저칼슘식이가 백서의 하악골 골절치유에 미치는 영향에 관한 실험적 연구

AN EXPERIMENTAL STUDY OF MANDIBULAR FRACTURE WOUND HEALING IN THE CALCIUM DEFICIENT RAT

The purpose of this study was to investigate effects of osteoporosis on fracture wound healing in the calcium deficient rat. To research the experiment some ten-week old Wistar strain rats with approximately 300 gms weight were selected. Then, the rats were divided into two groups: Normal diet group(rats given a normal diet before and after bone fracture) and Low calcium diet group(rats given a low calcium diet before and after bone fracture). Both groups had been provided with each diet for three weeks. When the rats became thirteen weeks old, the mandibular angle of rats in both groups was artificially fractured for test. The healing of fracture wounds was reviewed by using soft x-ray radiography and /sup 99m/Tc-MDP bone scan and also histopathologic examination. The obtained results were as follows : 1. The radiolucency of the fracture site for the Normal diet group started to decrease from the 14th day since the experiment was made, while the Low calcium diet group began decrease in the radiolucency from the 21st day of the experiment. The radiolucency for the Normal diet group disappeared at the 42nd day, but one for the Low calcium diet group disappeared at the 56th day of the experiment. 2. The highest uptake rate of /sup 99m/Tc-MDP stood at the 14th day of the experiment in the Normal diet group and the Low calcium diet group's maximum rate was recorded at the 21st day of the experiment. These both groups were gradually experiencing decrease in the uptake rate as the experiment time was going on. However, the uptake rate in the Low calcium diet group was lower than one in the Normal diet group. 3. For the Normal diet group, the newly formed trabeculae, which were similar to one of the surroundung bone, were seen at the 42nd day of the experiment. On the other hand, the Low calcium diet group showed at the 56th day of the experiment that the osteoporotic findings looked weak, irregular trabeculae, and also large bone marrow space were observed clearly. As a result of the above experiment, it is said that the healing of the fracture can be completed for both groups, the Normal diet group and the Low calcium diet group. However, the amount of the newly formed bone wound in the Low calcium diet group is rather decreased compared to one in the Normal diet group and at the same time the healing of the fracture is delayed in the Low calcium diet group. Consequently, for the successful healing of fracture in osteoporosis, it is considered that the management of the etiologic factors of osteoporosis must be preceded. The more study of calcium metabolism and functions of osteoblast and osteoclast needs to proceed on.