Income Level and Oral Health in Depressed Adults: A Study Utilizing the Korea National Health and Nutrition Examination Survey

Depressive symptoms negatively affect adults' health behaviors and overall well-being, including oral health. In particular, low income is a major factor that limits access to preventive oral care and dental services, thereby worsening oral health disparities. This study utilized data from the 8th(2020) and 9th(2022) Korea National Health and Nutrition Examination Survey (KNHANES) to examine the impact of income level and oral health behaviors on oral health among 460 adults with depressive symptoms (PHQ-9 ≥ 10). Key variables included income level, oral health behaviors, chewing discomfort, and the number of retained natural teeth. Complex sample chi-square tests and binary logistic regression analyses were conducted. The results showed that younger adults reported significantly less chewing discomfort compared to those aged 65 and older (OR=0.29, 95% CI:0.11-0.77). Chewing discomfort was also significantly associated with low education (OR=3.11, 95% CI:1.20-8.07) and smoking (OR=2.21, 95% CI:1.15-4.25). The number of retained natural teeth was significantly associated with age, education, alcohol consumption, recent dental checkups, and income level. Notably, individuals in the lower-middle income group were significantly less likely to retain 20 or more natural teeth compared to those in the highest income group (OR=0.17, 95% CI:0.03-0.80). These findings suggest that socioeconomic factors play a critical role in oral health among adults with depressive symptoms. Tailored public health policies targeting lower-income populations are needed, and integrated strategies that address both mental and oral health are essential.