Does age play a role in mylohyoideus muscle function?

Because swallowing disorders are frequent in the elderly, we assessed the r elationship between age and mylohyoideus muscle contraction, which is an im portant component of the initial step in swallowing. In a prospective study , 120 subjects without any personal history of diseases associated with swa llowing disorders underwent electromyographic recording (EMG) of mylohyoide us muscle activity. Four groups of equal size (n=30) were defined according to age (less than or equal to 50, 51-70, 71-85, > 85 years). The frequency and duration of mylohyoideus muscle asynchronisms were compared among the four groups. The comparison of mylohyoideus muscle EMG among groups did not show a significant difference in the mean number of asynchronisms, in dura tion per subject or in the frequency of long-lasting asynchronisms. Asynchr onisms were a very frequent event, observed in 98% of subjects, and were mo stly short, lasting less than 0.1 s in 90% of subjects. In healthy elderly patients, there was no linear relationship between the mean duration of asy nchronisms and ageing. The occurrence of one or more long-lasting asynchron isms or of at least six asynchronisms during a sequence of 10 successive sw allows should be considered to be abnormal.