An endoscopic study of the greater palatine nerve

Using an endoscopic approach, lateral sphenoid air cells and terminal branches of the internal maxillary artery often can be accessed through the pterygomaxillary fossa: however, injury to the greater palatine nerve (GPN) can occur if the anatomy of this region is not understood clearly. This study was undertaken to define the pathway of the GPN and to identify landmarks useful in preventing its injury.

Six cadaveric heads were used to endoscopically dissect and examine 11 pterygomaxillary fossae. An additional latex-injected cadaveric head was sectioned coronally and dissected bilaterally. The relationships between the vascular, neurological and bony structures and foramena were noted and described.

All specimens studied maintained consistent relationships. The sphenopalatine and posterior nasal arteries cross nearly perpendicular and just superficial to the GPN. The GPN traveled anteriorly and inferiorly to reach the greater palatine foramen. The lateral wall of the canal ranged from a thin bony covering to complete dehiscence and was thinnest as it crossed the inferior turbinate and approached the foramen. The foramen rotundum was located lateral and superior to the sphenopalatine foramen near the roof of the maxillary sinus.

When surgically approaching the pterygomaxillary fossa, injury to the GPN is avoidable by thorough knowledge of anatomy and awareness of the described landmarks.