Lateral pterygoid muscle
Musculus pterygoideus lateralis
- Latin synonym: Musculus pterygoideus externus
- Related terms: Lateral pterygoid
Definition
Lateral pterygoid muscle | |
Origin | Great wing of sphenoid and lateral pterygoid plate |
Insertion | pterygoid fovea, capsule of TMJ and intra-articular disc |
Blood supply | Pterygoid branches of maxillary artery |
Innervation | Nerve to lateral pterygoid (from anterior division of mandibular nerve CN V3) |
Action | Protrudes the jaw |
The lateral pterygoid is a short, thick, triangular muscle situated in the infratemporal fossa. It is one of the four muscles of mastication.
Anatomical details
1. Origin
The muscle has two heads — superior and inferior — arising from distinct bony parts:
Head | Origin |
Infratemporal surface and infratemporal crest of the greater wing of the sphenoid bone | |
Lateral surface of the lateral pterygoid plate of the sphenoid bone |
2. Insertion
Fibres from both heads converge to insert into:
Neck of the mandible (pterygoid fovea).
Innervation
Nerve to lateral pterygoid, a branch of the anterior division of the mandibular nerve (CN V3).
Actions
Bilateral contraction of the lateral pterygoid pulls the mandibular head and articular disc forward bringing it under the articular tubercle, producing protrusion and opening of the jaw.
Unilateral contraction moves the mandible toward the opposite side, enabling the side-to-side grinding movements of mastication.
Clinical correlate
Jaw Deviation: Lesion of the mandibular nerve (CN V3) or paralysis of the lateral pterygoid → jaw deviates toward the affected side when opening (due to unopposed action of the opposite or healthy side).
References
Basit H, Tariq MA, Siccardi MA. Anatomy, Head and Neck, Mastication Muscles. [Updated 2023 Jun 5]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2025 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK541027/
Gray, H. (2016) Gray’s Anatomy: The Anatomical Basis of Clinical Practice. 41st edn. Edited by S. Standring. New York: Elsevier. Chapter 32: Infratemporal and pterygopalatine fossae and temporomandibular joint, pp. 546-548.
