Salivary leptin levels in normal weight and overweight individuals and their correlation with orthodontic tooth movement.

OBJECTIVES: To assess and compare the concentration of leptin in saliva between normal weight and overweight individuals and to evaluate the rate of orthodontic tooth movement. MATERIALS AND METHODS: Thirty female subjects were divided into two groups: I (normal weight) and II (overweight group) based on their body mass index. All subjects underwent fixed appliance therapy requiring upper first premolar extraction and distal movement of the canine. Distal force was applied to the maxillary right canine using active lacebacks. Salivary samples were collected just before force application (T(0)), 1 hour (T(1)), and 1 month (T(2)) after force application. The rate of tooth movement was evaluated over 3 months and was measured on study models. RESULTS: At all three time intervals, mean leptin concentration was greater in overweight individuals than normal weight individuals. In both groups at T(1), the mean leptin concentration was found to increase significantly compared with the baseline value (T(0)), but at T(2), the leptin concentration declined to values lesser than the baseline values (T(0)). CONCLUSIONS: Overweight individuals had greater salivary leptin concentration. There was a positive correlation between salivary leptin concentration and rate of tooth movement in both normal and overweight individuals. The rate of tooth movement is decreased in overweight individuals as compared with normal weight individuals.