Den nye klassifikation af parodontitis

English summary The new classification on periodontitis. How to apply the classification in daily clinical work Nor Tannlegeforen Tid. 2022; 132: 10–20. The classification of periodontal diseases has been re-organised after extensive work in expert groups followed by an international workshop arranged by the American Academy Periodontology and the European Federation of Periodontology in 2017. The international expert panel at the workshop representing countries from around the world has agreed on the definitions, which in addition to a description of periodontitis include descriptions on the intact periodontium, periodontal health, biofilm-induced gingivitis, and non-biofilm-induced gingival disease. The present article focuses on periodontitis. Periodontitis is a condition with interdental clinical attachment loss (CAL) of at least 1 mm on at least two non-neighbouring teeth or a buccal/lingual CAL of at least 3 mm on at least two teeth. According to severity periodontitis is further subdivided in four stages (I – IV), and three grades (A, B, C) according to rate of progression and risk factors. Furthermore, the extent and distribution of the disease must be stated. Here we describe how the new classification on periodontitis applies to every-day clinical practice, how can patients and the clinical profession benefit from implementation of the new classification, and what is the magnitude of the problem, i.e. the prevalence of severe periodontitis? The article also presents representative cases to illustrate the new concept of staging and grading.