CTGF and apoptosis in mouse osteocytes induced by tooth movement.

It is known that experimental tooth movement stimulates the gene expression of connective tissue growth factor (CTGF) and induces apoptosis in osteocytes in rats. We hypothesized that there is a relationship between CTGF expression and the induction of apoptosis in osteocytes, to play a significant role in triggering bone remodeling during experimental tooth movement. In this study, CTGF mRNA expression was detected at 2 hours in osteocytes on the pressure side, followed by apoptosis at 6 hours after tooth movement in mice. The number of empty lacunae significantly increased on day 1 after mechanical stimulation. Thereafter, the number of osteoclasts significantly increased on the pressure side of the alveolar bone on day 3. Tooth movement increased rapidly on day 10. These findings suggest that CTGF expression, followed by apoptosis in osteocytes in response to mechanical stimulation, might play a significant role in triggering bone remodeling during tooth movement.