We examined immunohistochemical expressions of HSP70 and p-HSP70 in the orthodontic periodontal tissues. In the control group, the HSP70 and p-HSP70 expression was observed in the periodontal ligament fibroblasts and that was kept in low levels. In the experimental group, the strong expression of HSP70 was detected according to over time. However, p-HSP70 expression was a bit delayed. The data suggests that HSP70 has been closely involved in the repair of tissue to maintain homeostasis of the periodontal tissues by the activation of periodontal ligament fibroblasts. Farthermore, the data also suggests that HSP70 act as a molecular chaperone of osteogenesis through an activation of osteoblasts.

Heat shock proteins (HSPs) are induced by not only the heat shock but also the mechanical stress. Orthodontic tooth movement induced mechanical stress in the related periodontal ligament. It is important to examine the immunohistochemical profile change of the Heat shock proteins (HSPs) in the periodontal ligament cells after receiving the mechanical stress for orthodontic treatment. Therefore, we examined the HSPs in the periodontal ligament cells of ddY mice using the Waldo method. In the control group, periodontal ligament was observed as physiological arrangement, and which reacted weakly to HSP27 and HSP70. In the experimental group the extension site of the periodontal ligament cells and the expansion of the blood vessel occurred in the traction side. These tissues were strongly reacted to HSP27 and HSP70. The findings suggeste that the HSPs expression work as the mechanism of maintenance of homeostasis in the periodontal tissues.

: The purpose of this examination was to in vestigate the expression of BMP-2 and -4 in mouse orthodontic periodontal tension sides exposed orthodontic mechanical stress using the method of Waldo. Immnohistochemically, in the experimental group, strong expression of BMP-2 and -4 were observed in the periodontal tension sides at 20minutes. The results strongly suggested that the BMP-2 and -4 promoted the Runx2 expression for osteoblastic differention in the orthodontic periodontal tension sides at the early stage after receiving of the mechanical stress.

Orthodontic mechanical stress was exposed on mouse molars and histopathological changes as well as the expressions of HSP27 and p-HSP27 in the periodontal tissues were examined after removal of mechanical stress. The increased in mechanical stress up to 3 hours led to pathological changes that caused a space in between stretched periodontal ligament fibrous bundles and fibroblasts as well as narrowing of the periodontal ligament space. Degenerative changes were also occurred in the pressure side. Pathological changes did not only occur due to mechanical stress but also at the time of the release of mechanical stress exposure which increased over time. In the control group, both HSP27 and p-HSP27 were negative in the pressure side after mechanical stress was released 3 hours later. On the other hand, the tension side showed a strong positive reaction. The proteins were also expressed after 20 min, 1 hour, 3 hours and 9 hours. The strongest expression was observed 24 hours. A decreased in the intensity of expression was observed 3 days and 1 week later. The results suggest that HSP27 plays an important role in the recovery of injured cells in the periodontal tissues.

: The purpose of the study is to investigate the expression of Osterix in the mouse orthodontic periodontal tissues using Waldo method. Immunohistochemecally in the control group, without experimental orthodontic mechanical stress, there was almost negative and/or quietly weekly positive reactions in the periodontal tissues. In the experimental group after 9 hours, orthodontic tension sties react positively. The positive reactions became stronger over time. The result suggest that Osterix expression in the orthodontic periodontal tension sides act as one of the key factors of osteagenic cell differentiatim.