Clinical Correlates of the Anatomical Relationships of Foramen Ovale: A Radioanatomical Study

Introduction : Endonasal endoscopic transpterygoid approaches are valuable and commonly used techniques to access the infratemporal fossa and parapharyngeal space. Important endoscopic endonasal landmarks for the poststyloid parapharyngeal space, hence the internal carotid artery, include: the mandibular nerve at the level of foramen ovale and the lateral pterygoid plate. This study aims to define the anatomic relationships of the foramen ovale and the mandibular nerve, establishing their distance to other important anatomical landmarks such as the pterygoid process and columella. Methods : Distances between foramen ovale, foramen rotundum and fixed anatomical landmarks like the columella and pterygoid process were measured using CT scans and cadaveric dissections of the pterygopalatine and infratemporal fossae. Results : The mean distances from foramen ovale to columella and from foramen rotundum to columella were found to be 9.15 cm and 7.09 cm respectively. Analysis of radiological measurements detected no statistically significant differences between sides or gender. Conclusions : The pterygoid plates and V3 are prominent landmarks of the endonasal endoscopic approach to the infratemporal fossa and poststyloid parapharyngeal space. A better understanding of the endoscopic anatomy of the infratemporal fossa and awareness of the approximate distances and geometry among anatomical landmarks facilitates a safe and complete resection of lesions arising or extending to these regions.