Background: This study aimed to analyze correlations between depression, cognitive function, oral health state, ability to perform activities of daily living, oral dryness symptoms, and oral health-related quality of life, and determine factors influencing the latter. Methods: This was a cross-sectional study based on questionnaires completed by 260 participants with suspected dementia, residing in South Korea. Psychiatrists, psychiatric nurses, and dental hygienists visited clinics in the participating regions for examination and questionnaire administration. General characteristics, the geriatric depression scale, ability to perform activities of daily living, cognitive function, oral health state, and oral health-related quality of life were analyzed. Independent t-tests, one-way analysis of variance (ANOVA), correlation analysis and multiple regression analysis were conducted, identifying factors affecting oral health-related quality of life. Data analysis was performed using SPSS ver. 20.0 (IBM Corp., USA), and the significance was set at p＜0.05. Results: Approximately 65.0% of participants were female, 63.5% were in their 70s, and 90.0% had health insurance. About 21.5%, 42.0%, and 36.5% were normal, slightly impaired, and had dementia, respectively. High cognitive impairment was associated with poor oral health. Sex, education levels, marital status, and living arrangements influenced oral health-related quality of life. According to the regression analysis, geriatric depression and oral dryness affected the Geriatric Oral Health Assessment Index scores. Conclusion: In conclusion, oral dryness and depression levels among elders influenced oral health-related quality of life. The results showed that to enhance elders' oral health-related quality of life, it is essential to not only improve their oral health state, but also relieve oral health problems, especially oral dryness, and take into consideration their psychological aspects.
