Immunohistochemistry of the periodontal ligament fibroblasts in orthodontic tension sides

To establish an immunohistochemical basis for orthodontic treatment, we review early histopathological changes and immunohistochemical changes of Runx2 and Msx2 in vivo study using mouse periodontal ligament exposed to mechanical stress. Strong expressions of Runx2 and Msx2 were seen in periodontal fibroblasts of the tension side at 20 minutes after mechanical stress. Expressions of Runx2 and Msx2 became stronger in parallel with time, and at 24 hours after mechanical stress, the periodontal fibroblasts, cementoblasts, and osteoblasts showed strong expression. Moreover, ALP has also demonstrated similar strong expression. All these results strongly suggested that Runx2 promoted differentiation of osteoblasts at an early stage and Msx2 worked as an activator of Runx2 function.