POSTERIOR MAXILLARY ANATOMY - IMPLICATIONS FOR LE-FORT-I OSTEOTOMY

The most common site of haemorrhage in maxillary osteotomies is the po sterior maxilla. Better understanding of the anatomy in this region ma y minimize possible vascular complications. The aim of the study was t o study the osteology of the posterior maxillary region and establish clinical safety guidelines for the Le Fort I osteotomy Thirty human dr y skulls were selected and assessed by a combination of direct inspect ion, computerized imaging and computed tomography (CT) scan analysis. Results showed that the presence of. maxillary third molars influenced the transverse angulation of the posterior vertical cut. Synostosis o f the pterygomaxillary junction was noted in 12% of samples. The mean length of the medial sinus wall from the piriform rim to the descendin g palatine canal at the Le Fort I level was 34 mm. The three-dimension al CT-reconstructed descending palatine canal ran at 60 degrees antero inferiorly to the palatine plane and slightly medially to the exit thr ough the greater palatine foramen.