Three-dimensional fractal analysis of the mandibular condyle after bilateral sagittal split ramus osteotomy in class III patients: Rigid versus semirigid fixation

OBJECTIVE: To evaluate postoperative adaptive changes in the mandibular condyle after bimaxillary orthognathic surgery in skeletal Class III patients and compare these changes according to mandibular fixation type. METHODS: Twenty-six patients treated with Le Fort I osteotomy and bilateral sagittal split ramus osteotomy were divided into semirigid and rigid fixation groups. Preoperative and 1-year postoperative CBCT images were analyzed. Condylar trabecular microstructure was assessed by three-dimensional fractal analysis, and cortical bone thickness was measured in five regions. RESULTS: Baseline cephalometric variables, cortical thickness, and fractal dimension values were similar between groups. The semirigid group showed increased medial and decreased superior cortical thickness, while the rigid group showed no significant cortical changes. Fractal dimension values remained stable in both groups. Intergroup comparison showed a significant difference only in superior cortical thickness change. CONCLUSION: Fixation type did not markedly affect condylar trabecular microstructure, although superior cortical remodeling may differ by fixation method.