Fernando Suarez - Periodontics

Classification systems are essential to properly study the diagnosis, etiology, pathogenesis, and treatment of the different diseases. As such, the field of periodontology has witnessed the creation and continued update of different classification systems since the early 1940s. The first World Workshop in Periodontics 37was held in Ann Arbor, Michigan, on June 6 to 9, 1966, and the most recent World Workshop took place in Chicago on November 9 to 11, 2017, with the related publications released in June 2018. 38Understanding the development and the variations among the different classifications is critical for comprehending the literature published in different eras.

One of the first major and comprehensive classifications of periodontitis emerged from the World Workshop in 1989. 37On this date, the World Workshop in Clinical Periodontics gathered scientists and researchers to develop a classification for periodontal diseases. There were essentially five different classifications, which are listed in Box 2-3. 37

BOX 2-3 Classification proposed in 1989 World Workshop in Clinical Periodontics 37

Under the 1989 classification system, age of onset and distribution of lesions were taken into consideration for classifying adult periodontitis and early onset periodontitis as well as the subforms of early-onset periodontitis that included prepubertal periodontitis (generalized/localized), juvenile periodontitis (generalized/ localized), and rapidly progressive periodontitis. 37

The 1989 classification raised problems in several areas 39:

Considerable overlap in disease categories

Absence of a gingival disease component

Inappropriate emphasis on age of onset of disease and rates of progression

Inadequate or unclear classification criteria

Therefore, the next landmark classification was the 1999 International Workshop for a Classification of Periodontal Diseases and Conditions, which addressed some of the problems in the previous classification. The major changes in the classification system for periodontal diseases included ( Box 2-4) 39:

BOX 2-4 Summary of 1999 International Workshop for a Classification of Periodontal Diseases and Conditions 39

Addition of a section on gingival diseases

Replacement of “Adult periodontitis” with “Chronic periodontitis”

Replacement of “Early-onset periodontitis” with “Aggressive periodontitis”

Elimination of a separate disease category for Refractory periodontitis

Clarification of the designation “Periodontitis as a manifestation of systemic diseases”

Replacement of “Necrotizing ulcerative periodontitis” with “Necrotizing periodontal diseases”

Addition of “Periodontal abscesses” category

Addition of “Periodontic-endodontic lesions” category

Addition of “Developmental or acquired deformities and conditions” category

In order to update the 1999 classification of periodontal diseases and conditions, 39an organizing committee from the American Academy of Periodontology (AAP) and the European Federation of Periodontology (EFP) commissioned the world workshop that was held in Chicago on November 9 to 11, 2017. 38The world workshop included expert participants in the field of periodontology and implant dentistry from around the world. The scope of the 2017 world workshop was to align and update the classification scheme to the current understanding of periodontal and peri-implant diseases and conditions. Therefore, in addition to updating the 1999 classification of periodontal diseases and conditions, this was also the first world consensus to develop a classification scheme for peri-implant diseases and conditions. 38

A brief classification scheme for the 2017 world workshop is presented in Box 2-5, 38and major changes to the 1999 classification include the following 40:

BOX 2-5 2017 World Workshop on the Classification of Periodontal and Peri-implant Diseases and Conditions 38

The 2017 workshop characterized periodontal health and gingival inflammation in a reduced periodontium after completion of successful treatment of a patient with periodontitis.