Are Radiographic Changes in the Mandibular Canal Associated With Bone Mineral Density?

Background: Osteoporosis, highly prevalent among postmenopausal women, significantly reduces bone density and increases the risk of fractures. Cortical bone, which constitutes the largest calcium deposit in the human skeleton, is primarily affected in various conditions, including osteoporosis. Due to its visibility in panoramic radiography, the cortical area of the mandibular canal could be valuable in assessing decreases in bone mineral density (BMD).

Purpose: The study aimed to characterize and compare changes in the cortices of the mandibular canal between normal, osteopenic, and osteoporotic postmenopausal women.

Study Design, Setting, Sample: Our cross-sectional study analyzed postmenopausal patients. We included only patients with panoramic radiographs with good quality and who underwent osteoporosis risk assessment by dual-energy x-ray absorptiometry (DXA).

Independent Variable: BMD was measured by DXA at 3 sites (spine, femur, and forearm) and used to classify the patients into normal, osteopenic, or osteoporotic. This classification remained consistent across all measurement sites.

Main Outcome Variable: The main outcome variable was BMD of the mandibular canal cortices measured using black pixel intensity.

Covariates: Demographic covariates, including age, weight, height, and BMD, were assessed.

Analyses: One-way analysis of variance between groups considering a P < .05. The relationship between covariates and dependent variables was assessed using the Pearson correlation test.

Results: The sample comprised 52 postmenopausal women aged more than 40 years (mean age 61 ± 10 years), 26 (50%) normal, 18 (35%) osteopenic, and 8 (15%) osteoporotic. Significant differences were observed in the percentage of black pixels in the mandibular ramus between the groups. In this region, the average percentage of black pixels was 3.19% (± 0.65) for the normal group, 2.78% (± 0.65) for the osteopenia group, and 2.35% (± 0.65) for the osteoporosis group (P = .015). No significant differences were found in other mandibular regions.

Conclusion And Relevance: Our findings demonstrate an association between BMD assessed in the mandibular canal cortex and the presence of osteoporosis as determined by DXA. While the observed differences in black pixel percentages in the mandibular ramus are minor, they are statistically significant, suggesting that panoramic radiography may serve as an adjunctive tool for osteoporosis screening.