infratemporal

The infratemporal region, or infratemporal fossa, is an irregular, cone‑shaped space situated inferior to the temporal fossa, deep to the ramus of the mandible, and posterior to the maxilla. It serves as a conduit between the cranial cavity, face, and neck and contains several neurovascular structures as they traverse between compartments. It communicates with the temporal fossa, the pterygopalatine fossa via the pterygomaxillary fissure, and the orbit via the inferior orbital fissure, among other openings.

Boundaries and relationships are defined as follows: superiorly by the infratemporal surface of the greater wing of the sphenoid; anteriorly by the posterior surface of the maxilla; medially by the lateral pterygoid plate of the sphenoid; laterally by the mandible’s ramus; posteriorly by the tympanic plate and adjacent temporal bone; and the floor is formed in part by the medial and lateral pterygoid muscles.

Contents of the infratemporal fossa include the muscles of mastication, chiefly the lateral and medial pterygoid muscles. The vascular compartment is dominated by the maxillary artery and its branches, accompanied by the pterygoid venous plexus. The neural elements include the mandibular division of the trigeminal nerve (V3) and its branches, such as the inferior alveolar, lingual, buccal, and auriculotemporal nerves, as well as the nerve to the mylohyoid. The chorda tympani hitchhikes with the lingual nerve; the otic ganglion lies nearby with parasympathetic connections via the lesser petrosal nerve. The infratemporal region also contains autonomic fibers accompanying vessels.

Clinical relevance includes regional anesthesia (inferior alveolar nerve block), spread of infections or neoplasms from dental sources, and surgical approaches to access V3 branches and adjacent structures.