Association between masticatory function and Parkinson’s disease: A population-based study

Masticatory dysfunction may contribute to systemic diseases, including Parkinson’s disease (PD), but evidence from large populations is limited. Using data from 37,668 adults in NHANES 1999–2018, we assessed mastication with functional tooth units (FTUs), and defined PD by medication use. Logistic regression, restricted cubic spline (RCS), and stratified analyses were applied with adjustment for demographic, socioeconomic, lifestyle, and health covariates, and sensitivity analyses were performed. Among participants, 334 had PD (weighted prevalence 0.8%). Mean FTUs (5.70 vs. 8.31) and tooth counts (19.09 vs. 23.13) were significantly lower in PD than non-PD individuals (P < .001). Each unit increase in FTU was associated with reduced PD risk (OR = 0.923, 95% CI 0.879–0.969), and participants with FTU 10–12 had 48% lower PD prevalence (OR = 0.518, 95% CI 0.298–0.901). Molar FTU and tooth counts were inversely associated with PD, while masticatory dysfunction and incomplete dentition were linked to higher risk. RCS suggested a linear association, with stronger effects observed in older, non-diabetic, and non-hypertensive individuals (P for interaction < 0.05). Sensitivity analyses confirmed the robustness of findings. These results indicate that better mastication, reflected by higher FTUs, is associated with reduced PD risk, highlighting the potential role of oral health maintenance in PD prevention and management.