Contextual school performance, individual educational delay, income inequality and oral health among adolescents: A repeated cross-sectional study in Brazil, 2010 and 2023.

Objectives

To examine the association of contextual school performance, individual educational delay, and socioeconomic conditions with untreated dental caries and tooth loss in Brazilian adolescents.

Methods

Data from two nationally representative surveys (SB Brasil, 2010, n = 11,895; 2023, n = 9181 after exclusions). Outcomes were untreated caries and any tooth loss from the DMFT index. Contextual exposure was a Public School Performance Score (PSPS) derived by principal component analysis of school dropout, grade retention, and the Basic Education Development Index. Multilevel logistic models estimated odds ratios (ORs) per 1-unit SD increase in the PSPS for each survey year, adjusting for sex, age, equivalised income, educational delay, municipal income tertiles, and water fluoridation.

Results

The PSPS distribution shifted rightwards between surveys (median rose from 0.99 to 2.43), reflecting improvements in IDEB and reductions in dropout and grade retention. In 2010, a 1-SD higher PSPS was associated with significantly lower odds of untreated caries (OR = 0.92, 95%CI 0.84, 0.99) and tooth loss (OR = 0.88, 95%CI 0.81, 0.97). By 2023, the associations had weakened and were no longer statistically significant: caries OR = 0.97 (95%CI 0.86, 1.10); tooth loss OR = 0.95 (95%CI 0.83, 1.08). The year-by-score and cross-level interactions were not statistically significant.

Conclusion

The contextual gradient in oral health associated with school performance observed in 2010 was not detectable in 2023, despite overall improvements in educational indicators. Clinical Significance: Even when average school performance rises, additional school-based oral health strategies may be needed to maintain the health gradient, as universal improvements do not automatically translate into reduced inequalities.