Figure 20b.  Location of floor-of-mouth lesions with respect to the mylohyoid muscle. (Reprinted, with permission, from reference 25.) (a) Diagram illustrates how a mass above the mylohyoid muscle can be resected with an intraoral approach. (b) Diagram illustrates how resection of a mass below the mylohyoid muscle requires an external neck approach, usually through a transverse incision.