What Is the Pterygopalatine Fossa?

The pterygopalatine fossa is a depression or hollow in the human skull that is named for its location at the pterygoid process of the sphenoid bone. A winged-shaped feature consisting of laminae called the medial pterygoid plate and the lateral pterygoid plate, the pterygoid process forms the fossa’s posterior border with its front surface. Its formation enables the pterygopalatine fossa to separate the sphenoid bone from the palatine and maxilla bones.

Certain structures can be found in the pterygopalatine fossa. Chief among them is the pterygopalatine ganglion: a three-rooted, encapsulated network of cells that innervates certain sections of the neck and head. Also known as Meckel’s ganglion after the anatomist from 18th-century Germany who first described it, the pterygopalatine ganglion is one of the major ganglia of the automonic nervous system (ANS). A second structure is the maxillary artery, which supplies blood to the face’s deeper structures; the pterygopalatine ganglion houses its terminal section. The maxillary nerve, which is one of the three branches of the trigeminal nerve, or the fifth cranial nerve, can also be found in this hollow.

The pterygopalatine ganglion consists of six borders. The aforementioned posterior wall, which the pterygoid process forms, functions as the gap’s back wall. The other five are the anterior, superior, medial, lateral and inferior borders.

Forming the anterior, or front, boundary of the pterygopalatine fossa is the maxilla’s posterior surface, or the upper jaw’s rear section. The superior, or upper, border is primarily formed by the inferior orbital fissure’s posterior section and the palatine bone’s orbital process. The vertical part of the palatine bone, also known as the perpendicular plate, is mainly responsible for the fossa’s medial, or middle, boundary. The lateral boundary, consisting of left and right sections, is created by a vertical fissure of the skull called the pterygomaxillary fissure. The inferior boundary, which serves as the floor, is mainly formed by the palatine bone’s pyramidal process, with the apex leading to a passage that carries the terminal branch of the maxillary artery.

The pterygopalatine fossa is joined with the body's oral cavity through the aforementioned passage, known as the greater palatine canal, or pterygopalatine canal. It is not the only passage, however, that connects this fossa with other areas of the skull. For instance, at its medial boundary, the sphenopalatine foramen connects it with the nasal cavity. The inferior orbital fissure connects the pterygopalatine fossa with the orbit, which is the socket where the eye is located.