Case Definitions for Use in Population‐Based Surveillance of Periodontitis

TLDR

Periodontitis has been inconsistently defined across studies, with early research treating it as a continuum with gingivitis and evolving case definitions that rely on probing depth, clinical attachment level, bone loss, and bleeding on probing, yet no standard remains. The study aimed to create standardized clinical case definitions for population-based periodontitis surveillance, as initiated by a CDC–AAP working group in 2003. The authors reviewed national United States surveys from 1960 to 2000, whose case definitions and protocols illustrate the progressive refinement of periodontitis measurement. The resulting classification delineates severe and moderate periodontitis using specific probing depth and clinical attachment level thresholds and the number of affected sites, underscoring how these criteria influence prevalence estimates.

Abstract

Many definitions of periodontitis have been used in the literature for population‐based studies, but there is no accepted standard. In early epidemiologic studies, the two major periodontal diseases, gingivitis and periodontitis, were combined and considered to be a continuum. National United States surveys were conducted in 1960 to 1962, 1971 to 1974, 1981, 1985 to 1986, 1988 to 1994, and 1999 to 2000. The case definitions and protocols used in the six national surveys reflect a continuing evolution and improvement over time. Generally, the clinical diagnosis of periodontitis is based on measures of probing depth (PD), clinical attachment level (CAL), the radiographic pattern and extent of alveolar bone loss, gingival inflammation measured as bleeding on probing, or a combination of these measures. Several other patient characteristics are considered, and several factors, such as age, can affect measurements of PD and CAL. Accuracy and reproducibility of measurements of PD and CAL are important because case definitions for periodontitis are based largely on either or both measurements, and relatively small changes in these values can result in large changes in disease prevalence. The classification currently accepted by the American Academy of Periodontology (AAP) was devised by the 1999 International Workshop for a Classification of Periodontal Diseases and Conditions. However, in 2003 the Centers for Disease Control and Prevention and the AAP appointed a working group to develop further standardized clinical case definitions for population‐based studies of periodontitis. This classification defines severe periodontitis and moderate periodontitis in terms of PD and CAL to enhance case definitions and further demonstrates the importance of thresholds of PD and CAL and the number of affected sites when determining prevalence.