Evaluating the Changes of Osseous Structure of Mandibular Bone Following Protraction Face Mask Treatment by Fractal Analysis

OBJECTIVE: In this retrospective study, the changes following protraction face mask therapy on the trabecular structure of mandibular bone among Class III patients were assessed through fractal dimension (FD) assessment of panoramic radiographs. METHODS: A total of 32 patients (mean age 11.21 ± 1.35 years; 10 females, 22 males) were included who underwent treatment protraction face mask. FD analysis was performed on the following regions of interest (ROI): ROI 1, anterior mandibula; ROI 2, posterior, corpus mandibula; ROI 3, angulus mandibula; ROI 4, condylar process. These ROIs were applied bilaterally, and average values were documented as the FD value of each ROI. Before (T0) and after (T1) the treatment, FD values were put into comparison for each ROI. The statistical analysis employed the Kolmogorov-Smirnov test, Pearson test, Spearman Rho correlation test, Wilcoxon test, and paired samples t-test. RESULTS: FD values of ROI 2 (corpus mandibula) and ROI 4 (condylar process) significantly increased in T1 in comparison with T0 (P < 0.05). FD values of ROI 1 (anterior mandibula) and ROI 3 (angulus mandibula) did not significantly change between T0 and T1. CONCLUSIONS: The mandibular condyle and corpus region's FD values significantly changed following face mask therapy. This indicates that protraction face mask treatment induces mandibular bone remodeling and alters its form.