EFFECTS OF LOCAL-ADMINISTRATION OF OSTEOCALCIN ON EXPERIMENTAL TOOTH MOVEMENT

The purpose of this study was to evaluate the effects of local adminis tration of osteocalcin, a major noncollagenous bone matrix protein, on experimental tooth movement in rats. An orthodontic elastic band was inserted between the upper first and second molars, and the first mola r was moved mesially. Purified osteocalcin (0 to 10 mu g) in 20 mu l o f phosphate-buffered saline was injected into the region of the root b ifurcation of the first molar daily for 4 days. Tooth movement increas ed significantly following the injections. Histological studies reveal ed that the injections markedly stimulated the appearance of osteoclas ts on the pressured side of the alveolar bone surface. The results sug gest that osteocalcin has an additive effect on the rate of orthodonti c tooth movement through the enhancement of osteoclastogenesis on the pressured side.