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 Table of Contents  
Year : 2022  |  Volume : 14  |  Issue : 4  |  Page : 363-369

Effectiveness of oral exercise programs on oral function among independent elderly people: A cluster randomized controlled trial

1 Residency Training Program in Dental Public Health, Faculty of Dentistry, Prince of Songkla University, Songkhla, Thailand
2 Improvement of Oral Health Care Research Unit, Department of Preventive Dentistry, Faculty of Dentistry, Prince of Songkla University, Songkhla, Thailand

Date of Submission19-Feb-2022
Date of Decision11-Jun-2022
Date of Acceptance13-Jun-2022
Date of Web Publication29-Aug-2022

Correspondence Address:
Dr. Jaranya Hunsrisakhun
Improvement of Oral Health Care Research Unit, Department of Preventive Dentistry, Faculty of Dentistry, Prince of Songkla University, Songkhla 90110
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Source of Support: None, Conflict of Interest: None

DOI: 10.4103/JIOH.JIOH_47_22

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Aims: To compare the effectiveness of two oral exercise programs on oral function among independent elderly people. Materials and Methods: This was a cluster randomized controlled trial study conducted among 60–74 years old in Chonburi Province, Thailand. Participants in six senior schools were randomly allocated to one of two groups: the intervention group (n = 123) received a simple oral exercise program of 2 min/session (SOE) and the control group (n = 121) received a traditional oral exercise program of 15 min/session (TOE). They were required to practice twice daily. The baseline and 3-month follow-up oral function assessments included chewing ability, dry mouth status, Unstimulated Whole Saliva (UWS), dysphagia, and the Repetitive Saliva Swallowing Test (RSST). Paired t test and independent t test were used to compare the outcome variables within and across the two groups, respectively. Results: At the 3-month follow-up, the SOE group significantly improved in chewing ability and UWS, whereas in the TOE group, there was a significant improvement in UWS and RSST. Comparing oral function mean differences between groups, RSST in the TOE group was significantly greater than in the SOE group (P < 0.05) but there were no differences in chewing ability, dry mouth status, UWS, or dysphagia. Conclusion: Both oral exercise programs were similarly beneficial in enhancing elderly oral function in terms of UWS. TOE outperformed SOE in terms of improving swallowing function. The other oral function had a chance to improve in both programs.

Keywords: Independent Elderly, Oral Exercise Program, Oral Function, Xerostomia

How to cite this article:
Wongworasun S, Hunsrisakhun J, Watanapa A. Effectiveness of oral exercise programs on oral function among independent elderly people: A cluster randomized controlled trial. J Int Oral Health 2022;14:363-9

How to cite this URL:
Wongworasun S, Hunsrisakhun J, Watanapa A. Effectiveness of oral exercise programs on oral function among independent elderly people: A cluster randomized controlled trial. J Int Oral Health [serial online] 2022 [cited 2023 Mar 24];14:363-9. Available from:

  Introduction Top

Improving oral function in the elderly is crucial for oral health,[1] because age-related functional decline affects oral health in the elderly, especially dry mouth, dysphagia, and mastication capacity.[2] Forty-four percent of the Thai elderly population had a chewing problem and 14% had hyposalivation, which increases the risks of dental caries, periodontitis, and oral thrush.[3] Furthermore, decreased masticatory force, tongue-lip motor function, and tongue pressure lead to dysphagia, malnutrition, and respiratory system difficulties.[4],[5] To earlier avoid functional problems and pharmacological adverse effects,[6] this study focused on improving oral function in independent elderly people using an oral exercise.

Oral exercise has been shown to improve chewing and swallowing, and reduce dry mouth in the elderly after 3 months.[1],[6],[7] However, these oral exercise programs had different posture patterns and training time ranging from 15 min to 2 h. The commonly used traditional oral exercise programs (TOE) enhanced numerous oral functions but required approximately 15 min per session.[1],[6],[7] Prolonged administration and lack of follow-up will influence the elderly’s compliance, lowering the rate of improvement. Even though a simple 2-min oral exercise program (SOE) has been developed,[8] the results of that study remain unclear due to the short follow-up time and lack of a comparison group. Hence, this study aimed to evaluate the effectiveness of two oral exercise programs, TOE and SOE, among independent elderly people after 3 months of use to suggest a self-regulating oral exercise intervention for promoting oral health of the elderly in an earlier stage.

