title: Meta-analysis on the association between toothbrushing and head and neck cancer.
abstract: BACKGROUND
  Epidemiological studies have focused on the association between toothbrushing and head and neck cancer (HNC). However, the question of whether toothbrushing is associated with decreased risk of HNC remains unanswered. Since there is currently no systematic review or meta-analysis available to provide quantitative findings on this important clinical question; we consequently performed this meta-analysis to investigate the association between toothbrushing and HNC risk.
  
  
  METHODS
  We searched PubMed and Embase up to January 13 (updated on October 20), 2014 to identify observational studies that investigated the association between toothbrushing and HNC. After study section and data extraction, the meta-analysis was conducted using RevMan 5.2 software.
  
  
  RESULTS
  A total of 18 case-control studies involving 7068 cases and 9990 controls were included. The meta-analysis showed that compared with highest toothbrushing frequency, lowest level was significantly increased risk of HNC 2.08 times (odds ratio=2.08, 95% confidence interval=1.65-2.62). This significant association remained consistent after adjusting for smoking status and alcohol consumption. No publication bias was detected.
  
  
  CONCLUSIONS
  This meta-analysis found frequency of toothbrushing was significantly associated with HNC risk. Effective toothbrushing may be potentially important for the prevention of HNC and we suggest that the frequency be twice per day (morning and night).
authors.affiliation: Center for Evidence-Based and Translational Medicine, Zhongnan Hospital, Wuhan University, Wuhan, China; Department of Stomatology, Taihe Hospital, Hubei University of Medicine, Shiyan, China; Center for Evidence-Based Medicine and Clinical Research, Taihe Hospital, Hubei University of Medicine, Shiyan, China. Electronic address: zengxiantao1128@163.com.
authors.forename: Xian-Tao
authors.initials: XT
authors.lastname: Zeng
authors.affiliation: Department of Stomatology, Taihe Hospital, Hubei University of Medicine, Shiyan, China.
authors.forename: Wei-Dong
authors.initials: WD
authors.lastname: Leng
authors.affiliation: Center for Evidence-Based Medicine and Clinical Research, Taihe Hospital, Hubei University of Medicine, Shiyan, China.
authors.forename: Chao
authors.initials: C
authors.lastname: Zhang
authors.affiliation: Department of Otolaryngology, The 161 Hospital of PLA, Wuhan 430012, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Liu
authors.affiliation: School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China.
authors.forename: Shi-Yi
authors.initials: SY
authors.lastname: Cao
authors.affiliation: Department of Stomatology, Taihe Hospital, Hubei University of Medicine, Shiyan, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Huang
mesh_terms: D016022:Case-Control Studies; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D006258:Head and Neck Neoplasms / Q000517:prevention & control*; D006801:Humans; D014099:Toothbrushing
keywords: Head and neck neoplasms; Meta-analysis; Mouth neoplasms; Oral hygiene; Oropharyngeal neoplasms; Toothbrushing