Fractal analysis of mandibular condyle region and evaluation of bone components of TMJ with CBCT in patients with posterior crossbite

The term posterior crossbite refers to a discrepancy in the buccolingual relationship of the upper and lower teeth in the transverse direction. The posterior crossbite affects the temporomandibular joint (TMJ) and the entire stomatognathic system. In this study, the effect of posterior crossbite and maxillary narrowness on the bone structure of TMJ was evaluated using a fractal analysis method on cone beam computed tomography (CBCT) images. 34 patients with unilateral crossbite, 24 patients with bilateral crossbite, 39 patients with maxillary narrowness were included in the study. 36 patients with Angle class I occlusion were accepted as the control group. TMJ region was examined using CBCT, and the presence of degenerative changes was evaluated. Fractal analysis was performed in the mandibular condyle region with Image J program. The program has been downloaded from the website https://imagej.nih.gov. SPSS (IBM SPSS for Windows, ver.25) statistical package program was used for statistical evaluation. In the 266 TMJ regions of all patients, the most common degenerative change in the mandibular condyle was erosion. Erosion was observed in 41 condyle (right 20, left 21). For both right and left sides, there was no significant difference between the groups in terms of the frequency of degenerative changes (right p = 0.682, left p = 0.670). There was no significant difference in the distribution of degenerative changes between the genders (right p = 0.08, left p = 0.655). In coronal sections, the fractal dimension measured from the right mandibular condyle was significantly lower in the control group than in the other groups (p = 0.012). In the presence of malocclusion, erosive and sclerotic changes caused by adaptive remodeling in the mandibular condyle can be evaluated using fractal analysis on CBCT images.