The role of socio-economic position in predicting orthodontic treatment outcome at the end of 1 year of active treatment.

Socio-economic position (SEP) has not been tested as a predictor of orthodontic treatment outcome. This study aimed to determine whether SEP can predict orthodontic treatment outcome at the end of 1 year of active treatment. A hospital-based, prospective longitudinal design was adopted including 145 consecutively selected 12- to 16-year-old males and females. Patients were followed-up on a monthly basis during their orthodontic treatment with fixed appliances. After 1 year of treatment, orthodontic treatment outcome was assessed as the amount of improvement in occlusion achieved. Logistic regression analysis was used. The response rate was 98.6 per cent and the dropout was 5.6 per cent. Adolescents whose mothers were from a low social class were less likely to achieve a high improvement in occlusion than those whose mothers were from a high social class [odds ratio (OR) = 0.1; 95 per cent confidence interval (CI) = 0.01-0.97; P = 0.047). Adolescents from a low household social class were less likely to achieve a high improvement in occlusion compared with their counterparts from a high household social class (OR = 0.2; 95 per cent CI = 0.07-0.79; P = 0.019). The father's social class, parental education, and employment status were not significantly associated with improvement in occlusion (P > 0.05). The regression model confirmed the significance of maternal and household social class as predictors of orthodontic treatment outcome at the end of 1 year of active treatment.