[Radiological assessment of metacarpal diaphysis by the microdensitometry method--in relation to physiological aging]

In order to clarify the changes brought about in the bone mineral content by physiological aging, a quantitative assessment of bone density seen in X-ray pictures was performed by the microdensitometry method. X-ray pictures were taken of 490 cases (213 males and 277 females), and 768 second metacarpal bones were examined. Indices of the bone mineral content in the male subjects reached their peak in the 4th decade and thereafter gradually decreased with aging. In the female subjects, they reached their peak in the 3rd decade, gradually decreased between the 4th and 5th decade, and showed a marked decrease after the 5th decade. Lateralization of the hand was found. D values of the right hand were always larger than those of the left hand after the first decade, and additionally, delta GSmin, delta GSmax, sigma GS/D values of the right hand were much more than those of the left hand between the 4th and 5th decade. These results were observed in both sexes. In conclusion, the bone mineral content mainly corresponded to age and sex, but handedness was also regarded as an important factor in influencing the bone mineral content.