The relationship between osteoporosis and the panoramic mandibular index

Background : from a radiological point of view, the periodontium consists of anatomical structures of various densities: the gum and the periodontal ligament (radiolucent), as well as cementum and alveolar bone (radiopaque). The panoramic mandibular index (PMI) is a morphometric method which uses ortopantomography (OPT) in order to determine the width of the mandibular cortex. It can also be used to determine the degree of bone loss. The aim of this study was to research the possible correlations between: PMI and the presence or absence of osteoporosis in post-menopausal women; Bone mineral density (BMD) at levels L1-L4, femoral head, hip, mandible and PMI in post-menopausal women, with or without osteoporosis. Materials and methods: the present study included a total of 97 postmenopausal patients. The diagnosis of osteoporosis was made based on the WHO definition. The results were expressed as absolute BMD values in g/cm2 and as T score form. We used dual x-ray absortiometry (DXA) measurements in assessing the lumbar column, proximal femur and mandible and we calculated the T scores. All the patients were subjected to an OPT radiological investigation. We calculated PMI for all patients. Results: the present study allowed us to find significant differences between the mean PMI values in the group of post-menopausal women that suffered from osteoporosis (0.33), as compared to those without a diagnosis of osteoporosis (0.4), which shows that osteoporosis patients present bone loss at the level of the mandible. Conclusions: there are statistically significant differences between the panoramic mandibular index in post-menopausal women with osteoporosis as compared to non-osteoporotic ones. Statistically significant correlations were identified between L1-L4, femoral head and total hip bone mineral densities and the panoramic mandibular index; the lower the bone mineral density the more the panoramic mandibular index is decreasing.