Functions

• Sensory
  • Facial sensation: ophthalmic (CN V1), maxillary (CN V2), mandibular nerve (CN V3)
    • Anterior wall of the external auditory canal
    • Somatosensation of anterior ⅔ of the tongue
    • Afferent limb of the corneal and lacrimation reflexes (nasociliary branch)
    • Afferent limb of the jaw jerk reflex (muscle spindle from masseter)
• Motor (only mandibular nerve)
  • Muscles of mastication
    • Masseter, temporalis, medial pterygoid muscles close the jaw
    • Lateral pterygoid muscles open the jaw
    • Efferent limb of the jaw jerk reflex (masseter)

Etiology

• Tumor
• Vascular compression
• Trauma, including maxillofacial or oral surgery, and mandibular molar extractions
• Inflammation of the nerve
• Cavernous sinus thrombosis

Clinical features

• Altered sensation over the face and tongue
• Weakness in muscles of mastication
• Hearing impairment