Standard Values of Maximum Tongue Pressure Taken Using Newly Developed Disposable Tongue Pressure Measurement Device

Improvement of oral function and its impact on oral food intake in subacute stroke patients: A prospective study with dental intervention

BACKGROUND

The association between oral food intake and oral function during the subacute stage of stroke is not well known.

OBJECTIVE

To investigate (1) oral function changes in subacute stroke patients and (2) association between oral function and oral intake status at several time points.

METHODS

In a prospective study involving 324 stroke patients at a convalescent rehabilitation unit, four oral function parameters (maximum tongue pressure, MTP; lip-tongue motor function, LTMF; maximum occlusal force, MOF and oral health assessment tool, OHAT) were quantitatively measured upon admission (T0), at 1 month (T1) and 2 months (T2). Oral feeding status was assessed using the Functional Oral Intake Scale (FOIS) and divided based on the FOIS score into the dysphagic and regular diet groups. The changes in oral functions at the three time points were tested using generalized estimating equation analysis. The association between FOIS groups and oral functions at T1 and T2 was analysed by means of logistic regression analysis.

RESULTS

All oral function parameters improved significantly over time during the hospital stay (mean differences: 4.9 for MTP, 0.6 for LTMF, 1.1 for MOF and -1.8 for OHAT). The FOIS groups were significantly associated with MTP (p < .05) and OHAT (p < .05) at both T1 and T2.

CONCLUSION

Our findings suggest that oral function significantly improves in patients during subacute stroke rehabilitation and better oral health can be associated with better oral intake. Improved oral function through dental intervention and oral rehabilitation may contribute to gains in oral food intake.

A Review of In Vitro and In Silico Swallowing Simulators: Design and Applications

Swallowing is a primary and complex behaviour that transports food and drink from the oral cavity, through the pharynx and oesophagus, into the stomach at an appropriate rate and speed. To understand this sophisticated behaviour, a tremendous amount of research has been carried out by utilising the in vivo approach, which is often challenging to perform, poses a risk to the subjects if interventions are undertaken and are seldom able to control for confounding factors. In contrast, in silico (computational) and in vitro (instrumental) methods offer an alternate insight into the process of the human swallowing system. However, the appropriateness of the design and application of these methods have not been formally evaluated. The purpose of this review is to investigate and evaluate the state of the art of in vitro and in silico swallowing simulators, focusing on the evaluation of their mechanical or computational designs in comparison to the corresponding swallowing mechanisms during various phases of swallowing (oral phase, pharyngeal phase and esophageal phase). Additionally, the potential of the simulators is also discussed in various areas of applications, including the study of swallowing impairments, swallowing medications, food process design and dysphagia management. We also address current limitations and recommendations for the future development of existing simulators.

Decrease in Tongue Pressure in Frail Patients in the Sitting Position and Its Alleviation by Plantar Grounding

PURPOSE

The deterioration of oral function has received much attention, also being referred to as "Oral frailty". This study evaluated the change in tongue pressure, one of the objective items of oral frailty, to examine the relationship between body position and tongue pressure.

METHODS

This study was a prospective, observational study conducted in a single center. The participants were categorized by their Clinical Frailty Scale (CFS) scores. Tongue pressure was measured in the following positions: dorsal, sitting, and sitting with plantar grounding. Differences in tongue pressure between CFS and between body positions were statistically analyzed.

RESULTS

A significant decrease in tongue pressure was demonstrated in CFS4 compared to CFS3. Furthermore, in CFS5 and CFS6, tongue pressure decreased in the sitting position compared to that in the dorsal position, and tongue pressure recovered to the dorsal level with plantar grounding.

CONCLUSIONS

Tongue pressure decreased with the progression of frailty. It was decreased by sitting, and this decrease was alleviated by plantar grounding.

Effect of Inspiratory Muscle Training on Cough Strength in Older People With Frailty: A Single-Blind Randomized Controlled Trial

OBJECTIVE

To investigate the effect of inspiratory muscle training (IMT) on cough strength in older people with frailty.

DESIGN

Single-blind randomized controlled trial.

SETTING

Day health care centers at 2 sites.

PARTICIPANTS

Older people with frailty (N=60).

INTERVENTIONS

Eligible people were randomly assigned to receive IMT program in addition to general exercise training (IMT group), or general exercise training alone (control group). The IMT group performed training using a threshold IMT device with the load set at 30% of maximum inspiratory mouth pressure in addition to the general exercise training program throughout the 8 weeks. The IMT took place twice a day and each session consisted of 30 breaths.

MAIN OUTCOME MEASURES

Primary outcome was cough strength, measured as the cough peak flow (CPF), at the beginning and the end of the program.

RESULTS

Data from 52 participants (26 in each group) were available for the analysis. The mean age was 82.6 years; 33% were men. The change in CPF at the end of the program was 28.7±44.4 L/min in the IMT group and -7.4±26.6 L/min in the control group. A linear regression model showed that the presence or absence of IMT was associated with changes in CPF (mean difference between groups, 36.3; 95% confidence interval, 16.7-55.9; effect size, 0.99).

CONCLUSIONS

IMT may be a useful intervention to improve cough strength in frail older people.

High-intensity intermittent inspiratory and abdominal muscle combined training in respiratory, swallowing and systemic muscles of healthy adults

BACKGROUND

Low-intensity continuous inspiratory muscle training improves its strength. The abdominal muscles are the main expiratory muscles, and their training may improve expiratory muscle strength. Respiratory muscle strength regulates coughing effectiveness, which is critical for pneumonia management. In older people, risk factors for the development of pneumonia were respiratory muscle weakness and swallowing impairment. Currently, the impact of high-intensity intermittent inspiratory and abdominal muscle combined training on the respiratory, swallowing, and systemic muscles is unclear.

OBJECTIVE

We aimed to explore the effects of high-intensity inspiratory muscle training combined with or without abdominal muscle training on respiratory muscle strength as well as the strength, mass, and performance of swallowing and systemic muscles.

METHODS

Twenty-eight healthy adults were divided into two groups. Participants performed high-intensity intermittent inspiratory muscle single or its combination with abdominal muscle training for 4 weeks. Respiratory muscle strength, swallowing muscle strength and mass, systemic muscle strength, mass and performance were measured at baseline, Week 2 and Week 4.

RESULTS

Both groups showed greater maximal respiratory pressures at Week 2 and Week 4 than baseline. Both groups showed improved tongue pressure and geniohyoid muscle thickness at Week 4. In addition, the combined training group improved body trunk muscle mass, handgrip strength and five-time chair stand test, whereas the single training group did not.

CONCLUSION

This study revealed that high-intensity inspiratory muscle training improved inspiratory muscle strength and swallowing muscle strength and mass. Moreover, inspiratory and abdominal muscle combined training showed an additional benefit of improving systemic muscle strength, mass and performance.

CLINICAL TRIAL REGISTRATION NUMBER

UMIN000046724; https://upload.umin.ac.jp/cgi-open-bin/ctr/index.cgi?ctrno=UMIN000046724.

Effect of gum-chewing exercise on maintaining and improving oral function in older adults: A pilot randomized controlled trial

Background/purpose

Gum chewing has been found to improve oral function. Nevertheless, few randomized controlled trials have investigated the effects of gum-chewing exercises on oral function in older adults. This study aimed to examine the effect of gum-chewing exercises on oral function in older adults.

Materials and methods

This was a single-blind, randomized controlled trial, conducted from November 2021 to January 2022. A total of 130 participants were divided randomly into the intervention and control groups. The intervention group was told to chew experimental gums for one month, while the control group was instructed to chew experimental tablets for one month. Maximum bite force, occlusal contact areas, oral dryness, tongue pressure, tongue and lip functions (number of times each of the following syllables is pronounced per second:/pa/,/ta/, and/ka/), masticatory function, subjective masticatory function, and gum-chewing time were measured at baseline and one month following intervention to assess outcomes.

Results

One month following the intervention, tongue pressure was significantly higher in the intervention group than in the control group (P = 0.027). In the within-group comparisons, maximum bite force (P < 0.001), unstimulated saliva flow (P < 0.001), tongue and lip functions (/pa/: P < 0.001;/ta/: P < 0.001;/ka/: P < 0.001), color scale value (P = 0.019), and ΔE value (P = 0.024) were significantly increased in the intervention group.

Conclusion

The results suggest that gum-chewing exercises can improve oral functions in older adults, although additional increases in masticatory load may be necessary to establish a more effective oral function training method using gum-chewing exercises in older adults.

