- Skeletal system
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The lateral pterygoid (Latin: musculus pterygoideus lateralis) is a thick and short triangular-shaped muscle located in the infratemporal fossa of the skull. It is classified as one of the primary muscles of mastication. The lateral pterygoid muscle is composed of two heads - superior and inferior.
Superior head - infratemporal surface and crest of greater wing of sphenoid
Inferior head - lateral surface of lateral pterygoid plate (sphenoid bone)
|Insertion||Pterygoid fovea of mandible|
Bilateral contractions - push mandible forward, depress mandible
Unilateral contraction - pushes mandible to opposite side
|Innervation||Lateral pterygoid nerve of mandibular nerve|
|Blood supply||Pterygoid branches of maxillary artery, ascending palatine branch of facial artery|
The superior head of the lateral pterygoid originates from the infratemporal surface and crest of the greater wing of the sphenoid. The inferior head of this muscle originates from the lateral surface of the lateral pterygoid plate (of the sphenoid bone).
The lateral pterygoid inserts on the pterygoid fovea of the mandible. The pterygoid fovea is located on the condylar process of the mentioned bone.
Upon bilateral contractions, the lateral pterygoid muscles push the mandible forward (protrude the mandible). By contracting on one side, the activated lateral pterygoid muscle pushes the mandible to the opposite side. The lateral pterygoid muscles depress the mandible.
The lateral pterygoid muscle is innervated by the lateral pterygoid nerve, a branch of the mandibular division of the trigeminal nerve (CN V3).
The lateral pterygoid is provided with the arterial blood supply by the pterygoid branches of the maxillary artery and ascending palatine branch of the facial artery.