title: Periodontal Disease and Tooth Loss as Risks for Cancer: A Systematic Review of the Literature.
abstract: BACKGROUND
  Periodontal disease is a chronic destructive disease which occurs in adults, young people, and children. Periodontal disease and periodontal pathogens have been associated with several systemic diseases and more recently, several studies have suggested the relationship between periodontal disease and cancer. Studies with adjustment for the effect of smoking exposure, have found significant positive associations with different cancer sites. This review has outlined recent epidemiologic researches pointing to a possible role for tooth loss and periodontal disease in carcinogenesis.
  
  
  METHODS
  In this review, articles were selected from PubMed between1995 and June 2010 including human. Amongst 5,984 articles identified from the electronic search, 17 articles were selected for a full-text reading based on the inclusion and the exclusion criteria.
  
  
  RESULTS
  Nine out of 10 case-control studies reported a significant increase in the risk of oral cancer in patients with periodontitis and one with no significant association. Among 6 studies examining esophageal cancer and periodontal disease, 5 studies found a significant association between them and one study failed to find a significant increased risk of cancer. Also amongst 5 studies which focused on upper gastrointestinal, gastric cancer, and periodontal disease, 4 studies found an increased risk of cancer while one study did not report any relationship. In lung cancer evaluations, 3 out of 4 studies showed some levels of association between lung cancer and periodontal disease but after adjustment for smoking, no relationship were found. Three cohort studies have evaluated overall cancer rates in periodontal patients; two of them found small but significant association between cancers and periodontal disease.
  
  
  CONCLUSIONS
  The results indicate that there is a possible link between cancer and severe periodontal disease after adjustment for smoking and drinking habits.
authors: Department of Periodontology, Faculty of Dentistry, Islamic Azad University Khorasgan Brunch, Isfahan, Iran.
authors: M
authors: M
authors: Sadighi Shamami
authors: Department of Periodontology, Faculty of Dentistry, Tabriz University of Medical Sciences, Tabriz, Iran.
authors: M
authors: M
authors: Sadighi Shamami
authors: Department of Periodontology, Faculty of Dentistry, Islamic Azad University Khorasgan Brunch, Isfahan, Iran.
authors: S
authors: S
authors: Amini
keywords: Mouth neoplasm; Oral hygiene; Periodontitis; Tooth loss