Anatomical relationship of facial nerve with extratemporal markers and surgical significance

Abstract

Purpose: Correct identification of the location of the facial nerve trunk, which is likely to be damaged during surgical intervention, is very important to minimize possible complications. Therefore, it is aimed to provide a more practical way to evaluate the anatomical relationship between the facial nerve and surrounding structures and to determine the facial nerve trunk during surgery.
 Methods: Adult cadaver heads were used in 12 (6 Female - 6 Male) fresh frozen cadavers included in the cadaver collection of Dokuz Eylül University Faculty of Medicine, Department of Anatomy. Measurements were taken by determining the lower end of the Tragal pointer (TP) and the tip of the mastoid process (M) surrounding the nerve.
 Results: The mean distance between facial nerve truncus and tragal pointer was 6,538 mm; the tip of the mastoid process, 8,225 mm. Facial nerve truncus is approximately 8.446 mm deep to the line extending between the Tragal pointer-Mastoid tip.
 Conclusion: Instead of using the tragal pointer and the mastoid tip separately for the determination of the facial nerve truncus, the facial nerve trunk can be determined more reliably in the depth of the plane between the structures and does not carry the risk of nerve damage.