  Materials and Methods Top

The protocol of this study was registered in the Thai Clinical Trial Registry No.20200816001. All the procedures done in this study agreed with the Research Ethics Committee of Faculty of Dentistry, Prince of Songkla University, with approval number EC6306-020, dated July 23, 2020. Participants were explained clearly about the study purpose and a written informed consent was obtained before conducting the study.

Setting and design

A parallel-designed single-blind cluster randomized controlled trial was performed at six senior schools in Chonburi Province, Thailand, from September 2020 to February 2021. The sample size was calculated using G*Power with a two-sided 5% significance level, an 80% power, and an effect size of 0.39[6] to account for dropouts during the follow-up period, resulting in a total sample size of 262 participants.

Sampling criteria

The independent elderly aged 60–74 years with at least one oral function problem defined by Sakayori et al.[9] were eligible, whereas those with a neuromuscular illness or medications that influence saliva production or oral functioning were excluded.

Randomization and allocation process

Overall, 244 participants met the criteria. Three schools in an intervention group (123 subjects) and three schools in a control group (121 subjects) were simple randomly selected from opaque envelopes by an unrelated third party [Figure 1].
Figure 1: CONSORT flow diagram of the different phases of the study

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Oral exercise programs

The intervention group received a simple oral exercise program 2 min/session (SOE) applied by Kim et al.,[8] whereas the control group received a traditional oral exercise program 15 min/session (TOE) applied by Ibayashi et al.[1] and Sugiyama et al.[7] Participants were instructed by trained dental staff through oral health education, demonstration, and practices in groups of five. They were asked to conduct oral exercises twice daily for 3 months and were given a pamphlet with illustrations. They were reassessed after a week and retrained individually, if needed. The program is described in [Table 1].
Table 1: Procedures for the oral exercise program between SOE and TOE

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Subjective measurement

Three experts analyzed the questionnaire’s content validity, which was determined to be extremely good (IOC = 0.98), and reliability using the test–retest method (correlation coefficient = 0.72–0.83). Interviewers were trained to use a health questionnaire and oral function test. Chewing ability was assessed using a 21-item Thai food intake questionnaire with varied textures and hardness. The participants were asked to rate their ability to chew on a scale of “0” (unable to chew), “1” (difficult to chew), and “2” (easy to chew). The overall score was 70.[10],[11]

Dry mouth status was measured using the Xerostomia Inventory (XI), which includes 11 items (score range 11–55).[12] The median was used for chewing ability and XI for subgroup analysis into good and poor function groups. The Dysphagia Risk Assessment for the Community-dwelling Elderly (DRACE), a 12-item questionnaire, was utilized. A DRACE score of greater than 5 indicates inadequate oral function.[13]

Objective measurement

Two calibrated dentists with a 0.85 kappa coefficient performed oral health assessments. The spitting method[14] was used to obtain Unstimulated Whole Saliva (UWS). After 5 min, the participants were asked to spit collected saliva into a plastic beaker. The flow rate of UWS (mL/min) was calculated. Hyposalivation was defined as UWS less than 0.1 mL/min. The RSST was used to assess swallowing function.[15] Participants were asked to swallow saliva quickly and repeatedly for 30 s. The examiners assessed the up-and-down movement of the larynx and hyoid bone. RSST < 3 was denoted as poor swallowing.

Statistical analysis

The data were analyzed using SPSS version 23.0 (SPSS, Chicago, Illinois). Chi-square and independent t tests were used to compare questionnaire results and mean differences in oral health assessments between groups. Oral function changes within groups were assessed using paired t tests. The level of significance was P < 0.05.

  Results Top

The majority (79.9%) were female, with a mean age of 67.3 years. At baseline, there were no significant differences in demographic data between the two groups [Table 2].
Table 2: Baseline data on demographic, general health, and oral health status between groups

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Oral exercise practices

The SOE and TOE groups performed all motions as trained in 43% and 31% of cases, respectively, with the SOE group exercising more frequently on average than the TOE group (four times and three times per week, respectively).

