Tooth loss tends to increase with age as a result of caries and periodontal disease.  In 1992 the World Health Organisation indicated that the treatment goal for oral health should be the maintenance of a functional, aesthetic dentition of at least 20 teeth.   The aim of this review was to assess the relationship dentition status and chewing ability in older adults.

Searches were conducted in the Medline, Embase, Web of Science and the Cochrane Central Register of Controlled Trials (CENTRAL) databases. A wide range of studies designs was included, randomised Controlled Clinical Trials (RCTs), controlled trials as well as observational studies (longitudinal, prospective and retrospective cohort studies, cross-sectional, case–control studies). Studies including dentate older adults (≥ 65 years old) were considered. Only English language studies were included.  A qualitative summary was presented.

• 18 studies published in 20 scientific papers were included, all were cross-sectional in design.
• Most included studies found that chewing ability was closely correlated with the number of teeth.
• Chewing ability seems to be significantly impaired when >7 teeth are missing.

The authors concluded

There was much individual
 variation in the minimum number of teeth
 required to provide adequate function. Not only the number but the location and distribution of 
the teeth as well affect the chewing ability. Long-term prospective studies, comprising well-defined criteria, clinical variables, methods and utilising comprehensive questionnaires, should be preferred to obtain a clearer picture on the association between masticatory ability and functional tooth units.

Comment

As the authors note all the included studies were cross sectional and there was a great deal of heterogeneity. All the data regarding chewing ability were self-reported derived by validated instruments or non-validated questionnaires.

Links

Naka O, Anastassiadou V, Pissiotis A. Association between functional tooth units and chewing ability in older adults: a systematic review. Gerodontology. 2012 Nov 22. doi: 10.1111/ger.12016. [Epub ahead of print] PubMed PMID: 23170948.