Structure and Insertion
- Medial pterygoid muscle consists of two heads
- Deep head arises above medial surface of lateral pterygoid plate
- Superficial head originates from maxillary tuberosity and pyramidal process of palatine bone
- Fibers pass downward, lateral, and posterior
- Insertion joins masseter muscle to form a common tendinous sling
Nerve Supply
- Medial pterygoid muscle is supplied by medial pterygoid nerve
- Medial pterygoid nerve is a branch of mandibular nerve, itself a branch of trigeminal nerve (V)
- Medial pterygoid nerve also supplies tensor tympani muscle and tensor veli palatini muscle
- Medial pterygoid nerve is a main trunk from mandibular nerve, before division of trigeminal nerve
- Unlike lateral pterygoid muscle and other muscles of mastication, which are supplied by anterior division of mandibular nerve
Function
- Medial pterygoid muscle elevates the mandible (closing the mouth)
- Medial pterygoid muscle protrudes the mandible
- Medial pterygoid muscle aids in mastication, especially when maxillary teeth and mandibular teeth are close together
- Medial pterygoid muscle allows contralateral excursion of the mandible with unilateral contraction
Additional Images
- Position of medial pterygoid muscle (red)
- Left palatine bone, posterior aspect, enlarged
- Mandible, inner surface, side view
- Plan of branches of internal maxillary artery
- Distribution of maxillary and mandibular nerves, and submaxillary ganglion
References
- This article incorporates text in the public domain from page 387 of the 20th edition of Gray's Anatomy (1918)
- Wood, W W (1986-05-01). Medial pterygoid muscle activity during chewing and clenching. The Journal of Prosthetic Dentistry. 55 (5): 615–621. doi:10.1016/0022-3913(86)90043-0. ISSN1097-6841. PMID3458914.
- Wikimedia Commons has media related to Medial pterygoid muscles
- MedicalMnemonics.com: 70
- Anatomy diagram: 25420.000-1. Roche Lexicon - illustrated navigator. Elsevier. Archived from the original on 2015-02-26.
The medial pterygoid muscle (or internal pterygoid muscle), is a thick, quadrilateral muscle of the face. It is supplied by the mandibular branch of the trigeminal nerve (V). It is important in mastication (chewing).
| Medial pterygoid | |
|---|---|
 The Pterygoidei; the zygomatic arch and a portion of the ramus of the mandible have been removed. (Internus is visible at center bottom.) | |
 The otic ganglion and its branches. (Pterygoideus internus labeled at bottom right.) | |
| Details | |
| Origin | deep head: medial side of lateral pterygoid plate behind the upper teeth superficial head: pyramidal process of palatine bone and maxillary tuberosity |
| Insertion | medial angle of the mandible |
| Artery | pterygoid branches of maxillary artery |
| Nerve | mandibular nerve via nerve to medial pterygoid |
| Actions | elevates mandible, closes jaw, helps lateral pterygoids in moving the jaw from side to side |
| Identifiers | |
| Latin | musculus pterygoideus medialis, musculus pterygoideus internus |
| TA98 | A04.1.04.009 |
| TA2 | 2113 |
| FMA | 49011 |
| Anatomical terms of muscle | |
medial pterygoid muscle (plural medial pterygoid muscles)
