Abstract
OBJECTIVE: To evaluate the effect of cigarette smoking on the alveolar bone thickness and density in patients undergoing leveling and alignment of crowded lower anterior teeth. METHODS: This controlled clinical trial involved 17 smokers and 17 nonsmokers with mild to moderate crowding of the anterior mandibular teeth. Two cone-beam computed tomography images of the mandible were taken before and after treatment. The length of each tooth root was calculated in each T0 image, and the root was divided into three equal regions. Three lines were drawn parallel to the line of the cementoenamel junction at these three regions of the root, and the previously drawn lines were used to measure bone thickness and bone density. RESULTS: The mean changes in cortical bone thickness and bone density were significantly smaller in smokers than nonsmokers. Cortical bone thickness and bone density were significantly lower after than before treatment in both smokers and nonsmokers. CONCLUSION: In addition to all of its known dangers, cigarette smoking may also harm the alveolar bone by decreasing the bone thickness and density during orthodontic treatment in heavy smokers.