The periodontal disease classification system of the American Academy of Periodontology--an update

Abstract

Until recently, the accepted standard for the classification of periodontal diseases was the one agreed upon at the 1989 World Workshop in Clinical Periodontics. This classification system, however, had its weaknesses. In particular, some criteria for diagnosis were unclear, disease categories overlapped, and patients did not always fit into any one category. Also, too much emphasis was placed on the age of disease onset and rate of progression, which are often difficult to determine. Finally, no classification for diseases limited to the gingiva existed. In 1999, an International Workshop for a Classification of Periodontal Diseases and Conditions was organized by the American Academy of Periodontology to address these concerns and to revise the classification system. The workshop proceedings have been published in the Annals of Periodontology. The major changes to the 1989 proceedings and the rationale for these changes are summarized here. In addition, the potential impact of these changes is discussed.