[1][2] The nerve typically travels from the pons through the facial canal in the temporal bone and exits the skull at the stylomastoid foramen.

From the brain stem, the motor and sensory parts of the facial nerve join and traverse the posterior cranial fossa before entering the petrous temporal bone via the internal auditory meatus.

Upon exiting the internal auditory meatus, the nerve then runs a tortuous course through the facial canal, which is divided into the labyrinthine, tympanic, and mastoid segments.

In the temporal part of the facial canal, the nerve gives branch to the stapedius muscle and chorda tympani.

[4] It then splits into five branches (temporal, zygomatic, buccal, marginal mandibular and cervical), innervating the muscles of facial expression.

The lingual branch of the mandibular division (V3) of the trigeminal nerve supplies non-taste sensation (pressure, heat, texture) to the anterior part of the tongue via general somatic afferent fibers.

General sensation from the anterior two-thirds of tongue are supplied by afferent fibers of the third division of the fifth cranial nerve (CN V-3).

The intermediate nerve reaches the posterior cranial fossa via the internal acoustic meatus before synapsing in the solitary nucleus.

There is also a small amount of cutaneous sensation carried by the nervus intermedius from the skin in and around the auricle (outer ear).

The facial nerve carries axons of type GSA, general somatic afferent, to skin of the posterior ear.

The facial nerve also carries axons of type GVE, general visceral efferent, which innervate the sublingual, submandibular, and lacrimal glands, also mucosa of nasal cavity.

Axons of type SVE, special visceral efferent, innervate muscles of facial expression, stapedius, the posterior belly of digastric, and the stylohyoid.

The axons of type SVA, special visceral afferent, provide taste to the anterior two-thirds of tongue via chorda tympani.

Iatrogenic Bell's palsy may also be as a result of an incorrectly placed dental local-anesthetic (inferior alveolar nerve block).

This can be tested with a swab dipped in a flavored solution, or with electronic stimulation (similar to putting your tongue on a battery).