Relationship between functional masticatory units and cognitive impairment in elderly persons

BackgroundStudies on the elderly have reported that the risk of cognitive impairment is affected by chewing difficulty. ObjectiveTo determine whether there is a relationship between the number of pairs of antagonist teeth that come into contact when the mouth is closed (functional masticatory units [FMUs]) and the level of cognitive impairment. MethodsWe conducted a cross-sectional observational study with 502 institutionalised White individuals older than 65years, living in the northwest of Spain and Portugal. Through a direct visual inspection, we recorded the number of FMUs. Cognitive impairment was assessed by applying the Mini-Cognitive Examination (MCE), a test derived from the Mini-Mental State Examination. To describe the statistical relationship between the FMUs and the MCE values, a generalised linear model (GLM) was applied. We assessed the GLM predictive capacity for detecting cognitive impairment (MCE 23) in a new study group consisting of 156 elderly individuals. ResultsA large number of FMUs was significantly associated with a lower probability of cognitive impairment, regardless of the nature of the contact and its location (explained deviance, 30.1%). The model's discriminatory capacity for cognitive impairment based on the FMUs was good (0.820). The model's predictive capacity for cognitive impairment was acceptable (sensitivity, 0.786; positive predictive value, 0.900; accuracy, 0.729). ConclusionIn White, elderly institutionalised individuals, the absolute number of FMUs is significantly related to their MCE scores.