Magnified view of left infratemporal fossa. The zygomatic arch and anterior portion of the ramus of the mandible have been removed to expose the infratemporal fossa. The lateral pterygoid muscle has also been removed to show the foramen ovale and spinosum at the roof of this fossa for the mandibular nerve and middle meningeal artery, respectively. Several branches of the nerve can be seen, including the roots of the auriculotemporal nerve (enclosing the middle meningeal artery), deep temporal and masseteric nerves, the buccal nerve, and the lingual and inferior alveolar nerves crossing the surface of the medial pterygoid muscle. The nerve to mylohyoid leaves the inferior alveolar nerve before it enters the mandibular foramen and will supply the mylohyoid and anterior digastric muscles. The superficial head of the medial pterygoid muscle arises from the maxillary tuberosity while its deep head arises from the medial surface of the lateral pterygoid plate. The maxillary artery gives rise to several branches: deep temporal arteries that ascend on the deep surface of the temporalis muscle in company with deep temporal nerves, middle meningeal, buccal, posterior superior alveolar, inferior alveolar, and artery to the lingual nerve. Distally, the maxillary artery enters the pterygopalatine fossa through the pterygomaxillary fissure and gives rise to the sphenopalatine artery, which supplies much of the nasal cavity. The posterior superior alveolar nerve is a branch of the maxillary nerve and passes from the pterygopalatine fossa through the pterygomaxillary fissure to small foramina on the posterior wall of the maxilla. It provides sensory innervation to the maxillary sinus and maxillary molars. The maxillary vein forms from consolidation of the pterygoid venous plexus and courses behind the neck of the mandible with the maxillary artery. It will join the superficial temporal vein to form the retromandibular vein. The external acoustic meatus lies just posterior to the mandibular fossa containing the head of the mandible. (Image courtesy of AL Rhoton, Jr.)