STABILITY OF LEFORT-I OSTEOTOMY WITH MAXILLARY ADVANCEMENT - A COMPARISON OF COMBINED WIRE FIXATION AND RIGID FIXATION

Purpose: This study compares two types of fixation, intraosseous wires, skeletal suspension wiring, and maxillomandibular fixation (combined wire fixation; CWF) with rigid internal fixation (RIF) in patients who underwent Le Fort I osteotomy to correct maxillary hypoplasia. Materials and Methods: All patients were operated on by the same surgeon using a standard technique, which included bone grafting. The 12 patients in group A were treated with CWF for 4 weeks, Group B was made up of 13 patients who had RIF and training elastics for 4 weeks, Cephalometric analysis using a commercial software package was performed on radiographs that were taken immediately preoperatively (T-1), 1 day postoperatively (T-2), and at least 1 year postoperatively (T-4). The position of the maxilla in relation to the cranial base and Frankfort plane at each time interval was compared. Results: Postsurgical horizontal change (maxillary position change from T2 to T4) for both groups was in the posterior direction. In group A, six patients had less than 1 mm change, three had 1 to 2 mm change, and three had >2 mm change. In group B, 10 patients had less than 1 mm change, three had 1 to 2 mm change and 0 had >2 mm change, Comparison of mean values of groups A and B suggested improved stability with rigid versus wire fixation in the horizontal plane; however, statistical analysis of adjusted mean values showed no significant difference, Vertical changes in maxillary position were also measured from postoperatively to 1 year (T-2 to T-4), The vertical changes were minimal in those cases of maxillary advancement where no vertical changes were planned; however, there was a statistically significant (P = .0024) improved stability with RIF versus combined wire fixation cases. Comparison of adjusted means showed double the amount of vertical settling 1 year postoperatively in the CWF group. Conclusion: Overall, 22 of 25 patients with horizontal maxillary advancement had excellent stability at 1 year. Observed trends suggest that RIF may have improved stability over CWF.