title: Classifying periodontal diseases--a long-standing dilemma.
authors.forename: Gary C
authors.initials: GC
authors.lastname: Armitage
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D010520:Aggressive Periodontitis / Q000145:classification / Q000266:history; D016301:Alveolar Bone Loss / Q000145:classification / Q000266:history; D001424:Bacterial Infections / Q000175:diagnosis; D002648:Child; D018450:Disease Progression; D005889:Gingival Recession / Q000145:classification / Q000266:history; D049672:History, 19th Century; D049673:History, 20th Century; D006801:Humans; D010510:Periodontal Diseases / Q000145:classification* / Q000209:etiology / Q000266:history / Q000382:microbiology