The aims of this study were to evaluate the effect of normative treatment need, perceived social impact of malocclusion and satisfaction with dental appearance on self-perceived treatment need, self-perceived aesthetics, and self-esteem; the influence of self-perceived need and aesthetics on self-esteem; and whether receipt of orthodontic treatment influences self-esteem. A questionnaire was administered to a random sample of 410 students (195 males and 215 females) aged 14-16 years. Self-esteem was measured using the Global Negative Self-Evaluation (GSE) scale. The Aesthetic and Dental Health Components (AC and DHC) of the Index of Orthodontic Treatment Need (IOTN) were used to assess orthodontic treatment need. Students' AC scores determined their self-perceived dental aesthetics. Spearman correlation coefficient was used to analyse the association between all variables, and multiple stepwise regression analysis to study the effect of independent variables on self-perceived need for treatment, self-perceived aesthetics, and self-esteem. A correlation existed between the students' and examiner's AC scores (P < 0.01); however, students were less critical in evaluating their aesthetic appearance. Students who perceived themselves in need of treatment had a great need for treatment, as assessed by the DHC and the AC of the IOTN (r = 0.421 and 0.489, respectively), were dissatisfied with their dental appearance (r = 0.542) and avoided smiling to hide their teeth (r = 0.457). Students who scored high on the GSE scale perceived a need for orthodontic treatment, evaluated their dental aesthetics poorly, perceived an impact of malocclusion on social acceptance, and had a great normative orthodontic treatment need; the correlation, however, was weak with r values ranging from 0.134 to 0.317. Students who had received orthodontic treatment showed greater self-esteem than those who had not, although the correlation was weak. Dissatisfaction with dental appearance had a strong predictive effect on self-esteem.