Three-dimensional bone remodelling of glenoid fossa in patients with skeletal Class III malocclusion after bimaxillary orthognathic surgery.

This study aimed to characterize three-dimensional quantitative morphological changes of glenoid fossa in patients with skeletal Class III malocclusion treated with bimaxillary orthognathic surgery. Ninety-five eligible patients (50 male, 45 female; mean age 22.09 years) were enrolled retrospectively. Cone beam computed tomography obtained at 1 week preoperatively (T0), immediately after surgery (T1), and at ≥ 12 months postoperatively (T2) were registered based on cranial base using voxel-based registration in 3D Slicer. Glenoid fossa surface was divided spatially into four regions, and bone modelling in these regions was visualized with color maps. Our data revealed that the mean surface variations of glenoid fossa were small, with modest bone formation as a whole. No significant associations between anteroposterior or vertical mandibular displacement and overall glenoid fossa remodeling were found (P > 0.05). Moreover, bone deposition was frequently observed in the anterior-lateral region of glenoid fossa in patients with a larger mandibular movement during T0-T1 (P < 0.001). Paired bone formation in the anterior-lateral region of glenoid fossa and bone resorption in the anterior-lateral region of condylar head was frequently observed. Collectively, our results revealed that glenoid fossa underwent complex but modest bone remodeling after bimaxillary surgery in skeletal Class III patients.