auriculotemporalis

Auriculotemporalis, or nervus auriculotemporalis, is a sensory branch of the mandibular division (V3) of the trigeminal nerve. It also carries autonomic fibers that accompany the parotid gland, making it relevant for both sensation and secretomotor functions in its distribution.

Origin and course: The nerve arises in the infratemporal fossa from the posterior division of V3 near the otic ganglion. It often travels between the neck of the mandible and the sphenomandibular ligament, then ascends posterior to the temporomandibular joint and superficial to the temporalis muscle. It commonly runs with the superficial temporal vessels toward the temple, giving small branches to the external ear and tympanic membrane, as well as to the skin of the temple and lateral scalp in front of the ear. It also provides articular branches to the temporomandibular joint.

Distribution: The auriculotemporal nerve supplies sensory innervation to the skin of the anterior temple region, parts of the external acoustic meatus and tympanic membrane, and the skin over the temporal region and lateral aspect of the forehead. It also conveys articular fibers to the temporomandibular joint.

Functions and autonomic fibers: In addition to sensory fibers, the nerve carries postganglionic parasympathetic fibers destined for the parotid gland. These parasympathetic fibers originate from the otic ganglion via the lesser petrosal nerve and join the auriculotemporal nerve to reach the gland, where they stimulate salivary secretion. Sympathetic fibers from the carotid plexus also piggyback on its branches to surrounding vessels.

Clinical significance: Injury or compression can cause sensory loss in its distribution. The nerve is implicated in Frey syndrome, where aberrant parasympathetic reinnervation of facial sweat glands after parotid surgery leads to gustatory sweating and flushing during meals.