RESUMO
Aim: To investigate tooth loss and its determinants in adolescents, considering the effect of extractions due to orthodontics reasons. Methods: This cross-sectional study was performed in students from public and private schools aged 15-19 years old from Passo Fundo, Brazil. The proportional randomly chosen sample included 736 adolescents. Clinical examinations and interviews were performed. Associations between prevalence of tooth loss and exposure variables studied were analysed by Poisson Regression with uni- and multivariate robust variance in two models. One model comprised students who had experienced tooth loss without orthodontic reasons and the other with all of the subjects presenting tooth loss. Results: Prevalence of tooth loss was 21.1% (mean of 0.42). Higher chances for tooth loss were found in the following features: non-whites (PR=1.72; CI95%:1.15-2.60), poorly schooling mothers (PR=2.2; CI95%:0.96-5.02), from public schools (PR=4.16; CI95%:0.98-17.59), smokers (PR=1.91; CI95%:1.15-3.17). Conclusion: Demographic, socioeconomic and behavioural conditions were strongly associated with tooth loss. These associations were more evident when extractions for orthodontic reasons were not included in the analytical models