Muscle
Masseter
Powerful jaw-closing muscle
High-yield
Masseter closes the jaw and receives its motor supply from V3, like the other three main muscles of mastication.
Overview
Masseter covers the outer mandibular ramus. Its fibers descend from the zygomatic region to the jaw, generating force for biting. It works with temporalis and medial pterygoid to elevate the mandible.
Reference facts
- Origin
- Zygomatic arch; superficial fibers also arise from the zygomatic process of the maxilla
- Insertion
- Outer surface of the mandibular ramus and angle
- Action
- Raises the mandible for biting; superficial fibers also assist protrusion
- Innervation
- Masseteric nerve, a branch of the mandibular division of CN V (V3)
- Blood supply
- Masseteric branch of the maxillary artery
Clinical correlation
Repeated clenching or grinding can accompany enlargement of the masseter. Tetanus can cause sustained jaw-muscle spasm and restricted opening, often called lockjaw.
Frequently asked questions
What does the masseter do?
Raises the mandible for biting; superficial fibers also assist protrusion.
What nerve innervates the masseter?
The masseter is innervated by the masseteric nerve, a branch of the mandibular division of CN V (V3).
Where does the masseter attach?
Origin: Zygomatic arch; superficial fibers also arise from the zygomatic process of the maxilla. Insertion: Outer surface of the mandibular ramus and angle.
What is the blood supply of the masseter?
The masseter is supplied by the masseteric branch of the maxillary artery.