Association of tooth loss with diabetes and oral health indicators among adults served by federally qualified health centers — a case for prioritizing oral health in primary care

Tooth loss remains a persistent and unequal oral health outcome in the United States. Adults served by Federally Qualified Health Centers (FQHCs) represent a population with heightened vulnerability to both chronic disease and poor oral health outcomes, yet tooth loss within this safety-net setting remains understudied. This dissertation investigates the association between tooth loss and three interrelated domains informed by Social Determinant of Health (SDOH) and Andersen’s Behavioral Model framework: biological (diabetes), behavioral (oral healthcare utilization), and perceptual (self-rated oral health). Data was drawn from the 2022 Health Center Patient Survey, a nationally representative cross-sectional survey of FQHC patients. Analyses included 3,912 adults (≥18 years) for models examining diabetes and dental care utilization, while analyses involving self-rated oral health were limited to 2,841 participants due to missing data. Tooth loss was defined as self-reported loss of some or all adult teeth. Multivariable logistic regression assessed associations between diabetes, oral health care utilization, and tooth loss, adjusting for demographic (age, sex, race/ethnicity), socioeconomic (income, education, insurance), and behavioral factors (smoking status). Agreement between tooth loss and self-rated oral health was examined using Cohen’s kappa. Adults with diabetes had significantly higher odds of tooth loss compared with those without diabetes (AOR = 1.58; 95% CI: 1.32–1.89). Recency of dental visits was not independently associated with tooth loss, which may reflect episodic pattern of utilization in this population. Agreement between tooth loss and self-rated oral health was fair (κ = 0.22), indicating limited agreement between perceived and objective oral health status. Older age, race and socioeconomic factors (lower income, education), and smoking, were strong predictors of tooth loss. These findings highlight missed opportunities and underscore the need to integrate routine oral health screening, education, and referrals into primary care, particularly for patients with diabetes, as a feasible, low-cost strategy to reduce preventable oral health inequities in FQHC settings.