Objective: Endocrine disorders, including diabetes mellitus and thyroid dysfunctions, can significantly impact bone metabolism and structure. This study aimed to assess mandibular trabecular architecture in patients with type 1 diabetes mellitus (T1DM), type 2 diabetes mellitus (T2DM), hyperthyroidism, and hypothyroidism using fractal dimension (FD) and histogram analyses (HA), comparing the findings with a healthy control group. Methods: This retrospective study analyzed panoramic radiographs from 200 individuals, comprising 40 patients in each of the four endocrine disorder groups and 40 healthy controls. Fractal dimension and histogram-based pixel intensity analyses were conducted using ImageJ™ (version 1.53) software. Four standardized regions of interest (ROI) were evaluated on the right mandible, and statistical comparisons were conducted across groups using one-way analysis of variance (ANOVA), t-test, Mann–Whitney U, and Spearman correlation analyses. Results: Age and gender distributions did not differ significantly between groups. FD analysis revealed a significant reduction at ROI1 in the hyperthyroidism group compared to controls (p = 0.018); however, no other significant FD differences were observed among the remaining groups or ROIs. A significant positive correlation was found between FD and histogram values at ROI1 and ROI2 (p < 0.001), while pixel intensity values did not differ significantly across groups in any ROI. Conclusion: Although no significant differences were found in diabetic groups, the decreased FD in hyperthyroid patients suggests that FD analysis may be a useful non-invasive method to detect subtle bone alterations. Further research with larger sample sizes and comprehensive biochemical analyses are needed to confirm these findings.