Panoramic radiography for screening postmenopausal osteoporosis in India: a pilot study.

AIM The overall aim of this pilot study was to establish the role of dental practitioners in identifying patients at risk of osteoporosis from panoramic radiographs. METHODS The pilot study evaluated 32 randomly selected postmenopausal women with no known secondary cause of bone loss. A panoramic radiograph of each patient was taken and qualitative and quantitative radiomorphometric indices were determined. Bone mineral densities of the mandible and lumbar vertebrae were measured by dual energy x-ray absorptiometry. Using World Health Organization criteria, patients were divided into normal, osteopoenic and osteoporotic categories. The relationship of qualitative and quantitative indices with bone mineral densities of the mandible and lumbar area was analysed statistically. RESULTS Significant positive correlation (Pearson coefficient) was observed between bone mineral densities of the mandible and bone mineral densities of lumbar vertebrae. There was significant (P<0.05) association between the mandibular cortical index (MCI) and osteoporosis (chi-square test), incidence of osteoporosis increased from group C1 to C2 to C3. Strong positive correlation (Pearson coefficient) was observed between all quantitative indices and bone mineral densities of lumbar vertebrae. Intra-observer and inter-observer reproducibility for the quantitative indices was poor (paired and unpaired t-tests, respectively). However, it was excellent for the mandibular cortical index (kappa coefficient). CONCLUSIONS The mandibular cortical index, a qualitative index based on morphological changes in the inferior cortex observed on panoramic radiograph, is useful tool for the screening of postmenopausal osteoporotic patients. Quantitative indices (mental index, inferior and superior panoramic mandibular indices, antegonion index and gonion index), although well correlated with skeletal bone loss, were not useful because of their poor reproducibility. A study with a larger sample is needed to confirm the results from this pilot.