Which of the following muscles has an attachment to the MAXILLA?

Correct answer: A. Buccinator and medial pterygoid

• A. CORRECT. Both attach to the maxilla. The BUCCINATOR originates from the alveolar processes of BOTH the maxilla and mandible opposite the molars, plus the pterygomandibular raphe. The MEDIAL PTERYGOID has a small SUPERFICIAL head arising from the maxillary TUBEROSITY and the pyramidal process of the palatine bone (its larger deep head arises from the medial surface of the lateral pterygoid plate).
• B. The MASSETER arises from the zygomatic arch and maxillary process of the zygomatic bone and inserts on the lateral ramus and angle. Its attachment is zygomatic, not maxillary proper.
• C. TEMPORALIS arises from the temporal fossa and inserts on the coronoid process. The LATERAL PTERYGOID arises from the greater wing of sphenoid and lateral pterygoid plate. Neither touches the maxilla.
• D. MYLOHYOID and GENIOHYOID are suprahyoid muscles attaching to the mandible and hyoid bone — both are entirely mandibular in their upper attachment.

Note: The medial pterygoid's maxillary tuberosity origin explains a classic complication: needle trauma or haematoma here during a PSA block or a high IAN block produces TRISMUS, because the muscle is elevating and its spasm limits opening.