Association between tongue and lip motor functions and mixing ability in complete denture wearers.

BACKGROUND: Masticatory performance of elderly complete denture wearers is low, which may lead to restriction on intakes of several foods such as fresh fruit or raw vegetables.

AIM: The aim of this study was to investigate the relationship between tongue motor function, lip motor function, and mixing ability in complete denture wearers.

MATERIALS AND METHODS: Participants comprised 54 complete denture wearers with a mean age of 77.1 years. Maximum tongue pressure and oral diadochokinesis were measured to evaluate tongue and lip motor functions. A color-changeable, chewing gum was used to evaluate mixing ability. The relationship between tongue and lip motor functions and mixing ability was assessed using stepwise multiple regression analysis.

RESULTS: The stepwise multiple regression analysis identified maximum tongue pressure, the number of repetitions of the syllable "ka", and gender as significant predictors for mixing ability among complete denture wearers.

DISCUSSION: The elderly edentulous individuals mainly used tongue motor function in oral motor functions for mixing color-changeable chewing gums, which might be ascribable to wearing complete dentures.

CONCLUSIONS: Under the limited conditions of this study, factors relating to tongue motor function, tongue pressure and the number of repetitions of the syllable "/ka"/ significantly contributed to the mixing ability of complete denture wearers. It was suggested that tongue motor function had positive effect on the mixing ability of complete denture wearers.