Origin: Mylohyoid line (mandible)
Insertion: Median raphé
Artery: Mylohyoid branch of inferior alveolar artery
Nerve: Mylohyoid nerve, from inferior alveolar branch of mandibular nerve
Action: Raises oral cavity floor, elevates hyoid, depresses mandible
The Mylohyoideus (Mylohyoid muscle), flat and triangular, is situated immediately above the anterior belly of the Digastricus, and forms, with its fellow of the opposite side, a muscular floor for the cavity of the mouth. It arises from the whole length of the mylohyoid line of the mandible, extending from the symphysis in front to the last molar tooth behind. The posterior fibers pass medialward and slightly downward, to be inserted into the body of the hyoid bone. The middle and anterior fibers are inserted into a median fibrous raphé extending from the symphysis menti to the hyoid bone, where they joint at an angle with the fibers of the opposite muscle. This median raphé is sometimes wanting; the fibers of the two muscles are then continuous.