The Surgical Predictability of Maxillary Advancement and Impaction in Le Fort I Osteotomy

Objective: The aim of this study was to evaluate and compare the amount of preoperatively planned surgical movement of the maxilla and postoperatively obtained maxillary repositioning. Materials and Method: Thirty-one patients (16 female and 15 male) were included in this study. Fifteen combined maxillary advancement and impaction, 5 isolated maxillary impaction, and 11 isolated maxillary advancement surgeries were performed by the same surgical team. The 31 patients were divided into 2 groups: group 1 (GoGnSN <= 38 degrees) and group 2 (GoGnSN. 388). Various measurements from the horizontal and vertical reference lines were used to compare the predicted maxillary movement and the postoperatively obtained maxillary position. All variables were evaluated by Student's 2-tailed paired t tests. Results: There were statistically significant differences between the preoperatively planned and surgically obtained impaction movements of all evaluated landmarks, but no significant difference was seen between the planned and obtained advancement movement. For the differences between the planned and acquired maxillary advancement movements, 51% were within 2 mm of prediction. For the differences between the planned and the acquired maxillary anterior impaction movements, 51% were within 1 mm of the prediction. The difference was 35% for the impaction of posterior maxilla. Conclusion: The predictability of vertical movement of the maxilla via Le Fort I osteotomy was lower than that for sagittal movement. The difference between planned surgical movement and actual surgical outcome should be taken into consideration during treatment planning.