The vascular anatomy of the digastric muscle.
There are plenty of flaps for the reconstruction of defects of the head and neck region. In the literature, local muscle and myocutaneous flaps such as sternocleidomastoid, pectoral, and deltopectoral flaps are proposed for obliteration of pharyngocutaneous fistulas. Restoration of facial nerve palsies in which nerve repair and nerve grafting are not feasible is accomplished by means of regional muscle transpositions. The vascular anatomy of the digastric muscle to be used in such instances is investigated after latex application to 18 neck regions of nine cadavers. The dissection continued anteriorly from the origin of the facial artery to the end of the submental artery, preserving all the branches piercing and nourishing the muscle. The submental artery courses over the posterior surface of the anterior belly of the digastric muscle, giving off the major pedicle of the muscle 1 cm after exiting behind the submandibular gland. The submental artery gives off another branch, the first minor pedicle of the muscle distal to the major pedicle at a distance of two thirds of the muscle length in a standard fashion in all the cadavers. The artery ends in the distal portion of the muscle, the second minor pedicle of the muscle. The artery gives off periosteal branches to the mandible after coursing through the insertion muscle. The anterior belly of the digastric muscle could be classified as a type II muscle, with a major pedicle and two minor pedicles, according to the system of Mathes and Nahai. The anterior digastric muscle can be a good alternative in obliteration of pharyngocutaneous fistulas, and defects of the mandible, including the body and angle of the mandible, can be amended with the split mandibular myo-osseous digastric flap.