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Masseter Muscle Anatomy
Masseter Muscle – Anatomy: The masseter muscle is a thick, quadrilateral muscle in the human head. It is the muscle of mastication, or chewing. The masseter muscle is the largest and most superficial muscle of the cheek. It is innervated by the mandibular branch of the trigeminal nerve, the fifth cranial nerve.
The masseter muscle arises from the zygomatic arch, and inserts into the mandible, specifically the ramus and the coronoid process. The muscle has two bellies, or heads, and a tendon that connects the two bellies. The muscle fibers of the two bellies run in different directions. The lateral or superficial belly is larger, and the fibers run vertically. The medial or deep belly is smaller, and the fibers run horizontally.
The masseter muscle is responsible for the majority of the force that is used to chew food. It elevates the mandible, and helps to close the mouth. The muscle also assists in the movement of the jaw from side to side.
The Masseter Muscle Structure
The Masseter Muscle is a muscle of mastication. It is the muscle on the side of the face that moves the mandible (jawbone) up and down. The muscle is bilateral, meaning it is present on both the left and right sides of the face. The Masseter Muscle is the most superficial muscle of the face. It is located in the superficial fascia of the face, and is covered by the superficial temporal fascia and the skin. The muscle is triangular in shape, and has three origins: the zygomatic bone, the medial pterygoid muscle, and the lateral pterygoid muscle.It has two insertions: the mandible and the temporal bone. The muscle innervated by the mandibular division of the trigeminal nerve (CN V3).
Innervation of the Masseter Muscle
The masseter muscle innervated by the facial nerve (CN VII). The facial nerve provides motor control to the muscles of facial expression, including the masseter muscle. The facial nerve also provides sensation to the face, including the skin over the masseter muscle.
Function of the Masseter Muscle
The masseter muscle is a large muscle in the face that helps to chew food. It is located on the side of the face below the eye and above the jaw. Therefore muscle is responsible for elevating the jaw and clenching the teeth. The masseter muscle is a muscle in the jaw that helps to close the mouth. It is the largest muscle in the jaw and is responsible for most of the chewing action. The masseter muscle innervated by the mandibular nerve, which is a branch of the trigeminal nerve.
Examination of the Masseter Muscle
- The masseter muscle is a muscle of mastication. It is a thick, quadrilateral muscle that is superficial to the TMJ. It arises from the zygomatic arch and inserts into the mandible.
- Therefore muscle innervated by the masseteric nerve, a branch of the mandibular nerve. The masseteric nerve enters the muscle at its medial border.
- The masseter muscle is responsible for elevating the mandible and clenching the teeth.
