The relationship between labial pressure during swallowing and maximum labial pressure

―A comparison of adults and elderly subjects―

Abstract

The labium plays an important role in feeding and swallowing． Labial pressure during predation increases as a function of feeding and swallowing development．Accordingly，it is used as a standard assessment for the feeding and swallowing functions．However，there has been almost no research presented regarding labial pressure during the feeding and swallowing functions in the period of diminution．The purpose of this study is to clarify the differences in labial pressure between adults and elderly subjects．The subjects were 12 healthy adults（6 males： mean age ＝ 28.5 years，6 females： mean age ＝ 23 years） and 10 healthy elderly persons (5 males： mean age ＝ 74.8 years，5 females： mean age ＝ 75.2 years)．Two pressure sensors were secured in cavities prepared in an acrylic plate（2 millimeters thick）to measure labial pressure during swallowing and maximum closure．A comparison of adults and elderly subjects was undertaken in terms of the relationship between labial pressures at maximum closing and those during swallowing．Based upon the evaluation，the following results were obtained．

1） No significant difference in labial pressure was observed between adults and elderly subjects during swallowing．

2） The maximum labial pressure in adult subjects was significantly higher compared to elderly subjects．

3） A remarkable decline in the reserve pressure（the difference between the maximum labial pressure and labial pressure during swallowing）was recognized in elderly subjects as compared to the adult subjects．

4） The duration of labial pressure during swallowing was significantly greater in elderly persons as compared to adults．

5） No significant difference in the integral of labial pressure was observed between adults and elderly subjects during swallowing．

The healthy elderly subjects did maintain sufficient labial pressure during swallowing in the same manner as healthy adults．However，it was observed that there was a decrease in their reserve capacity and a lengthening of the duration of labial pressure，which suggests that the labial function is physiologically affected by the aging process．