Intra-surgical optimized identification of masseteric nerve for central facial nerve neurorrhaphy: A retrospective study.

It is the aim of the study to provide a detailed intraoperative assessment of the masseteric nerve and the facial branch of the smiling muscles complex through the same superficial musculoaponeurotic system (SMAS) incision. This observational retrospective study aimed to define the straightest and safest surgical route to identify the facial nerve for the smiling muscles complex and the masseteric nerve, using distance from the tragus and zygomatic arch as anatomical landmarks. 30 patients were included in the study. The mean distance from the tragus to the masseteric nerve was 40.03 mm, the mean distance from the zygomatic arch was 12.24 mm, and the mean depth from the SMAS was 10.84 mm. Data were consistent, with little variation. The distance from the zygoma was found to be higher in male patients. There was a positive correlation between the depth to the nerve and the distance from the zygoma, but no correlation between body mass index and the other parameters studied. Within the limitations of the study it seems that the proposed standardized direct approach to the masseteric nerve is a reproducible technique that may be used to increase the safety of the procedure, reduce the operating time, and decrease the amount of dissection and related postoperative scarring, thereby fostering positive results.