Reproducibility of Maxillary Positioning in Le Fort I Osteotomy: A 3-Dimensional Evaluation

Abstract

Purpose: In the present study, we evaluated the difference between the model surgery movement and the actual surgical movement in the horizontal (X), vertical (Y), and transverse (Z) directions using the same reference coordinates. Patients and Methods: Twelve patients (6 male and 6 female, mean age of 24.3years) who underwent Le Fort I osteotomy and sagittal split ramus osteotomy were included in the study. The maxillary position was controlled by an intermediate splint and face-bow/bite-fork combination system. A coordinate transformation system with transition matrices was developed, which enabled objective comparison between the planned surgical change of the maxilla on the articulator and the actual surgical change assessed by the 3-dimensional cephalogram. Results: The absolute mean difference was 2.2 mm. The difference between the model surgery and the surgical result ranged from 7.7 mm to 6.6 mm. The surgical result differed from the planned surgical movement by more than 2 mm in more than 45% of the measured coordinate values. Conclusion: Although all of the patients were satisfied with their postsurgical appearance and occlusion, the result shows that further development is required in the maxillary positioning system.