The mandibular nerve (V3) is the largest of the three branches of the trigeminal nerve.
It is made up of two roots:
- a large sensory root proceeding from the inferior angle of the trigeminal ganglion.
- a small motor root (the motor part of the trigeminal), which passes beneath the ganglion, and unites with the sensory root, just after its exit through the foramen ovale.
The two roots (sensory and motor) exit the middle cranial fossa through the foramen ovale. The two roots then combine. The nerve descends, soon splitting into an anterior division and a posterior division.
Immediately in the infratemporal fossa beneath the base of the skull, the nerve gives off two branches from its medial side: a recurrent branch (nervus spinosus) and the nerve to the medial pterygoid muscle. The mandibular nerve then divides into two trunks, an anterior and a posterior.
The mandibular nerve gives off the following branches:
- From the main trunk of the nerve (before the division)
- From the anterior division
- From the posterior division
The mandibular nerve also gives off branches to the otic ganglion
The mandibular nerve innervates:
- mucous membrane of the anterior two-thirds of the tongue
- the inside of the cheek (the buccal mucosa)
- teeth and gums of the mandible
- skin of the temporal region
- lower lip, and chin
- muscles of mastication
- the muscles tensor tympani and tensor veli palatini