Bilateral abnormal anterior bellies of digastric muscles

During dissection of the submental region of a male cadaver, we encountered an abnormal digastric muscle on both sides. Two muscle bundles, both of which fused with mylohyoid muscle close to the midline, were observed on the right side. The anterior one originated from the digastric fossa and its length and width were 27 and 9 mm, respectively. The posterior accessory belly originated from the right intermediate tendon and it was 32 mm in length and 11 mm wide. On the left side, there was a single accessory bundle that originated from the left intermediate tendon and inserted into the mylohyoid raphe at the fusion point of the right accessory bundles. The length and width of this belly were 29 and 9 mm, respectively. The remaining suprahyoid muscles of both sides were normal. Anatomical variations of digastric muscle have to be considered in the imaging procedures of the soft tissue masses in the submental region.