Associations between tooth loss, denture use, and dementia in older Taiwanese adults.

Background: The literature has mainly focused on the association between tooth loss and dementia, and evidence regarding the separate and joint effects of tooth loss and denture use on the risk of dementia is limited. This study investigated the links among tooth loss, denture use, and dementia risk in Taiwanese adults aged 65 years or older.

Methods: This retrospective cohort study utilized data from the 2009 National Health Interview Survey and 2008-2017 National Health Insurance claim records, including the records of 2247 individuals free from dementia treatment in 2008-2009. Dementia diagnoses were tracked until 2017. The Cox proportional hazards model was used to calculate hazard ratios (HRs) for exploring the correlations among tooth loss, denture use, and dementia risk.

Results: Older adults with 20 or more natural teeth and dentures had the lowest dementia incidence (1.43 per 100 person-years). Those with <20 natural teeth, with or without dentures, experienced high dementia incidence rates of 2.31 and 3.33 per 100 person-years, respectively. After adjusting for various factors (i.e., sociodemographic characteristics, health conditions/comorbidities, and lifestyles), having <20 natural teeth or not using dentures was associated with non-significantly increased HRs of 1.30 (95% CI, 0.99-1.71) and 1.20 (95% CI, 0.95-1.52). Subgroup analysis revealed that compared to older adults with 20 or more natural teeth and dentures, those with <20 natural teeth and not wearing dentures had a significantly increased risk of dementia (adjusted HR, 1.57; 95% CI, 1.04-2.37).

Conclusion: This study found that having <20 natural teeth and not using dentures was significantly associated with an increased risk of dementia in Taiwanese individuals aged 65 years or above.