Mapping Tooth Loss at the Tooth Level: Associations with Demographic, Health, and Behavioral Factors

This cross-sectional observational study analyzed patterns of tooth loss across different population groups using National Health and Nutrition Examination Survey (NHANES) data from 2009 to 2018, aiming to identify the teeth most at risk and the key contributing factors.

Data from 24,945 adults aged 20 y and older were analyzed. Tooth presence/absence was modeled in relation to age, income, education, smoking history, and glycemic status. To improve robustness, missing covariate data were imputed using k-nearest neighbors, and survey weights were applied in regression analyses to account for NHANES's complex sampling design. A 2-step analytic approach was used: (1) survey-weighted quasi-Poisson regression estimated associations with total tooth count and (2) unweighted generalized estimating equations identified explanatory variables associated with individual tooth loss, accounting for intraoral clustering. Dental implants were excluded.

Tooth-level models suggested distinct intraoral and demographic patterns. Males retained more posterior teeth but lost more mandibular incisors than females did. Older adults (≥60 y) exhibited markedly higher loss in mandibular anterior and premolar regions. High-income and high-education participants retained more teeth overall but were more likely to lack first premolars, likely reflecting orthodontic extractions. Smoking and diabetes were associated with anterior tooth loss, especially in visible, functionally important regions. Glycemic control showed a clear gradient, with low-normal HbA1c levels protective in posterior sites.

Tooth-level modeling suggested anatomically and socially patterned vulnerabilities often masked in whole-mouth analyses. Findings underscore the need for site-specific prevention strategies that address biological risk and structural inequity, advancing more equitable approaches to oral health care and policy.Knowledge Transfer Statement:This study identified which specific teeth are most at risk of loss across age, health, and socioeconomic groups. Understanding these tooth-level patterns can help clinicians tailor preventive care to vulnerable patients, guide patient education, and inform public health strategies that target oral health disparities. These findings support more precise, equitable dental care to help people keep their natural teeth longer.