Oral Health Inequalities among and Within Neo-Marxian Social Classes in South Korea: A Nationwide Cross-sectional Study

Introduction: The objectives of this study were to examine the association between the neo-Marxian social class (NMSC) and oral health indicators, to determine the role of mediating factors in social class inequalities, and to assess the relationship between a combination of two subjective indicators and normative dental treatment needs (NDTN) according to the NMSC. Methods: Data were from the 4^th Korean National Health and Nutrition Examination Survey 2007-2009 with 6710 respondents aged 19-54. The outcomes were self-reported oral health (SROH), self-perceived unmet dental needs (SPUDN), and NDTN. Material (M), psychosocial (PSY), health behavior (HB), and workplace environment were used as mediating factors for SROH and SPUDN. The combination of both outcomes was used in the analysis along with NDTN. Results: Non-skilled groups (10%) and petty bourgeoisie (13.2%) had lower proportions of good SROH as well as the highest proportion of SPUDN (48.5% and 48.7%). Further, expert supervisors reported the highest good SROH (22.6%). The M factor (odds ratio [OR] 1.52 [1.24-1.86]) was the highest in several social classes. Managers had a higher probability of SPUDN (OR 1.27 [0.84-1.92]) than the others. Unhealthy patients - except capitalists - had the highest ORs (7.05 [3.89-12.78]), particularly significantly for NDTN. The pattern of the OR was V-shaped, J-shaped, and increasing shape. Conclusion: There was non-gradient inequality among Korean workforces. The M, PSY, and HB appeared to play an important role. SPUDN appears to be a better indicator for NDTN and disadvantaged groups among Korean workforces was revealed.