Comparison of mandibular bone density and morphology in patients with Angle Class I, II, and III malocclusion using panoramic radiography: a cross-sectional study

Variations in sagittal jaw relationships may be accompanied by adaptive changes in mandibular cortical thickness and contour, potentially affecting bone quality and the biomechanical response to orthodontic forces. In this context, the present cross-sectional study aimed to investigate the relationship between different sagittal malocclusion types and mandibular bone morphology through comparison of radiomorphometric parameters obtained from panoramic radiographs. A total of 150 female patients were included and equally divided into three groups according to their Angle malocclusion classification: Class I, Class II, and Class III. Measurements of mental index (MI), panoramic mandibular index (PMI), gonial index (GI), antegonial index (AI), antegonial notch depth (AND), mandibular cortical index (MCI), and grayscale value (GS) were performed using ImageJ software. Intergroup comparisons were analyzed by Kruskal-Wallis tests followed by Bonferroni-corrected pairwise comparisons. Significant differences were identified among groups in MI, PMI, and AND measurements. Specifically, Angle Class III subjects exhibited significantly lower MI and PMI values than Angle Class I and II groups (p < 0.001), indicating thinner mandibular cortical bone. AND was shallower in Angle Class III individuals compared to Class I (p = 0.005) and Class II (p = 0.049), indicating a less pronounced antegonial concavity along the mandibular lower border. No statistically significant differences were observed among the groups in GI, AI, or GS measurements (p > 0.05). Mandibular cortical index (MCI) categorical distributions also showed no significant intergroup differences. These findings demonstrate that mandibular cortical bone thickness and antegonial notch morphology vary with sagittal malocclusion, with Class III malocclusion associated with thinner cortical bone and altered mandibular contours. These morphological differences highlight the importance of considering bone quality and morphology during orthodontic diagnosis and treatment planning, since they may influence treatment biomechanics and long-term stability.