Oral function

Chewing ability was satisfactory, with a mean score of 63.70. Most of the participants had mild dry mouth, with a mean XI of 20.71 and a normal UWS of 0.37 mL/min. However, 16.4% of the elderly were found to have hyposalivation. The elderly had an average RSST of 3.26, indicating normal swallowing levels, but a mean DRACE of 4.28 (DRACE ≥ 5 = 40.2%), indicating the onset of swallowing problems

Changes in oral function after 3 months within and between groups

At baseline, there were no statistically significant differences in oral functions between the SOE and TOE groups. After 3 months, the chewing ability and UWS in the SOE group were significantly improved (P = 0.043 and P < 0.001, respectively). In the TOE group, UWS and RSST improved statistically significantly (P < 0.001). Comparing the mean difference between groups, only RSST in the TOE group was significantly higher than in the SOE group (P = 0.002) [Table 3].
Table 3: Changes in oral functions after 3 months within and between groups

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Changes in the good- and poor-oral function groups after 3 months

Changes in oral functions were examined in two subgroups: good and poor. Only UWS improved in the good function group, but RSST decreased in the SOE group but remained within the normal range (RSST ≥ 3). Individuals with impaired oral function in the SOE, on the contrary, improved in all oral functions, whereas the TOE improved in XI, DRACE, and RSST. Notably, the poor function group had a higher percentage improvement than the good function group. However, there were no significant mean differences between the two exercise programs in the poor function group [Table 4] and [Table 5].
Table 4: Changes in good oral function group after 3 months within and between interventions

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Table 5: Changes in poor oral function group after 3 months within and between interventions

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  Discussion Top

Several studies previously examined the effects of two oral exercises (SOE and TOE) on oral functions, their benefits, and drawbacks and probable mechanisms.[1],[6],[7],[8],[9] This study compared the effectiveness of these two programs in each function for future selection.

Only the RSST mean difference in the TOE was significantly greater than in the SOE group in this study. In the TOE group, the RSST significantly increased in the overall group from 3.1 to 3.5 with a clinically significant increase from 1.9 to 2.7 in the poor-swallowing group, which this almost reached normal (RSST ≥ 3), consistent with Ibayashi et al.,[1] who reported that, after 6 months of the TOE, the RSST was greater than the control group, increasing from 4 to 5, and Kawamura et al.,[16] who discovered that at the end of the TOE program at 12 months, the RSST in participants aged 70–80 years old increases almost to a low risk of dysphagia (from 2 to 2.8). This implies that the TOE is more successful than the SOE in increasing the number of swallowing cycles in the elderly, owing to the variety of exercise actions associated with swallowing, tongue, neck, and shoulders, and pronunciation, whereas the SOE solely emphasizes swallowing.

There was no statistically significant difference in chewing ability between the two exercise programs. Only SOE improved masticatory performance in the overall group and particularly in the poor function group by 2.8% or 4.8%, implying that the elderly could chew a wider variety of hard or sticky foods. It was, however, less successful than in the study of Kim et al.,[8] who discovered that after only 1 week of SOE training, the mixing ability index (MAI) improved by up to 16%. The explanation could be the differing assessments, with Kim’s study employing an objective one (MAI) against the subjective one used in this study.

Dry mouth and hyposalivation in the elderly affect mastication and swallowing.[17] In this study, there was no statistically significant difference in UWS ​between two exercise programs with an increase of 0.07–0.08 mL/min, indicating that both programs can stimulate saliva in the elderly with similarly good results, but SOE has taken less time to learn than TOE and has an impact on both good and poor salivation groups, which makes it more attractive. The rate of UWS in the SOE group increased from 0.4 to 0.47 mL/min, which was consistent with Kim et al.[8] who reported that after 1 week of taking SOE, the elderly experienced less dry mouth and a significant increase in UWS from 0.26 to 0.34 mL/min. A previous study[18] reported that UWS of less than 0.14-0.16 mL/min is capable of promoting demineralization. In the SOE, elderly people with inadequate salivation had an increase in UWS from 0.07 to 0.17 mL/min, reducing the risk of dental caries.

