Lip-closing function of elderly people during ingestion: comparison with young adults.

In this study the relationship between the functional vertical labial pressure and aging during ingestion in the elderly is examined. The subjects were 84 community-dwelling elderly (mean: 79.4 years old), 109 elderly needing long term care (mean: 81.3 years old), and 59 healthy young adults (mean: 32.0 years old) as control. Labial pressure was measured with a pressure sensor embedded in acrylic plate. There was no correlation between age and labial pressure or the coefficient of variation of labial pressure during ingestion. In people with a history of "choking on food", labial pressure was, however, significantly lower (p < 0.01) than people without a history of "choking on food", while the coefficient of variation of labial pressure was significantly higher (p < 0.05). Poor labial pressure and movement were noted in subjects who experienced "choking on food", suggesting that lip-closing function also plays an important role in the pharyngeal stage of feeding/swallowing. On the other hand, the coefficient of variation of labial pressure during ingestion was not changed in the elderly group in comparison to the control group. These results showed that skilled movement of lip-closing might be compensated by labial pressure. Labial pressure and skilled movement were, however, decreased in the elderly needing care because of "choking on food".