimal nerve: it is the smallest. It supplies the lacrimal gland
& the conjuntiva. It pieces the orbital septum and ends in the
skin of the upper eyelid.
2. Frontal nerve: it is the smallest branch& appears to be the
direct continuation of the ophthalmic division. It enters the orbit
through the SOF divides into 2 branches.

3. The supra orbital branch: It is larger & more laterally placed.
It supplies the skin of the forehead & scalp as far back as the
vertex. It also supplies the mucous membrane of the frontal
sinus & pericranium
The supra trochlear branch: It is smaller & more medially
placed. It curves upward on the forehead , close to the bone.
It supplies the skin of the upper eyelid & lower part of the
forehead.
Nasocilliary nerve: It is intermediate in size & runs more
deeply. Its branches are divided as following;
Branches in the: -
Orbit
Nasal cavity
On the face
Branches in the Orbit:
Long root of the cilliary ganglion: It is sensory & passes
through the ganglion without synapsing andsupplies to
the eyeball.
Long ciliary nerve: Supplies the Iris & Cornea.
Posterior ethmoidal nerve: It enters the post. Ethmoidal
canal & supplies to the mucous membrane lining of the
Post. Etmoidal & Sphenoidal paranasal air cells.
Anterior ethmoidal nerve: It supplies to the Ant.
Ethmoidal & frontal paranasal air cells. In the upper part
of the nasal cavity, it further divides into: -
Internal nasal branches: It has medialseptal branches
to the septal membrane. It also has lateral branches,
which supply the nasal conchae & the ant. nasal wall
External nasal branches: supplies the skin on the tip
& ala of the nose.
2) Branches in the nasal cavity:

4. The branches arising here supply the mucous membrane
of the nasal cavity.
3) Terminal branches on the face:
They supply sensory nerves to the skin of the medial
parts of the both eyelids, the lacrimal sac. They also
supply skin on the bridge of the nose.
MAXILLLARY NERVE
• This is the second & intermediate division of the trigeminal nerve.
• It is wholly sensory.
• Course: It begins at the middle of the trigeminal ganglion as a
flattened, plexiform band, passes horizontally forwards along the
lateral wall of the cavernous sinus.
It leaves the skull through the foramen rotundum & becomes more
cylindrical & firmer in texture.
It crosses the upper part of the pterygopalatine fossa, inclines
laterally on the posterior part of the orbital process of the maxilla &
enters the orbit through the inferior orbital fissure.
It is now termed as the infra orbital nerve. It passes through the infra
orbital groove & canal in the floor of the orbit & appears on the face
through the infra orbital foramen.
• The branches of the maxillary nerve can be divided into the following
4 groups:
1. In the cranium: Meningeal
2. In the pterygopalatine fossa: Ganglionic, Zygomatic,
Post.superior alveolar.
3. In the infra orbital canal: Middle sup. alveolar,
Anterior superior/ Greater alveolar

5. 4. On the face: Palpebral, nasal, superior
labial
 Meningeal branch: It is given off near the
foramen rotundum. It supplies the duramater of
the anterior & middle cranial fossae.
 The ganglionic branches: They connect the
maxillary nerve to the pterygopalatine ganglion.
They contain secretomotor fibres to the lacrimal
gland. They provide sensory fibres to the orbital
periosteum & mucous membrane of the nose,
palate & pharynx.
 The zygomatic nerve: It arises in the
pterygopalatine fosssa from the maxillary
nerve.the nerve then enters the zygomatic bone
& then divides into 2 branches.. The
Zygomaticofacial nerve perforates the facial
surfaces & supplies the skin over the zygomatic
bone. The Zygomaticotemporal nerve
perforates the temporal surface of the zygomatic
bone , pierces the temporalis fascia, & supplies
the skin over the anterior temporal fossa region.
 The superior alveolar(dental) nerves: They
arise from the maxillary nerve before it leaves the
pterygopalatine fossa. They are:
1) Posterior superior alveolar nerve: It
begins in the pterygopalatine fossa but
divides into 3 branches which emerge
through the pterygomaxillary fissure.2
branches enter the posterior wall of the
maxilla above the tuberosity & supply the 3
molar teeth(except the mesiobuccal root of
first molar). The third branch pierces the

