LOCATION OF THE DESCENDING PALATINE ARTERY IN RELATION TO THE LEFORT-I OSTEOTOMY

Purpose: This study evaluated the positional relationship of the desce nding palatine artery to the Le Fort I osteotomy. Materials and Method s: Three separate examinations were performed. In the first, 30 human skulls were used, and measurements were made of the greater palatine c anal and foramen in relation to maxillary landmarks pertaining to the Le Fort I osteotomy. In the second, 40 patients with normal or minimal sinus mucosal thickening were selected from a pool of patients who un derwent computed tomography (CT) scanning for sinus evaluation. These patients were scanned on a Somatome Plus spiral CT scanner as part of a routine sinus protocol, with the addition of an axial image 3 mm abo ve the nasal floor where the Le Fort I osteotomy is usually performed. The distance from the greater palatine canal to the piriform rim was measured, In the third, eight fresh cadavers were used, and the distan ce from the internal maxillary artery to the nasal floor was measured. Results: The internal maxillary artery enters the pterygopalatine fos sa approximately 16.6 mm above the nasal floor and gives off the desce nding palatine artery, The descending palatine artery travels a short distance within the pterygopalatine fossa and then enters the greater palatine canal, It travels approximately 10 mm within the canal in an inferior, anterior, and slightly medial direction to exit the greater palatine foramen in the region of the second and third molars. Conclus ion: Injury to the descending palatine artery during Le Fort I osteoto my can be minimized by not extending the osteotomy more than 30 mm pos terior to the piriform rim in females, This distance can be extended t o 35 mm in males. Pterygomaxillary separation should be made by closel y adapting the cutting edge of a curved osteotome or right-angled saw to the pterygomaxillary fissure while avoiding excessive anterior angu lation, Furthermore, the superior cutting edge of the osteotome or saw blade should be less than 10 mm above the nasal floor.