Articles

Anatomy

Masseter Muscle

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 FactDetails
OriginSuperficial 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.
InsertionSuperficial 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.
ActionElevation 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).
InnervationMasseteric nerve, a branch of the mandibular nerve (cranial nerve V3).
Blood SupplyMasseteric artery, a branch of the maxillary artery, and muscular branches of the transverse facial artery (superficial temporal artery).
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July 13, 2024
Anatomy

The Temporalis Muscle

Temporalis Muscle

The temporalis muscle is one of the four muscles of mastication, which are primarily responsible for the movements of the jaw during chewing and speaking. The temporalis muscle is notable for its fan-shaped appearance and is a crucial component in the elevation and retraction of the mandible. Understanding the anatomy, function, and clinical significance of the temporalis muscle can provide valuable insights into its role in both normal mastication and potential disorders of the temporomandibular joint (TMJ).

Key FactsDetails
OriginBony surfaces of the temporal fossa, inferior temporal line, and overlying temporal fascia.
InsertionMedial aspect of the coronoid process of the mandible and anterior margin of the mandibular ramus, extending almost to the last molar tooth.
ActionElevation of the mandible (closing the mouth), retraction of the mandible (pulling the jaw backward), and maintaining the resting position of the mandible.
InnervationDeep temporal nerves, branches of the mandibular nerve (cranial nerve V3).
Blood SupplyDeep temporal arteries (branches of the maxillary artery) and anastomoses with branches of the middle temporal artery.
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July 13, 2024
Anatomy

Understanding the Muscles of Mastication

Muscles of Mastication

The muscles of mastication are a group of four muscles that are primarily responsible for the movement of the jaw. These muscles are essential for chewing (mastication), speaking, and any other activity that involves the opening and closing of the mouth. The muscles of mastication are located in the parotid and infratemporal regions of the head, and they work in harmony to allow for complex movements of the jaw. This article gives an overview of each muscle of mastication, their function, insertion and origin, and blood and nerve supplies.

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July 13, 2024