Masseter Muscle
The masseter muscle is one of the most powerful muscles of mastication, playing a crucial role in the elevation of the mandible (jaw). Its strength and positioning make it essential for chewing and other jaw movements. This article explores the anatomy, function, and clinical relevance of the masseter muscle in detail.
Key Fact | Details |
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Origin | Superficial head: Maxillary process of the zygomatic bone and inferior aspect of the anterior two-thirds of the zygomatic arch. Deep head: Medial aspect of the zygomatic arch and inferior margin of the posterior third of the zygomatic arch. |
Insertion | Superficial head: Angle of the mandible and lateral surface of the mandibular ramus. Deep head: Central and upper part of the mandibular ramus, extending as high as the coronoid process. |
Action | Elevation of the mandible (closing the mouth), protrusion of the mandible (superficial fibers), retrusion of the mandible (deep fibers), and lateral movement of the mandible (ipsilateral). |
Innervation | Masseteric nerve, a branch of the mandibular nerve (cranial nerve V3). |
Blood Supply | Masseteric artery, a branch of the maxillary artery, and muscular branches of the transverse facial artery (superficial temporal artery). |