Excessive forward movement of lower incisors during presurgical orthodontic treatment could cause alveolar bone loss around the lower incisors; thus, special care should be considered in individuals with mandibular prognathism.

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Objective: To evaluate the effect of postoperative condylar axis changes on mandibular condylar remodeling by comparing the condylar head in three-dimensional (3D) surface reconstructions before and after surgery in skeletal Class III deformities (one-jaw [mandibular setback] or two-jaw surgery), and also to determine the relationship between condylar inward rotation and condylar surface remodeling after orthognathic surgery. Materials and Methods: A retrospective analysis was conducted of 30 patients with skeletal Class III deformities who had received orthognathic surgery. Group 1 underwent one-jaw surgery (10 men, five women, age 22.4 6 3.3 years), and group 2 underwent two-jaw surgery (10 men, five women, age 22.3 6 2.2 years). Sixty condyles were reconstructed and superimposed pre-and postoperatively to compare the changes of condylar surfaces. The relation between the condylar axis change and the surface change using the Pearson correlation were investigated from the 3D image software. Results: Condylar surface changes before and after the surgery were significant. The postoperative inward rotation of the condyles was correlated with the average absolute deviation of the condyles, regardless of the surgery type (one-or 2-jaw surgery; r 5 .70, P , .05). Conclusion: After orthognathic surgery, condylar surface changes occurred, and condylar inward rotation was closely related to changes of condylar surface. (Angle Orthod. 2014;84:316-321.)

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The purpose of this study was to compare the short- and long-term changes in condylar position related to the glenoid fossa, and skeletal and occlusal stability after orthognathic surgery. All of the study patients were assessed by cone-beam computed tomography images for condylar rotational changes and anteroposterior position in the pre-surgery, post-surgery and post-retention period. The condylar positions were evaluated on three planes: axial, coronal and sagittal. In the skeletal and occlusal measurements, there was no significant difference between the post-surgery group and the post-retention group. After sagittal split ramus osteotomy (SSRO), the condyle on the axial plane rotated inward (P < 0.05) and maintained during the post-retention period. In the anteroposterior condylar position related to the glenoid fossa, the condyles had changed from the anterior position in the pre-surgery group to a concentric position in the post-surgery group and then returned to the anterior position in the post-retention groups. These results suggested that the changed anteroposterior condylar position in the glenoid fossa after SSRO with rigid fixation had moved from a concentric to anterior position for post-retention period.