Évaluation de la stabilité de l'ostéotomie de type LeFort I multisegmentaire
Introduction : The aim of this study was to evaluate the medium and long term stability of segmented LeFort I surgery in all three planes of space (transverse, sagittal and vertical). Materials and methods : The sample consisted of 31 private practice patients that received a two, three, or four-piece segmented LeFort I surgery and who had finished their orthodontic treatment. Study models and cephalometric radiographs were analyzed before treatment, before surgery, after surgery, and at the end of the orthodontic treatment for the 31 patients as well as a minumum two years into retention for 17 patients (mean of 3 years post-treatment). T-tests and Pearson correlation tests were used. Intra and inter-examiner reliability were verified with Bland Altman and intraclass coefficient tests. Results : A statistically significant transverse relapse was seen at the premolars and molars between surgery and the end of orthodontic treatment, that has little clinical significance. The relapse is correlated with the effective expansion. There was no significant relapse after orthodontic treatment was completed. There was no correlation between the amount of relapse observed and the amount of segments. Statistically significant changes were measured in the post surgical phase for maxillary advancement and impaction cases, but were shown to be of limited clinical significance. After removal of fixed appliances, no significant changes were noted. Conclusion : Multisegmented Lefort I surgery appears to have good stability in all three planes of space in the studied sample.
Expansion maxillaire Orthognathic surgery Segmental LeFort I Maxillary expansion Transverse stability