Accessory digastric and mylohyoid muscles – a case report

Introduction The mylohyoid muscle in the floor of the mouth forms part of the oral diaphragm. It also forms the floor of the submental triangle, the sides of which are formed by anterior bellies of the digastric muscles. There are a number of reports which suggest variations of the digastric muscle to be more frequent in comparison to variations of the mylohyoid muscle [1, 2]. The present report describes a rare combination of an accessory anterior belly of digastric and mylohyoid. The anterior bellies of the digastric and the mylohyoid muscles have a common embryological origin, being derived from the first pharyngeal arch [3]. Hence digastric–mylohyoid muscle variations may occur simultaneously [4]. The significance of such variations reinforces the need for awareness of the possibility of variants presenting in the submental region.