Accuracy of a LeFort I maxillary osteotomy.

An optimal outcome of combined surgery and orthodontics involving the maxilla is dependent on many factors. Accurate placement of the maxilla by the surgical team is ultimately of paramount importance. The aim of this retrospective study was to evaluate the accuracy of LeFort I maxillary osteotomy with respect to the presurgical prediction. The sample comprised 42 patients (33 females, nine males) who had undergone LeFort I osteotomy procedure alone or in combination with a mandibular osteotomy with or without genioplasty. Tracings of presurgical and immediate postsurgical lateral cephalograms and surgical predictions were digitized and compared using Quick Ceph software analysis. Vertical and horizontal measurements to various skeletal landmarks were used to assess the discrepancy between the predicted maxillary position and the actual postsurgical result. Statistically significant differences were found between the predicted and actual postsurgical maxillary molar vertical position, and significant differences were also found for the palatal plane angular measurements. Two surgical teams were compared, and surgical team 1 had significantly less variation in the surgical outcomes than did surgical team 2. When single-jaw and bimaxillary surgery were compared, no significant differences were found. Similarly, there were no statistically significant differences found when assessing the primary direction of movement (impaction vs downgraft vs advancement). Overall, 66% of the results were within two mm of prediction and 26% of the results were within one mm of prediction. A LeFort I maxillary osteotomy can be an accurate procedure with a wide range of discrepancy.