Abstract
A questionnaire survey and examinations of the taste function were conducted in order to investigate how systemic and local conditions and life habits as well as sensitivity to four basic tastes are related to the decline of the taste function in the elderly. The questionnaire survey consisted of questions regarding subjects' sensations about the taste function and physical and mental status, their medications and the state of the oral cavity. There were a total of 185 subjects, 117 older and 165 younger. In the examinations of the taste function, measurement of saliva secretion, determination of tastes threshold with a whole mouth method and electric gustometry were performed on 45 older and 30 young subjects.
Dry mouth, abnormal oral mucosa and complaints about the dentures were indicated as factors related to subjective sensation of dysgeusia from the questionnaire survey. From the examinations of taste function, however, the increase of taste threshold was not observed in the subjects with dry mouth or abnormal oral mucosa. On the contrary, subjects taking medications or having systemic diseases which showed little association with the sensation of dysgeusia had high taste thresholds. Furthermore, subjects who reported the sensation of dysgeusia did not necessarily have a declining taste function.
It is concluded that not only the taste function affected by medications or systemic diseases but also the effect of the unpleasant conditions of the oral cavity on taste sensation should be carefully examined in elderly people who complain of a declining of taste function.
