Precision of maxillary repositioning during orthognathic surgery: a prospective study

The purpose of this study was to evaluate the accuracy of surgical splints and an external reference point to reposition the maxilla during orthognathic surgery. Before surgery, a radiological marker was inserted inside the orthodontic bracket of the first right maxillary molar. A surgical splint was utilized to reposition the maxilla in the sagittal and coronal planes after the osteotomy. The vertical position was established by measuring the distance between a Kirschner wire inserted at bony nasion and the orthodontic wire. Preoperative and postoperative cephalometric radiographs were obtained and manually traced. The radiological marker and the tip of the right maxillary incisor were used as specific landmarks. Their displacement on the pre- and postoperative radiographs was measured. The actual surgical movement of the maxilla was compared to the initial surgical planning. 23 patients met the inclusion criteria to participate in the study. The mean difference between the planned and executed movements of the maxilla was 0.1mm (p=0.71). The difference was not statistically significant for any given movements of the maxilla. The use of surgical splints made from model surgery combined with an external reference point at bony nasion is accurate methods for repositioning the maxilla during orthognathic surgery.