The medial pterygoid muscle consists of two heads. The bulk of the muscle arises as a deep head from just above the medial surface of the
lateral pterygoid plate. The smaller, superficial head originates from the
maxillary tuberosity and the pyramidal process of the
palatine bone. Its fibers pass downward, lateral, and posterior, and are inserted, by a strong tendinous lamina, into the lower and back part of the medial surface of the
ramus and angle of the
mandible, as high as the
mandibular foramen. The insertion joins the
masseter muscle to form a common tendinous sling which allows the medial pterygoid and masseter to be powerful elevators of the jaw.
Nerve supply The medial pterygoid muscle is supplied by the
medial pterygoid nerve, a branch of the
mandibular nerve, itself a branch of the
trigeminal nerve (V). This also supplies the
tensor tympani muscle and the
tensor veli palatini muscle. The medial pterygoid nerve is a main trunk from the mandibular nerve, before the division of the trigeminal nerve - this is unlike the
lateral pterygoid muscle, and all other muscles of
mastication which are supplied by the anterior division of the mandibular nerve. == Function ==