Objective To study the effects of both osteocalcin(OC) and low-energy laser in the movement of experimental rat tooth. Methods A total of 96 SD rats were separated into four groups. In group A, the rats were injected daily with1 μg of OC into the palatal bifurcation site of the first molar. In group B, the rats were irradiated daily by low energy laser during tooth movement. In group C, the rats were injected with OC and were irradiated by low-energy laser daily. Group D was the control group. The distance of the first molar movement was measured on the model. All values were statistically analyzed. Results The tooth movement in group C was greater than that in the other groups(P
