title: Periodontitis and obstructive sleep apnea's bidirectional relationship: a systematic review and meta-analysis.
abstract: OBJECTIVE
  The aim of this study is to evaluate the association between periodontal disease and obstructive sleep apnea (OSA).
  
  
  METHODS
  Electronic search using PubMed, Cumulative Index to Nursing and Allied Health (CINAHL), Cochrane Central Trial Registry, Cochrane Database of Systematic Reviews, Scopus, and Embase was carried out for randomized controlled trials, longitudinal, cohort, case-control, and epidemiological studies on humans, published until October 2014. Manual searches were also performed. The participants considered were adult subjects with OSA and chronic periodontitis. The authors reviewed all articles and extracted data using a customized data abstraction sheet. Methodological quality assessment was carried out using the Newcastle-Ottawa Quality Assessment Scale.
  
  
  RESULTS
  Six studies met the inclusion criteria set for this review. They evaluated the association between periodontal disease and OSA and the efficacy of periodontal interventions on OSA occurrence and severity. The periodontal disease outcome measures included clinical attachment loss, periodontal pocket depth, oral hygiene indices, radiographic alveolar bone loss, and salivary cytokines. Meta-analysis of four studies revealed a statistically significant association between periodontal disease and OSA (pooled odds ratio = 1.65, 95 % confidence interval (CI) = 1.11, 2.46, P = 0.01). There is insufficient evidence on the efficacy of periodontal disease interventions.
  
  
  CONCLUSIONS
  There is some evidence to a plausible association between periodontal disease and OSA. Evidence on the efficacy of periodontal disease interventions is insufficient. The causal-effect relationship of periodontal disease and OSA is debatable. Further research with case-control studies is warranted.
authors: Division of Dental Public Health, Department of Preventive Dental Sciences, College of Dentistry, University of Dammam, Dammam, Saudi Arabia. taljewair@gmail.com.
authors: Thikriat S
authors: TS
authors: Al-Jewair
authors: Department of Periodontics, State University of New York at Buffalo, Buffalo, NY, USA. r.aljasser@gmail.com.
authors: Reham
authors: R
authors: Al-Jasser
authors: Division of Periodontology, Department of Preventive Dental Sciences, College of Dentistry, University of Dammam, Dammam, Saudi Arabia. kalmas@uod.edu.sa.
authors: Khalid
authors: K
authors: Almas
mesh_terms: D006801:Humans; D016017:Odds Ratio; D010518:Periodontitis / Q000175:diagnosis / Q000503:physiopathology* / Q000628:therapy; D016032:Randomized Controlled Trials as Topic; D020181:Sleep Apnea, Obstructive / Q000175:diagnosis / Q000503:physiopathology* / Q000628:therapy; D013223:Statistics as Topic; D016896:Treatment Outcome
keywords: OSA; Oral and systemic health; Periodontal disease; Periodontal intervention