Evaluation of the effects of obesity on orthodontic TOOTH movement

Objective: The aim of this prospective randomized clinical study was to biochemically evaluate bone remodeling in gingival groove fluid during canine distalization in obese individuals and to compare with normal weight individuals. It was also aimed to measure the speed of tooth movement in obese individuals and compare it with normal weight individuals. Materials and Methods: A total of 36 patients between the ages of 12-18 years, 18 obese and 18 normal weight, who were planned to be treated with maxillary first premolar tooth extraction due to Angle Class II malocclusion, were included in the study. The groups were formed according to the WHO obesity classification as normal weight group with BMI percentile 16-85% and obese group with BMI percentile ≥95%. After orthodontic leveling of the teeth, 150 g force was applied with NiTi closed coil springs for canine distalization. During the study period, DOS samples were taken from the patients before the distalization force was applied (T0), 24 hours after the force was applied (T1), and on day 7 (T2), day 14 (T3) and day 21 (T4) with the help of periopaper. From the taken DOS samples, the levels of leptin, RANKL, OPG and IL-6 markers were measured with the use of ELISA method. In addition to the time periods of DOS sampling (T1,T2,T3,T4), digital model records were obtained with intraoral scanning method on the 28th day (T5) and 3rd month (T6). The amount of movement of the canine tooth was calculated on the digital models obtained. The study lasted for a total of 3 months. Results: Statistically significant differences in biochemical marker measurements were found between the groups in biochemical marker measurements. Leptin, RANKL, OPG and IL-6 levels were significantly higher in the obese group compared to the normal weight group (p<0.05). There were no statistically significant differences between the groups in terms of DOS volume, plaque index, gingival index and bleeding on probing index (p>0.05). Reproducibility rate was found to be high in digital model measurements (CCT-0.990). There was no significant difference between the groups in terms of the amount of tooth movement (p>0.05). When the relationship between the change in leptin level in the first 21 days of the study and tooth movement was analyzed, the correlation coefficient was calculated as r=-0.002 (p=0.994) in the study group and r=-0.121 (p=0.634) in the control group. Accordingly, there is no statistically significant linear relationship between the change in leptin level and tooth movement. Conclusion: According to the results of our study, biomarker levels responsible for tooth movement differ between obese and normal weight individuals. There is no difference between the groups in terms of the amount of tooth movement. No relationship was found between leptin level and the amount of tooth movement. Key words: Obesity, leptin, RANKL, OPG, IL-6, orthodontic tooth movement