Condylar positional changes up to 12 months after bimaxillary surgery for skeletal class iii malocclusions

摘要

Purpose Postsurgical changes in the condylar position are of great importance to surgical stability, especially in asymmetric double-jaw surgery. The aims of this study were to evaluate positional changes of the condyle up to 12 months after surgery in patients with Class III malocclusion and to identify the factors affecting postsurgical condylar position. Materials and Methods The study included 33 adult patients diagnosed with skeletal Class III malocclusion who underwent bimaxillary surgery and had full cone-beam volumetric imaging (CBVI) records up to 1 year after surgery. The CBV images were obtained before surgery and 2 weeks, 3 months (T2), 6 months (T3), and 12 months after surgery. Condyles with deviated and nondeviated sides were examined separately regardless of the degree of asymmetry. Analyses of variance and multiple regression analysis were performed to identify factors that could affect the position of the mandibular condyles. Results The condyles exhibited anterior displacement at T2, which returned to a more distal position afterward in the axial view, and an inward rotation in the coronal view up to T3. From the sagittal view, the deviated and nondeviated condylar sides rotated forward and remained stable after T2. The degree of menton deviation affected the angle of condylar rotation (horizontal angle). Conclusion The results of this study suggest that condyles tend to move in a certain direction, and this can influence postsurgical relapse up to 6 months after surgery. However, they remain relatively stable afterward.