ABSTRACT
Generally, osteoporosis is caused by the age-related physiologic bone loss. In cases of severe osteoporosis, the reduced bone mass and increaed skeletal fragility make the risk of fracture high. Recently, the relationship between the mandible and the condition of the skeletal bone, the molphometric data about the quality and quantity of the mandible are very important in the diagnosis and treatment of osteoporosis. This study was undertaken to clarify the correlations of the mineral density between mandible and other bones, to predict the bone mineral density (BMD) of the mandible. Cervical (2nd~5th) and lumbar (1st~4th) vertebrae, the bones of forearm and proximal femurs, mandibles from 42-embalmed cadavers (22/M, 20/F, mean age: 66.95 years) were examined. The BMD was measured by dual energy X-ray absorptiometry. The data were analysed with SPSS 12.0 program according to age, gender, to verify the statistical significance. 1. The BMD in the mandibular areas were variable. The BMD in the angle of the mandible (mean 0.40 g/cm2) was similar with that of ultra-distal part of the forearm (mean 0.34 g/cm2). 2. The BMD in the mandible was highly correlated with that of around the forearm. The correlation coefficient between density in the angle, the part between 1st and 2nd molar, the part between 1st molar and 2nd premolar and incisor portion of the mandible and density in the 1/3-distal part of the forearm was high (r=0.742, 0.697, 0.618, 0.652). The correlation coefficient between density in the part between 1st and 2nd premolar and density in the total femur was high (r=0.542). 3. The BMD in the mandible was correlated with that of around the femur neck (r=0.607). 4. The correlation coefficient between the BMD in the 1st and 2nd molar of the mandible and the BMD in the 5th cervical vertebra was high (r=0.543). And also, the correlation coefficient between the BMD in the incisor area of the mandible and the BMD in the 3rd lumbar vertebra was high (r=0.561). 5. Bony status of the mandible was classified into normal, osteopenia, osteoporosis by BMD of WHO criteria. The data represented that BMD of the mandible was decreased as BMD of the skeletal bones decreased. It is concluded that it could be possible to predict BMD of the mandible by the measurement of BMD in the forearm.