Oral health and social engagement of older adults: a longitudinal study

OBJECTIVES: This study examines whether better oral health is associated with greater social engagement in later life and whether oral health and social engagement are associated with depressive symptoms among older adults. METHODS: We analyze Waves 7-9 (2018, 2020, 2022) of the Korean Longitudinal Study of Ageing, restricting to adults aged ≥65 years. Oral health is measured by the General Oral Health Assessment Index (GOHAI). Social engagement is captured as a binary indicator for meeting close friends/relatives/neighbors in the past year and the annual frequency of such meetings (days/year). Depressive symptoms are defined as self-reported depression lasting ≥2 weeks or antidepressant use. We estimate associations using panel fixed-effects model and Double Machine Learning to address unobserved individual heterogeneity and reduce model misspecification bias. RESULTS: A standard deviation improvement in GOHAI was associated with an approximately 2-percentage-point higher likelihood of meeting close contacts and about 3 additional meeting days per year. Both meeting close contacts and better oral health were associated with a lower probability of depressive symptoms. Results are robust across sensitivity and falsification tests. CONCLUSIONS: The findings indicate that better oral health is linked to greater social engagement in later life, with potential welfare gains for older adults through a lower risk of depression. CLINICAL SIGNIFICANCE: Interventions that improve oral health in older adults may yield benefits beyond function and comfort by supporting social connectedness and reducing psychological risk. Conventional evaluations may understate the social benefits of improving oral health.