Endoscopic Transnasal Study of the Infratemporal Fossa

Objective 1)Introducing a new endoscopic orientation to the medial portion of the infratemporal fossa (ITF) which is not infrequently involved in sinonasal and related skull base pathologies. 2) Describing the anatomical details and measurement variations of some key ITF landmarks from the unique transnasal endoscopic perspective. Methods Using an extended endoscopic approach, the pterygopalatine and infratemporal fossae were dissected in 10 sides of 5 adult cadaver heads. After an extended transethmoid and transmaxillary approach, a plane of dissection along the pterygoid base and the infratemporal surface of the greater sphenoid wing was developed. The related masticatory muscles were dissected through the endoscopic approach. High quality images have been produced by coupling the video camera to a digital recording system. Results The foramen rotundum, ovale and spinosum were identified and new landmarks were described from the surgical endoscopic point of view. The sphenomandibularis muscle, recently named in anatomic literature, was also highlighted. Along with various neurovascular structures, the maxillary and mandibular divisions of the trigeminal nerve as well as the middle meningeal artery were 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. Conclusions The current study provides a novel endo‐scopic orientation to the medial ITF. Such knowledge should provide an anatomic basis for experienced surgeons to endo‐scopically address this complex region with more safety and efficacy.