Effect of post-orthognathic surgery condylar axis changes on condylar morphology as determined by 3-dimensional surface reconstruction

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 Ill 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 Ill deformities who had received orthognathic surgery. Group 1 underwent one-jaw surgery (10 men, five women, age 22.4 +/- 3.3 years), and group 2 underwent two-jaw surgery (10 men, five women, age 22.3 +/- 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 = .70, P < .05). Conclusion: After orthognathic surgery, condylar surface changes occurred, and condylar inward rotation was closely related to changes of condylar surface.