The trigeminal nerve emerges from the side of the pons and has sensory and motor functions. It divides into three main branches - the ophthalmic, maxillary, and mandibular nerves. The mandibular nerve is the largest division and supplies sensation to the lower face and motor function to the muscles of mastication. It gives off several branches including the mylohyoid, lingual, and inferior alveolar nerves.
2. Trigeminal Nerve
The fifth cranial nerve or the trigeminal nerve, emerges from
the side of the pons and has a large sensory root and a small
motor root.
The roots cross the apex of the petrous temporal bone
beneath the superior petrosal sinus, to enter the middle
cranial fossa.
Chief sensory nerve for the face and head has sensations of
pain, temperature and touch.
Motor action on muscles of mastication.
3. Branches of the
Trigeminal Nerve
Three main branches-
The ophthalmic branch – sensory – lacrimal glands, conjunctiva,
forehead, eyelids, anterior aspect of scalp and the mucous
membrane of the nose
The maxillary branch – sensory – cheeks, upper gums, upper teeth
aned lower eyelids
The mandibular branch sensory and motor – teeth and gums of the
lower jaw, pinnas lower lip and tongue – muscles of mastication
8. Mandibular Nerve
This is the largest of the three divisions of the trigeminal
nerve also known as n. mandibularis; inferior maxillary nerve.
It has both sensory and motor fibers and supplies the teeth
and gums of the mandible, the skin of the temporal region,
the auricula, the lower lip, the lower part of the face, and the
muscles of mastication; it also supplies the mucous
membrane of the anterior two-thirds of the tongue
It is the nerve of the first brachial arch and supplies all
structures derived from the mandibular or first brachial arch.
9. Course and Relations of
the Mandibular Nerve
Mandibular nerve begins in the middle cranial fossa through a
large sensory root and small motor root.
The sensory root arises from the lateral part of the trigeminal
ganglion and leaves the cranial cavity through Foramen Ovale.
The motor lies deep to the trigeminal ganglion and to the
sensory root. It also passes through the foramen ovale to join
the sensory root just below the foramen thus forming the main
trunk which passes through the infratemporal fossa.
After a short course, the main trunk divides into a small anterior
trunk and a large posterior trunk.
13. Branches Of The Mandibular Nerve
Main Trunk
Meningeal Branch Nerve to medial pterygoid
14. From The
Anterior
Trunk
Nerve To
Deep
Massetric Lateral
Buccal Nerve Temporal
Nerve Pterygoid
Nerves
15. From The
Posterior
Trunk
Auriculotemporal Inferior Alveolar
Lingual Nerve
Nerve Nerve
16. MENINGEAL BRANCH
Also known as Nervus Spinosus.
It enters the skull through Foramen
Spinosum with the middle meningeal artery.
It supplies dura mater of the middle cranial
fossa.
17. NERVE TO MEDIAL PTERYGOID
It arises close to the otic ganglion and supplies
the medial pterygoid from its deep surface.
This nerve gives a motor root to the otic ganglion
which does not relay.
It supplies the tensor veli palatini, and the tensor
tympani muscles.
19. BUCCAL NERVE
It is the only SENSORY branch of the anterior
division of the mandibular nerve.
It passes between the two heads of the lateral
pterygoid, runs downwards and forwards and
supplies the skin and mucous membrane related
to the buccinator.
It also supplies the labial aspect of gums of molar
and premolar teeth.
20. MASSETRIC NERVE
Massetric nerve emerges at the upper
border of the lateral pterygoid just in front of
the TMJ, passes laterally through the
mandibular notch in company with the
massetric vessels, and enters the deep
surface of the masseter.
It also supplies to the TMJ.
21. DEEP TEMPORAL NERVES
Deep Temporal Nerves are two in number, the
anterior and the posterior nerves.
They pass between the skull and the lateral
pterygoid, and enters the deep surface of the
temporalis.
The anterior nerve is often a branch of the buccal
nerve and posterior nerve may arise in common
with the massetric nerve.
22. NERVE TO LATERAL PTERYGOID
Nerve to lateral pterygoid enters the deep
surface of the muscle.
It may be an independent branch or may
arise in common with the buccal nerve.
24. AURICULOTEMPORAL NERVE
Auriculotemporal nerve arises by two roots which
run backwards, encircles the middle meningeal
artery and unite to form a single trunk.
The nerve continues backwards between the
neck of the mandible and the sphenomandibular
ligament, above the maxillary artery.
Behind the neck of the mandible, it turns upwards
and ascends on the temple behind the superficial
temporal veins.
25. LINGUAL NERVE
Lingual nerve is one of the terminal
branches of the posterior division of the
mandibular nerve.
It is sensory to the anterior 2/3rd of the
tongue and to the floor of the mouth.
26. Course and Relations of the Lingual
Nerve
It begins 1cm below the skull runs between the
lateral and the medial pterygoids and about 2cm
below the skull it is joined by the Chorda Tympani
nerve.
Emerging at the lower border of the lateral
pterygoid, the nerve runs downwards and
forwards between the ramus of the mandible and
the medial pterygoid.
27. Next it lies in direct contact with the
mandible, medial to the third molar between
the origins of the superior constrictor and
the mylohyoid muscles.
It leaves the gums, runs over the
hyoglossus deep to the mylohyoid and
round the submandibular duct dividing into
terminal branches.
29. INFERIOR ALVEOLAR NERVE
Inferior Alveolar Nerve is the largest terminal
branch of the posterior division of the mandibular
nerve.
It runs vertically downwards lateral to the medial
pterygoid and to the sphenomandibular ligament.
It enters the mandibular foramen and runs in the
mandibular canal accompanied by the inferior
alveolar artery.
30. Branches of the Inferior Alveolar
Nerve
The MYLOHYOID BRANCH contains all motor fibers of
the posterior division.
It arises just before the inferior alveolar nerve enters the
mandibular foramen, pierces the sphenomandibular
ligament with the mylohyoid artery and supplies the
mylohyoid muscle and the anterior belly of the digastric.
While running in the mandibular canal the inferior alveolar
nerve gives branches supplying the lower teeth and the
gums.
31. The MENTAL NERVE emerges at the
mental foramen and supplies the skin of the
chin, skin and the mucous membrane of the
lower lip.
Its incisive branch supplies the labial aspect
of the gums of canine and incisor teeth.