3D Printer-Assisted Layered Fabrication of a Novel Appliance for Oral Myofunctional Therapy and Functional Evaluation of Its Effects on Orofacial Muscles During Wear

Aim Balanced function of the orofacial muscles is important for normal occlusion and dentition; however, patients with malocclusion often present with myofunctional disorder (MFD). Myofunctional therapy (MFT) has received much attention as a method for reducing MFD. Moreover, prefabricated functional appliances (PFAs) have been developed as a method to eliminate abnormal muscle pressure and guide the tongue into the correct position. However, PFAs have disadvantages, such as poor intraoral retention, limited usage time due to discomfort and poor patient compliance, and changes in the axis of the mandibular anterior teeth. Therefore, this study aimed to develop a new custom-made splint-type orthodontic appliance with CAD/CAM technology. Moreover, we evaluated the characteristics of the appliance and conducted functional tests to determine the effects of the appliance on the orofacial muscles and the discomfort associated with its use. Materials and methods Twenty-five volunteers (nine females and 16 males; mean age 28.4 ± 3.4 years) with normal swallowing function were included in the study. Lip-closing strength (LCS), electromyogram during swallowing, oxygen saturation, and pulse rate were measured and compared when the appliance was not worn and when it was worn. In addition, tongue habits were evaluated, and the maximum tongue pressure was measured when the appliance was not worn. The subjects were asked to answer a questionnaire using a numerical rating scale (NRS) regarding discomfort when wearing the appliance. The evaluation items were swallowing difficulty, speaking difficulty, and breathlessness, which were rated on an 11-point scale ranging from 0 to 10. Statistical tests were conducted using IBM SPSS version 28.0.1 (IBM, Armonk, NY, USA) with the Shapiro-Wilk and Levene's test, followed by the Wilcoxon signed rank sum test. The significance level was set at α = 0.05. The measurement error for each measurement item was evaluated using an intraclass correlation coefficient. Results A new custom-made splint-type orthodontic appliance was fabricated for each subject. The fit and retention of the appliance in the mouth were good when fitted, and a comparison of the functional test measurements of 25 subjects with and without the appliance showed that the LCS decreased significantly (p<0.05) before and after wearing the appliance. However, no statistically significant differences were found for the other items. The Mann-Whitney U test regarding the effects of sex, previous orthodontic treatment, or MFT, and oral habits did not statistically significantly influence the effects of wearing the device. In the NRS results, "difficulty swallowing" was observed in half of the subjects, "difficulty breathing" was rarely observed, and "difficulty speaking" was observed in all subjects. Conclusions A novel custom-made splint-type orthodontic appliance was designed and fabricated using digital workflow and 3D printing technology. This appliance was designed to correct oral habits and was made from a new material classified as a class II medical appliance according to the international harmonized classification.

Relationship between maximal isometric tongue pressure and limit of fracture force of gels in tongue squeezing

BACKGROUND

There is no clear objective indicator for selecting soft foods that are required for food bolus formation in older people with impaired oral function.

OBJECTIVE

This study aimed to investigate the relationship between maximal isometric tongue pressure (MITP) and the mechanical properties of gels that can be crushed by the tongue.

METHODS

This study included 65 healthy participants aged 22-96 (young group; 15 males, 15 females; older dentate group; 7 males, 8 females; older edentulous group; 10 males, 10 females). MITP was measured by the balloon-probe device. Agar gel with 10 different kinds of fracture force from 10N to 100N was used. The limit of fracture force of gels (LFFG) that were crushed by the tongue was measured by the up-and-down method. In the older edentulous group, two items were measured with and without dentures. Spearman's rank correlation coefficient was used to evaluate the relationship between MITP and LFFG in each group (p < .05).

RESULTS

There were positive correlations between MITP and LFFG in all groups (overall groups: rs  = .66, young group: rs  = .46, older dentate group: rs  = .61, older edentulous group with dentures: rs  = .60, older edentulous group without dentures: rs  = .47).

CONCLUSION

MITP and LFFG were positively correlated in young, older dentate and older edentulous groups, suggesting that MITP has the potential to be an objective indicator of the range of mechanical properties of soft food that can be crushed by the tongue.

Use of suction electrodes for measurement of intrinsic tongue muscular endurance during lingual pressure generation

BACKGROUND

Lingual pressure (LP) generation is cooperatively controlled not only by the intrinsic tongue (I-ton) muscles but also by hyoid muscle activation. However, the measurement of endurance and fatigue properties of I-ton muscles is difficult due to the instability of electrodes.

OBJECTIVE

The purpose of this study was to apply suction electrodes to measure electromyograms (EMGs) of I-ton muscle and to evaluate integrated EMG amplitude (iEMG) and mean power frequency (MPF) of EMG in the I-ton and hyoid muscles performing continuous LP.

METHODS

Twenty healthy adult volunteers (10 males, 10 females, mean age 28.8 years) were instructed to perform 10-s LP generation tasks at 25%, 50%, 75% and 100% of maximum LP in randomised order with visual feedback. During each task, EMGs of the I-ton, suprahyoid (S-hyo), infrahyoid (I-hyo) and masseter (Mass) muscles were simultaneously recorded. The iEMG and MPF of EMG burst during 10-s LP tasks were compared. The recording period was divided into three substages to analyse temporal changes with the Friedman test.

RESULTS

During the 10-s task, the iEMG significantly increased as the LP strength increased (p < .001). There was no time-dependent change in the I-ton iEMG; however, the MPF of the I-ton EMG burst decreased in all tasks (p < .05). The S-hyo and I-hyo iEMGs gradually increased, especially with strong LP (p < .01).

CONCLUSION

While I-ton muscles may easily fatigue during 10-s LP generation, S-hyo and I-hyo muscles may help compensate for the weakened I-ton muscle activity by increasing their activity to maintain LP.

Quantitative evaluation of swallowing function in Parkinson's disease using tongue pressure measurement: a mini-review

Dysphagia is a common symptom of Parkinson's disease (PD) associated with aspiration pneumonia, choking, malnutrition, and a decreased quality of life, and is a leading cause of death among patients with PD. Tongue dysfunction in patients with PD affects the oral phase of swallowing, including the formation and propulsion of a bolus into the pharynx. Assessing tongue pressure, generated between the tongue and palate, is a method that quantitatively measures tongue function and is related to dysphagia in PD. Two assessment methods are used to measure tongue pressure: tongue strength and tongue pressure during swallowing. Previous studies measuring tongue pressure in PD have reported decreased tongue strength and pressure during swallowing, as well as a prolonged tongue pressure rise time, which are symptoms associated with PD severity and dysphagia. In this mini-review, we present a method for measuring tongue pressure and discuss its relationship with dysphagia in PD. We also describe limitations and future perspectives in tongue pressure measurement research.

Prospective Observational Study for the Comparison of Screening Methods Including Tongue Pressure and Repetitive Saliva Swallowing With Detailed Videofluoroscopic Swallowing Study Findings in Patients With Acute Stroke

BACKGROUND

Simple, noninvasive, and repeatable screening methods are essential for assessing swallowing disorders. We focused on patients with acute stroke and aimed to assess the characteristics of swallowing screening tests, including the modified Mann Assessment of Swallowing Ability score, tongue pressure, and repetitive saliva swallowing test (RSST), compared with detailed videofluoroscopic swallowing study (VFSS) findings to contribute as a helpful resource for their comprehensive and complementary use.

METHODS AND RESULTS

We enrolled first-ever patients with acute stroke conducting simultaneous assessments, including VFSS, modified Mann Assessment of Swallowing Ability score, tongue pressure measurement, and RSST. VFSS assessed aspiration, laryngeal penetration, oral cavity residue, vallecular residue, pharyngeal residue, and swallowing reflex delay. Screening tests were compared with VFSS findings, and multiple logistic analysis determined variable importance. Cutoff values for each abnormal VFSS finding were assessed using receiver operating characteristic analyses. We evaluated 346 patients (70.5±12.6 years of age, 143 women). The modified Mann Assessment of Swallowing Ability score was significantly associated with all findings except aspiration. Tongue pressure was significantly associated with oral cavity and pharyngeal residue. The RSST was significantly associated with all findings except oral cavity residue. Receiver operating characteristic analyses revealed that the minimum cutoff value for all VFSS abnormal findings was RSST ≤2.

