Frequency of Periodontitis Using Different Clinical Protocols and Case Definitions

Objectives: It is understood that the use of partial mouth clinical examination in surveys to estimate prevalence of periodontitis will result in some underestimation of disease. However, the extent to which different clinical definitions and partial clinical examination underestimates the true prevalence of periodontitis in U.S. national surveys is unknown. The objective of this study was to compare the frequency of periodontitis using several clinical definitions in partial mouth examination versus full mouth examination using the National Health and Nutrition Examination Survey (NHANES) protocol.

Methods: A convenience sample of 456 adults, aged 35 years and older was recruited among non-Hispanic whites and blacks, and Hispanics. A full-mouth periodontal examination was performed with pocket depth and attachment loss assessed at six sites per tooth for all teeth (except the third molars) using the NHANES examination protocol. Frequency of periodontitis was assessed by six clinical definitions previously used in surveillance of periodontitis versus full mouth and partial mouth examinations and using the Centers for Disease Control-American Academy of Periodontology (CDC-AAP) definition for severe and moderate periodontitis as the reference.

Results: Frequency of total periodontitis (severe and moderate combined) ranged from 13.6% to 41.5% using various definitions and based on data from full mouth examination. Frequency based on the CDC-AAP definition was 22.4%. When using data that simulates the NHANES 2003-04 partial examination protocol, frequency for the various definitions ranged from 4.4% to 25.2% (CDC-AAP definition was 8.3%), and similarly when simulating the NHANES III partial examination, frequency ranged from 2.2% to 22.2% (CDC-AAP definition was 5.9%).

Conclusion: Partial mouth examination as used in previous NHANES may underestimate the frequency of periodontitis by more than two-fold regardless of clinical definitions used; and within each examination protocol there are wide variations in the prevalence when using different case definitions.