Qualitative and quantitative assessment of condylar displacement after orthognathic surgery: A voxel-based three-dimensional analysis

Purpose: This study aimed to evaluate the morphometric changes in the position of the mandibular condyles before and after orthognathic surgery.Methods: A retrospective single-center cohort study was conducted and included patients with a presurgical (T1) and postsurgical (T2) Cone Beam computed tomography (CBCT). The primary predictor variable was the orthognathic surgical treatment. Pre-operative and post-operative CBCT scans were superimposed using voxel-based registration. Semitransparent overlays of the models of condylar regions at T1 and T2 were cre-ated for the qualitative analysis. The primary outcome variable was the quantitative displacement of con-dyles (CoR; CoL) analyzed in X, Y, Z axis and the 3D distances. Descriptive and bivariate statistical analysis was performed, setting a=0.05.Results: The study sample included 33 patients (mean age: 25.33 +/- 2.49 years) affected by skeletal class III malocclusion with or without skeletal asymmetry. The X-axis showed a mean movement of 0.25 +/- 0.17 mm for CoR, and 0.52 +/- 0.51 mm for CoL. The Y-axis showed a mean movement of 0.29 +/- 0.2 mm for CoR, and 0.51 +/- 0.8 mm for CoL. The Z-axis was 0.33 +/- 0.2 mm for CoR, and 0.5 +/- 0.49 mm for CoL. No statistically sig-nificant difference was calculated comparing the movement of condylar surface between asymmetric and not asymmetric patients (p = 0.26 for CoR; p = 0.13 for CoL). No statistically significant difference was found in intercondylar distance between T1 and T2 (p = 0.39).Conclusion: No statistically nor clinically significant condylar displacement are recorded in orthognathic sur-gery patients at 12 to 18 months of follow-up.(c) 2021 Elsevier Masson SAS. All rights reserved.