Abstract:

Objective： To evaluate the effect of orthognathic surgery on condylar morphology changes by comparing three-dimension surface reconstructions of condyles using cone-beam computed tomography (CBCT) data. Methods: In the study, 18 patients with mandible retrognathism deformities were included and CBCT data of 36 temporomandibular joints were collected before surgery and 12 months after surgery. Condyles were reconstructed and superimposed pre-and post-operatively to compare the changes of condylar surfaces. One-sample t test and χ² test were performed for the analysis of three-dimension metric measurement and condylar head remodeling signs. P＜0.05 was considered significant. Results: The root-mean-square (RMS) of condylar surface changes before and after the surgery was (0.37±0.11) mm, which was significant statistically (P<0.05). The distribution of condylar remodeling signs showed significant difference (P<0.05). Bone resorption occurred predominantly in the posterior area of condylar head and bone formation occurred mainly in the anterior area. Conclusion: Three-dimension superimposition method based on CBCT data showed that condylar morphology had undergone remodeling after mandibular advancement.

Key words: Retrognathia, Mandibular condyle, Orthognathic surgery, Cone-beam computed tomography, Imaging, three-dimensional