The UWS increased from 0.34 to 0.42 mL/min in the TOE group, which is consistent with the previous studies by Cho et al.[6] and Sugiyama et al.,[7] who reported that after 3 months of TOE in the elderly with dysphagia and hyposalivation, the UWS increased significantly by 0.08–0.12 mL/min. Although increasing UWS has been observed in good and poor functions in both programs, only XI in the poor oral function group improved in both programs. However, it was not clinically significant. According to Thomson’s[19] suggestions, a change in XI score of 6 or more points appears to be clinically meaningful.

Dysphagia is a serious problem among the elderly due to age-related physiological changes.[20] DRACE ≥ 5 has been recognized as dysphagia. This study found that 40.2% of the elderly had dysphagia, which is similar to Miyoshi et al.’s study.[21] There was no significant difference in DRACE between programs; however, it improved within programs. The seniors also reported less food dropping out of their mouths and less choking. Recovering from dysphagia was suggested to take from 4 weeks to 1 year.[22],[23]

A high acceptable kappa value and blinding in clinical assessments and interpretation were strengths of this study. The oral exercise programs were rigorously trained and had regular follow-ups. As a result, more than 50% of participants practiced 1-6 times a week. The study’s limitation was the loss of volunteers owing to COVID-19. This study used an intention-to-treat (ITT) analysis, which showed the similar results as per-protocol comparisons.

In all, the TOE was better than SOE only in improving swallowing ability. Certain oral functions were improved in SOE and TOE groups after 3 months, notably for UWS and in individuals with impaired oral function. Although the SOE saved time and required the simplest training postures suitable for the elderly, the TOE improved swallowing capacity. Therefore, for the foundation method, SOE is recommended, and TOE is suggested to boost RSST. If a risk assessment is possible, an oral exercise program may be more useful for independent elderly with impaired oral function.


Comparing two exercise programs, the TOE was superior to the SOE for improving swallowing ability. The SOE showed improvement in chewing ability and UWS. TOE improved UWS and RSST.

Future scope/clinical significance

Long-term research is required to establish a community-based oral exercise program for the elderly, especially those with poor oral function.


We are grateful to the Faculty of Dentistry, Prince of Songkla University and to all of the elderly for their active involvement.

Financial support and sponsorship

This study was supported by Research Budget from Graduate School, Research Center and Faculty of Dentistry, Prince of Songkla University, Thailand.

Conflicts of interest

There are no conflicts of interest.

Authors’ contributions

All authors performed the majority of the work including concepts, research design, review literature, data analysis and writing paper. SW performed the intervention and data collections. JH considered the overall of the study.

Ethical policy and institutional review board statement

This study was approved by the Ethics Committee, Faculty of Dentistry, Prince of Songkla University, Thailand under the Research Project Code EC6306-020, dated July 23, 2020 registered in the Thai Clinical Trial Registry No.20200816001. All the procedures have been performed as per the ethical guidelines laid down by Declaration of Helsinki (2013) to be mentioned for all articles.

Patient declaration of consent

Participants were explained clearly about the study purpose and a written informed consent was obtained before conducting the study.

Data availability statement

The data set used in this study is available on request from the corresponding author (Jaranya Hunsrisakhun, e-mail: [email protected]).

