RESUMEN
OBJECTIVES: This study examines the relationships between socio-economic status, psychosocial factors, health-related behaviours and the incidence of dental caries amongst 12-year-old schoolchildren living in deprived communities in Manaus, Brazil. METHODS: A longitudinal study involving 312 children aged 12 years was conducted in the city of Manaus, Brazil. Baseline data including socio-economic status (number of goods, household overcrowding, parents' schooling, family income), psychosocial factors (sense of coherence [SOC-13], social support [Social Support Appraisals questionnaire]) and health-related behaviours (frequency of toothbrushing, sugar consumption, sedentary behaviour) were collected through structured questionnaires. The number of decayed teeth was clinically assessed at baseline and one-year follow-up. A hypothesised model evaluating the direct and indirect pathways between the variables was tested using confirmatory factor analysis and structural equation modelling. RESULTS: The incidence of dental caries at the one-year follow-up was 25.6%. Sugar consumption (ß = 0.103) and sedentary behaviour (ß = 0.102) directly predicted the incidence of dental caries. A higher socio-economic status was directly linked with lower sugar consumption (ß = -0.243) and higher sedentary behaviour (ß = 0.227). Higher social support directly predicted lower sugar consumption (ß = -0.114). Lower socio-economic status (ß = -0.046) and lower social support (ß = -0.026) indirectly predicted the incidence of dental caries via sugar consumption and sedentary behaviour. CONCLUSIONS: In the population studied, sugar consumption and sedentary behaviour are meaningful predictors of the incidence of dental caries amongst schoolchildren living in deprived communities. Indirect pathways of lower socio-economic status and low social support with dental caries incidence via sugar consumption and sedentary behaviour were detected. These findings should be considered in oral interventions and oral health care policies to prevent dental caries amongst children living in deprivation. CLINICAL SIGNIFICANCE: Social conditions, social support, sedentary behaviour and sugar consumption directly influence dental caries in children.