In a car accident, a driver has received multiple traumas to the side of his head, including a zygomatic arch fracture. What muscle will impaired in this case?

Answer options

1. M. buccinator
2. M. masseter
3. M. risorius
4. M. orbicularis oris
5. M. Procerus

Explanation

Chewing / Mastication• Chewing is achieved by the moving of mandible = lower jaw • The joint of the mandible is called temporomandibular joint. • The nerve that supply all chewing muscle is trigeminal nerve (5)Chewing muscles: 1. Masseter: • Move mandible Upward. • Attachment : Angle of the mandible (gonial angle)2. Temporalis (posterior bundles): • Move mandible Backward. • Attachment: coronoid process & temporal bone • Temporal Articular tubercle: Pull mandible downward3. Medial pterygoid: • Move mandible Medial sides. • Attachment : inner angle of mandible4. Lateral pterygoid: • Move mandible Forward and lateral sides. • Pulls a capsule and interarticular disc of temporomandibular articulation exteriorly. • Attachment : Condyle process of mandible.