CONCLUSIONS

The modified Mann Assessment of Swallowing Ability is useful for broadly detecting swallowing disorders but may miss mild issues and aspiration. The RSST, with a score of ≤2, is valuable for indicating abnormal VFSS findings. Tongue pressure, especially in oral and pharyngeal residues, is useful. Combining these tests might enhance accuracy of the swallowing evaluation.

Low tongue pressure and depression using Kihon Checklist for assessing frailty status among community-dwelling Japanese older adults: A pilot study

BACKGROUND

Evaluation of low tongue pressure is used to diagnose oral hypofunction. The pathophysiology of oral hypofunction is hypothesized to be associated with oral dysfunction related to ageing. Depression in older adults is a major problem and is related to handgrip strength, which is related to tongue pressure. We hypothesized that low tongue pressure could indicate depression mood in community-dwelling older adults.

OBJECTIVES

This study aimed to measure maximum tongue pressure and compare it to the responses to the Kihon Checklist (KCL), which is used to check mental and physical deterioration of community-dwelling older adults.

METHODS

A total of 49 community-dwelling independent older adults with stable dental condition (23 men, 26 women; median age, 79 years) answered the KCL, which contained questions on frailty status, cognitive function, nutritional and sarcopenia status. Oral function was measured to assess oral hypofunction. The relationship between tongue pressure differences and frailty status, cognitive function, nutritional and sarcopenia status was analysed using logistic regression analyses after adjusting for age and sex.

RESULTS

Nine participants (6 men and 3 women; median age, 81 years) had a tongue pressure <23.0 kPa, which was the lowest limit of the standard value of maximum tongue pressure in patients aged ≥70 years. Logistic regression analyses showed that only Question 21, which is related to a lack of fulfilment in daily life, was significantly associated with low tongue pressure (p = .027).

CONCLUSION

Low tongue pressure may be associated with sociopsychological factors in older adults.

Association between tongue pressure and oral status and activities of daily living in stroke patients admitted to a convalescent rehabilitation unit

BACKGROUND

Clarifying how tongue pressure in convalescent stroke patients affects oral condition and activities of daily living (ADL) is important for developing oral rehabilitation programs and for rehabilitation care to reacquire ADL.

OBJECTIVE

To clarify how tongue pressure is associated with oral status, ADL, and nutritional status in stroke patients.

METHODS

Sixty-eight patients aged 77.9 ± 10.0 years participated. The Japanese version of the Oral Health Assessment Tool was used to evaluate oral status. Data such as the ADL index functional independence measure (FIM), nutritional intake method, serum albumin, and body mass index were extracted from medical records. To examine factors associated with tongue pressure, multiple regression analysis was performed adjusting for confounding factors. The level of statistical significance was set at p < .05.

RESULTS

In recovery phase stroke patients, tongue pressure was significantly lower in the total assistance group than in the partial assistance/independent group. In addition, tongue pressure was significantly lower in tube feeding patients than in oral feeding patients. FIM cognition score was an independent factor that had a significant effect on tongue pressure.

CONCLUSION

These findings suggest that ADL status also affects tongue pressure, thus patients' ADL including the FIM cognition subscale should also be evaluated while measuring tongue pressure.

Influence of Spinal Sagittal Alignment in Sitting Posture on the Swallowing Speed of Older Adult Women: A Cross-Sectional Study

Thoracolumbar kyphosis in sitting posture is associated with forward head posture and may adversely affect swallowing function. However, few studies have investigated the effect of spinal alignment in the sitting posture on the swallowing function of older adults. This cross-sectional study aimed to investigate whether spinal alignment in the sitting posture influences the swallowing function of older adult women. Overall, 18 older adult women (mean age, 69.78 ± 3.66 years) without dysphagia were enrolled. Participants were positioned in two sitting postures, namely, comfortable sitting (CS) and thoracic upright sitting (TUS). In each sitting posture, the kyphosis index (using a flexicurve), sagittal angles (head, cervical, shoulder, and pelvic angles; using a digital camera), and cervical range of motion (ROM) were evaluated. Swallowing speed (100-mL water swallowing test), maximum tongue pressure (MTP), and oral diadochokinesis (ODK) were also evaluated. Compared with TUS, CS showed a greater kyphosis index, anterior head translation, and posterior pelvic tilt. CS had greater flexion (p < 0.001) and less extension (p < 0.001) of cervical ROM than TUS. Swallowing speed was significantly decreased in CS compared with TUS (p = 0.008). MTP and ODK were not significantly different between CS and TUS. Thus, changes in sitting posture with spinal alignment may affect swallowing speed. Consequently, adjustments to reduce sitting postural kyphosis in older adult women may improve swallowing speed.

Decreased serum creatinine to cystatin C ratio is associated with low tongue pressure

AIM

Tongue strength plays an important role in the process of food intake, and low tongue pressure has been associated with aspiration pneumonia, cognitive decline, and mortality. However, special equipment for tongue pressure measurement is uncommon in general practice. Recently, the serum creatinine-to-cystatin C (Cr/CysC) ratio has been validated as a marker of muscle volume mass. Thus, we aimed to investigate the association of the serum Cr/CysC ratio with tongue pressure in a cross-sectional study.

METHODS

This single-center, cross-sectional study enrolled 73 participants (mean age, 71.7 years; men, 49.3%) who regularly attended the hospital for treatment of chronic disease. A tongue pressure of <30 kPa was defined as low tongue pressure. We evaluated the relationships between the serum Cr/CysC ratio and tongue pressure using multiple regression analysis.

RESULTS

The serum Cr/CysC ratio was correlated with tongue pressure (R2  = 0.25, P < 0.0001). In multiple regression analyses adjusted for confounders including age, sex, body mass index, and serum albumin, the association remained significant (P = 0.0001). In logistic analyses, the multivariable-adjusted odds ratios of the Cr/CysC ratio for tertiles 1 and 2 compared with tertile 3 for low tongue pressure were 7.81 (95% confidence interval, 1.45-51.73) and 2.71 (95% confidence interval, 0.60-13.19), respectively.

CONCLUSIONS

We demonstrated that a decreased serum Cr/CysC ratio was associated with a higher risk of low tongue pressure. Our findings suggest that this simple serum surrogate marker may be a first step toward an intervention for oral function by general practitioners. Geriatr Gerontol Int 2024; 24: 102-108.

Relationship between the jaw-closing force and dietary form in older adults without occlusal support requiring nursing care

In clinical practice, we encounter cases wherein older adults lacking occlusal support consume foods requiring mastication and adequate swallowing function. This study investigated the relationship between jaw-closing force (JCF) and dietary form in older adults without occlusal support requiring nursing care. This prospective cross-sectional study included 123 older adults requiring nursing care who lost their molar occlusal support and consumed food orally without dentures. JCF was defined as the force required for crushing food with the edentulous ridges or with the tooth and edentulous ridge while closing the mouth. Participants were classified into four groups based on the International Dysphagia Diet Standardization Initiative framework for recommended dietary forms. Basic information was collected, and tongue pressure and JCF were measured. Differences in JCF were analyzed using one-way analysis of variance, while factors related to dietary form were evaluated using ordinal logistic regression analysis. Significant differences in JCF were observed among the four groups. Factors such as the Barthel Index, tongue pressure, and JCF were dietary form-related. Our findings suggest that older adults requiring nursing care tend to have higher JCF when consuming meals requiring mastication. Therefore, JCF could serve as an index for determining appropriate dietary forms in this population.

Tongue Strength of Older Adults Requiring Long-Term Care Varies throughout the Day

Physical performance shows approximately 30% diurnal variation; however, diurnal variation in oral function remains unclear. This study aimed to determine the diurnal variation in oral and swallowing function in older adults requiring long-term care. The participants included 13 adults aged >60 years (3 men and 10 women, mean age: 77.2 ± 6.3 years, age range: 62-90 years) requiring long-term care. Tongue strength (TS) and oral mucosal moisture were measured as indices of oral and swallowing function, while hand grip strength was measured as an index of general muscle strength. The patients were asked to participate in a "test" after breakfast, lunch, and dinner on the same day. Multilevel linear regression analysis was used to examine diurnal differences in each item. Multilevel linear regression analysis with adjustment for age and sex revealed that TS was significantly higher at noon (p = 0.001) than in the morning. Therefore, caregivers who provide support during meals to older people requiring long-term care should consider the possibility of swallowing function differing according to the time of the day. In conclusion, it may be beneficial to establish a nutritional therapy that accounts for the diurnal variation in TS.

