The facial nerve between the stylomastoid foramen and the parotid: computed tomographic imaging.

A small segment of the facial nerve between its exit from the stylomastoid foramen and its entrance into the parotid is surrounded by fat and, therefore, can be imaged well using modern computed tomography. A small dot can be seen surrounded by fat just beneath the stylomastoid foramen on computed tomographic scan. To verify that this indeed represented the facial nerve, tissue sections and an injection into the mastoid segment of the intratemporal facial nerve were performed. The anatomic correlation and clinical material demonstrating involvement of the facial nerve in this region are presented.