Bilateral variations of the head of the digastric muscle in Korean: a case report

The digastric muscle, as the landmark in head and neck surgery, has two bellies, of which various variations have been reported. In the submental region of a 72-year-old Korean male cadaver, bilateral variations were found in the anterior belly of the digastric muscle. Two accessory bellies, medial to the two normal anterior bellies of the digastric muscle, ran posterior and medially, merging and attaching at the mylohyoid raphe of the mylohyoid muscle. The 3rd accessory belly originated from the right intermediate tendon and ran horizontally, merging the right lower bundle of the right accessory belly and inserted together. These accessory bellies had no connection with the left anterior belly. This unique variation has not been reported in the literature previously, and this presentation will guide clinicians during surgical interventions and radiological diagnoses.