Endoscopic transnasal study of the infratemporal fossa: a new orientation.

INTRODUCTION: The medial portion of the infratemporal fossa (ITF) is not infrequently involved in sinonasal and skull base pathologies. However, endoscopic view of the ITF remains unclear with lack of studies addressing this region from the endoscopic perspective. METHODS: Using an extended endoscopic approach, the pterygopalatine and infratemporal fossae were dissected in 10 sides of five adult cadaver heads. A plane of dissection along the pterygoid base and the infratemporal surface of the greater sphenoid wing was developed. High-quality images were produced by coupling the video camera to a digital recording system. RESULTS: The foramen rotundum, ovale, and spinosum were accessed and new landmarks were described from the endoscopic point of view. The sphenomandibularis muscle was also highlighted. Maxillary and mandibular nerves and middle meningeal artery were all identified. Columellar measurements to the foramen rotundum and ovale ranged from 6.1 to 8.0 cm for the former and 7.0 to 9.1 cm for the latter, with a mean of 6.75 cm and 7.78 cm respectively. CONCLUSION: The current study provides a novel endoscopic orientation to the medial ITF. Such knowledge should provide an anatomical basis for experienced surgeons to endoscopically address this region with more safety and efficacy.