ビタミン D 欠乏による歯槽骨の変化に関する X 線的, 光顕的および走査型電顕的研究

Abstract

Three-week-old male rats of Wistar strain were given normal food, calcium deficient food, vitamin D deficient food, or calcium deficient food + vitamin D deficient food, and changes in the alveolar bone were investigated radiologically, and light and electron microscopically. The results were as follows : 1. Findings from the analysis on the X-ray microanalyzer Quantitative analysis of Ca and P in the four groups showed no significant difference between the normal food control group and vitamin D deficient food group. However, significant difference with 1% significance level was found between the normal food control group and calcium deficient food group and between the control group and calcium and vitamin D deficient food group. The control group showed high values. Furthermore, relative Ca ratio (Ca/[Ca]c) and relative P ratio (P/[P]c) as compared with those of the control group were determined. In (Ca/[Ca]c), the normal food control group and vitamin D deficient food group showed high values followed by the calcium and vitamin D deficient food group and calcium deficient food group in descending order. In (P/[P]c), the normal food control group showed the highest values, and vitamin D deficient food group, calcium deficient food group, and calcium and vitamin D deficient food group showed low and the same values. 2. Histopathological findings In the alveolar bones of the calcium deficient food group as compared with those of the normal food control group, enlargement of bone marrow, decrease in Haversian system, enlargement of Haversian canals, and resorption cavities were marked, and bone tissue was displaced by low calcification layers. In the vitamin D deficient food group, bone marrow showed an increasing tendency and bone lacunae showed about the same findings as those in the normal food control group. The calcium and vitamin D deficient food group showed increase in bone tissue and increase in areas of low calcification layers as compared with the calcium deficient food group. 3. Scanning electron microscopic findings As compared with the alveolar bones of the normal food control group, those in the calcium deficient food group showed bone resorption in excess of bone formation, wide resorption cavities, shallow cavity bottoms and networks of collagen fibrils. Bundles of collagen fibers were not observed. The vitamin D deficient food group showed findings of bone resorptions and bone formation, and showed balanced bone construction. Bundles of collagen fibers were formed in bone matrix and openings of bone tubles were seen. The calcium and vitamin D deficient food group as compared with the calcium deficient food group showed bone matrices in part near the sites of bone resorption. However, osseous layers on the whole were decreased. On the basis of the foregoing findings, with regard to changes in the alveolar bone due to vitamin D deficiency, the effect on the bone tissue was great when calcium is deficient.