Lateral view of left infratemporal fossa and proximal neck. The zygomatic arch and much of the ramus of the mandible have been removed to expose the superficial aspect of the infratemporal fossa. Here, one can view the superior and inferior heads of the lateral pterygoid muscle, whose fibers run more horizontally to insert into the capsule of the temporomandibular joint and neck of the mandible. The superficial head of the medial pterygoid muscle is seen arising from the maxillary tuberosity. Fibers of its deep head can also be seen (attach to the medial surface of the lateral pterygoid plate). This muscle has fibers that descend inferolaterally to insert into the medial surface and angle of the mandibular ramus. Coursing superficial to the lateral pterygoid is the maxillary artery. The deep temporal arteries are branches that ascend on the deep surface of the temporalis muscle in company with deep temporal nerves, branches of the mandibular nerve. These usually emerge above the superior head of the lateral pterygoid as does the masseteric nerve. The masseteric nerve passes over the mandibular notch to enter the deep surface of the masseter muscle (removed). The inferior alveolar artery and artery of the lingual nerve are branches of the maxillary artery and accompany their respective nerves. The buccal nerve emerges between the two heads of the lateral pterygoid and courses onto the superficial surface of the buccinator muscle. It is sensory to the skin and mucous membrane of the cheek. The inferior alveolar and lingual nerves emerge from under the inferior head of the lateral pterygoid between it and the medial pterygoid. The inferior alveolar nerve enters the mandibular foramen and supplies the lower teeth. The lingual nerve, located superior to the inferior alveolar, enters the oral cavity to provide sensory innervation to the anterior two-thirds of the tongue and floor of the mouth. The maxillary vein forms from consolidation of the pterygoid venous plexus and courses behind the neck of the mandible with the maxillary artery. The maxillary artery is the larger of its terminal branches. The superficial temporal artery, the other terminal branch, crosses the root of the zygomatic arch to the lateral scalp region in company with the auriculotemporal branch of the mandibular nerve. Emerging from behind the ramus of the mandible is the facial nerve, which courses through the parotid gland (removed). Posterior to the condyle of the mandible is the external auditory canal. In the neck, the sternocleidomastoid muscle is reflected to expose the internal jugular vein and the common carotid and external carotid arteries anterior to it. The digastric muscle (its anterior and posterior bellies) and the lower border of the mandible outline the submandibular triangle whose floor is the mylohyoid muscle. Here the facial artery crosses onto the face. The hypoglossal nerve descends deep to the posterior digastric and abruptly courses forward deep to the mylohyoid to enter the floor of the mouth. (Image courtesy of AL Rhoton, Jr.)