Discriminant validity of the current gingivitis classification in adolescents: a cohort study

To compare the prevalence of gingivitis estimated by the 2018 European Federation of Periodontology/American Academy of Periodontology (EFP/AAP) classification with the other case definitions and assess the ability of this classification system in discriminating sociodemographic and clinical factors associated with the presence of gingivitis in a cohort study.

A multistage random sample of 1134 12-year-old adolescents was submitted to a full-mouth examination according to the Community Periodontal Index. Socioeconomic and clinical variables were collected at baseline. Gingivitis was considered according to the following criteria: (a) ≥ 10% of bleeding sites (the 2018 EFP/AAP criteria); (b) ≥ 15% of bleeding sites; and (c) the mean full-mouth bleeding sites. Adjusted multilevel Poisson regression assessed the association between independent variables at baseline and each definition of gingivitis at 2-year follow-up.

Seven hundred forty-two 14-year-old adolescents were re-revaluated at follow-up. The prevalence of gingivitis was 28.7% according to 10% of bleeding threshold. The 2018 EFP/AAP criteria and other definitions showed higher prevalence and mean of gingivitis for low-household income adolescents and for those with higher levels of dental plaque and untreated dental caries. Nonetheless, the highest strengths of association were observed for the threshold of ≥ 15% of bleeding sites.

The 2018 EFP/AAP case definition of gingivitis showed a similar discriminant validity compared to the 15% threshold and the mean full-mouth bleeding sites.

The 2018 EFP/AAP classification allows the discrimination of important risk factors and should be used for the establishment of priorities for large-scale therapeutic programs.