Topics

Topic

design image
Mandibular nerve

The mandibular nerve is the third division of the trigeminal nerve (cranial nerve V3), emerging from the trigeminal ganglion within Meckel’s cave. It exits the skull through the foramen ovale and enters the infratemporal fossa, giving off motor and sensory branches. As the only mixed branch of the trigeminal nerve, CN V3 provides motor innervation to the muscles of mastication and sensory innervation to the lower face, anterior two-thirds of the tongue (general sensation), mandibular teeth, and part of the external ear. Its anatomical course, branching pattern, and imaging characteristics are critical for diagnostic evaluation, nerve blocks, and surgical planning.

Synonyms

  • Third division of trigeminal nerve

  • CN V3

  • Mandibular division of CN V

Function

  • Motor innervation to muscles of mastication: masseter, temporalis, medial and lateral pterygoids

  • Motor innervation to mylohyoid, anterior belly of digastric, tensor veli palatini, and tensor tympani muscles

  • Sensory innervation to lower jaw, mandibular teeth, anterior two-thirds of tongue (general sensation), chin, lower lip, and part of external ear

  • Transmits tactile, pain, and temperature sensations from its area of distribution

MRI Appearance
T1-weighted images:

  • The mandibular nerve appears as a small, linear low-to-intermediate signal structure as it passes through the foramen ovale and mandibular canal

  • Surrounded by hyperintense fat in the infratemporal fossa and mandibular canal, providing natural contrast

  • Pathology such as nerve sheath tumors, inflammation, or compressive lesions may appear hyperintense or show contrast enhancement

T2-weighted images:

  • The nerve is low-to-intermediate signal, with adjacent fat and soft tissues appearing bright

  • Useful for detecting edema, demyelination, or compressive lesions

STIR (Short Tau Inversion Recovery):

  • Suppresses fat signal to highlight pathology

  • Normal mandibular nerve is low signal, while inflammation, neuritis, or tumors appear hyperintense

CT Appearance

  • The mandibular nerve itself is not directly visualized, but its course is inferred from bony foramina such as the foramen ovale, mandibular canal, and mental foramen

  • The mandibular canal and foramen margins are well-corticated and hyperdense, providing landmarks for nerve location

MRI images

Mandibular nerve mri AXIAL image -img-00000-00000

MRI images

Mandibular nerve mri AXIAL image -img-00000-00000_00001

MRI images

Mandibular nerve mri AXIAL image -img-00000-00000_00002

MRI image

Mandibular nerve