成年期ラットの虚弱下顎骨における食餌療法に関する X 線学的骨塩量および病理組織学的研究 : 骨基質形成

Abstract

Just as long bones, the craniofacial bones develop and grow all through the suckling, the infant (primary sexual characteristic period), the school age, the puberty (secondary sexual characteristic period) and the adulthood. Now in dental field, dentists pay more attention to the mandible because it is a special bone that is affected by masticatory force and serves as a support for teeth. From our serial studies, it has been seen that dietary calcium and bone hormone have great effects on bone mass. In the present study, we used thirty adult rats and divided them into three groups : control group (standard diet), calcium deficient group and low calcium (30%) group. After the mandible debility having been fallen into by the low or deficient calcium diet, we gave them standard diet and then study the dietary therapy effect on it. The results were shown as follows. 1. Body weight No significant differences were observed between the control and experimental groups. 2. Radiographic findings No differences among the three groups were found by naked eyes. 3. Microdensitometric finds There were no significant differences of mandible microdensitometry between the three groups. 4. X-ray microanalysis of Ca and P By surface microanalysis, it has been found that density of calcium was higher than phosphorus in any group. 5. Hematological findings No significant differences were found among the control and experimental groups in serum electrolyte levels. 6. Histopathological findings As contrasted with control group, reduction of lacunae and enlargement of marrow cavities were observed in calcium deficient group, the bone remodeling was also seen in this group. Compared with calcium deficient group, the reduction of marrow and increase of lacunae were seen in low calcium group, and resorption was rarely seen. These findings were equivalent to that of control group. From the above results, it is suggested that bone loss in adult rats can be well restored by dietary therapy, particularly in the low calcium group. We think that balance food is able to have bone recovered from debility. The reasons for the recover are thought as balance diet and bone hormone take great part in this process based on sufficient bone mass having formed till adult hood.