Left anterior medial exposure of the pterygopalatine fossa. For orientation, superior is toward the bottom of the image, left is toward the left side, and anterior is toward the viewer. The auditory tube opens into the lateral wall of the nasopharynx at about the level of the inferior turbinate and approximately 1 to 1.5 cm posterior to its tip. The pterygopalatine fossa or space in vertical profile has a teardrop shape with its narrow tail directed inferiorly. It is bounded anteriorly by the maxilla, medially by the perpendicular plate of the palatine bone, posteriorly by the pterygoid process, superiorly by the greater wing of the sphenoid, and it opens laterally to the infratemporal fossa via the pterygomaxillary fissure. It receives the maxillary and Vidian nerves along its posterior wall (with Vidian nerve and the pterygoid canal located a bit more inferior and lateral relative to the maxillary nerve and foramen rotundum). The terminal branches of the maxillary artery arise within the pterygopalatine fossa. The sphenopalatine artery enters the nasal cavity through the sphenopalatine foramen. The descending palatine artery gives rise to greater and lesser palatine arteries within the greater palatine canal, which accompany nerves of the same name (branches of the maxillary nerve) to the hard and soft palate, respectively. The pharyngeal artery traverses the palatovaginal canal to supply the roof of the nasaopharynx, sphenoid sinus, and auditory tube. (Image courtesy of AL Rhoton, Jr.)