6. buccinator & supplies the adjoining part of
the gingivae & cheek along the 3 molar
teeth.
2) Middle superior alveolar nerve: It
arises from the Infra orbital nerve & runs
downwards & forwards along the infraorbital
groove along the lateral wall of the maxillary
sinus. It divides into branches which supply
the maxillary premolars & mesiobuccal root
of the first molar teeth.
3) Anterior superior alveolar nerve: It
also arises in the infraorbital canal near the
mid point. It runs in the anterior wall of the
maxillary antrum. It runs inferiorly & divides
into the branches, which supply the canine
& incisors. A nasal branch from this nerve,
given off from the superior dental plexus
supplies the mucous membrane of the
anterior part of the lateral wall & floor of the
nasal cavity. It ends in the nasal septum.
( The Infraorbital nerve is consisted of the
Middle & Superior alveolar dental nerves)
 The palpebral branches: They arise deep to the
orbicularis oculi.& pierce the muscle,
supplying the skin over the lower
eyelid& lateral angle of the eye along
with the Zygomaticofacial & Facial
nerves.
 The nasal branches: They supply the skin of
the nose & tip of the nasal septum &
join the External nasal branch &
anterior ethmoidal nerve.

7.  The superior labial branches: These are large
& numerous. They supply the skin
over the anterior part of the cheek &
upper lip including the mucous
membrane & labial glands. They are
joined by the facial nerve & form the
infraorbital plexus.
The SphenopalatinePterygopalatine ganglion
It is the largest of the peripheral ganglia. It is associated with the
greater petrosal nerve.( it is part of the 7th cranial/facial nerve). It
acts as arelay staion bn the superior salivatory nucleus in the pons
and the lacrimal gland & mucous & serous glands of the palate, nose
& paranasal sinuses.
It lies in the pterygopalatine fossa, suspended from the maxillary
division of the trigeminal nerve by 2 roots.branches from the maxillary
nerve through its ganglionic branches. They do not establish any
sympathetic connections with its cells. The branches are: -
1. Orbital branches: They are made up of afferent fibres
& convey sensory impulses from the
periosteum of the orbit. Others supply the
mucous membrane of the Post. Ethmoidal &
sphenoidal air cells.
2. Palatine branches: they are distributed to the roof of
the mouth, soft palate, tonsil & lining
membrane of the nasal cavity. It gives of
three branches

8. I. Greater palatine nerve: it emerges from
the foramen medial to the 3 rd molar,
continues forward splitting into number
of branches. It is sensory to the mucosa
of the hard palate & palatal gingivae.
II. Middle palatine nerve: This nerve
emerges from a small foramen in the
medial aspect of the pyramidal part of
the palatine bone. Sensory supply is to
the Mucous membrane of the soft
palate.
III. Posterior palatine nerve: It emerges
from a foramen slightly lateral to the
median palatine nerve. It contains
sensory & secretomotor fibres to the
mucous membrane of the Tonsillar
area.
3. Nasal branches: They are divided into 2 groups: -
I. Posterior superior lateral nerves: they
supply they Posterior part of the nasal
conchae
II. Nasopalatine(Sphenopalatine) nerve:
It passes downwards & forwards
between the periosteum &mucous
membrane in the region of the vomer,
continues downwards & forwards,
reachs the floor of the nasal cavity.
Descends into the incisal canal to
appear in the anterior part of the hard
palate & supplies the mucous
membrane of the premaxilla.

