Periodontitis Classification: Advances and Challenges

Agreement between international periodontal experts using the 2017 World Workshop Periodontitis Classification

Highlights

This study assessed inter-examiner agreement on the clinical application of the 2017 World Workshop on Periodontitis Classification. Additionally, "gray areas" related to classification were identified. A group of 9 cases with different degrees of severity were classified by 103 clinical evaluators with experience in the management of periodontal diseases.
For staging, grading, and extension assessments, overall interexaminer agreement was 76.6%, 82%, and 84.8%, respectively, with moderate interexaminer reliability. Gray areas were observed in 3 of the 9 cases, indicating the need for greater clarity in classification.
The authors have presented all the questions that arose during the study and have provided answers with suggested readings that will be useful for doctors. With all cases available to readers, the authors present a step-by-step approach to diagnosing each case with a rationale based on the 2017 classification, which will be helpful for clinical readers to calibrate against the “gold standard” panel.
The authors recommend continued refinement and the incorporation of diagnostic challenges.

Periodontitis is a global healthcare problem with increasing individual and societal costs, and current evidence indicates that up to 42% of dentate adults in the US have periodontitis.

The 2017 World Workshop on Classification of Periodontal and Peri-Implant Diseases and Conditions agreed on a new classification of periodontal diseases based on a multifaceted classification and staging system that recognizes a subset of people who develop more severe periodontitis than most adults.

Furthermore, it has been known for many years that segments of patients with moderate to severe periodontitis do not respond predictably to standard periodontitis treatment protocols administered by well-trained clinicians.

The new periodontitis classification system was developed in recognition that previous classifications for periodontal disease did not easily translate into diagnoses and treatment plans for individual patients.

It was recognized that several phenotypes of periodontitis exist, and the 2017 classification incorporates the use of several factors as part of the multifactorial influences on an individual patient’s past disease and the likelihood of a future response to standard principles of periodontal treatment and maintenance. .

It remains uncertain whether the structure and integrated information of the staging and classification system allows clinicians to predictably classify individual patients.

The primary objective of this study was to determine the degree of consistency in staging, classification, and outreach among people trained to manage cases of severe periodontitis and with prior exposure to the new classification of periodontitis. The cases selected for this study were based on the training and experience of the clinicians invited to participate.

Background

Recently, a new classification of periodontitis was introduced that involves multidimensional grading and grading.

The objective of the study was to evaluate whether people well trained in periodontology consistently used the new classification for patients with severe periodontitis.
The secondary objective was to identify “gray areas” related to classifications.

Methods

Participants (raters) individually classified 10 preselected severe periodontitis cases using the World Workshop 2017 classification. An internet-based case study was conducted after inviting members of the American Academy of Periodontology and the European Federation of Periodontology.

The gold standard diagnoses were determined by five experts who developed the new classification of periodontitis.

Interrater reliability agreement was assessed using the Fleiss Kappa index with the jackknife method for linearly weighted kappa calculations. McNemar’s test was used to determine symmetry between raters and the gold standard panel.

Results

A total of 103 evaluators participated and classified nine clinical cases. Fleiss Kappa values showed moderate interexaminer consistency among raters for stage (K value: 0.49; 95% CI, 0.19 to 0.79), grade (K value: 0.50; 95% CI, 95%, 0.30 to 0.70) and grade (K value: 0.51 95% CI, 0.23 to 0.77).

When analyzed as a composite (stage, grade, extent), there was moderate interreliability between raters, k = 0.479 (K value: 0.47; 95% CI, 0.442 to 0.515).

Agreement between raters and the gold standard panel was 76.6%; rating 82%; and extension 84.8%.

In six of the nine cases, between 77% and 99% of raters consistently agreed with the gold standard panel, and the other three cases had gray zone factors that reduced rater consistency.

Conclusions

Physicians appropriately trained in the management of patients with periodontal disease demonstrated moderate overall agreement in their diagnostic classification of periodontitis cases using the 2017 World Workshop Classification system.
Although cases of severe periodontitis showing well-defined features were scored consistently, gray areas that introduced complexities of interpretation reduced inter-rater agreement.
Continued identification, refinement, and incorporation of such diagnostic challenges are necessary to guide the training of a broad range of clinicians and predictably improve their diagnostic agreement in the classification of periodontitis.

Periodontitis Classification: Advances and Challenges

Advances in periodontitis classification underscore the need for continued refinement and incorporation of diagnostic challenges to enhance the accuracy and reliability of periodontal disease diagnosis and management, informing evidence-based approaches to periodontal care.