Jaw-opening Force Research Articles

Associations of sex, age, and number of remaining teeth with performance on oral hypofunction tests.

Oral hypofunction comprises seven aspects of oral condition, including oral hygiene, oral dryness, bite strength, tongue-lip motor function, tongue pressure, masticatory function, and swallowing function. Each of these seven has a single diagnostic criterion; however, the use of a single indicator without consideration of sex, age, or other factors is controversial. The purpose of this study was to evaluate the association between the oral hypofunction test and sex, age, and number of remaining teeth. The study was conducted at 12 facilities by the members of the Japanese Society of Geriatric Dentistry during April to December 2019. The participants comprised 181 healthy older adults aged 65 years and over (56.9% female; age range 65-95 years) who regularly visited these facilities. All tests of oral function and oral status available in Japan were performed on the participants, and the association between these tests and sex, age, and number of remaining teeth was examined. Sex differences were observed in masticatory function, bite force, lip closure force, jaw-opening force, oral diadochokinesis "ka," and tongue coating index (p < .05). In men, age was weakly (r = 0.20-0.40) associated with masticatory function, jaw-opening force, maximum tongue pressure, oral diadochokinesis, and swallowing function. In women, the number of remaining teeth, masticatory function, jaw-opening force, and oral diadochokinesis "ta" and "ka" was also weakly associated with age. Performance on the oral hypofunction test differs by sex, age, and number of remaining teeth. This means that the current single criterion for evaluation requires caution in its interpretation.

Effect of Peripheral Magnetic Stimulation for Dysphagia Rehabilitation: A Systematic Review.

Recently, a therapeutic method to stimulate the suprahyoid muscle using peripheral magnetic stimulation for dysphagia rehabilitation has been reported. However, clinical evidence, application protocol, and intervention method remain unclear. Therefore, a systematic review of the published literature is needed. The objective of this study was to systematically review clinical studies of peripheral magnetic stimulation applied for rehabilitation of dysphagia. Issues to be considered in future studies are also suggested. This systematic review performed a literature search of four databases (Medline, Embase, CINAHL, and Web of Science) to identify relevant studies published on the application of repetitive peripheral magnetic stimulation (rPMS) for swallowing-related muscles between 2010 and 2022. Seven studies were reviewed. Randomized controlled trials and one-group pre–post, case study designs were included. In the included studies, rPMS was applied to strengthen the submental suprahyoid muscles. The intervention regime varied. The rPMS was applied at a frequency of 30 Hz for 2 s. Rest time ranged from 8 s to 27–28 s. The number of intervention sessions ranged from 2–3 to 30. The intensity ranged from pain-inducing minimum intensity (90% of maximum stimulus output) to non-painful intensity (70–80% of maximum intensity). The rPMS on the suprahyoid muscles had positive effects on physiological changes in the swallowing function, such as displacement of the hyoid bone, muscle strength (cervical flexor, jaw-opening force), swallowing safety, swallowing performance, and swallowing-related quality of life. Participants also reported little pain and adverse reactions during rPMS. Although rPMS is a therapeutic option that can help improve the swallowing function as a non-invasive stimulation method in the rehabilitation of dysphagia, clinical evidence is needed for the development of clear stimulation protocols and guidelines.

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.

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.

Jaw-Opening Force as a Useful Index for Dysphagia: A Cross-Sectional and Multi-Institutional Study

Introduction: Jaw-opening force (JOF) can be a potential screening tool for dysphagia. However, confounding variables such as comorbidities or physical and oral functions that are associated with the physiology of swallowing have not previously been examined. Adjusting for these variables could reveal the relationship between JOF and dysphagia and indicate whether JOF is an independent factor associated with dysphagia. We therefore aimed to assess the efficacy of using JOF for dysphagia screening in this multi-institutional study. Methods: Community-dwelling older adults over the age of 65 years (N = 403) who visited the university dental hospitals and participated in health surveys (mean age ± standard deviation, 77.1 ± 7.0 years; range, 65–96 years) between November 2018 and January 2020 were included in this study. The JOFs of all participants were measured. The measured JOF was compared with the presence of dysphagia, which was defined using the Functional Oral Intake Scale and the Eating Assessment Tool-10. Results: Multiple logistic regression analysis revealed that the presence of dysphagia was independently associated with JOF, calf circumference, and dependence after adjusting for age and sex. Discussion/Conclusion: Decreased JOF can be a risk factor for dysphagia in older adults.

