Several years ago, the American Academy of Periodontology (AAP) and European Federation of Periodontology launched a joint effort to review and revise the 1999 disease classification system. The World Workshop on the Classification of Periodontal and Peri-Implant Diseases and Conditions was conducted in November 2017, the proceedings of which are now available in both the July 2018 supplement to the Journal of Periodontology and the Journal of Clinical Periodontology (2018, volume 45, special edition). The 2018 classification scheme is based on the most current and best available scientific evidence from population studies, basic science investigations, and prospective studies evaluating environmental and systemic risk factors related to periodontal and peri-implant disease and conditions. The new classification system has eliminated much of the confusion and overlap encountered between the classification categories of the 1999 version and introduces new perspectives on the evaluation and diagnosis of gingival health and disease, periodontal health and disease and peri-implant health and disease. In particular, the introduction of staging and grading of periodontitis “packages” all of the parameters and findings normally evaluated in a comprehensive examination in a manner that better defines the state of the patient’s disease, complexity of management, rate of progression, and assessment of known and potential risk factors. It is anticipated that the staging and grading of periodontal disease will enhance communication with both patients and referring practitioners, promote earlier referral of patients, and aid in the selection of appropriate patient-based therapy and long-term management. In addition to the staging and grading element, other key changes in the 2018 Disease Classification compared to the 1999 version include:
- Clinical distinctions between presence of gingival inflammation and a true gingivitis case
- Clinical distinctions between a reduced periodontium in a non-periodontitis patient and a successfully treated periodontitis case
- Identification of three forms of periodontal disease based on pathophysiology:
- Necrotizing periodontal diseases
- Periodontitis as manifestation of systemic disease
- Periodontitis
- Replacement of the “chronic” and “aggressive” categorization of periodontitis with the classification of periodontitis dependent on severity, complexity, extent, distribution/pattern, and rate of progression are defined within the staging and grading System
- Classification of periodontitis as a manifestation of systemic disease and other conditions affecting the supporting periodontal tissues that are not dental plaque biofilm-induced based on the primary systemic disease.
- A new classification of gingival recession combining interproximal attachment loss, gingival phenotype, ability to identify CEJ, and presence or absence of root concavity
- Replacement of the term biologic width with supracrestal attached tissues
- Introduction of a much needed and universally agreed upon classification of peri-implant health and peri-implant diseases
The Journal of Periodontology and Journal of Clinical Periodontology publications not only include the original commissioned review papers, but also the consensus reports from the various Workshop groups which summarize the classification, more importantly, provide case definitions for better clarity and practical applications.
To assist in the broad dissemination of the Workshop proceedings, the AAP has established a Disease Classification Steering Committee for which I serve as the chair. The committee is composed of experts from both the Organizing Committee for the 2017 World Workshop and those who represent periodontal education, clinical practice, and the insurance industry. Our committee is in the process of identifying key messages and resources to facilitate the adoption the 2018 Disease Classification by all communities of interest. Remember, this has literally been a global effort that has produced a dynamic classification system that will evolve as new and better evidence is discovered. Stay tuned to perio.org and AAP Connect for updates and more information.
Michael P. Mills, DMD, MS
Chair, Disease Classification Steering Committee