Cognitive decline/oral health link still unclear

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  • Findings of the first large systematic review were inconclusive regarding the link between cognitive decline and oral health.

Study design

  • PubMed/Medline/CINAHL search identified 1,412 articles related to older adults between January 1993 and March 2013, of which 56 met eligibility criteria (40 cross-sectional; 16 longitudinal).
  • 11 longitudinal studies examined the effect of oral health (number of teeth, periodontal disease, caries, denture use) on risk of cognitive decline/dementia on the basis of Mini-Mental State Examination or diagnosis, and the other 5 studies examined the reverse.

Key results

  • In some but not all studies, oral health measures were associated with the risk of cognitive decline or incident dementia.
  • Cognitive decline was inconsistently linked to tooth loss or decay.


  • Interstudy variability on measurement of oral health and cognitive state and other methodological limitations.

Why this matters

  • If poor oral health predicts faster cognitive decline, monitoring and maintaining good oral hygiene may be preventive.
  • Poor nutrition and systemic diseases (diabetes, cardiovascular disease) are associated with poor oral health and cognitive function.
  • Additional research is needed with greater agreement on assessment of the relationship between oral health and cognitive decline.