mylohyoidi

Mylohyoidi, or the mylohyoid muscles, are a pair of slender muscles that form the floor of the mouth. Each muscle arises from the mylohyoid line on the inner surface of the mandible near the lower teeth and extends medially and downward to insert into the body of the hyoid bone; the two muscles meet at a midline raphe.

Together, the mylohyoidi create a muscular floor under the tongue and provide a platform for the tongue and salivary glands. The superior surface of each muscle is covered by the mucosa of the floor of the mouth, and the sublingual gland lies atop this muscle, with the deep part of the submandibular gland near its posterior border.

Innervation of the mylohyoidi is via the nerve to the mylohyoid, a motor branch of the mandibular division (V3) of the trigeminal nerve. The nerve to the mylohyoid also supplies the anterior belly of the digastric muscle. Arterial supply is typically through the mylohyoid artery, a branch of the inferior alveolar artery, with venous drainage accompanying the arterial pathways into the pterygoid venous plexus or facial veins.

Functionally, the mylohyoidi elevate the floor of the mouth and the hyoid bone during swallowing and speaking. When the hyoid is fixed, they can assist in depressing the mandible. They also help stabilize the floor of the mouth during mastication and swallowing.