Cutaneous branch of the nerve to the mylohyoid muscle: Potential cause of postoperative sensory alteration in the submental area

Abstract

BackgroundPrevious studies suggest that the nerve to the mylohyoid muscle could have a cutaneous branch. However, its clinical relevance has rarely been discussed because there is insufficient evidence for it. Our aim in this study was to investigate the anatomy of the cutaneous branch of the nerve to the mylohyoid muscle and extend the discussion to surgical management. MethodsTwenty sides from ten embalmed cadaveric heads were dissected to identify the cutaneous branch of the nerve to the mylohyoid muscle. The cutaneous branch was traced up to its termination. ResultsThe cutaneous branch was observed in 90% and classified into types I and II. In type I, the terminal trunk reached the anterior belly of the digastric muscle. In type II there were two types of terminal trunks, superior and inferior branches, which were identified on all sides. The number of the terminal trunk was one in 23.1% (type I; 6/26) and two in 76.9% (type II; 20/26). The terminal points of the cutaneous branch were all located within a 3 cm × 2 cm rectangular segment in the center of the submental area. ConclusionsWe propose a new dermatome including the nerve to the mylohyoid muscle in the center. Understanding the cutaneous branch of the nerve could help surgeons to prevent iatrogenic sensory loss of the submental area.