title: Inflammatory bowel disease and oral health: systematic review and a meta-analysis.
abstract: BACKGROUND
  The objective of this systematic review was to systematically investigate whether there is an association between inflammatory bowel disease (IBD) and oral health.
  
  
  METHODS
  Literature searches for randomized and non-randomized studies were performed up to January 2017. Risk of bias within studies was assessed with the Downs and Black checklist. Across-studies risk of bias was assessed with the GRADE framework. Quantitative synthesis was conducted with random-effects meta-analyses.
  
  
  RESULTS
  A total of 9 cross-sectional studies including 1297 patients were included. IBD was associated with increased risk of periodontitis (332 more patients per 1000 patients; 95% confidence interval (CI): 257-388 patients; p < 0.001) compared to non-IBD patients. Additionally, the Decayed-Missing-Filled-Teeth index of IBD patients was significantly worse than non-IBD patients (mean difference: 3.85; 95% CI: 2.36-5.34; p = 0.005). Patients with ulcerative colitis had considerably worse oral health for most of the assessed factors, while the quality of overall evidence ranged from high to low, due to the observational nature of contributing studies.
  
  
  CONCLUSIONS
  Inflammatory bowel disease was associated with significantly higher risk of periodontitis and worse oral health compared to non-IBD patients. However, longitudinal studies are needed in order to establish a causality link between IBD and periodontal disease.
authors.affiliation: Clinic of Orthodontics and Pediatric Dentistry, Center of Dental Medicine, University of Zurich, Zurich, Switzerland.
authors.forename: Spyridon N
authors.identifier: http://orcid.org/0000-0003-1968-3326
authors.initials: SN
authors.lastname: Papageorgiou
authors.affiliation: Private Practice, Bonn, Germany.
authors.forename: Martin
authors.initials: M
authors.lastname: Hagner
authors.affiliation: Department of Diagnosis and Surgery, School of Dentistry, UNESP Univ Estadual Paulista, Araraquara, SP, Brazil.
authors.forename: Andressa Vilas Boas
authors.initials: AV
authors.lastname: Nogueira
authors.affiliation: Institute of Clinical Molecular Biology, Christian-Albrechts-University of Kiel, Kiel, Germany.
authors.forename: Andre
authors.initials: A
authors.lastname: Franke
authors.affiliation: Department of Orthodontics, School of Dentistry, University of Bonn, Bonn, Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Jäger
authors.affiliation: Section of Experimental Dento-Maxillo-Facial Medicine, School of Dentistry, University of Bonn, Bonn, Germany.
authors.forename: James
authors.initials: J
authors.lastname: Deschner
mesh_terms: D006801:Humans; D015212:Inflammatory Bowel Diseases / Q000150:complications*; D009909:Oral Health; D010510:Periodontal Diseases / Q000453:epidemiology* / Q000209:etiology*
keywords: Crohn's disease; inflammatory bowel disease; meta-analysis; oral health; periodontal disease; systematic review; ulcerative colitis