Variation of the mylohyoid: implications for Ludwig angina, cervical contouring, and digastric muscle transfer

Abstract

The mylohyoid (MH) musculature separates the sublingual and submandibular spaces and is, therefore, important with regard to the spread of infection and space occupying lesions. Moreover, the MH may be elevated and included in the myocutaneous submental island flap or sutured in conjunction with the platysmas and the anterior bellies of the digastric muscles (ABDMs) to add stability to submental muscular medialization procedures. Therefore, variation in the anatomy of the MH musculature must be considered in the management of the spread of infection and space occupying lesions as well as in surgical planning. This report reviews mylohyoid variations and documents a unique case in which several suprahyoid muscular variations occurred concurrently. The variations included isolated anterior bellies of the mylohyoid inserting into the geniohyoid thereby forming mylo-geniohyoid muscles as well as isolated posterior bellies of the mylohyoid inserting into the ABDM and the intermediate tendon of the digastric muscle thereby forming mylo-digastric muscles. Surgeons operating in the suprahyoid region should be aware of potential anatomical variation of the mylohyoid to develop contingency plans.