Geniohyoid muscle

Overview
The Geniohyoid muscle is a narrow muscle situated superior to the medial border of the mylohyoid muscle.

Origin and insertion
It arises from the inferior mental spine, on the back of the symphysis menti, and runs backward and slightly downward, to be inserted into the anterior surface of the body of the hyoid bone; it lies in contact with its fellow of the opposite side. It thus belongs to the suprahyoid muscles. The nerve supply to geniohyoid comes via the hypoglossal nerve via C1.

Action
During the first act of deglutition, when the mass of food is being driven from the mouth into the pharynx, the hyoid bone and with it the tongue, is carried upward and forward by the anterior bellies of the Digastrici, the Mylohyoidei, and Geniohyoidei.

Variations
It may be blended with the one on opposite side or double; slips to greater cornu of hyoid bone and Genioglossus occur.