Fig. 7. Comparative observations of the intermolar distance and osteoclast number at 3, 7, and 14 days after insertion of a 30-g orthodontic force application device 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, Intermolar distance. B, Osteoclast number. The median, maximum, and minimum values at 3, 7, and 14 days were expressed as the representative values for each group.