Spatiotemporal Co-occurrence Patterns of Periodontitis and Oral Cancer: A Global Risk Factor and Network Analysis

To characterise global co-occurrence patterns of periodontal disease and oral cancer using Global Burden of Disease (GBD) 2021 data (1990-2021) and identify shared and condition-specific risk factors.

We analysed adult incidence (≥25 years) across 204 countries and 68 risk factors. Countries were classified by incidence quartiles as concordant, periodontal-dominant, or oral-cancer-dominant. Shapley Additive Explanations (SHAP) modelling, negative binomial regression, network analysis, and Granger causality testing were applied.

In 2021, global Periodontitis incidence: 1740.92 per 100,000 population (males: 1746.63; females: 1735.63) far exceeded oral cancer (8.97 per 100,000 population (males: 11.81; females: 6.21). Of 204 countries, 72 countries (35.29%) were periodontal-dominant, 62 countries (30.39%) oral-cancer-dominant, and 70 countries (34.31%) concordant. High-burden clusters appeared in South/Southeast Asia, while Northern Europe and North America showed the lowest rates. Key oral cancer risks included tobacco chewing (risk ratio [RR] = 1.075, 95% CI: 1.053-1.096), iron deficiency (RR = 1.067, 95% CI: 1.002-1.136), and high alcohol use (RR = 1.019, 95% CI: 1.000-1.038). Primary periodontal risks were high systolic blood pressure (RR = 1.007), lead exposure (RR = 1.006), and processed meat consumption (RR = 1.006). Granger causality testing suggested potential temporal precedence of periodontal disease (F = 3.323, P = .020), though causal inference is limited by the ecological study design and potential unmeasured confounding.

Periodontal disease and oral cancer exhibit overlapping yet distinct global distributions. Shared exposures (tobacco, pollutants) drive comorbidity, while condition-specific risks necessitate tailored prevention. Integrated primary care approaches targeting modifiable risks could substantially reduce disease burden.