9. 4. Pharyngeal branches: This branch supplies sensory
& secretory fibers to the mucous
membrane of the nasopharynx, behind
the opening of the auditory tube. It
arises from the posterior part of the
ganglion & passes through the
palatovaginal canal along with the
pharyngeal branch of the maxillary
artery.
MANDIBULAR NERVE
It is the third & largest division of the trigeminal nerve.it is made up of 2
roots: a large sensory root which proceeds from the lateral part of the &
semilunar ganglion & almost immediately emerges out through the foramen
ovale( of the sphenoid) & a small motor root which passes below the ganglion,
& unites with the sensory root just outside the foramen.
Immediately beyond the junction of the 2 roots, the nerve sends off the
meningeal branch & the nerve to the medial pterygoid. Now the main trunk
divides into a small anterior & a large posterior trunk.
As it descends from the foramen, the mandibular nerve lies at a distance of 4
cm from the surface & a little in front of the neck of the mandible. The various
brancnes given off are as follows: -
1) Branches of the undivided nerve.
i. Meningeal branch/nervus spinosus.
ii. Nerve to the medial pterygoid
2) Branches of the divided nerve:
A) Anterior division:
i. Buccal nerve
ii. Massetric nerve
iii. Deep temporal nerve

10. iv. Nerve to the lateral pterygoid.
B) Posterior division:
i. Auriculotemporal nerve
ii. Lingual nerve
iii. Inferior alveolar nerve
1) Undivided nerve branches
i. Meningeal nerve:
• It enters the skull through the foramen spinosum
along with MMA.
• It has anterior & posterior divisions that supply the
dura of the middle &
ant.cranial fossae.
ii. Nerve to the medial pterygoid:
 It is a slender branch that enters the deep surface of
the muscle.
 It also gives 1-2 filaments to the tensor tympani & the
tensor veli
palati muscles.
2) Divided nerve branches.
A) Anterior division: It has 1 sensory branch. i.e.
long buccal nerve &3 branches that are motor to
the massetric, deep temporal & lateral pterygoid
muscles.
i. The buccal nerve:
• It passes between the 2 heads of the
lateral pterygoid & descendsbeneath or
through the temporalis. It emerges from
under cover of the ramus & ant. border

11. of the masseter & unites with the
buccal branches of he facial nerve.
• It supplies the skin over the ant. part of
the buccinator & mucous membrane
lining the buccal surface of the gum.
ii. The massetric nerve:
• Passes laterally above the lateral
pterygoid in front of the TMJ & behind
the tendon of temporalis.
• It passes through the mandibular notch
to sink into the masseter.
• It also gives a branch to the joint.
iii. The deep temporal nerves:
• They are 2 in number.
• They pass above the upper head of
the lateral pterygoid, turn above the
infra temporal crest & sink into the
deep part of the temporalis.
iv. The nerve to the lateral pterygoid.
• These are also 2 in number one for
each head.
(2) Posterior division:
The posterior trunk is mostly sensory but
receives a few filaments from the motor
root.
i. The Auriculotemporal nerve:
• The auriculotemporal nerve arises by a
medial & lateral roots, that enclircle

12. theMMA & unite behind it just below
the foramen spinosum.
• The united nerve passes backwards,
deep to the lateral pterygoid muscle &
passes between the
sphenomandibular ligament & the neck
of the condyle.
• It then passes laterally behind the TMJ
I.r.t. to the upper part of the parotid. It
emerges from behind the TMJ,
ascends posterior to the superficial
temporal vessels & crosses the
posterior root of the zygomatic arch.
Communications of the nerve:
 2 roots of the nerve:- both tghese
roots receive communications
from he OTIC ganglion. They are
postganglionic secretory fibres to
the Parotid gland.i.e they control
the secretions from the gland
 Communicating branches to the
postganglionic sympathetic
fibres:- These are vasomotor
fibres that pass to the parotid
through the auriculotemporal
nerve.
 Communicating branches to the
facila nerve: These are purely
sensory from the
Auriculotemporal nerve.
Branches of the nerve:

