The effect of obesity on orofacial pain during early orthodontic treatment with fixed appliances: a prospective cohort study.

Introduction: We have investigated orofacial pain in a prospective cohort of obese and normal-weight subjects undergoing fixed-appliance orthodontic treatment.
Methods: Fifty-five subjects (27 males, 28 females) mean age 15.1 (1.6) years and mean body mass index 30.2 (3.5) in obese and 19.4 (2.2) kg/m2 in normal-weight groups were followed for 1 week after appliance placement. Primary outcome was maximum-pain measured using a 100-mm visual analogue scale. Secondary outcomes included mean pain and oral analgesic consumption.
Results: Mean maximum pain for the total sample was 73.7 (standard deviation 14.8; 95% confidence interval 69.8-77.7) mm with no significant differences among groups (P = 0.247). However, mean maximum pain was higher at all time-points for the obese group and significant at 72 hours (P = 0.034). Total analgesia consumed by the obese group was also significantly higher than normal weight (P = 0.041). Multivariable regression found the only significant predictor for mean pain was time. After adjusting for confounding, obesity was associated with higher (+4.47 mm) mean pain at each time-point (P = 0.018). A significant association existed between obesity and total analgesic consumption (univariable-analysis, P = 0.035; multivariable analysis, P = 0.023). After accounting for confounders, obese patients were associated with taking a higher quantity of oral analgesics. Conclusions: We found a trend towards increased mean pain and an association with increased analgesic consumption in obese subjects during the first week following fixed-appliance placement.