Three-dimensional evaluation of changes in condylar volume and position after orthognathic surgery in mandibular prognatism

Aim: The purpose of this study is to evaluate changes in condylar volume and position after bilateral sagittal split ramus osteotomy in severe mandibular prognathism patients with dentofacial deformity. Material and Method: Twenty-four patients (12 male and 12 female) with severe class III deformity, who undergone bimaxillary orthognathic surgery, were included in this study. Cone beam computed tomography (CBCT) scans were obtained from the patients before the surgery and 12 months after the surgery. DICOM images of the CBCT scans were assessed three dimensionally using Dolphin Imaging Version 11.95 Software (Dolphin Imaging & Management Solutions, Chatsworth, Calif). Depending on the normal distribution of parameters, the paired t test or Wilcoxon signed rank test were used for statistical analysis.. Results: No significant change was found in condylar position after the surgery, but the condyles showed statistically significant inward rotation on axial plane. Due to the inward rotation of condyles, inter-condylar angle decreased significantly on axial plane. No significant change was found in condylar volume after the surgery. Conclusion: Our findings mostly showed that the condyles showed significant inward rotation on axial plane after the surgery, and this rotation may cause condylar resorption and skeletal and dental instability and relapse in mandibular prognathism surgery patients. This finding must be taken into consideration before orthodontic treatment-orthognathic surgery planning and during the surgery.