  References Top

Ibayashi H, Fujino Y, Pham TM, Matsuda S Intervention study of exercise program for oral function in healthy elderly people. Tohoku J Exp Med 2008;215:237-45.  Back to cited text no. 1
Xu F, Laguna L, Sarkar A Aging-related changes in quantity and quality of saliva: where do we stand in our understanding? J Texture Stud 2019;50:27-35.  Back to cited text no. 2
Samnieng P, Ueno M, Shinada K, Zaitsu T, Wright FA, Kawaguchi Y Association of hyposalivation with oral function, nutrition and oral health in community-dwelling elderly Thai Community Dent Health 2012;29:117-23.  Back to cited text no. 3
Minakuchi S, Tsuga K, Ikebe K, Ueda T, Tamura F, Nagao K, et al. Oral hypofunction in the older population: Position paper of the Japanese Society of Gerodontology in 2016. Gerodontology 2018;35:317-24.  Back to cited text no. 4
Sakai K, Nakayama E, Tohara H, Kodama K, Takehisa T, Takehisa Y, et al. Relationship between tongue strength, lip strength, and nutrition-related sarcopenia in older rehabilitation inpatients: A cross-sectional study. Clin Interv Aging 2017;12:1207-14.  Back to cited text no. 5
Cho EP, Hwang SJ, Clovis JB, Lee TY, Paik DI, Hwang YS Enhancing the quality of life in elderly women through a programme to improve the condition of salivary hypofunction. Gerodontology 2012;29:e972-80.  Back to cited text no. 6
Sugiyama T, Ohkubo M, Honda Y, Tasaka A, Nagasawa K, Ishida R, et al. Effect of swallowing exercises in independent elderly. Bull Tokyo Dent Coll 2013;54:109-15.  Back to cited text no. 7
Kim HJ, Lee JY, Lee ES, Jung HJ, Ahn HJ, Kim BI Improvements in oral functions of elderly after simple oral exercise. Clin Interv Aging 2019;14:915-24.  Back to cited text no. 8
Sakayori T, Maki Y, Ohkubo M, Ishida R, Hirata S, Ishii T Longitudinal evaluation of community support project to improve oral function in Japanese elderly. Bull Tokyo Dent Coll 2016;57:75-82.  Back to cited text no. 9
Miura H, Sato K, Hara S, Yamasaki K, Morisaki N Development of a masticatory indicator using a checklist of chewable food items for the community-dwelling elderly. ISRNGeriatr 2013;2013:1-4.  Back to cited text no. 10
Kunon N, Kaewplung O Comparison of chewing ability of mandibular implant-retained overdenture patients using the subjective and the objective assessments. CU Dent J 2014;37:171-82.  Back to cited text no. 11
Thomson WM Dry mouth and older people. Aust Dent J 2015;60 Suppl 1:54–63.  Back to cited text no. 12
Takeuchi K, Aida J, Ito K, Furuta M, Yamashita Y, Osaka K Nutritional status and dysphagia risk among community-dwelling frail older adults. JNutrHealth Aging 2014;18:352-7.  Back to cited text no. 13
Yamuna PK, Muthu PK Methods of collection of saliva-A Review. Int J Oral Health Dent 2017;3:149-53.  Back to cited text no. 14
Yoshimatsu Y, Tobino K, Sueyasu T, Nishizawa S, Goto Y, Murakami K, et al. Repetitive Saliva Swallowing Test and water swallowing test may identify a COPD phenotype at high risk of exacerbation. Clin Respir J 2019;13:321-7.  Back to cited text no. 15
Kawamura YI, Shigeishi H, Uchida S, Kawano S, Maehara T, Sugiyama M, et al. Changes in physical and oral function after a long-term care prevention program in community-dwelling Japanese older adults: A 12-month follow-up study. Healthcare 2021;9:719.  Back to cited text no. 16
Lu TY, Chen JH, Du JK, Lin YC, Ho PS, Lee CH, et al. Dysphagia and masticatory performance as a mediator of the xerostomia to quality of life relation in the older population. BMC Geriatrics 2020;20:521.  Back to cited text no. 17
Bardow A, Nyvad B, Nauntofte B Relationships between medication intake, complaints of dry mouth, salivary flow rate and composition, and the rate of tooth demineralization in situ. Arch Oral Biol 2001;46:413-23.  Back to cited text no. 18
Thomson WM Measuring change in dry-mouth symptoms over time using the xerostomia inventory. Gerodontology 2007;24:30-5.  Back to cited text no. 19
Madhavan A, LaGorio LA, Crary MA, Dahl WJ, Carnaby GD Prevalence of and risk factors for dysphagia in the community dwelling elderly: A systematic review. J Nutr Health Aging 2016;20:806-15.  Back to cited text no. 20
Miyoshi S, Shigeishi H, Fukada E, Nosou M, Amano H, Sugiyama M Association of oral function with long-term participation in community-based oral exercise programs in older Japanese women: A cross-sectional study. J Clin Med Res 2019;11:165-70.  Back to cited text no. 21
Krekeler BN, Rowe LM, Connor NP Dose in exercise-based dysphagia therapies: A scoping review. Dysphagia 2021;36:1-32.  Back to cited text no. 22
Naoko M Effect of 12 months of oral exercise on the oral function of older Japanese adults requiring care. OBM Geriatrics 2021;5:1-14.  Back to cited text no. 23


  [Figure 1]

  [Table 1], [Table 2], [Table 3], [Table 4], [Table 5]


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