RESUMO
OBJECTIVES: This study aimed (1) to investigate the evolution of self-esteem through orthodontic treatment, and (2) to study how key demographic factors would affect these evolutions and to assess relationships between self-esteem and orthodontic treatment need. METHODS: This longitudinal prospective cohort study comprised of 326 adolescents (172 girls and 154 boys) aged 11-16 years; data were obtained from 325 adolescents at T0 and 123 at T2. Three hundred twenty-one adolescents filled in questionnaires at T0, whereas 118 at T2. They were selected in the University Hospitals Leuven, Belgium, where they all received orthodontic treatment. Self-esteem was assessed with the Dutch adaptation of the Harter's test and treatment need was defined by the Index of Orthodontic Treatment Need (IOTN). Data were analysed with multivariate linear models and Spearman correlations. RESULTS: There was no evidence of a change in global self-esteem during orthodontic treatment. A significant gender by time interaction for scholastic competence (P < 0.05), a decrease in self-esteem for females, and an increase for males between T0 and T1 was observed. A significant age (at T0) by time interaction for physical appearance and global self-worth (P < 0.05) and a negative correlation between self-esteem and self-assessed IOTN aesthetic component for the subdomain of close friendship (P < 0.05) were found. CONCLUSIONS: Global self-esteem acts as a stable construct during orthodontic treatment. The subdomains of self-esteem could be influenced by age and gender. Self-esteem and the subjective need for orthodontic treatment were found to be negatively correlated.