Background: This report adds a new definition for mild periodontitis that allows for better descriptions of the overall prevalence of periodontitis in populations. In 2007, the Centers for Disease Control and Prevention in partnership with the American Academy of Periodontology developed and reported standard case definitions for surveillance of moderate and severe periodontitis based on measurements of probing depth (PD) and clinical attachment loss (AL) at interproximal sites. However, combined cases of moderate and severe periodontitis are insufficient to determine the total prevalence of periodontitis in populations.
Methods: The authors proposed a definition for mild periodontitis as ≥ 2 interproximal sites with AL ≥ 3 mm and ≥ 2 interproximal sites with PD ≥ 4 mm (not on the same tooth) or one site with PD ≥ 5 mm . The effect of the proposed definition on the total burden of periodontitis was assessed in a convenience sample of 456 adults ≥ 35 years old and compared with other previously reported definitions for similar categories of periodontitis.
Results: Addition of mild periodontitis increases the total prevalence of periodontitis by ≈31% in this sample when compared with the prevalence of severe and moderate disease.
Conclusion: Total periodontitis using the case definitions in this study should be based on the sum of mild, moderate, and severe periodontitis.