Surgical anatomy of the infratemporal fossa using the transmaxillary approach

In this study we evaluated the ability of the transmaxillary route to expos e the elements of the infratemporal fossa (ITF). Five adult cadaver heads w ere dissected on both sides, after making a paralateronasal incision. The m axillary branch of the trigeminal nerve served as a superior landmark to pr ogress into the retroantral space and pterygopalatine fossa. The maxillary artery, lateral pterygoid muscle, pterygoid venous plexus, foramen rotundum and foramen ovale were identified. Distances between those elements and an gle of approaches of the foramen ovale and foramen rotundum were measured i n the horizontal plane. In all cases, the anterior loop of the maxillary ar tery and the sphenopalatine artery were located in the proximal retroantral fatty space and could be ligated without optic magnification. The maxillar y nerve could be followed up to the foramen rotundum at a 44 mm mean distan ce from the opening. The mean angle of vision to the foramen rotundum was 3 1 degrees. Under the greater sphenoid wing and lateral to the pterygoid pro cess, desinsertion and partial resection of the lateral pterygoid muscle we re required to identify the pterygoid venous plexus and foramen ovale. The pterygoid venous plexus was organized as a compact network of channels betw een and superior to the muscle fibers; it was in close relation with the fo ramen ovale. Access to the foramen ovale was deep (mean 56 mm) and narrow ( 20 degrees). Our results indicate that the transmaxillary approach is a min imally invasive procedure that gives an appropriate window to the structure s of the retroantral space and to the pterygomaxillary fissure and pterygop alatine fossa. Monitoring of the retropterygoid portion of the infratempora l fossa by this route is inadequate.