K K Li1, J G Meara, A Alexander. 1. Department of Otolaryngology-Head and Neck Surgery, University of California, Irvine, Orange 92668, USA.
Abstract
PURPOSE: This study evaluated the positional relationship of the descending palatine artery to the Le Fort I osteotomy. MATERIALS AND METHODS: Three separate examinations were performed. In the first, 30 human skulls were used, and measurements were made of the greater palatine canal 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 underwent 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 above 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 distance from the internal maxillary artery to the nasal floor was measured. RESULTS: The internal maxillary artery enters the pterygopalatine fossa approximately 16.6 mm above the nasal floor and gives off the descending 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. CONCLUSION: Injury to the descending palatine artery during Le Fort I osteotomy can be minimized by not extending the osteotomy more than 30 mm posterior to the piriform rim in females. This distance can be extended to 35 mm in males. Pterygomaxillary separation should be made by closely adapting the cutting edge of a curved osteotome or right-angled saw to the pterygomaxillary fissure while avoiding excessive anterior angulation. Furthermore, the superior cutting edge of the osteotome or saw blade should be less than 10 mm above the nasal floor.
PURPOSE: This study evaluated the positional relationship of the descending palatine artery to the Le Fort I osteotomy. MATERIALS AND METHODS: Three separate examinations were performed. In the first, 30 human skulls were used, and measurements were made of the greater palatine canal 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 underwent 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 above 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 distance from the internal maxillary artery to the nasal floor was measured. RESULTS: The internal maxillary artery enters the pterygopalatine fossa approximately 16.6 mm above the nasal floor and gives off the descending 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. CONCLUSION: Injury to the descending palatine artery during Le Fort I osteotomy can be minimized by not extending the osteotomy more than 30 mm posterior to the piriform rim in females. This distance can be extended to 35 mm in males. Pterygomaxillary separation should be made by closely adapting the cutting edge of a curved osteotome or right-angled saw to the pterygomaxillary fissure while avoiding excessive anterior angulation. Furthermore, the superior cutting edge of the osteotome or saw blade should be less than 10 mm above the nasal floor.