Anatomical Study of the Extracranial Segment of the Facial Nerve: Preliminary Results

Background and Aim: The aim of the study is to establish normative data of the extracranial segment of the facial nerve to identify the nerve trunk and peripheral branches quickly and safely and to preserve important anatomical structures during surgical operations of the parotid gland, the mastoid process, the skull base, and the nerve itself.

Material and Methods: This is a prospective anatomical dissection study of cadaver specimens. Eleven human cadaver heads (22 facial nerves) were dissected by 2 prosectors: (1) a professor of human anatomy with experience in anatomical dissection and basic knowledge of the facial nerve disposition and (2) an ENT surgeon with experience in the anatomy of the parotid region. During each procedure, various topographical measurements were recorded, including the diameter of the main trunk of the facial nerve and its distance from the tragal pointer, the mastoid process, the tympanomastoid fissure, the digastric muscle, the pes anserinus, and the skin level.

Results: In all cases, the facial nerve was uneventfully dissected and preserved. The most standard references for its intraoperative localization were the mastoid process, the tragal pointer, and the tympanomastoid fissure.

Conclusions: The proposed localization landmarks allow a fast and safe identification of the facial nerve and may be of significant help during surgery around the nerve region.