title: Tooth loss and risk of head and neck cancer: a meta-analysis.
abstract: BACKGROUND
  Observational studies suggest an association between tooth loss and risk of head and neck cancer. However, whether tooth loss is an independent risk factor for head and neck cancer still remains controversial. The aim of this study is to assess the association between tooth loss and head and neck cancer risk.
  
  
  METHODS
  Eligible studies were searched in PubMed and Embase databases from their inception to March 2013. A random-effects model or fixed-effects model was used to calculate the overall combined risk estimates.
  
  
  RESULTS
  Eight case-control studies and one cross-sectional study involving 5,204 patients and 5,518 controls were included in the meta-analysis. The overall combined odds ratio for tooth loss and head and neck cancer was 2.00 (95% confidence interval, 1.28-3.14). Similar results yielded both in the moderate and severe tooth loss group. Sensitivity analysis based on various exclusion criteria maintained this significance with respect to head and neck cancer individually. Little evidence of publication bias was observed.
  
  
  CONCLUSIONS
  This meta-analysis suggests that tooth loss is associated with increased risk of head and neck cancer. This increase is probably independent of conventional head and neck cancer risk factors.
authors.affiliation: Department of Radiotherapy, The First Affiliated Hospital, Guangxi Medical University, Nanning, Guangxi, People's Republic of China.
authors.forename: Ren-Sheng
authors.initials: RS
authors.lastname: Wang
authors.forename: Xue-Ying
authors.initials: XY
authors.lastname: Hu
authors.forename: Wan-Jie
authors.initials: WJ
authors.lastname: Gu
authors.forename: Zhen
authors.initials: Z
authors.lastname: Hu
authors.forename: Bo
authors.initials: B
authors.lastname: Wei
mesh_terms: D016022:Case-Control Studies; D003430:Cross-Sectional Studies; D006258:Head and Neck Neoplasms / Q000150:complications* / Q000175:diagnosis*; D006801:Humans; D016017:Odds Ratio; D012107:Research Design; D012307:Risk Factors; D016388:Tooth Loss / Q000150:complications*; D016896:Treatment Outcome