Landmarks for facial nerve identification in parotid surgery: A clinico-anatomical study

Abstract

Background: Preserving the integrity of the facial nerve during parotid surgery depends on its exposure, and this requires a detailed knowledge of its anatomy by the operating surgeon. For easy identification of the facial nerve, a number of landmarks have been described. Objective: The purpose of this study was to review the distances of the facial nerve trunk (FNT) from four commonly used landmarks, namely the tragal pointer, tympanomastoid suture, posterior belly of the digastric muscle (PBDM), and junction of the bony and cartilaginous external auditory canal. It was a clinico-anatomic study which included 15 patients who underwent parotidectomy for various indications and 15 cadavers from the laboratory of human anatomy. Results: PBDM is the most reliable and consistent landmark. Conclusion: Considering the variation in distances of these landmarks from the FNT as reported by various authors, the closest landmark is not necessarily the best or the most identifiable and more than one landmark may need to be used for the safe identification of the FNT.