TOOTH SPECIFIC SURVIVAL ACROSS THE LIFESPAN: MAPPING THE NATURAL HISTORY OF PERMANENT DENTITION USING POPULATION-LEVEL DENTAL EXAMINATION DATA

Abstract

Background: Permanent teeth do not share a common life-course trajectory. Eruption timing, morphology, caries susceptibility, periodontal loading, restorative history, and clinical treatment decisions differ by tooth position. Medication burden may add a further layer of risk through salivary dysfunction and multimorbidity, yet population studies usually reduce dentition to a single tooth count. Objective: To map age-specific retention of individual permanent teeth in U.S. adults and examine whether prescription-medication burden and a pragmatic xerogenic medication proxy are associated with natural-tooth retention. Methods: We analyzed NHANES 2017–2018 dentition, demographic, prescription-medication, smoking, diabetes, medical-condition, and oral-health data. Adults aged ≥20 years with a completed dentition examination and positive MEC examination weight were included (n = 5,057). The primary dentition comprised 28 permanent teeth, excluding third molars. Natural retention was defined as a permanent natural tooth present; implants, absent teeth, and root fragments were classified as non-retained. Survey-weighted estimates incorporated MEC weights, strata, and primary sampling units. Fully adjusted models included age, age squared, sex, race/ethnicity, education, family income-to-poverty ratio, smoking status, diagnosed diabetes, multimorbidity, and dental-attendance recency. Medication exposure was modeled as 0, 1–4, and ≥5 prescriptions and as a continuous count; secondary analyses used a prespecified name-based proxy for potentially xerogenic prescription exposure. Results: The survey-weighted mean age was 48.3 years; 51.9% were women. Participants retained a mean 23.30 of 28 natural teeth (95% CI, 22.83–23.76), 83.3% had ≥20 natural teeth, and 4.9% had none of the 28 teeth. Retention was highest for mandibular canines and lowest for mandibular first molars. Polypharmacy (≥5 prescriptions) was present in 17.0%. In the demographic and socioeconomic model, polypharmacy was associated with fewer retained teeth; however, after additional adjustment for smoking status, diagnosed diabetes, multimorbidity, and recency of dental attendance, the association was markedly attenuated (adjusted difference, −0.37 teeth; 95% CI, −1.58 to 0.84; p = 0.527). Medication count was likewise not associated with retained-tooth count in the fully adjusted model (−0.04 teeth per additional prescription; 95% CI, −0.17 to 0.09; p = 0.493). A burden of ≥2 pragmatic xerogenic-proxy medications showed borderline evidence for fewer retained teeth (−0.71; 95% CI, −1.44 to 0.01; p = 0.054), but not for functional dentition. No tooth-specific polypharmacy association survived false-discovery-rate correction. Conclusions: Retention differed substantially by tooth position and age, with molars showing earlier population loss than anterior teeth. Apparent associations between medication burden and tooth retention were substantially reduced after accounting for smoking, diabetes, multimorbidity, and dental-care recency, suggesting that health status and related confounding explain an important part of the medication–dentition relationship. Tooth-specific mapping remains clinically informative, while medication effects require longitudinal designs with stronger exposure measurement.