title: Masticatory muscular activation in elderly individuals during chewing.
abstract: BACKGROUND
  Old-age is the last stage of human evolution and, unfortunately, the ageing of the oral cavity and masticatory system seems accelerated. As a consequence, there is a reduction in the amount of food ingested, which can lead to an imbalance in nutrition.
  
  
  OBJECTIVE
  The purpose of this study was to investigate the levels of muscular activation of elderly individuals, during chewing, and to compare with young individuals.
  
  
  METHODS
  An electromyographical analysis of the masticatory system in 10 individuals aged between 60 and 75 years (elderly group) and a similar number between 23-30 years old (young group - control) was carried out. The analysis was performed using a MyoSystem-Br1 electromyographer with differential active electrodes. The test was recorded during functional conditions, and the muscles assessed were the temporalis and masseter. Data were normalised by maximum voluntary contraction (MVC), and the results were analysed using an independent t-test for comparison between the groups.
  
  
  RESULTS
  The normalised electromyographic data obtained showed significant differences in both groups. Comparing the normalised values obtained for MVC, the mean values for the masseter and temporalis muscles of elderly group were statistically lower (p </= 0.05) than control group for harder foods, but there were no significant differences for food with the lowest consistency.
  
  
  CONCLUSIONS
  It can be concluded that elderly individuals show slight hypoactivity of their masticatory musculature during chewing when compared to young individuals.
authors.affiliation: Department of Morphology, Stomatology, and Physiology, Laboratory of Electromyography, School of Dentistry of Ribeirão Preto, São Paulo University, São Paulo, Brazil.
authors.forename: Rodrigo
authors.initials: R
authors.lastname: Galo
authors.forename: Mathias
authors.initials: M
authors.lastname: Vitti
authors.forename: Maria da Glória Chiarello
authors.initials: Mda G
authors.lastname: Mattos
authors.forename: Simone Cecílio Hallak
authors.initials: SC
authors.lastname: Regalo
mesh_terms: D000328:Adult; D000368:Aged; D000375:Aging / Q000502:physiology*; D004576:Electromyography; D005260:Female; D006801:Humans; D008297:Male; D008406:Masseter Muscle / Q000502:physiology*; D008409:Mastication / Q000502:physiology*; D008875:Middle Aged; D009119:Muscle Contraction; D013703:Temporal Muscle / Q000502:physiology*