Effects of lingual exercises on oral muscle strength and salivary flow rate in elderly adults: a randomized clinical trial

Aim The present study investigated the effects of two types of lingual exercise (tongue-hold swallowing and tongue-pressure resistance training) on oral muscle strength, salivary flow rate and subjective oral health of the elderly. Methods We randomly assigned 74 elderly adults (≥65 years) to three groups (tongue-hold swallowing, tongue-pressure resistance training and control groups). Each group participated in 8 weeks of their appropriately prescribed intervention. We measured anterior tongue strength, posterior tongue strength, lip strength, salivary flow rate and Oral Health Impact Profile-14 score before and after 8 weeks. Differences before and after intervention were observed with a paired sample t-test. Moreover, analyses of covariance and variance were performed to determine the differences in the measured values between the groups. Results The tongue-hold swallowing group showed improvement in both anterior and posterior tongue strength, while the tongue-pressure resistance training group showed a significant increase in only anterior tongue strength. Both the tongue-hold swallowing and tongue-pressure resistance training groups showed increased salivary secretion, with the tongue-pressure resistance training group showing a higher level of salivary secretion. However, the difference in the subjective oral health scores before and after the intervention was not significant. Conclusions The two lingual exercises strengthened some aspects of tongue muscles and increased the salivary flow rate, with more salivary secretion in the tongue-pressure resistance training group than in the tongue-hold swallowing group. Any evidence of the lingual exercises being able to enhance subjective oral health could not be found. Geriatr Gerontol Int 2020; ••: ••-••.