Socioeconomic (SES) gradients in oral health: exploring the impact of education and income

Abstract Background Periodontitis and dental caries contribute to tooth loss and impaired nutrition. SES gradients illustrate how social factors shape health beyond genetics. We assessed the independent effects of education and income on clinically measured oral diseases using, data from a population-based survey in Norway, with exposures measured 22 years prior to outcomes. Methods Study included 1,298 individuals (born 1950/51) participating in Hordaland Health Study (1997/99; HUSK2) and Hordaland Oral Health Survey (2020/22; HUSK-T). Information on education (tertiary’ vs. prim. /sec.’) and income (‘≥300,000’ vs. <300,000’ NOK*) were collected at HUSK2. Information on study outcomes (periodontitis, DMFT index, and no. retained teeth) were assessed at HUSK-T. We applied appropriate regression models, adjusting for sex, smoking, BMI, and diabetes, and reported ORs, IRRs, and 95% CIs. Results 45.6% of the study population were men, 51.2% had tertiary education, 79.6% earned ≥300 000 NOK, 49.2% had BMI≥25 kg/m2, 22.3% smoked, and 2.2% had DM. SES and oral health. Periodontitis: Tertiary education was associated with lower odds of periodontitis (OR = 0.78;95% CI:0.61-1.00); no association was found for higher income (OR = 1.13; 95% CI:0.84-1.54). DMFT index: Tertiary education was associated with the lower DMFT index (IRR=0.94;95% CI:0.93-0.96); no differences in DMFT index were observed across income levels (IRR=1.01;95% CI:0.97-1.02). Retained teeth: Tertiary education and higher income were associated with more retained teeth (IRR=1.05; 95% CI: 1.03-1.07 and IRR=1.03; 95% CI:1.01-1.05, respectively). Conclusions Individual SES proxies show different patterns of association with oral health, with education more consistently linked, highlighting multiple pathways through which SES influences disparities. Key messages • SES gradients in oral health highlight the need to consider multiple SES dimensions when examining inequalities. • Understanding underlying mechanisms and pathways, could help improving long-term oral health outcomes.