Simple oral exercise with chewing gum for improving oral function in older adults

Background: As general and oral health are closely interrelated, promoting oral health may extend a healthy life expectancy. Aims: To evaluate the long-term effects of simple oral exercise (SOE) and chewing gum exercise on mastication, salivation, and swallowing function in adults aged ≥ 65 years. Methods: Ninety-six participants were assigned to control, SOE, and GOE (chewing gum exercise with SOE) groups. The SOE comprised exercises to improve mastication, salivation, and swallowing function. Control group participants performed no exercises. The intervention period was 8 weeks, followed by a 3-week maintenance period. The Mixing Ability Index (MAI), occlusal force, unstimulated saliva, and repetitive saliva swallowing test were evaluated at baseline and 2, 5, 8, and 11 weeks later. Self-reported discomfort was re-evaluated after 8 weeks. Results: After 8 weeks, mean MAI differences from baseline significantly increased in both groups; the increase in the GOE group was largest and four times higher than in the control group. Mean differences of occlusal force from baseline increased by 56 N (SOE group) and 60 N (GOE group). The increase of salivation was greater in the SOE (3.6-fold) and GOE (2.2-fold) groups than in the control group. Furthermore, 27% and 18% of SOE and GOE group participants, respectively, were re-categorized as having good swallowing function. Participants reported less discomfort as oral functions improved. Discussion: These findings may facilitate the development of clinical practice guidelines for optimal oral care in older adults. Conclusion: While both SOE and GOE may improve oral function in older adults, GOE is recommended for those with impaired mastication. Trial registration: KCT0003305, retrospectively registered 31/10/2018.