RESUMO
OBJECTIVES: To examine the relationships between dental appearance, characteristics of the individual and their environment, and oral health-related quality of life (OHQoL) in young people over time. METHODS: A total of 374 young people (122 boys, 252 girls) aged 11-12 years from seven different XX schools were recruited at baseline and 258 (78 boys, 180 girls) followed-up 3 years later, aged 14-15 years (69 per cent response rate). Participants completed a measure of OHQoL (CPQ11-14 ISF-16) and self-esteem (SE, CHQ-CF87). A clinical examination was undertaken, including clinician and self-assessed normative measures of need [Index of Orthodontic Treatment Need (IOTN)] and dental caries. The Index of Multiple Deprivation was used to indicate socio-economic status (SES). RESULTS: There was a general improvement between baseline and follow-up in the measures of malocclusion, as well as OHQoL. Multiple linear regression indicated that there were significant cross-sectional associations at baseline between OHQoL and SES (rho = -0.11; P = 0.006), SE (rho = -0.50; P < 0.001), and self-assessed IOTN (rho = 0.27; P < 0.001). There were significant longitudinal associations between the change in OHQoL and change in SE (rho = -0.46; P < 0.001) and change in the decayed, missing, or filled surfaces (rho = -0.24; P = 0.001). The mean improvement in the total CPQ11-14 ISF-16 score for those with a history of orthodontic treatment was 3.2 (SD = 6.9; P = 0.009) and 2.4 (SD = 8.8; P < 0.001) for those with no history of treatment. The difference was not statistically significant (P = 0.584). CONCLUSIONS: OHQoL improved in young people over time, whether they gave a history of orthodontic treatment or not. Individual and environmental characteristics influence OHQoL and should be taken into account in future studies.