The histological changes of alveolar bone, cementum and periodontal fiber due to experimental progeria-like syndrome of rat

Disturbance due to the long term administration of Dihydrotachysterol (DHT) are known on the experimental to cause a progeria-like syndrome. In the present study, DHT was administered once daily for 28th days with 50μg per 100g weight of Sprague-Dawley female rats weighing 180-220g by the tuberculin syringe and attached stomach tube, and traumatic occlusion was experimentally induced by loading abnormal forces to rats. The rats were divided into 4 groups; 1) control group, 2) DHT administered group, 3) DHT administration plus traumatic occlusion group, 4) Traumatic occlusion group. The traumatic occlusion was induced by the method of Hieda and Ikeda. In Group 2 and 3, the animal weight showed a trend of decrease until the 5th day of experiment but after the both groups were maintained with same weight and Group 1 and 4 showed almost linear increase until the 28th day of experiment. The rats administered with DHT showed a tendency of almost atrophy of skin, kyphosis and atrophy of skelton. According to the DHT administration, serum calcium level was markedly increased and serum phospholic acid or mandibular bone calcium were reduced. On histological changes in Group 2 or Group 3, the eosinophilic substance like a layer or hematorylino-philic substance on the surface of alveolar bone or comentum. This substance was recognized like inmineralized tissue (Cementoid, Osteoid) and was markedly seen at the root apex area or root central area and and especially, a periodontal space showed a tendency of narrowing at the above area and arrangement of the periodontal fiber was irregular. In Group 3, changes of the periodontal structure showed marked histological changes in the central area of buccal root surface, a periodontal space was narrowed on the compressed side and widend on the traction side and alveolar bone of the compressed side showed osteoclastic resorption and almost were not observed eosinophilic substance, but in periodontal space of the traction side was observed a little osteoid formation and in generally eosinophilic substance formation at root apex area or bifurcation area were reduced compaired with Group 2.