Usefulness of simultaneous use of anatomical landmarks in identification of facial nerve in parotid gland dissection

Abstract

INTRODUCTION: Identification of Facial nerve trunk is important in parotid surgery to avoid an iatrogenic injury. The objective of our study was to assess consistent and reliable landmarks for identification of the main trunk of facial nerve during parotid surgery. METHODS: This prospective study was carried out in the department of Anatomy, faculty of Medicine, Ragama from 2022 to 2023. Our study included 35 fresh cadavers (70 parotid regions). The anatomical landmarks of tragal pointer (TP), tympanomastoid suture (TMS), and superior border of posterior belly of digastric (PBD) muscle to the facial nerve trunk was measured. The shortest distances were taken from the facial trunk by using a slide calliper. RESULTS: The age of subjects of the cadavers ranged from 42 to 64 years with a mean of 54.4 years. The mean distance between the TP and the facial nerve trunk was 9.15 mm (8.1–11.7 mm). The mean distance between PBD and the facial nerve trunk was 8.6 mm (7.2–9.8 mm). The mean distance between the TMS and the facial nerve trunk was 6.5 mm (5.2–7.5 mm). CONCLUSION: Our study showed that the tympanomastoid suture line is the closest to the facial nerve trunk, followed by the posterior belly of digastric muscle and the tragal pointer respectively. Further clinical studies are needed to assess these landmarks through various parameters to determine their usefulness in surgical practice.