Improvements in Maximum Bite Force with Gum-Chewing Training in Older Adults: A Randomized Controlled Trial

No specific methods have been officially proposed for the prevention and improvement of oral hypofunction. Therefore, in this randomized controlled trial, we aimed to develop a gum-chewing training program and determine its effects in older adults. A total of 218 older adults, aged 65-85 years, were randomly allocated to the intervention or control groups. The intervention group chewed the experimental gum daily, whereas the control group consumed the experimental granular food daily. The outcome assessments measured the maximum bite force, occlusal contact areas, oral dryness, tongue pressure, tongue and lip functions, masticatory function, and gum-chewing time. The measured values for each outcome were compared between groups using the Mann-Whitney U test and within groups pre- and post-intervention using the Wilcoxon signed-rank test. A total of 211 participants completed the study. After 2 months, the intervention group had a significantly higher maximum bite force than the control group (p = 0.01), indicating that gum-chewing training improved maximum bite force in older adults. This was determined using one type of bite force measuring device. Therefore, it is suggested that gum-chewing training has a high potential to improve oral hypofunction.

Factors related to masticatory performance in patients with removable dentures for jaw defects following oral tumor surgery

Purpose In the treatment of oral tumors, extensive jaw defects due to surgical resection can reduce masticatory performance. Herein, we aimed to clarify the factors related to masticatory performance in patients with jaw defects.Methods In total, 76 patients (42 male and 34 female) underwent prosthetic treatment with a removable denture for a jaw defect following oral tumor surgery. Data on history of radiation therapy, period of time since surgery, period of use of the present denture, number of remaining teeth, and site of the jaw defect were collected. Masticatory performance was evaluated using test gummy jelly. In addition, maximum bite force, tongue pressure, tongue-lip motor function (oral diadochokinesis /pa/, /ta/, /ka/), and oral dryness were evaluated. Logistic regression analysis was performed with lower masticatory performance scores as the dependent variable. Since multicollinearity was suspected between the oral diadochokinesis /ta/ and /ka/ syllables, two logistic regression analyses were conducted: Model 1 with the /ta/ syllable as an explanatory variable, and Model 2 with the /ka/ syllable as an explanatory variable.Results In Model 1, a history of radiation therapy, maximum bite force, number of remaining teeth, tongue pressure, and oral diadochokinesis /ta/ were significant explanatory variables. In Model 2, a history of radiation therapy, maximum bite force, number of remaining teeth, and tongue pressure were significant explanatory variables.Conclusions A history of radiation therapy, maximum bite force, tongue pressure, number of remaining teeth, and motor function of the proglossis are related to decreased masticatory performance in patients with jaw defects.

Effects of Age and Lingual-Palatal Pressure Levels on Submental Surface Electromyography Measures

Submental surface electromyography (sEMG) may provide information about the lingual-palatal pressure (LPP) during swallowing. However, the extent to which changes in age and LPP levels are reflected in different sEMG measures is unclear. This study aimed to understand the effects of age and different levels of submaximal LPPs on submental sEMG peak, average, and integrated values in healthy adults. Ninety community-dwelling healthy participants were categorized into three age groups (young: 20-39 years, middle age: 40-59 years, older: 60 ≥ years). sEMG and LPP measurements were collected concurrently. After placing the sEMG electrodes, the maximal isometric LPP was established using the Iowa oral performance instrument (IOPI) on the anterior tongue. sEMG recordings were conducted for three submaximal LPP levels, including 40%, 60%, and 80% of the maximum LPP. Two-way repeated measure ANOVAs were conducted to find the effects of age and varying LPP levels on mean sEMG peak, average, and integrated measures. A significant age by LPP level interaction was identified for sEMG peak [F (4, 172) = 4.116, p < 0.007, ηp2 = 0.087], sEMG average [F (4, 170) = 5.049, p < 0.001, ηp2 = 0.106], and sEMG integrated values [F (4, 170) = 4.179, p < 0.003, ηp2 = 0.090]. Post hoc testing demonstrated that, in general, sEMG values significantly increased with rising LPP levels, primarily for younger and middle-aged adults. Furthermore, at 80% of maximum LPP, older adults generated less sEMG average and integrated values than middle age (only significant for sEMG integrated value) and younger adults. Likewise, max LPP was lower in older adults compared with young and middle-aged groups. Submental sEMG has the potential to be incorporated into a skill-based lingual exercise paradigm to improve tongue function during swallowing. Moreover, submental sEMG can characterize some age-related subclinical changes in swallowing.

Evaluating the effect of management on patients with oral hypofunction: A longitudinal study

INTRODUCTION

Declining oral function may affect subsequent physical frailty in the older population. The aim of this longitudinal study was to summarise data on patients who underwent functional oral examination and evaluate the impact of management on patients with oral hypofunction (OHF).

METHODS

Dental outpatients aged over 65 years at their initial visit to the Niigata University Hospital received detailed assessment of seven oral function items to diagnose oral hypofunction using diagnostic criteria defined by the Japanese Society of Gerodontology. Patients with OHF at the first assessment received management including oral health guidance for low function and dental treatment. They were re-evaluated approximately 6 months later and the two assessments were compared. According to the results of the second assessment, the patients were divided into two groups: OHF improved and OHF re-diagnosed.

RESULTS

Of the 273 patients who underwent the first assessment, 86 (31.5%) were diagnosed with OHF and received management. Of those, 42 (48.8%) completed the second assessment. Comparing the first and second assessment, significant improvement was observed in oral hygiene, occlusal force, tongue-lip motor function of /pa/, mastication and swallowing. The change in values from the first assessment demonstrated a significant difference between the OHF improved and re-diagnosed groups only in occlusal force.

CONCLUSION

Management for patients with OHF can contribute to the improvement of poor oral function, and an increase in occlusal force was notable in the recovery from OHF.

Evaluation of usefulness of tongue pressure measurement device for dysphagia associated with treatment of patients with head and neck cancer (ELEVATE)

INTRODUCTION

Dysphagia is often caused by radiotherapy (RT) in patients with head and neck cancer (HNC), and reduced tongue pressure (TP) is often associated with swallowing dysfunction in the oral stage. However, the evaluation of dysphagia by measuring TP has not yet been established in HNC patients. Herein, we conducted a clinical trial to evaluate the usefulness of TP measurement using a TP-measuring device as an objective indicator of dysphagia induced by RT in HNC patients.

METHODS AND ANALYSIS

This ELEVATE trial is a prospective, single-center, single-arm, non-blind, non-randomized trial to evaluate the usefulness of a TP measurement device for dysphagia associated with the treatment of HNC. Eligible participants include patients with oropharyngeal or hypopharyngeal cancer (HPC) undergoing RT or chemoradiotherapy (CRT). The TP measurements are conducted before, during, and after RT. The primary endpoint is the change in the maximum TP values from before RT to 3 months after RT. Moreover, as secondary endpoints, the correlation between the maximum TP value and the findings of video-endoscopic and video-fluoroscopic examinations of swallowing will be analyzed at each evaluation point, as well as changes in the maximum TP value from before RT to during RT and at 0, 1, and 6 months after RT.

DISCUSSION

This trial aimed to investigate the usefulness of evaluation by measuring TP for dysphagia associated with HNC treatment. We expect that an easier evaluation for dysphagia will improve rehabilitation programs for dysphagia. Overall, we expect this trial to contribute to the improvement of patients' quality of life (QOL).

Relationship of preoperative oral hypofunction with prognostic nutritional index in gastric cancer: A case-control retrospective study

Preoperative nutritional status is an important prognostic factor in gastric cancer patients. This study will evaluate whether preoperative oral dysfunction is associated with prognostic nutrition index (PNI). This case-control study analyzed 95 patients who underwent oral function management. We assessed the following parameters: body mass index, stage of gastric cancer, C-reactive protein, total lymphocyte count, albumin, and prognostic nutritional index. The patients were divided into groups with prognostic nutritional indexes <45 and >45. Logistic regression analysis was used to assess the association between the measurements of oral function and the prognostic nutritional index. Univariate analysis of factors associated with decreased oral function and prognostic nutritional index showed significant differences between the two groups in C-reactive protein, neutrophils, and tongue pressure (p<0.01). However, oral hygiene, oral dryness, occlusal force, tongue-lip motor function, masticatory function, and swallowing function were not significantly different. Multivariate analysis showed that C-reactive protein (odds ratio: 0.12, 95% confidence interval: 0.30-0.45, p<0.01) and tongue pressure (odds ratio: 3.62, 95% confidence interval: 1.04-12.60, p<0.05) were independent risk factors for oral hypofunction. Oral function decreased in perioperative patients with gastric cancer, and decreased tongue pressure is associated with a decreased prognostic nutritional index.

