Anatomical Evaluation of Localized Mandibular Trabecular Texture Differences in Children with Hypodontia Using Radiographic Fractal Analysis.

Background/Objectives: This study aimed to evaluate mandibular trabecular bone structure in children with and without hypodontia using fractal analysis (FA) and to determine whether fractal dimension (FD) values vary according to hypodontia pattern and the localization of the affected alveolar region. Methods: This study included 75 children aged 8-12 years, divided into three age- and gender-matched groups: controls without agenesis (Group 1, n = 25), mandibular second premolar agenesis (Group 2, n = 25), and agenesis of both mandibular first and second premolars (Group 3, n = 25). Panoramic radiographs were analyzed using a semi-automated FA method involving manual ROI placement followed by automated image processing and FD calculation. FD values were measured in three regions of interest (ROIs): the mandibular condyle (ROI1), mandibular angle (ROI2), and alveolar region corresponding to the agenetic area (ROI3). Results: FD values did not differ significantly by age or gender in any ROI (p > 0.05). The pattern of FD differences among the study groups varied significantly according to anatomical region, as demonstrated by the significant Group × ROI interaction (p < 0.001). Post hoc comparisons showed that the most pronounced intergroup difference occurred in ROI3, where Group 2 had a significantly lower FD value (0.78 ± 0.26) than Group 1 (1.10 ± 0.21) and Group 3 (1.04 ± 0.23). Conclusions: Mandibular trabecular texture differences in children with hypodontia appeared to be localized mainly to the alveolar region corresponding to tooth agenesis. The lower FD value observed in the mandibular second premolar agenesis group suggests that these regional differences may be related to the anatomical localization of the agenetic area rather than to the number of missing teeth alone. Although such findings may help draw attention to site-specific alveolar changes during radiographic assessment, they are based on two-dimensional panoramic radiographic texture analysis and should be regarded as preliminary and hypothesis-generating.