Table 2.

Case definitions for denoting periodontitis in epidemiological studies

Authors/context	Case severity	Case definition
Tonetti & Claffey, 2005. Consensus report of the 5th European Workshop on Periodontology [28]	Mild/incipient cases	Presence of proximal attachment loss of ≥ 3 mm in ≥ 2 non-adjacent teeth
	Severe cases	Presence of proximal attachment loss of ≥ 5 mm in ≥ 30% of teeth present
Page & Eke, 2007. US Centre for Diseases Control and Prevention (CDC) and American Academy of Periodontology (AAP) [27,29]	Mild periodontitis	Two or more interproximal sites with attachment loss ≥ 3 mm and two or more interproximal sites with probing depths ≥ 4 mm, not on the same tooth, or one site with probing depth ≥ 5 mm
	Moderate periodontitis	Two or more interproximal sites with attachment loss ≥ 4 mm, not on the same tooth, or two or more interproximal sites with probing depths ≥ 5 mm, not on the same tooth
	Severe periodontitis	Two or more interproximal sites with attachment loss ≥ 6 mm, not on the same tooth, and one or more interproximal sites with probing depth ≥ 5 mm