Effects of tongue right positioner use on tongue pressure: a pilot study

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).

Severe Periodontitis Increases the Risk of Oral Frailty: A Six-Year Follow-Up Study from Kashiwa Cohort Study

Oral frailty, overlapping a decline in multi-faceted oral functions and often seen in older adults, increases risks of adverse health outcomes, thereby necessitating earlier measures. Tooth loss, a major element of oral frailty, is mainly caused by periodontal disease and is an irreversible event. Therefore, this study aimed to clarify whether advanced periodontal disease increases the risks of "new-onset" oral frailty through a longitudinal analysis based on the 2012 baseline survey of the Kashiwa cohort and the follow-up assessments conducted in 2013, 2014, 2016, and 2018. The participants were disability-free, non-orally frail older adults living in Kashiwa City. Of the 1234 participants (72.2 ± 5.1 years old; 50.8% men) analyzed in this study, oral frailty occurred in 23.1% within the six-year period. The group with Community Periodontal Index (CPI) ≥ 3 at baseline had no significant difference in the risk of oral frailty compared with CPI ≤ 2; however, CPI4 at baseline was related to the increased risk of oral frailty compared with CPI ≤ 3 (an adjusted hazard ratio (95% confidence interval): 1.42 (1.12-1.81). Conclusively, severe periodontitis (CPI4) might be associated with new-onset oral frailty, suggesting that prevention of periodontal disease could contribute to oral frailty prevention.

Effect of Spinal Sagittal Alignment in Sitting Posture on Swallowing Function in Healthy Adult Women: A Cross-Sectional Study

Swallowing function is both directly and indirectly related to postures, such as head and cervical angle and body position. However, the effects of different sitting postures on oropharyngeal swallowing have not been investigated. This study aimed to investigate whether the change in thoracolumbar alignment affected the oropharyngeal swallowing. A total of 58 healthy adult women (mean age 22.2 ± 1.67 years) without dysphagia were enrolled in this cross-sectional study. Participants were positioned in three sitting postures: comfortable sitting (CS), thoracic upright sitting (TUS), and slump sitting (SS). In each sitting posture, the kyphosis index (using a flexicurve), head and cervical angles (using a digital camera), swallowing speed (100-ml water swallowing test), and oral and articulatory function [by maximum tongue pressure (MTP) and oral diadochokinesis (ODK)] were evaluated. SS showed the largest kyphosis index and was associated with a greater anterior translation of the head. Swallowing speed was significantly decreased in SS compared with CS (p = 0.002) and TUS (p = 0.020) and ODK was significantly decreased in SS compared with other postures, for both /ta/ (p = 0.004) and /ka/ (p < 0.001) syllables. Further, MTP tended to decrease in SS compared with TUS (p = 0.064). Our results suggest that changes in sitting posture with different thoracolumbar alignments affect swallowing speed and oral and articulatory function. Consequently, adjustments to reduce sitting postural kyphosis may improve swallowing speed and oral and articulatory function.

Associations of swallowing-related muscle quantity and quality with sarcopenic parameters

PURPOSE

To examine the associations between swallowing-related muscle characteristics and sarcopenic parameters.

METHODS

We included 147 community-dwelling older adults (age: 71.6 ± 4.7 years, body mass index: 23.0 ± 2.7 kg/m² (mean ± standard deviation), men: 50; women: 97) and categorized them into robust (n = 125), low-function (n = 17), and sarcopenia (n = 5) groups based on the diagnostic criteria of the Asia Working Group for Sarcopenia 2019. We evaluated the geniohyoid muscle (GHM) and tongue characteristics (muscle quantity and quality). The cross-sectional area (CSA) indicated the muscle quantity, and echo intensity (EI) values indicated the muscle quality. A multiple regression analysis was performed to clarify the relationship of swallowing-related muscle characteristics and strength with sarcopenic parameters.

RESULTS

The grip strength (CSA of GHM: β = 1.64, p = 0.03) and skeletal muscle mass index (CSA of tongue: β = 74.81, p = 0.003, EI of tongue: β = 1.92, p = 0.009) were better indicators of swallowing-related muscle characteristics.

CONCLUSION

These findings may facilitate the early detection of aging-related deterioration in swallowing-related musculature through the diagnostic process of sarcopenia and increase our understanding of muscle physiology.

Peak expiratory flow, but not tongue pressure, can predict pneumonia development in older adults

PURPOSE

Pneumonia is the leading cause of mortality and morbidity in aging populations. Major causes of pneumonia in older adults are swallowing dysfunction and decreased airway clearance capacity, including an impaired cough reflex. Maximal tongue pressure is useful for evaluating swallowing function, and peak expiratory flow indirectly reflects cough strength. However, it is unclear whether they can predict pneumonia development in older adults. In this study, we investigated whether tongue pressure and peak expiratory flow could predict pneumonia development in older adults.

METHODS

This two-center prospective observational study included older adults aged 65 years or older without respiratory disease or head and neck cancer. We enrolled 383 consenting participants, many of whom had a history of stroke, and followed them for 2 years. The association between time to pneumonia development and tongue pressure or peak expiratory flow at enrollment was examined in a Cox proportional hazards model.

RESULTS

The mean age of the participants was 77.1 ± 6.2 years, and 36.0% of them were women. The mean tongue pressure was 35.4 ± 10.5 kPa and median peak expiratory flow was 218 L/min at enrollment. Six patients developed pneumonia during the study period. A low peak expiratory flow at enrollment was significantly associated with pneumonia development in the multivariate Cox proportional hazards model, but this association was not observed for tongue pressure.

CONCLUSION

Decreased peak expiratory flow may predict pneumonia development in older adults. Future studies should investigate interventions for peak expiratory flow improvement.

Population-based reference values for tongue pressure in Japanese older adults: A pooled analysis of over 5,000 participants

PURPOSE

To establish age- and sex-specific population reference values for tongue pressure (TP) in community-dwelling Japanese older adults.

METHODS

For this analysis, we pooled four population-based studies on community-dwelling adults aged ≥65 years that measured TP using a JMS tongue pressure measuring device. We calculated the means and deciles of TP per 5-year age group for each sex. We also estimated age trends in TP for men and women.

RESULTS

In total, 5,083 individuals (2,150 men and 2,933 women, with a mean [standard deviation] age of 75.2 [6.5] years) were included in the present analysis. In male participants, the mean (standard deviation) TPs for ages 65-69, 70-74, 75-79, 80-84, and ≥85 years were 34.0 (8.4), 32.2 (8.1), 30.8 (8.3), 28.4 (8.9), and 24.4 (8.2) kPa, respectively. In female participants, the corresponding values were 31.5 (7.1), 30.5 (7.5), 29.6 (7.3), 28.4 (8.0), and 26.4 (7.6) kPa, respectively. For both sexes, there were significant declining trends in TP with advanced age. In addition, the interaction between age and sex had a significant effect on TP (regression coefficient [95% confidence interval] = -0.18 [-0.25 to -0.11] when age was modeled as a continuous variable and sex was modeled as a categorical variable [coded as 0=women, 1=men]).

CONCLUSIONS

This study determined age- and sex-specific reference values for TP, presented as means and deciles, in community-dwelling Japanese older adults aged ≥65 years. This study also demonstrated sex differences in age-related declines in TP.

Visual evaluation for the elasticity of suprahyoid muscles using sonographic elastography during tongue pressure measurement: A pilot study

BACKGROUND

Suprahyoid muscles behavior during the tongue lifting movement has not yet been elucidated.

OBJECTIVE

The purpose of this study was to investigate the potential of elastography imaging to examine developmental oral dysfunction in children and oral hypofunction in older adults using sonography.

METHODS

Tongue pressure was measured using a manometer with a probe. The tongue pressure was measured with simultaneously scanning the geniohyoid muscle (GHM) and the anterior belly of the digastric muscle (DGM) using sonographic elastography. Sagittal images of the GHM and coronal images of the DGM were used for the strain ratio measurement. The strain ratio of the muscles was measured three times for each subject with the tongue pressure values of 0-30 kPa.

RESULTS

The strain ratio of the GHM were higher than those of the DGM at tongue pressure of 10, 20 and 30 kPa. The strain ratio of the GHM increased as the tongue pressure increased in all participants. In contrast, the strain ratio of the DGM tended to slowly decrease as tongue pressure increased in female participants.

CONCLUSION

Sonographic elastography is useful for visual and quantitative evaluation of elastic properties in suprahyoid muscles during tongue lifting movements.

The Cross-Sectional Area of the Middle and Base of the Tongue is Associated with Swallowing-Related Muscle Strength

Muscle strength and function are generally positively correlated with muscle quantity and negatively correlated with muscle quality; however, the tongue shows a unique tendency, different from limb muscles. The relationship between the characteristics of each part of the tongue, muscle strength and function, and systemic factors has been unclear. The aim of the study was to investigate the relationship between cross-sectional area (CSA) and echo intensity (EI) of the middle and base of the tongue and swallowing, articulation function, and body composition. Eighty-nine healthy individuals were included in this cross-sectional study. Swallowing was assessed using tongue pressure (TP) and jaw opening force (JOF) as they indicate swallowing-related muscle strength. Articulation function was evaluated through oral diadochokinesis (ODK). Bioelectrical impedance analysis was performed for body composition. CSAs and EIs of the middle and base of the tongue were measured using ultrasound. Multiple regression analysis was used to examine the relationship between the characteristics of the tongue, swallowing-related muscle strength, and ODK. In multiple regression analysis with TP as the dependent variable, age (β = - 0.22, P < 0.01) and CSA of the middle part (β = 0.02, P < 0.01) were significant explanatory variables. In multiple regression analysis with JOF as the dependent variable, sex (β = - 2.76, P < 0.01) and CSA of the base (β = - 0.004, P < 0.05) were significant explanatory variables. Multiple regression analysis with articulation function as the dependent variable did not yield significant results. The CSA of the tongue is a better indicator of swallowing-related muscle strength than EI. Ultrasonography may be used for assessing swallowing-related muscle strength.

Lower SMI is a risk factor for dysphagia in Japanese hospitalized patients with osteoporotic vertebral and hip fracture: A retrospective study

Objectives

Many patients with osteoporotic fragile fracture often suffer from dysphagia that results in malnutrition, further deterioration of physical strength, and rehabilitation difficulties. This study aims to investigate the risk factors for dysphagia in hospitalized patients with osteoporotic vertebral and/or hip fractures.

Methods

Between January 2020 and December 2021, 569 inpatients were managed for osteoporotic vertebral or hip fractures. Of these, 503 patients were analyzed and 66 were excluded as the required data could not be obtained or dysphagia with causative diseases such as cerebrovascular disease. The patients were divided into 2 groups: patients with dysphagia (P-group) and patients without dysphagia (N-group). We investigated gender, fracture site, age, systemic skeletal muscle mass index (SMI), bone mineral density (BMD), and body mass index (BMI) in early stage of hospitalization and studied their relationship with dysphagia.

Results

There were no significant differences in gender and fracture site between the 2 groups. A significant difference was observed in age, SMI, BMD, and BMI (P < 0.01). We performed a logistic regression analysis with the P-group as the objective variable and age, SMI, BMD, and BMI as explanatory variables. We divided objective groups into all patients, patients with vertebral fracture, patients with hip fracture, men, and women. SMI was an independent risk factor in all groups.

Conclusions

Lower SMI was a risk factor for dysphagia in hospitalized patients with osteoporotic vertebral and hip fractures. We carefully observed swallowing function of patients with decreased SMI to maintain the nutritional status and prevent rehabilitation difficulties.

The relationship between sarcopenia, dysphagia, malnutrition, and frailty: making the case for proactive swallowing exercises to promote healthy aging

PURPOSE OF REVIEW

The purpose of this review is to summarize current evidence regarding the relationship between sarcopenia of the swallowing muscles, dysphagia, malnutrition, and frailty in the context of aging. Further, this review will provide preliminary support for proactive swallowing exercises to reverse and/or prevent sarcopenia of the swallowing muscles.

RECENT FINDINGS

Recent studies lend support to a cyclic relationship between sarcopenia of the swallowing muscles, dysphagia, malnutrition, and frailty. Unfortunately, all studies are limited by their study design and lack instrumental imaging of swallowing function. Research (in the limbs) supports the use of proactive exercises and protein supplementation to reverse sarcopenia, especially in prefrail individuals. This provides a foundation to design and test similar preventive exercises for the swallowing muscles.

SUMMARY

As the population is rapidly aging, it is vital to understand how the natural loss of muscle in aging impacts swallowing function and the downstream impact on nutritional and physical function. Prospective, longitudinal research with sophisticated outcome measures are required to fully understand this cycle and provide an opportunity to test methods for interrupting the cycle.

Effect of Tongue-Pressure Resistance Training in Poststroke Dysphagia Patients With Oral Motor Dysfunction: A Randomized Controlled Trial

OBJECTIVES

The aims of the study were to investigate the effect of tongue-pressure resistance training in poststroke dysphagia patients with oral motor dysfunction and to examine the therapeutic value of tongue-pressure resistance training in the oral and pharyngeal phases.

DESIGN

Patients were divided into an experimental and a control group. Both groups received 30 mins of traditional swallowing rehabilitation treatment every day for 4 wks. In addition, the experimental group received tongue-pressure resistance training for an extra 20 mins/d. Maximum tongue pressure and fiberoptic endoscopic examination of swallowing were assessed before and after treatments.

RESULTS

Compared with the control group, the experimental group showed significant improvement in Functional Communication Measure for swallowing, Oral Motor Function Scale, maximum tongue pressure, Murray Secretion Scale, Rosenbek Penetration-Aspiration Scale, and food residue in pyriform sinuses ( P < 0.05). There was no significant difference in food residue in epiglottic vallecula between both groups ( P > 0.05).

CONCLUSIONS

This study demonstrated that tongue-pressure resistance training is an effective approach to improve the overall swallowing function in patients with oral motor dysfunction. The improvement of oral motor function could facilitate the recovery of pharyngeal motor function. Tongue-pressure resistance training seems to have more clearance of residue in piriform sinus than epiglottic vallecula.

Use of Maximum Tongue Pressure Values to Examine the Presence of Dysphagia after Extubation and Prevent Aspiration Pneumonia in Elderly Emergency Patients

Background: Tongue pressure values in patients with dysphagia are reported to be significantly lower than those in healthy controls. The aim of this study was to measure the maximum tongue pressure (MTP) values after extubation in order to assess the presence of post-extubation dysphagia for the safe initiation of oral intake in elderly patients. Methods: Data from 90 patients who were extubated after mechanical ventilation under tracheal intubation were collected retrospectively. The patients were divided into two groups as follows: normal group (those who did not develop aspiration pneumonia after extubation; median age 62 years) and aspiration group (those who developed aspiration during the evaluation period; median age 75 years). The MTP values were measured at 6 h, 24 h, 3 days, and 7 days after extubation. Results: The values were significantly increased 24 h after extubation in the normal group (p < 0.05). Alternatively, no increase was observed even after 1 week of extubation in the aspiration group, and the values were significantly lower than those in the normal group. The cutoff values at 6 and 24 h after extubation, which were measured using the receiver operator characteristic (ROC) curve, were 17.8 and 23.2 kpa, respectively; furthermore, the results of these assessments were strongly related to the development of aspiration 6 h after extubation (χ2-value: 6.125; p = 0.0133). Conclusions: The presence of post-extubation dysphagia in patients who are intubated for ≥24 h can be predicted based on age and the MTP values at 6 h after extubation.

Relationship between Knowledge and Attitude toward Oral Function in Middle-Aged and Older Adults

Oral hypofunction is the stage at which recovery can be expected with proper diagnosis, management, and motivation before oral dysfunction occurs. The knowledge and attitude toward oral function can influence the maintenance and improvement of oral function. However, whether middle-aged and older adults with declining oral function have knowledge of their oral function and how this knowledge and their attitude affect their oral function are unclear. Therefore, we aimed to examine (1) the relationship between knowledge and attitude toward oral function and hypofunction in individuals with suspected oral hypofunction and (2) changes in knowledge and attitude toward oral function through evaluation and education. Participants aged ≥50 years were enrolled during their first community dental clinic visit. A questionnaire assessment of knowledge and attitudes before and after oral function evaluation was performed. The oral function was initially assessed with seven criteria: oral hygiene; oral dryness; occlusal force; tongue pressure; tongue-lip motor, masticatory, and swallowing function. Associations between knowledge and attitudes and their changes were statistically analyzed. Fifty-nine participants (93.7%) were unaware of “oral hypofunction.” Associations between knowledge and attitudes and their changes in the negative to positive response groups, from 86.4% and 61.0% to 6.8% and 25.4%, respectively, after oral function evaluation, indicated that participants understood their oral function and the need for training. Middle-aged and older individuals with poor knowledge and attitudes were more likely to have a worse oral function; however, their knowledge and attitudes toward oral function could be improved through oral function assessment and education.

Association between Tongue Pressure and Jaw-Opening Force in Older Adults

Tongue pressure (TP) is used to assess tongue muscle strength and is related to function and frailty. While performing TP, it is necessary to elevate the tongue and oral floor by contracting the suprahyoid muscles. However, the association between TP and suprahyoid muscle strength remains unclear. Accordingly, this study investigated the relationship between TP and jaw-opening force (JOF), an indicator of suprahyoid muscle strength. This cross-sectional study included 88 independent community-dwelling participants aged ≥65 years. Age, sex, and the number of remaining teeth were recorded. Ultrasonography was used to evaluate the cross-sectional area of the tongue and geniohyoid muscle, as representatives of the suprahyoid muscles. Sarcopenia was diagnosed based on appendicular skeletal muscle mass index, handgrip strength, and gait speed. Multiple regression analysis was performed with TP as the dependent variable. TP was significantly associated with JOF (β = 0.371, p = 0.003). This study revealed that decreased TP was associated with a decline in JOF and suprahyoid muscle mass in older adults. Thus, low TP may be associated with decreased JOF. Prevention of the weakness of the suprahyoid muscles and maintaining TP may also contribute to the prevention of frailty associated with TP.

Comparison of Lingual Pressure Generation Capacity in Parkinson Disease, Amyotrophic Lateral Sclerosis, and Healthy Aging

PURPOSE

The tongue plays a key role in bolus propulsion during swallowing, with reduced lingual pressure generation representing a risk factor for impaired swallowing safety and efficiency. We compared lingual pressure generation capacity in people with Parkinson disease (PwPD), people with amyotrophic lateral sclerosis (PwALS), and healthy older adults. We hypothesized that both patient cohorts would demonstrate reduced maximum anterior isometric pressure (MAIP) and regular effort saliva swallow (RESS) pressures compared with healthy controls, with the greatest reductions expected in the ALS cohort.

METHOD

We enrolled 20 PwPD, 18 PwALS, and 20 healthy adults over 60 years of age. The Iowa Oral Performance Instrument was used to measure MAIP, RESS, and lingual functional reserve (LFR, i.e., MAIP - RESS). Descriptive statistics were calculated; between-groups differences were explored using univariate analyses of variance and post hoc Sidak tests with alpha set at .05.

RESULTS

Mean MAIPs for the PD, ALS, and heathy cohorts were 54.7, 33.5, and 47.4 kPa, respectively. Significantly lower MAIP was found in PwALS compared with PwPD and healthy controls. RESS values did not differ significantly across groups. LFR was significantly higher in PwPD versus PwALS and healthy controls.

CONCLUSIONS

Lingual pressure generation capacity and functional reserve were reduced in PwALS, but not in PwPD, beyond changes seen with healthy aging. Both patient cohorts displayed preserved lingual pressure during saliva swallows. Future studies exploring longitudinal changes in tongue pressure generation on isometric and saliva swallowing tasks will be needed to confirm whether tongue pressure measures serve as noninvasive clinical biomarkers of swallowing impairment.

Factors Predicting Tongue Pressure Decline among Community-Dwelling Older Adults: The Takashimadaira Study

A limited number of longitudinal studies have explored factors contributing to decreases in tongue pressure (TP). This longitudinal study aimed to clarify the factors affecting TP decline among community-dwelling older adults. We followed the Takashimadaira Study participants with a baseline TP ≥ 30 kPa for 2 years. A TP of <30 kPa at follow-up was defined as TP decline. We used Poisson regression with robust standard errors to explore the factors related to TP decline. The studied baseline variables were dental status, sociodemographic characteristics, health behaviors, appetite, medical conditions, physical function, cognitive status, and anthropometric and body composition characteristics. Inverse probability weighting (IPW) was used to adjust for selection bias. Overall, 357 individuals (159 men and 198 women) with a mean (standard deviation) age of 75.9 (4.1) years were included in the analyses. Of these, 59 study participants (16.5%) exhibited TP decline. After adjusting for baseline TP and applying IPW, poor appetite (incident rate ratio [95% confidence interval] = 1.58 [1.01−2.48]), low skeletal muscle mass index (1.66 [1.02−2.70]), and cognitive impairment (1.93 [1.12−3.33]) were associated with TP decline. In conclusion, we demonstrated that baseline appetite, body composition, and cognitive status could predict future TP decline among community-dwelling older adults.

Relationships between cystatin C and creatinine‐based eGFR with low tongue pressure in Japanese rural community‐dwelling older adults

Background

Sarcopenia is prevalent in patients with chronic kidney disease (CKD), which is defined as a low estimated glomerular filtration rate (eGFR). It has been reported that oral hypofunction characterized by decreased tongue pressure is related to sarcopenia. Although there are several previous reports regarding the association of renal dysfunction with oral hypofunction characterized by low tongue pressure, the association between tongue pressure and renal function is not fully understood.

Methods

This cross‐sectional study included 68 men aged 79.0 ± 4.8 years and 145 women aged 77.3 ± 5.4 years from a rural area in Hyogo Prefecture, Japan. We examined the relationships between cystatin C‐based CKD (CKDcys), creatinine‐based CKD (CKDcre), ratio of cystatin C‐based GFR (eGFRcys) divided by creatinine‐based GFR (eGFRcre): eGFRcys/eGFRcre, and tongue pressure in community‐dwelling older adults.

Results

Tongue pressure was significantly lower in participants with CKDcys than in those without CKDcys in men and women. However, there were no significant differences in tongue pressure with or without CKDcre. Tongue pressure was significantly lower in participants with eGFRcys/eGFRcre <1.0, than in those with eGFRcys/eGFRcre ≧ 1.0 in men. According to the receiver operating characteristic analysis, the optimal cut‐off value of tongue pressure for the presence of CKDcys was 36.6kPa, area under the curve (AUC) 0.74 (specificity 54.8%, sensitivity 84.6%) in men and 31.8kPa, AUC 0.65 (specificity 67.3%, sensitivity 60.5%) in women.

Conclusions

CKDcys but not CKDcre is associated with low tongue pressure. In addition, a lower eGFRcys/eGFRcre ratio is a useful screening marker of low tongue pressure in community‐dwelling older adults.

Higher extracellular water/total body water ratio is associated with lower tongue and grip strength: a cross-sectional study

PURPOSE

This study aimed to investigate the relationship between tongue factors (tongue strength and tongue volume), systemic factors (grip strength and walking speed), and the extracellular water/total body water ratio.

METHODS

This cross-sectional study included community-dwelling adults. Body water composition and skeletal muscle mass index were measured using bioelectrical impedance analysis. Moreover, tongue grip strength, tongue volume, occlusal support condition (Eichner classification), and walking speed were measured. Multiple linear regression analysis was performed to investigate the relationship between the tongue and systemic factors as dependent variables and body water composition.

RESULTS

We included 171 community-dwelling adults (62 men and 109 women) aged 70.0 years (interquartile range: 8). Tongue strength (r=-0.22, p=0.004) and grip strength (r=-0.39, p<0.001) were correlated with the extracellular water/total body water ratio. In multiple linear regression analysis, tongue strength was associated with the extracellular water/total body water ratio (β=-0.20, p=0.034), and grip strength was associated with the extracellular water/total body water ratio (β=-0.12, p=0.047), sex, body mass index, skeletal muscle mass index, and occlusal support condition.

CONCLUSIONS

A higher extracellular water/total body water ratio indicates lower tongue and grip strength. Dentists and dental hygienists should be aware of systemic factors present in patients with lower tongue and grip strength. These findings may lead to further medical investigations and diagnosis of other systemic diseases.

Factors associated with frailty in patients with neurodegenerative diseases

PURPOSE

To identify the factors associated with frailty in patients with neurodegenerative diseases.

METHODS

Cross-sectional study, whose sample consisted of 150 patients diagnosed with neurodegenerative diseases seen at a speech-language therapy clinic in a reference hospital in southern Brazil. A secondary exploratory analysis of the medical records of patients treated at this clinic between April 2016 and May 2019 was performed. The information collected was sex, age, education, type of neurodegenerative disease, time of disease, frailty (Edmonton Frail Scale-EFS), swallowing (Northwestern Dysphagia Patient CheckSheet-NDPCS, Eating Assessment Tool-EAT 10), and cognition (Mini-Mental State Examination-MMSE and Montreal Cognitive Assessment-MoCA). Continuous quantitative variables were analyzed using mean and standard deviation and categorical quantitative variables from absolute and relative frequency, as well as their association with the outcome using the Chi-square test. Crude and adjusted Prevalence Ratios were assessed using Poisson regression with robust variance. All statistical tests were considered significant at a level of 5%.

