Abstract
Early changes of Osterix expression were examined by immunohistochemistry (IHC) and fluorescent immunohistochemistry (FIHC) in mouse periodontal ligament exposed to experimentally induced orthodontic mechanical stress. Eight-week-old ddY mice were used as experimental animals. To provide continuous orthodontic mechanical stress on the periodontal ligament, a rubber dam sheet was placed between the upper molars of the mice. At 20 min, 1 h, 3 h, 9 h and 24 h after the insertion, related parts of the animal tissues were evaluated by IHC and FIHC regarding Osterix and Runx2 expressions. In the 3-h and 9-h experimental groups, orthodontic tension sites reacted positively. The positive reactions became weak in the experimental group at 24-h. The results suggest that Osterix acts as one of the key factors of osteogenic cell differentiation, which expresses the following after the expression of Runx2, down-steam of Runx2.
