Fig. 8. Volumetric measurements of trabecular bone changes occurring in the region of interest in the left maxillary first molar at 3, 7, and 14 days after insertion of a 30-g orthodontic force application device of in the control (saline 0.5 mL daily, white bar) and experimental (nicotine 0.83 mg/kg daily, grey bar; nicotine 1.67 mg/kg daily, deep gray bar) groups, to assess the effects of nicotine on orthodontic tooth movement and bone remodeling in rats. A, Bone volume fraction. B, Bone mineral density. C, Trabecular thickness. D, Trabecular volume. The median, maximum, and minimum values at 3, 7, and 14 days were expressed as the representative values for each group.