Naval Postgraduate Dental School Navy Medicine Professional Development Center 8955 Wood Road Clinical Update Bethesda, Maryland 20889-5628

Vol. 41, No. 2 June 2019

A New Classification Scheme for Periodontal Diseases and Conditions: A Review of the 2017 AAP World Workshop on the Classification of LT Ryan Kaye, DC, USN; CDR Keith Merchant, DC, USN

Introduction Over the past three decades, the American Academy of Table 1 (AAP) has revised the diagnostic classification scheme for periodontal diseases and conditions. Since 1986, the classification system has been modified on only two occasions in 1989 and 1999. For the past 19 years, periodontists and the field of dentistry as a whole have employed the 1999 diagnostic classification scheme published by Armitage in treatment planning applications across the globe.1 In 2017, global leaders in the field of periodontics met at the World Workshop on the Classification of Periodontal Disease with the goal of devising a modernized classification system that reflects significant advances in the understanding and pathophysiology of periodontal diseases and conditions. The purpose of this review is to summarize significant changes to the diagnosis of periodontal diseases and provide guidance for application of the Table 2 new diagnostic scheme in education and clinical practice. Classification of Periodontitis Based on the most current evidence, periodontitis can be manifested in one of three distinct forms: Necrotizing Periodontitis, Periodontitis as a Manifestation of Systemic Disease or Periodontitis—an all-inclusive term that considers the formerly recognized chronic and aggressive profiles as a single disease entity.1 Periodontitis is further differentiated through a tiered staging (Stage I, II, III or IV) and grading (Grade A, B or C) system. Staging considers the severity and complexity of disease treatment, while grading considers

