[Measurement of mandible bone mineral density of adults in north China].

Objective: To measure the bone mineral density (BMD) of mandible and investigate the relationship between mandible and the whole body skeleton BMD.

Methods: Healthy volunteers were recruited in north China, which were divided into 6 groups by age: > or = 20, > or = 30, > or = 40, > or = 50, > or = 60 and > or = 70 years older, 10 male and 10 female in each group. Dual-energy X-ray absoptiometery (DXA) was used to measure the BMD of the lumbar spine, the mentum of mandible and the mandibular angle. The results were analyzed statistically.

Results: The mineral density (MD) of the mentum was (1.310 9 +/- 0.035 5) g/cm2, the left mandibular angle (1.048 9 +/- 0.013 7) g/cm2, the right mandibular angle (1.0547 +/- 0.014 1) g/cm2, the lumbar spine (L2-L4) (1.121 1 +/- 0.017 2) g/cm2. There was a significant difference in mandibular angle and lumbar MD between men and women (P < 0.05). The MD of mandibular angle and lumbar spine decreased significantly after 50 years of age.

Conclusions: The normal BMD of the mandibular mentum, mandibular angles and lumbar spine is obtained. The BMD of the mandibular angles is closely related to that of the lumbar spine. Mandible can be an appropriate measurement site in the evaluation of skeleton BMD status for the forecast of osteoporosis.