Methods: Thirteen individuals (6 men, 7 women; mean age:30.0±11.5years) who provided informed consent, completed the tongue rotation exercise. The tongue rotation exercise is performed with the mouth closed. The tongue is rotated while forcing the apex of the tongue onto the gingivobuccal fold, first with rotation 20 times to the right and then 20 times to the left. This exercise set was performed three times daily for 3 months. To evaluate oral function, we examined maximum tongue pressure and strength of lip closure. Measurement was performed 5 times: before training (baseline), after 2 weeks of training, and after 1 , 2 and 3 months of training. We calculated the ratio of change at each time from the value of the baseline.
Results: Maximum tongue pressure before tongue rotation exercise and after 2 weeks of training increased markedly and was further increased after 1 month and again after 2 and 3 months of training. Likewise, strength of lip closure was higher after 2 weeks and further again after 1 , 2 and 3 months of training. The ratio of tongue pressure change was significantly higher than after 2 weeks in all subjects after 2 months as well as after 3 months (p<0.01), and the ratio of strength of lip closure was also the same. We believe that the effects of this training are comparatively short term, but could be maintained over the 3 months of training by the daily program.
Conclusions: The tongue rotation exercise presented here may be an effective means for improving oral function.