Evaluation of the Effects of Diabetes Mellitus and Periodontitis on Alveolar Bone Radiodensity Using Hounsfield Unit Measurement and Fractal Analysis.

This retrospective study aimed to evaluate the effects of diabetes mellitus and periodontitis on alveolar bone density and trabecular bone quality using cone-beam computed tomography (CBCT) and to compare fractal analysis with Hounsfield unit (HU) measurements. CBCT images of 217 individuals aged 20-80 years were retrospectively analyzed and divided into four groups. A standardized square region of interest was defined in the trabecular bone between the apex of the mandibular first molar and the superior border of the mandibular canal. HU values were obtained using CBCT software, while fractal dimension (FD) values were calculated using an automated single-click fractal analysis method. Significant differences in FD values were observed among groups in axial and coronal sections (p < 0.05), but sagittal sections showed no significant differences. HU values differed significantly among all groups in most sections (p < 0.05). Systemically and periodontally healthy individuals demonstrated higher HU values and lower FD values compared with those affected by diabetes mellitus or periodontitis. A weak positive correlation was observed between FD axial and HU sagittal values. Age was weakly negatively correlated with HU axial values, while no significant association with gender was found. Age had a significant negative effect on HU values in the axial and sagittal models, but no significant effect on any FD sections. CBCT-based analysis revealed section-dependent sensitivity of FD, with significant differences in axial and coronal sections but not sagittal. HU values partially reflected alveolar bone density differences between healthy and diseased individuals. FD and HU measurements provide complementary, not interchangeable, information on alveolar bone quality.