Nerve to mylohyoid muscle

At a glance

English

Nerve to mylohyoid muscle

Latin (TA2)

Nervus mylohyoideus

System

Nerve

Region

Head

Side

Paired, left and right

About the nerve to mylohyoid muscle

The nerve to mylohyoid comes from the mandibular division of the trigeminal nerve. It leaves the inferior alveolar nerve in the infratemporal fossa, just before that nerve enters the mandibular foramen on the inner surface of the ramus of the mandible. It then pierces the sphenomandibular ligament and runs downwards and forwards in the mylohyoid groove on the medial surface of the mandible, accompanied by the mylohyoid branch of the inferior alveolar artery.

Below the mylohyoid line it reaches the lower, superficial surface of mylohyoid in the submandibular region and runs forwards on it, deep to the submandibular gland. It gives several branches into mylohyoid from below and ends in the anterior belly of digastric.

Both of these muscles develop from the first pharyngeal arch, as do the muscles of mastication, which is why they share a trigeminal supply; the posterior belly of digastric, from the second arch, is supplied instead by the facial nerve. Mylohyoid forms the muscular floor of the mouth. With the anterior belly of digastric it raises the hyoid bone and the floor of the mouth during swallowing, and when the hyoid is held steady it helps to open the jaw. In some people the nerve also carries sensory fibres to the skin under the chin or to the lower front teeth, which is one explanation given when dental anaesthesia of these teeth is incomplete.

Course and supply

Arises from

Inferior alveolar nerve (mandibular division of the trigeminal nerve), just above the mandibular foramen.

Ends in

Ends in branches to mylohyoid and the anterior belly of digastric.

Supplies

Motor supply to mylohyoid and the anterior belly of digastric.