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Chewing muscles
Last reviewed: 07.07.2025
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The chewing muscles develop on the basis of the first visceral (lower jaw) arch. These muscles originate on the bones of the skull and are attached to the lower jaw - the only movable bone, providing a variety of movements in humans in the temporomandibular joint.
The chewing muscle (m.masseter) has a quadrangular shape and is divided into superficial and deep parts.
The superficial part begins with a thick tendon on the zygomatic process of the maxilla and the anterior two-thirds of the zygomatic arch. The bundles pass downward and backward and are attached to the masseteric tuberosity of the mandible. The deep part of the muscle is partially covered by the superficial part, begins on the posterior third of the lower border and the entire inner surface of the zygomatic arch. The bundles of this part pass almost vertically from above downward and are attached from the lateral surface of the coronoid process of the mandible to its base.
Function: Raises the lower jaw, developing great force. The superficial part of the muscle also participates in moving the lower jaw forward.
Innervation: trigeminal nerve (V).
Blood supply: masseteric and transverse arteries.
The temporal muscle (m.temporalis) is fan-shaped and occupies the region of the same name (temporal fossa) on the lateral surface of the skull. This muscle begins on the entire surface of the temporal fossa and the inner surface of the temporal fascia. The muscle bundles, converging downwards, continue into a thick tendon that attaches to the coronoid process of the lower jaw.
Function: elevates the lower jaw, acts mainly on the anterior teeth ("biting muscle"). The posterior bundles of the muscle pull the forward-thrusting lower jaw backwards.
Innervation: trigeminal nerve (V).
Blood supply: deep and superficial temporal arteries.
The medial pterygoid muscle (m pterygoideus medialis) is thick and quadrangular. The muscle begins in the pterygoid fossa of the eponymous process of the sphenoid bone. The muscle bundles extend downwards, laterally and posteriorly, continuing into a highly developed tendinous plate that attaches to the pterygoid tuberosity on the inner surface of the angle of the lower jaw. The direction of the fibers of this muscle corresponds to the direction of the fibers of the masseter muscle.
Function: raises the lower jaw, moves the lower jaw forward.
Innervation: trigeminal nerve (V).
Blood supply: pterygoid branches of the maxillary artery.
The lateral pterygoid muscle (m.pterygoideus lateralis) is a thick, short muscle that begins with two heads - upper and lower. The upper head begins on the maxillary surface and the infratemporal crest of the greater wing of the sphenoid bone, the lower head - on the outer surface of the lateral plate of the pterygoid process of the same bone. The bundles of both heads of the muscle, converging, are directed backward and laterally and are attached to the anterior surface of the neck of the lower jaw, to the articular capsule of the temporomandibular joint and to the intraarticular disk.
Function: With bilateral contraction of the muscle, the lower jaw moves forward, pulling the joint capsule and intra-articular disc of the temporomandibular joint forward. With unilateral contraction, it moves the lower jaw to the opposite side.
Innervation: trigeminal nerve (V).
Blood supply: pterygoid branches of the maxillary artery.
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