BACKGROUND: Associations of risk factors/indicators with periodontitis may depend on the included case criterion. The objective was to evaluate differences in outcome by applying five periodontitis case definitions for cross-sectional associations with lifestyle factors among participants of The Danish Health Examination Survey (DANHES).

METHODS: A total of 4,402 adults aged 18-96 years from the general health examination of DANHES had a periodontal examination consisting of half-mouth registration at 6 sites per tooth including probing pocket depth (PPD) and clinical attachment level (CAL). Periodontitis was defined according to severe periodontitis, EWP-specific, meanCAL≥2.55mm, CAL-tertile, and PPD-CAL definition. Multivariable logistic regression models fitted the association of age, gender, smoking status, diabetes, educational level, alcohol consumption, body mass index, physical activity, body fat percentage, waist circumference, triglycerides, total cholesterol, and C-reactive protein with periodontitis.

RESULTS: Number of cases captured by the five periodontitis case definitions ranged from 337 (9.2%) to 1,136 (31.0%). A total of, 224 participants were defined as periodontitis cases by all five criteria. Analyses on 3,665 participants with complete data revealed statistically significant associations of age and smoking with all periodontitis case definitions and of male gender with Severe periodontitis and EWP specific definitions. Educational level (two lowest groups) was related to three periodontitis criteria. Among obesity and hyperlipidemia measures no factors were related to periodontitis.

CONCLUSION: Regression analyses showed little difference in OR across the five periodontitis case definitions, however, the level of significance did show some variation.