title: Purpose and problems of periodontal disease classification.
authors.affiliation: Department of Periodontology, Academic Centre for Dentistry Amsterdam , Universiteit van Amsterdam and Vrije Universitiet, Amsterdam, The Netherlands.
authors.forename: Ubele
authors.initials: U
authors.lastname: van der Velden
mesh_terms: D000208:Acute Disease; D000367:Age Factors; D002908:Chronic Disease; D006801:Humans; D010518:Periodontitis / Q000145:classification*; D009626:Terminology as Topic