QS Study

Mandibular nerve is the largest of the three division of the trigeminal nerve. It is a terminal branch of the trigeminal nerve. It has a sensory function in the head and is connected with parasympathetic fibers of other cranial nerves. The sensory fibers of the mandibular nerve innervate several skin regions of the face, as well as mucosa of the oral cavity, the lower teeth, and gingiva.

Course

It begins in the middle cranial fossa through a small motor root & a large sensory root.

The sensory root: Arises from the lateral part of the trigeminal ganglion & leaves through the foramen ovale. Their distribution pattern is similar to the dermatome supply of spinal nerves (except there is little overlap in the supply of the divisions).

The motor root: Lies deep to trigeminal ganglion & the sensory root. It also passes through the foramen ovale & form the main trunk by joining the sensory root. The motor root runs along the floor or the trigeminal cave, beneath the ganglion, joining the sensory root before leaving the cranium through the foramen ovale.

After a short course, the main trunk is divided into an anterior & posterior trunk.

mandibular nerve 1

Fig: Course and Distribution of Mandibular Nerve

Branches & distribution

(A) From the main trunk:

  • Meningeal branch: Supplies the dura mater middle cranial fossa.
  • Nerve to medial pterygoid: Supplies the medial pterygoid, tensor palati & tensor tympani.

(B) From the anterior trunk:

(a) Sensory branch

Buccal nerve: Supplies the skin & mucous membrane related to buccinator.

(b) Motor branch:

  • Masseteric: Supplies the masseter muscle & temporomandibular joint.

Deep temporal: Supplies the temporalis muscle.

(C) From the posterior trunk:

  • Auriculotemporal nerve: Supplies the parotid gland & temporomandibular joint.
  • Lingual nerve: Supplies tongue.
  • Inferior alveolar nerve.
Related Study: