PurposeProducing tongue pressure (TP) by pushing the tongue against the palate consists of lifting the tongue muscles and elevating the floor of the mouth via suprahyoid muscle contraction. Though studies have shown that tongue-pressure resistance training (TPRT) increases tongue function, none have focused on suprahyoid muscle function enhancements. Our study aimed to verify whether TPRT improves both tongue function and hyoid movement during swallowing.Materials and methodsEighteen patients (mean age: 76.8±6.2 years) with presbyphagia presenting with symptoms such as coughing and choking were enrolled. All patients performed daily living activities independently. None of the participants had diseases causing dysphagia or previous oral or pharyngeal surgery. Participants were instructed to push their tongues against the palate as hard as possible with their mouths closed for 10 seconds, and then resting for 10 seconds. A set consisted of five consecutive exercise and resting periods; two sets per day were performed for a month. TP and the oral diadochokinetic rate (ODKR), measured by repetitions of the syllables /ta/ and /ka/, assessed tongue function. The extent of anterior and superior hyoid movement and parameters related to swallowing, including the penetration aspiration scale (PAS) and the normalized residue ratio scale (NRRS) in the valleculae (NRRSv) and piriform sinus (NRRSp), were evaluated based on videofluoroscopic data.ResultsThe anterior (P=0.031) and superior hyoid movement (P=0.012), TP (P=0.002), ODKR/ta/ (P=0.034), ODKR/ka/ (P=0.009), and the width of the upper esophageal sphincter (P=0.001) were larger at follow-up than at baseline. NRRSp (P=0.022), PAS (P=0.016), and pharyngeal transit times (P=0.004) were smaller at follow-up than at baseline.ConclusionTPRT improved tongue strength, dexterity, both anterior and superior hyoid elevation, and swallowing functions. Therefore, TPRT could improve tongue function and suprahyoid muscle function simultaneously and contribute to prevention of sarcopenic dysphagia.

Background: Maximum bite force (MBF) is a common and useful index of masticatory function; it correlates with physical strength in elderly people. Palpation of stiffness in the masseter muscle during forceful biting has been considered to be associated with MBF. However, this assessment method relies on subjective judgments; no study has verified the relationship between MBF and quantitative measurements of masseter muscle stiffness (MMS). Objective:We aimed to verify the association between masseter muscle myotonometric assessment results and MBF. Methods: In total, 117 community-dwelling >65-year-old individuals from the Tokyo metropolitan area were assessed. MMS on the dominant side during forceful biting was measured with a MyotonPRO device. Masseter muscle thickness (MMT) during rest and forceful biting was measured with an ultrasonic diagnostic apparatus, and the difference in MMT (DMMT) between the rest and forceful biting conditions was determined. MBF data were obtained with a pressure-sensitive sheet and an associated device. To determine the independent variables affecting MBF and MMS, multivariate linear regression analyses with adjustments for age, sex and number of teeth were performed. Results:The multivariate analysis revealed that MBF correlated with the number of teeth (β = .489, P < .001) and MMS (β = .259, P = .003) (R 2 = .433). MMS correlated with MBF (β = .308, P = .003) and DMMT (β = .430, P < .001) (R 2 = .326). Conclusion:Masseter muscle stiffness possibly reflects a force generated by the masseter muscle during forceful biting. Therefore, MMS is effective to assess tooth loss as well as an index of masseter muscle strength when evaluating MBF. K E Y W O R D Sbite force, masseter muscle, muscle stiffness, myotonometric assessment, occlusal force | 751 HARA et Al.

Dysphagia is a common problem among older adults, causing aspiration pneumonia and malnutrition. It has been reported that calf circumference (CC), an index of nutritional status and physical activity, correlated with dysphagia in acute care hospitals, suggesting that CC can be a useful index for assessing dysphagia. We therefore aimed to explore the association between dysphagia and CC among community elderly people who require long-term care and determined the optimal CC cutoff value for patients with dysphagia. Our cross-sectional study, conducted at Tokyo Metropolis, included 154 participants (65 men) aged > 65 years (mean age: 80.1 ± 7.1) who required long-term care and were examined for dental disease and dysphagia during home visiting treatment. Age, body mass index (BMI), mini-nutritional assessment short-form (MNA-SF) score, Barthel index (BI), CC, functional oral intake scale (FOIS), and dysphagia severity scale (DSS) were evaluated. A DSS score < 5 was defined as dysphagia. To determine the association between CC and dysphagia, we performed logistic regression analysis and calculated the CC cutoff value for dysphagia. Thirty-seven participants (24.0%) were diagnosed with dysphagia. The logistic regression analysis showed that the presence of dysphagia was independently associated with CC after adjusting for age and sex. The CC cutoff value for the presence of dysphagia was 31.0 cm in men (sensitivity, 0.818; specificity, 0.868) and 29.3 cm in women (sensitivity, 0.760; specificity, 0.859). CC is a useful index for assessing dysphagia among community dwelling individuals who require long-term care.

Background Although age‐related changes in muscle quality influence muscle strength, the relationship between masseter muscle (MM) quality and maximum biting force (MBF) has never been studied. Objective The aims of the study were to verify the relationship among MM quality, MBF, and the displacement of the MM while biting forcefully (MMD) and to clarify the age‐related decline in MBF in healthy elderly persons. Methods Seventy‐four healthy community‐dwelling individuals (mean age, >65 years) from Tokyo metropolis were recruited. The thickness (index of muscle quantity), echo intensity (index of muscle quality) and displacement of the MM while biting forcefully (MMT, MMEI and MMD, respectively) were measured by ultrasonography. MBF was measured using a pressure‐sensitive sheet. Independent predictors of MBF and MMD were determined using multivariate linear regression analyses adjusted for age, sex and the number of present teeth. Results MBF was significantly correlated with the number of teeth (β = 0.577, P < .001) and MMD (β = 0.302, P = .015), but not with MMT (β = 0.019, P = .868) or MMEI (β = 0.054 P = .703). MMD was significantly correlated with MMEI (β = −0.606, P < .001), but not with MMT (β = 0.048, P = .681) or the number of teeth (β = 0.065, P = .613). Conclusions MMEI was associated with MMD, an index of MBF, regardless of tooth number. The age‐related quality change in the MM might cause a decrease in its contraction, resulting in age‐related decline in MBF.

The effectiveness of the tongue right positioner (TRP) use on oral and swallowing functions remains unclear. To investigate the effects of TRP use on tongue function in patients with dysphagia. This interventional study included eight participants with dysphagia who visited a university dental hospital. The measurement variables included tongue pressure (TP) as the primary outcome and lip and tongue movements, peak nasal inspiratory flow, and changes in the tongue and suprahyoid muscle regions on ultrasonography as the secondary outcomes. Each participant was asked to use a TRP for at least 8 h every night for 2 months. The measurement variables before and after the intervention were compared using the paired t test and Wilcoxon signed-rank test. TP after intervention (31.5 ± 13.1 kPa) was significantly higher than that before intervention (23.0 ± 13.4 kPa), while other measurement variables did not significantly improve. Numerous exercises have been suggested to improve TP; however, most require patients’ adherence to instructions. In contrast, although participants did not perform active exercises, most participants in this study observed an improved TP. Our findings show that TRP can greatly improve TP after 2 months of usage.Trial registration number: University Hospital Medical Information Network Clinical Trials Registry (UMIN000040253, date of first registration: 27/04/2020).