RESULTS

The significant factors associated with frailty were the presence of oropharyngeal dysphagia and altered cognitive performance. Individuals with frailty have a higher prevalence of oropharyngeal dysphagia (PR= 1.772(1.094-2.872)), while cognition alteration presented a lower prevalence (PR= 0.335(0.128-0.873).

CONCLUSION

Oropharyngeal dysphagia can be an important clinical predictive factor for consideration in cases of frailty in patients with neurodegenerative diseases.

Effects of Tongue-Strengthening Exercise on Tongue Strength and Effortful Swallowing Pressure in Young Healthy Adults: A Pilot Study

PURPOSE

The purpose of this study was to investigate the effects of tongue-strengthening exercise (TSE) on tongue strength and effortful swallowing pressure in young healthy adults.

METHOD

Thirteen young healthy volunteers (six men, seven women; M _age = 20.5 ± 0.5 years) performed 8 weeks of isometric TSE 3 days per week. A tongue pressure measurement device was used to measure maximum isometric tongue pressure (MITP) and conduct the TSE, and a tactile sensor system attached to the hard palate was used to measure effortful swallowing pressure. MITP and effortful swallowing pressure were measured at baseline, after 4 and 8 weeks of training, and at 4 and 8 weeks after the last training session to examine the detraining effects.

RESULTS

The results indicated that both MITP and effortful swallowing pressure increased significantly from baseline to 8 weeks after training. Although the improved MITP significantly decreased at 4 and 8 weeks after training cessation, no detraining effect was observed for effortful swallowing pressure.

CONCLUSIONS

TSE is an effective method for increasing tongue pressure in wide tongue-palate contact areas during effortful swallow. The effortful swallowing pressure gained with TSE appears to be maintained for at least eight nontraining weeks.

Tongue Pressure Declines Early on in Patients with Malocclusion

(1) Background: The tongue plays a key role in the stomatognathic system in carrying out oral functions. The aim of this study was to identify the association between tongue pressure and orthodontic parameters. (2) Methods: This study is a cross-sectional multicentered cohort study with IRB approval. During routine orthodontic initial examinations, the following data were recorded: age, sex, angle classification, overjet (OJ), overbite (OB), arch sizes, tongue width, and maximum tongue pressure (MTP). The association between MTP and orthodontic parameters was analyzed using Pearson’s correlation analysis and the Student’s t-test. (3) Results: There is a positive correlation between MTP and age between ages 10 and 20 (R = 0.47, p < 0.01). There is a negative correlation with MTP and age between 20 and 40 (R = −0.30, p < 0.05). There are negative correlations between MTP and OJ (R = −0.278, p < 0.01)) and OB (R = −0.374, p < 0.01). While there is no statistical significance between MTP and tongue width, there is a statistically significant difference between age and tongue width (R = 0.22482, p < 0.05). There is no statistical significance between MTP and sex, angle classification, arch length, intercanine width, and intermolar width. (4) Conclusion: An earlier decline in MTP is observed with patients with malocclusion. This implies that patients with malocclusion should seek early treatment for the malocclusion.

Relationship between Rate of Force Development of Tongue Pressure and Physical Performance

In the assessment of skeletal muscle strength, rate of force development (RFD) is clinically identified as a functional index that reflects the effects of aging, but there are few reports on RFD of the tongue. The purpose of this study was to examine the relationship between RFD of tongue pressure (RFD-TP) and oral and whole-body physical performance in older adults, and to clarify its characteristics. We enrolled adults aged ≥65 years with pathological occlusal contact in premolar and molar regions of teeth in the Tamba-Sasayama area, Japan, from 2017 to 2018. Maximum tongue pressure (MTP) and the speed to reach the maximum tongue pressure (RFD-TP) were evaluated as measures of tongue function. Oral functions related to objective measures of tongue function, such as repetitive saliva swallowing test, oral diadochokinesis, and physical status or performance, such as mini mental state examination, body mass index, skeletal mass index, knee extension force, one-leg standing time, grip strength, walking speed, timed up-and-go test, and five-time chair stand speed was evaluated. No significant correlation was found between MTP and age, but RFD-TP had a significant negative correlation with age. Neither RFD-TP nor MTP showed a significant correlation with oral function. RFD-TP was associated with physical performance, such as knee extension force and one-leg standing time. RFD-TP is more sensitive to aging than MTP. In addition, RFD-TP is related to physical performance and may be useful for the early detection of frailty.

Effect of decreased tongue pressure on dysphagia and survival rate in elderly people requiring long-term care

Background/purpose

Tongue pressure plays an important role in swallowing function. The purpose of this study is to investigate whether decreased tongue pressure is associated with dysphagia and the development of pneumonia in the elderly requiring long-term care.

Materials and methods

Tongue pressure measurement and swallowing videoendoscopic (VE) examination were performed in 60 hospitalized elderly people (33 males and 27 females, with an average age of 84.3 years) to investigate the relationship with the clinical course. Factors related with dysphagia was analyzed by Fisher's exact test and one-way ANOVA, followed by multivariate logistic regression. The relationship between each variable and survival were analyzed by cox regression.

Results

Twenty-one patients had dysphagia by VE examination. Multivariate analysis showed that smaller BMI and reduced tongue pressure were significantly correlated with dysphagia. Smaller number of remaining teeth and dysphagia were significantly related to pneumonia-related death. No patients with tongue pressure of larger than 20 kpa died by pneumonia within one year, while in those with tongue pressure of smaller than 20 kpa, one-year cumulative survival rate by pneumonia was 44.3%.

Conclusion

Decreased tongue pressure was significantly associated with dysphagia and may increase the risk of pneumonia-related death in the elderly requiring long-term care.

Application of a balloon-type pressure sensor in texture evaluation of tongue-crushable foods

A relationship has recent been suggested to exist between tongue pressure measured using balloon-type sensors and the tongue-crushable food range of individuals. This study was conducted to investigate the applicability of a balloon-type pressure sensor for texture evaluation of tongue-crushable soft foods. Six gellan gum gels were used as a soft food model. The fracture force and strain of gels were controlled at two and three levels by changing the gum concentration and acyl-group content, respectively. The pressure sensor was inserted between a food sample and texture analyzer probe, and pressure values during compression of gels was measured. During the compression test, both the food and tongue-pressure sensor were deformed, eventually leading to fracture of food gels. Using the tongue-pressure sensor, the food gels fractured at lower force because of the shape of the sensor but showed longer displacement as the sensor deformed compared to without the sensor. Gels with low fracture force in the conventional test without the sensor exhibited lower fracture force, work, gradient, and true stress than those with high fracture force in the sensor test. Displacement, clearance or distance from the bottom plate, and true stress at fracture were appropriate parameters for expressing the fracture characteristics. Both the true fracture stress and fracture pressure in the sensor test decreased with the fracture strain of gels in a conventional test. These results suggest that by using a larger balloon and faster sampling, the sensor can be used to determine the fracture behavior of tongue-crushable foods.

Relationship between Food Crushing and Oral Function in Older Adults Requiring Nursing Home Care: A Pilot Study

We investigated how jelly is crushed and examined the relationship between tongue pressure and tongue food crushing ability among older adults requiring nursing home care. Seventy-two participants were instructed to freely crush the test foods soft jelly (SJ) and hard jelly (HJ). We visually evaluated the crushability of the test food and identified the intraoral tissues (active sites) used to crush the test food. The active sites were consistent for all participants for both SJ and HJ, and they included the maxillary and mandibular teeth in 41 participants, teeth and residual ridges in 15 participants, maxillary and mandibular residual ridges in 10 participants, and tongue and palate in six participants. Two participants failed to crush the SJ; the active sites in both participants were the tongue and palate. No participant using the tongue and palate as active sites could crush the HJ. Furthermore, 64 participants could crush the SJ and 23 could crush the HJ using the tongue and palate. The cutoff value of the tongue pressure for crushability of the HJ was 22.0 kPa. Assessing tongue pressure and intraoral active sites involved in food crushing could help determine an appropriate diet for older adults requiring nursing home care.