[State of the art diagnostic criteria of severe periodontitis].

Periodontitis could be categorized as mild, moderate, and severe according to the severity of the disease. This categorizing system could also be used together with other classification systems. The present article introduced the status about the case definition of severe periodontitis, including the standard of case definitions for surveillance of periodontitis reported by the Centers for Disease Control and Prevention (CDC) in partnership with the American Academy of Periodontology (AAP) and the consensus report on the definition of periodontitis case for use in risk factor research by Europe workshop. A consensus on the state of the art definition of severe periodontitis for use in clinical work was gained base on the expertise of Chinese Society of Periodontology, Chinese Association of Stomatology. The background of this consensus and the significance of the criteria for the case definition were discussed.