Masticatory muscles include temporalis, masseter, medial pterygoid and lateral pterygoid muscles, which are distributed around the lower collar joint and participate in chewing exercise.

① temporalis starts from the temporal fossa, and the muscle bundles converge downward like a fan through the deep surface of the zygomatic arch to the coronal process of the mandible, so that the mandible can be lifted up and backward.

② masseter starts from the lower edge and inner surface of zygomatic arch, and the fibers end obliquely backward and downward at the masseter tuberosity, and lift the mandible when contracting.

③ medial pterygoid starts from pterygoid fossa, and its fiber direction is the same as that of masseter muscle, and ends at the inner surface of mandibular angle. When it contracts, it lifts the mandible and makes it move forward.

④ The lateral pterygoid is located in the infratemporal fossa, starting from the underside of the sphenoid greater wing and the lateral pterygoid process, and ending in the mandibular neck. During contraction, the mandibular joint disc and the lower lead are pulled forward to the lower part of the articular tubercle for mouth opening movement, and when one side acts, the mandible moves to the opposite side.