Impact of varying food hardness on mastication/swallowing.

The purpose of this study was to analyze mastication and swallowing in the elderly and confirm the association with dysphagia characteristics. A questionnaire was developed to evaluate the masticating and swallowing functions of the elderly. Mastication was analyzed using electromyography, and tongue/lip pressures were measured using Iowa Oral Performance Instrument. The results of the questionnaire showed that statistical difference in the number of teeth between the group without and with, decreased ability to swallow, and there was a correlation with lip pressure. Additionally, the higher number of teeth, the higher muscle activity, and there is a positive correlation between the number of chews and the lip pressure. Consequently, our findings suggested oral health parameters are closely associated with mastication/swallowing ability. Finally, based on the results obtained for different foods tested, we suggested that texture-modified foods are necessary to enhance swallowing ability.