Modified Relative Handgrip Strength and Tooth Loss: A Nationwide Study

Handgrip strength (HGS) reflects overall muscular fitness and health. Although associations between absolute or BMI-adjusted HGS and systemic conditions have been studied, no research has examined its link to tooth loss using modified relative HGS indices from other anthropometric factors.

This study aimed to investigate, for the first time, the association between tooth loss and various modified relative HGS indices using nationally representative data.

Using the 2014-2023 Korean National Health and Nutrition Examination Survey data (n = 52 206), relative HGS was calculated by adjusting dominant HGS with various body indices. Oral status was classified as functional (≥ 20 teeth) or reduced (< 20 teeth). Statistical analysis to assess associations and diagnostic accuracy was performed using the chi-square test, t-test, incidence rate ratio (IRR), and the receiver operating characteristic (ROC).

In the fully adjusted IRR analysis, waist circumference (WC)-based relative HGS showed the strongest inverse association with tooth loss (IRR = 0.505, 95% confidence interval [CI] = 0.388-0.656). The ROC analysis revealed that relative HGS indicators adjusted for WC, waist-to-height ratio (WHtR), and weight-adjusted waist index (WWI), which represent central adiposity, had the highest diagnostic accuracy for predicting tooth loss (area under the curve [AUC] = 0.6367, 0.6323, and 0.6316, respectively). Significant differences were observed in all HGS indicators based on the functional dentition criterion (p < 0.001).

WC-adjusted relative HGS showed the strongest inverse association with tooth loss, indicating its potential utility for early identification of high-risk individuals and informing multidisciplinary approaches to oral rehabilitation.