disease progression risk relative to age and the impact of Tables from Tonetti (2018) systemic health. Extent and distribution (Generalized, Localized or Molar/Incisor Pattern) are determined by an assessment of the number of teeth affected by the disease. The Stage III and IV disease can be distinguished from Stage I and II by term generalized is appropriate when 30% of teeth are periodontitis-related loss (4 or less for Stage III and 5 or more affected, while localized applies when <30% of teeth are for Stage IV), Grade 2+ furcation invasion and VBL 3mm. involved. Molar/Incisor Pattern is reserved for cases Distinguishing features of Stage IV disease include advanced loss 2 of masticatory function, occlusal trauma and hypermobility involving disease focused in the molar and incisor regions. resulting in the need for complex, multidisciplinary 2 Primary staging criteria involve a determination of maximum rehabilitation. Unlike the previous classification system in which Radiographic Bone Loss (RBL), Clinical Attachment Level severity could be described at both a generalized and local level (CAL) loss, RBL patterns, and periodontitis-related tooth loss. (e.g. Generalized Moderate Chronic Periodontitis with Localized Stage I and II periodontitis represent mild to moderate disease Severe Periodontitis), the new scheme allows for the selection of with CAL loss ranging from 1-4mm and RBL up to 33% of only one stage that reflects the maximum relevant severity level root length. Limits for Stage I and II disease include maximum and remains constant throughout the course of treatment. probing depths of 4-5mm, Grade I furcation involvement and Vertical Bone Loss (VBL) of 1-2mm. Stage III and Stage IV Primary grading criteria involve direct and indirect evidence of periodontitis represent severe to very severe disease with CAL historical disease progression rates relative to age, the relationship of biofilm to host susceptibility and the impact of loss 5mm and RBL >33% of root length. behavioral and systemic factors known to influence disease treatment and progression. Grade A represents slow syndromes). Such diseases are associated with the group progression with minimal attachment loss, while Grade B, heading of Periodontitis as a Manifestation of Systemic the default grade consideration, represents moderate Disease. The second group includes those systemic disorders progression at 0.25 to 1.0mm per year. Grade C represents that result in a loss of periodontal tissues independent of rapid progression at >1.0mm per year, thus capturing those plaque-induced periodontitis (e.g., neoplastic conditions, individuals diagnosed with the former “aggressive” disease Langerhans cell histiocytosis, and granulomatosis), earning profile.2 Grading may be modified by smoking, diabetes a group heading of Systemic Diseases or Conditions 4 and/or systemic inflammation. Unlike staging of Affecting the Periodontal Supporting Tissues. It is important periodontitis, grading can change over time. Tables 1 and 2 to clarify that although diabetes is a significant modifier of provide a summary for periodontal staging and grading.3 periodontal disease, the pathophysiology of periodontal disease in diabetic patients is not unique. Thus, diabetes- Necrotizing Periodontal Disease associated periodontitis is not included in either of the above Necrotizing Ulcerative (NUG) and Necrotizing categories in favor of its position as a grade modifier for 1 Ulcerative Periodontitis (NUP) were previously classified as periodontitis. separate disease entities; however, current evidence suggests that they represent different stages of the same disease, Conclusion sharing similar etiology, clinical characteristics and The changes in the new classification scheme represent a treatment.2 The descriptor term “ulcerative” has been monumental paradigm shift in the diagnostic approach to omitted in favor of less redundant terminology, as ulceration periodontal disease. As advances in periodontal research and is considered to be a known consequence of the necrotic related science occur, disease classifications must be lesion. The prevalence, pathophysiology and risk profile for modified to reflect the progress in knowledge. The new Necrotizing Periodontal Disease (NPD) remains unchanged World Workshop classification of the spectrum of from historical reporting in the periodontal literature, and periodontal disease resulted from a global collaboration and diagnostic features still include necrosis, bleeding and pain consensus of European and American experts. While the with secondary findings of pseudomembrane, malodor, fever new classification brings implementation challenges to and lymphadenopathy.2 Necrotizing Gingivitis (NG) affects dental professionals and associated industries, the goal of the only soft tissue, while Necrotizing Periodontitis (NP) affects change is to promote improved communication with our soft tissue and bone manifesting as clinical and/or dental and medical colleagues, establish a universal radiographic loss of supporting tissues. Necrotizing classification system that encourages standardized research (NS), often seen in patients with severe and ultimately, enhances the management of our patients. malnutrition or systemic disease, is a result of osteitis and denudation of bone with potential spread to include large References 2 1. Caton J, Armitage G, Berglundh T, et al. A new classification areas of the face. This extreme form of NPD is classified as scheme for periodontal and peri-implant diseases and conditions – , orofacial gangrene that causes horrific, penetrating Introduction and key changes from the 1999 classification. J mutilation of infected tissues. The updated classification Periodontol. 2018;89(Suppl 1):S1–S8. scheme requires assessment of systemic compromise as 2. Papapanou PN, Sanz M, et al. Periodontitis: Consensus report either “chronically, severely compromised” or “temporarily of Workgroup 2 of the 2017 World Workshop on the and/or moderately compromised.” Advanced disease stages Classification of Periodontal and Peri‐Implant Diseases and (NS and Noma) are more commonly seen in cases of extreme Conditions. J Clin Periodontol. 2018;45(Suppl 20):S162–S170. systemic compromise, while NPD associated with modern 3. Tonetti MS, Greenwell H, Kornman KS. Staging and grading clinical practice is more likely a result of temporary systemic of periodontitis: Framework and proposal of a new classification and case definition. J Clin Periodontol. 2018;45 (Suppl20): compromise (NG and NP). In summary, the new S149–S161. classification of NPD includes a spectrum of clinical 4. Albandar JM, Susin C, Hughes FJ. Manifestations of systemic manifestations modified by the level of systemic diseases and conditions that affect the periodontal attachment compromise, as follows: NGNPNSNoma. apparatus: Case definitions and diagnostic considerations. J Clin Periodontol.2018;45(Suppl 20):S171–S189. Systemic Disease and Periodontitis Current evidence demonstrates that numerous conditions Dr. Kaye is a recent graduate the NPDS Periodontics residency and diseases may contribute to destruction of periodontal program. Dr. Merchant is the Program Director of the NPDS tissues through impairment of the host response. When Periodontics Residency Program. systemic disease contributes to periodontitis, the primary The opinions and assertions contained in this article are the diagnosis should be the systemic disease, as defined by the private ones of the authors and are not to be construed as official 2 International Classification of Diseases (ICD). The new or reflecting the views of the Department of the Navy. periodontal classification scheme describes two groups of diseases with the first group including those that increase The Naval Postgraduate Dental School is affiliated host inflammation, thereby exacerbating the pathogenesis of with the Uniformed Services University of the periodontal disease (e.g., Down, leukocyte adhesion Health Sciences’ Postgraduate Dental College. deficiency, Papillon-Lefèvre and Chediak-Higashi