Facial nerve

The facial nerve is the most vital structure within the temporal bone. It is also called the seventh cranial nerve.

The facial nerve is either of a pair of nerves that originate in the pons, traverse the facial canal of the temporal bone, and pass through the parotid gland.1 They reach the facial muscles through various branches, control facial muscles, and relay sensation from the taste buds of the front part of the tongue.

1 The facial nerve is responsible for all movements on the same side of the face. It is particularly vulnerable in temporal bone surgery, because it is a structure that doesn’t become apparent until the surgeon is on top of it.

Most of the techniques for a cortical mastoidectomy will rely on the preservation of this nerve. Injury to the facial nerve will cause paralysis of the face.

There are no circumstances where it is preferable or even possible to injure the facial nerve and keep normal facial movement.

1 Baylor College of Medicine, Core curriculum syllabus, http://www.bcm.edu/oto/studs/anat/tbone.html