Stability of the Le Fort I maxillary osteotomy after rigid internal fixation

The purpose of this study was to evaluate the postsurgical stability of the Le Fort I osteotomy with impaction in which rigid internal fixation was used for stabilization.

Lateral cephalograms of 19 patients were evaluated. Descriptive statistics were compiled that included absolute linear and angular measurements as well as absolute changes in measurements for successive cephalometric radiographs. Comparisons were made from 1) presurgery to immediate postsurgery, 2) immediate postsurgery to splint removal, 3) splint removal to longest follow-up, and 4) immediate postsurgery to longest follow-up. Repeated measures analysis of variance were used to describe significant differences for absolute changes in measurements.

All surgical movements were significant except for horizontal position of dental structures, horizontal position of the posterior mandible, and posterior vertical facial height. All significant movement from immediate postsurgery to splint removal was secondary to removal of the occlusal splint. Changes were minimal from splint removal to longest follow-up, with only 3 of 24 measurements showing statistically significant differences. These measurements related to tooth position and were affected by postsurgical orthodontics. The data derived from this study were also compared with those found in similar studies in which fixation was by wire osteosynthesis.

The magnitude of postoperative movement was considerably less with rigid internal fixation than that reported with the use of wire fixation. This is attributed to the increased stabilizing effect of rigid internal fixation.