title: Association Between Oral Health and Cognitive Status: A Systematic Review.
abstract: OBJECTIVE
  To systematically review longitudinal studies examining the association between oral health and cognitive decline.
  
  
  METHODS
  Studies published between January 1993 and March 2013 were identified by search of English language publications in PubMed/Medline using relevant Medical Subject Heading terms and title and abstract keywords and from CINAHL using relevant subject headings. After applying eligibility criteria and adding four studies identified from article references, 56 of the 1,412 articles identified remained; 40 were cross-sectional, and 16 were longitudinal; 11 of the latter examined the effect of oral health on change in cognitive health or dementia incidence, five examined the reverse.
  
  
  METHODS
  Sources of information included administrative data, subject evaluations in parent studies, medical and dental records, self-reports, and in-person evaluations.
  
  
  METHODS
  Older adults.
  
  
  METHODS
  Most studies used subjects whose oral or cognitive status was known, using standard approaches to impute for missing information. The oral health information most frequently studied included number of teeth, periodontal and caries problems, and denture use. Cognition was most frequently evaluated using the Mini-Mental State Examination or according to a diagnosis of dementia.
  
  
  RESULTS
  Some studies found that oral health measures such as number of teeth and periodontal disease were associated with risk of cognitive decline or incident dementia, whereas others did not find an association. Similarly, cognitive decline was not consistently associated with greater loss of teeth or number of decayed teeth. It is likely that methodological limitations play a major role in explaining the inconsistent findings.
  
  
  CONCLUSIONS
  It is unclear how or whether oral health and cognitive status are related. Additional research is needed in which there is greater agreement on how oral health and cognitive states are assessed to better examine the linkages between these two health outcomes.
authors.affiliation: School of Nursing, Duke University, Durham, North Carolina.
authors.forename: Bei
authors.initials: B
authors.lastname: Wu
authors.affiliation: Center for the Study of Aging and Human Development, Duke University Medical Center, Durham, North Carolina.
authors.forename: Gerda G
authors.initials: GG
authors.lastname: Fillenbaum
authors.affiliation: Center for the Study of Aging and Human Development, Duke University Medical Center, Durham, North Carolina.|Department of Psychiatry and Behavioral Sciences, Duke University Medical Center, Durham, North Carolina.
authors.forename: Brenda L
authors.initials: BL
authors.lastname: Plassman
authors.affiliation: School of Nursing, Duke University, Durham, North Carolina.
authors.forename: Liang
authors.initials: L
authors.lastname: Guo
mesh_terms: D003072:Cognition Disorders / Q000175:diagnosis*; D006304:Health Status; D006801:Humans; D009483:Neuropsychological Tests; D009909:Oral Health
keywords: cognitive decline; dementia; oral health