13. i. Parotid branches
ii. Articular branches--- to the
TMJ.
iii. Auricular branches---to the
skin of the helix & tragus.
iv. Meatal branches-----
Meatus of the tymphanic
membrane
v. Terminal branches----
Scalp over the temporal
region
Lingual nerve
This is the smaller of the 2 branches of the
posterior division,
It passes medial to the lateral pterygoid & it
lies between the ramus of the mandible &
the muscle in the pterygomandibular space.
It gives off sensory fibresto the tonsil & the
mucous membrane of the posterior part of
the oral cavity.
In the pterygomandibular space, it lies
parallel to the inferior alveolar nerve, but
medial & anterior to it.
It then passes deep to reach the side of the
tongue. Here it lies in the lateral lingual
sulcus against the deep surface of the
mandible on the medial side of the roots of
the third molar tooth where it is covered
only by mucous membrane of the gum.
From here it passes on to the side of the the
side of the tongue where it is crosses the
styloglossus & runs on the lateral surface of
the hyoglossus & deep to the mylohyoid in

14. close relation to the deep part of the
submandibular gland &its duct.
Communication of the facial nerve
(Chorda tymphani)
As the lingual nerve passes
medially to the lateral pterygoid, it is joined
by the chorda tympani. This nerve conveys
secretory fibres from the facial nerve. The
parasympathetic secretory fibres control the
submandibular & sublingual salivary glands.
Inferior alveolar nerve.
It is the largest terminal branch of the
posterior division of the mandibular nerve.
The nerve descends deeep to the lateral
pterygoid muscle 7& at the lower border of
the muscle, it passes b/n the
sphenomandibular ligament & the ramus to
enter the mandibular foramen.
In the canal the nerve runs alongside the
inferior alveolar artery.as far as the mental
foramen where it emerges out& gives off
the mental & incisive branches.
From here the nerve runs in the canal giving
of branches to the mandibular teeth as
apical fibres & enters the a[pical foramena
of the teeth to supply the pulp mainly as
well as the periodontium.
Branches of the nerve

15. Mental nerve: it supplies to the skin of the
chin & the mucous membrane as well as
the skin of the lower lip.
Incisive branch: continues anteriorly from
the mental nerve in the body of the
mandibleto form the incisive plexus &
supplies the canine & incisors.
Mylohyoid nerve: it is given of before the
nerve enters the canal & contains both
sensory & motor fibres.it pierces the
sphenomandibular ligament, descends in a
groove in the medial side of the ramus &
passes beneath the mylohyoid line
supplying the mylohyoid muscle as well as
the anterior belly of the digastric.
Autonomic ganglia associated with the
mandibular division
Submandibular ganglion:
It is a small ovoid body that is
suspendedfrom the lingual nerve above the
submandibulat salivary gland. The
preganglionic parasympathetic fibres reach
the ganglion arising from the superior
salivatory nucleus, reaching through the
facial, chorda tympani & the lingual nerve.
Post ganglionic fibres are conveyed through
the submandibular, sublingual & anterior
lingual salivary glands.
The sensory nerves reach the
gangliothrough the lingual nerve.

16. Sympathetic fibres are derived from the
plexus around the facial artery & contain
post ganglionic fibres arising in the superior
cervical ganglion. They provide
secretomotor fibres to the submandibular &
sublingual galands.
Otic ganglion
It is a flattened ovoid body located on the
medial side of the undivided nerve. It is
situated below the for. ovale & the MMA.
It has 2 main roots:-
1) Parasympathetic preganglionic
(secretory) fibres: they arise from the
inferior salivatory nucleus.the
efferent fibres pass by way if the
glossopharyngeal nerve through the
jugular canal.below the canal it
passes through the tympanic branch
of the glossopharyngeal
nerve( Jacobson’s nerve), passing
through the tympanic plexus & the
lesser petrosal branch to reach the
Ganglion.( the lesser superficial petrosal
nerve is the parasympathetic root of the otic
ganglion) the postganglionic fibres pass
through the auriculotemporal nerve.
2) Sympathetic root: It is made up of
the postganglionic fibres that have
originated in the superior cervical
sympathetic ganglion & the plexus of
the MMA. The fibres pass through

17. the ganglion uninterrupted. These
fibres reach the parotid thru the
auriculotemporal nerve.
Afferent of sensory nerves come
from the parotid through the
auriculotenporal nerve.