The submental artery (SMA) is a constant branch arising 5 to 6.5 cm from the origin of the facial artery (1, 10, 11) (Fig. 123.1). The SMA runs in a groove on the medial aspect of the submandibular gland and is bound medially by the mylohyoid muscle and above by the mandibular border. It ends at the level of the anterior belly of the digastric muscle and may give off a branch to the sublingual gland or one to the lower lip. The skin territories measure 4 × 5 cm to 15 × 7 cm, but possible dimensions of the skin flap are much larger because of the rich subcutaneous and subdermal anastomoses between the two submental arteries.

There is a constant submental vein draining into the facial vein and at least one anastomosing vein between facial and external jugular veins. In some cases, the submental vein may be used for venous drainage of the flap.

The upper limit of the flap is along the mandibular arch in the submental region, from the ipsilateral angle to a contralateral point across the midline (Fig. 123.2). The extent of the flap depends on the width of the cutaneous paddle at the midline. If cervical and submental skin has enough laxity, a 7 × 16-cm flap is possible. A pedicle flap may reach any part of the oral cavity or the lower two thirds of the side of the face and a part of the forehead. A free flap, using good-caliber vessels in the pedicle, including facial artery and veins, and is extremely
reliable. It is also possible to use a distal or composite pedicle, taking a segment of the internal basilar margin (Fig. 123.3).