Transpterygoid approach, step-by-step. The posterior wall of the maxillary sinus has been removed to expose the pterygopalatine fossa. The sphenoid process of the palatine bone has been removed to expose thepalatosphenoidal artery, which forms a defined groove on the pterygoid process. The descending palatine nerve can be identified after removal of the vertical plate of the palatine bone. The inferior orbital fissure is exposed superiorly after removal of the orbital process. During surgery it is important to keep the periosteal layer that covers the pterygopalatine fossa intact to facilitate it mobilization in a subperiosteal fashion. (Image courtesy of JC Fernandez-Miranda)