Most Recent Re-Classification of Periodontal Diseases (1999)
As demonstrated in the chapter “Forms of Plaque-associated Diseases” (p. 79), new scientific and clinical findings, accumulating long-term experiences as well as the rapid exchange of this knowledge (internet) resulted in the necessity to freshly define the classifications and nomenclature of diseases and clinical “conditions.”
Toward the end of 1999, a workshop in Oak Brook, Illinois, was convened with members of the American Academy of Periodontology (AAP) and the European Federation of Periodontology (EFP), and the result of this meeting is presented on the following two pages as the original and unabridged illustration of the new classification (Types I-VIII), as published by Armitage (1999) in Annals of Periodontology.
Classification 1999—For and Against
The “old classification” (AAP 1989) described five disease classes. This classification too heavily weighted the patient age at disease onset—e.g., “early onset periodontitis,” EOP and “adult periodontitis,” AP, as well as the course of the disease, e.g., rapidly-progressing (EOP/RPP). It was necessary to change this type of classification because “rapidly progressive periodontitis” (RPP) does not occur only in young patients, and also a chronic periodontitis (AP) in elderly patients with reduced immune function can unexpectedly and quickly evolve into an acute status.
But even the new 1999 classification will only last for a limited period of time: It is too all-inclusive and combines the disease entities that are practice-relevant and most common with those disease entities that are rather quite rare. The 1999 classification is similar in many ways to the extensive catalog provided by the WHO list of diseases, but does not consider the multifactorial character of periodontal diseases (risks!).
This problem has been described thematically in numerous subsequent publications (Van der Velden 2000, Burgermeister & Schlagenhauf 2002, Brunner et al. 2002, DGP 2002, Bengel 2003, Lang 2003).