Lateral pterygoid muscle

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Lateral pterygoid muscle
Musculuspterygoideuslateralis.png
The Pterygoidei; the zygomatic arch and a portion of the ramus of the mandible have been removed (labeled as "pterygoideus externus", visible in pink at center)
Gray311.png
Sagittal section of the temporomandibular joint (labeled as "pterygoideus externus", visible in gray at bottom right)
Details
OriginSuperior head: infratemporal surface of sphenoid bone. Inferior head: lateral pterygoid plate
InsertionSuperior head: anterior side of the condyle. Inferior head: pterygoid fovea
Arterypterygoid branches of maxillary artery
Nervelateral pterygoid nerve from mandibular nerve
Actionsdepresses and protrudes mandible, side to side movement of mandible
Identifiers
LatinMusculus pterygoideus lateralis,
musculus pterygoideus externus
TA98A04.1.04.006
TA22109
FMA49015
Anatomical terms of muscle

The lateral pterygoid muscle (or external pterygoid muscle) is a muscle of mastication. It has two heads. It lies superior to the medial pterygoid muscle. It is supplied by pterygoid branches of the maxillary artery, and the lateral pterygoid nerve (from the mandibular nerve, CN V3). It depresses and protrudes the mandible. When each muscle works independently, they can move the mandible side to side.

Structure[edit]

The lateral pterygoid muscle has an upper head and a lower head.[1][2]

It lies superior to the medial pterygoid muscle.

Blood supply[edit]

The lateral pterygoid muscle is supplied by pterygoid branches of the maxillary artery.[citation needed]

Nerve supply[edit]

The lateral pterygoid muscle is supplied by the lateral pterygoid nerve, a branch of the mandibular nerve (CN V3), itself a branch of the trigeminal nerve (CN V).

Function[edit]

The primary function of the lateral pterygoid muscle is to pull the head of the condyle out of the mandibular fossa along the articular eminence to protrude the mandible.[2] A concerted effort of the lateral pterygoid muscles helps in lowering the mandible and opening the jaw. Unilateral action of a lateral pterygoid muscle causes contralateral excursion (a form of mastication), usually performed in concert with the medial pterygoids.[citation needed] When they work independently, they can move the mandible side to side.[2]

Unlike the other three muscles of mastication, the lateral pterygoid alone can assist in depressing the mandible (opening the jaw). At the beginning of this action it is assisted by the digastric, mylohyoid and geniohyoid muscles.

Clinical significance[edit]

The lateral pterygoid muscle may be involved in temporomandibular joint dysfunction.[1][2]

Additional images[edit]

References[edit]

  1. ^ a b Murray, Greg M.; Bhutada, Manish; Peck, Christopher C.; Phanachet, Intira; Sae-Lee, Daraporn; Whittle, Terry (1 April 2007). "The human lateral pterygoid muscle". Archives of Oral Biology. Special Issue: International Mastication Symposium, Brisbane, June 2006. 52 (4): 377–380. doi:10.1016/j.archoralbio.2006.10.002. ISSN 0003-9969.
  2. ^ a b c d Murray, G. M.; Phanachet, I.; Uchida, S.; Whittle, T. (2004). "The human lateral pterygoid muscle: A review of some experimental aspects and possible clinical relevance". Australian Dental Journal. 49 (1): 2–8. doi:10.1111/j.1834-7819.2004.tb00042.x. ISSN 1834-7819.

External links[edit]