Socioeconomic Inequalities in Oral Health Across Age Groups Among Single-Person Households in South Korea

Introduction and aims: This study examined oral health inequalities by socioeconomic position (SEP) among single-person households in South Korea, a growing but understudied demographic group. While prior research has highlighted oral health disparities in older adults, few have explored how SEP is associated with oral health across the life course in individuals living alone. Methods: Using data from the 2023 Korea Community Health Survey, we identified 59,275 single-person households and assessed chewing discomfort and subjective oral health across three age groups (19-44, 45-64, ≥65 years). Inequalities by income and education were quantified using the Slope Index of Inequality (SII) and the Relative Index of Inequality (RII) in the complete-case analytic sample (n = 34,857). Results: The prevalence of chewing discomfort and poor subjective oral health was higher in lower income and education groups across all age categories. Income-related inequalities were greatest among adults aged ≥65 years (chewing discomfort: SII −0.113, RII 5.848; subjective oral health: SII −0.106, RII 4.010). Education-related relative inequalities were more salient among young adults aged 19 to 44 years (chewing discomfort: SII −0.004, RII 11.509; subjective oral health: SII −0.014, RII 2.769). Conclusions: This study identified distinct age-specific patterns of socioeconomic inequalities in oral health among single-person households in South Korea, with income-related inequalities more pronounced in older adults and education-related inequalities more salient in younger adults. These findings suggest that efforts to reduce oral health inequalities in single-person households may need to address different dimensions of SEP across age groups, and further research is needed to clarify the underlying mechanisms. Clinical relevance: When addressing oral health inequalities in single-person households, age-specific socioeconomic determinants should be considered, with a focus on income-related inequalities in older adults and education-related disparities in younger adults.