The medial pterygoid (also medial pterygoid muscle, latin: musculus pterygoideus medialis) is one of the masticatory muscles. The medial pterygoid is located in the infratemporal fossa and is involved in several movements of the mandible.
The medial pterygoid originates from the pterygoid fossa of the sphenoid bone and inserts on the pterygoid tuberosity of the mandible.
Upon bilateral contractions the medial pterygoid muscles push the mandible forward. By contraction on one side the medial pterygoid muscle pushes the mandible to the opposite side. The medial pterygoid also contributes to the elevation of the mandible acting as a synergist to the temporalis and masseter muscles.
The medial pterygoid is innervated by the medial pterygoid nerve, branch of mandibular division of the trigeminal nerve (CN V3).