Figure 1. Local gene transfer area and systemic effects. (a) Schema of local gene transfer. Vector-solution was injected into the sub-periosteal area, adjacent to the first molars. Bu: buccal side. Pa: palatal side. (b) Body weight curve of experimental animals. The body weights of the experimental animals were measured throughout the experiment. There were no significant differences among the 3 groups. The results are expressed as the mean ± SD. N = 3, 8, and 9, respectively (control group, tooth-movement group, OPG-transfection group). (c) X-ray photograph of proximal rat tibiae. The densitometric patterns inside the standardized white box area were measured. (d) Bone mineral density values of tibiae of both groups. The results are expressed as the mean ± SD (N = 8). There were no significant differences among the groups.