Endoscopic and three-dimensional radiographic imaging of the pterygopalatine and infratemporal fossae: Improving surgical landmarks

Objectives: We sought to define the surgical endoscopic anatomy of the pterygopalatine fossa (PPF) and infratemporal fossa (ITF) through endoscopic cadaver dissections and radiographic imaging analysis. Methods: Eleven fresh cadavers were submitted to computed tomography (CT) and endoscopic dissection. We used 3-dimensional (3-D) CT reconstruction and endoscopic video imaging for analysis of the bony and soft tissue landmarks. One fixed cadaver head was grossly dissected to confirm the endoscopic anatomic findings. Results: The CT and 3-D CT reconstruction measurements between the pterygoid canal and the foramen rotundum averaged 4.36 mm and 5.09 mm, respectively. An osseous ridge (pterygoid ridge) was identified on the anterior face of the pterygoid process as a novel identifiable anatomic landmark in all of the specimens. The average length of the pterygoid ridge on 3-D CT reconstruction was 7.84 mm. The internal maxillary artery entered the PPF posteromedial to the temporalis tendon and anterolateral to the lateral pterygoid muscle. The average distance from the anterior edge of the lateral pterygoid plate to the foramen ovale was 17.1 mm. Conclusions: The pterygoid ridge is a novel and reliable osseous landmark that could assist surgeons during endoscopic surgery on the PPF and ITF. The neurovascular and muscular anatomic relationships were characterized for both the PPF and the ITF.