An Analysis of Bone Mineral Content in the Distal Portions of the Second Metacarpal Bone Shaft
1993 Volume 6 Issue 2 Pages 374-385
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1993 Volume 6 Issue 2 Pages 374-385
As for a preoperative and postoperative examination of X-ray radiography for dental implants, the evaluation for standard X-ray photography of the second metacarpal bone is necessary. At that time, forty male and female dental patients in their 20 s were examined on the parameters of bone thickness, bone mineral content and bone density at the two distal portions a and b of the second metacarpal bone shaft. The following results were obtained.
1. The parameters of bone thickness D increased gradually, as the examination points drew nearer from the middle of the bone shaft to the distal portion. It increased more significantly,(p＜0.01) 12% and 35%, at the distal portion a and b than at the middle of the bone shaft m. As the examination points neared the distal portions, the parameters of cortical thickness d1 and d2 and combined cortical thickness 2 C decreased significantly (p＜0.01). However, the medullary thickness d became significantly (p＜0.01) wider, 55% and 236%, at the distal portion a and further distal portion b.
2. The parameter of MCI(BN) decreased as the examination points approached the distal portions, and it showed 0.60 at the middle of the bone shaft m, 0.45 and 0.30 at the distal portions a and b, no difference was recognized between the parameters on the examined portions for MCI (GR). The distal portion b for the parameter of cortical area CA increased significantly,(p＜0.01) 12%, larger than the middle of the bone shaft m.
3. The bone mineral contents at h1, h2, GSmax and GSmin decreased gradually as the examining points were changed to further from the middle of the bone shaft (p＜0.01), but the differences of decreasing rate for the parameter of h1 and h2 and GSmax and GSmin did differ greatly between the two parameters.
4. The parameters of bone mineral contents at BMC and E decreased gradually as the examined points went away from the middle of the bone shaft,but no difference was observed between the portions for the parameters of tBMC.
5. A decreasing rate of the bone mineral content was the largest value of GSmin.
From these results, in evaluating the bone thickness, bone mineral content and bone density of the second metacarpal bone shaft, it is necessary to think of not only the parameters at the middle of the bone shaft but also that at a and b portions.