Will Suprahyoid Muscle Release be Effective to Improve Swallowing in Patients with Temporomandibular Disorders? A Single Group Experimental Study

Background: As for jaw opening force, hyoid resting position and hyoid dynam­ics are very important and are considered to be affected directly by the suprahyoid muscles. MFR is found to be effective in giving symptomatic relief and increasing jaw ROM in patients with myofascial TMD. The study will specify the importance of Suprahyoid MFR in improving swallowing &amp; jaw function in TMD.&#x0D; Objectives: The study aimed at finding out the effectiveness of suprahyoid muscle MFR on swallowing and jaw function in patients with TMD.&#x0D; Methods: 20 participants with myogenous TMD were included after fulfilling the selection criteria. Treatment strategies involved MFR to suprahyoid muscle for 3 sessions in a week for one week and home exercise program involving the tongue proprioception exercises. The outcome measures were evaluated through Sydney swallowing questionnaire (SSQ-17), LDF-TMD questionnaire and maximal interincisal opening (IIO). The data was analysed and inference was drawn through paired and unpaired t tests.&#x0D; Results: The result of the present study showed that participants improved significantly (p &lt;0.05) at post one week on all the outcome measures (IIO, SSQ &amp; LDF-TMD).&#x0D; Conclusion: This study demonstrated that suprahyoid release is effective in improving swallowing in patients with TMD.

Age-related changes in swallowing muscle intramuscular adipose tissue deposition and related factors.

To investigate age-related changes in the intramuscular adipose tissue (IAT) of the tongue and geniohyoid muscle (GHM) and associated factors. Exploratory cross-sectional study. This study included 89 participants recruited from a health survey, which included 38 younger adults (age range, 20-63years) and 51 older adults (age range, 65-87years). Age, body mass index, body fat, lean body mass, skeletal muscle mass index, trunk muscle mass index, tongue pressure, jaw opening force, and oral diadochokinesis were assessed. The cross-sectional area (CSA) and echo intensity (EI) of the tongue and GHM were measured using ultrasonography. IAT was assessed according to EI values. The factors related to the IAT of each muscle were examined using multiple regression analysis. We also investigated the correlation of IAT with factors related to oral function and systemic and morphological factors. Neither the EI of the tongue nor that of the GHM had a significant correlation with factors related to oral function and systemic factors. In the multiple regression analysis, significant explanatory variables for EI of the tongue and GHM were age (β=0.14, P=0.019; tongue and β=0.13, P=0.017; GHM) and the CSA of each muscle (β=-0.01, P=0.042; tongue and β=-0.04, P=0.003; GHM). EI was positively associated with age and negatively associated with muscle CSA. Age-related changes in the IAT show the same trend for both the tongue and GHM, unlike age-related changes in muscle mass. The IATs of the tongue and GHM were not significantly correlated with oral function and systemic factors. Therefore, EI may not be a useful index for the functional evaluation of the tongue and GHM.

Ultrasonography Shows Age-related Changes and Related Factors in the Tongue and Suprahyoid Muscles

ObjectivesTo investigate age and other factors related to the deterioration of the muscles used for swallowing, including the tongue and suprahyoid muscles. DesignCross-sectional study. Setting and ParticipantsThis study included 146 participants: 47 younger adults (23 men and 24 women; age range 23-44 years) recruited from a dental hospital and 99 community-dwelling older adults (37 men and 62 women, age range 65-86 years). MethodsAge (<65 years or ≥65 years), body mass index (BMI), skeletal muscle mass index (SMI), and tooth loss (Eichner classification) were measured. The cross-sectional areas (CSAs) of the tongue, geniohyoid muscle, and anterior belly of the digastric muscle were measured using an ultrasonic diagnostic apparatus. The correlation between each muscle's CSA and strength was examined. Multiple regression analyses were performed separately for each sex using each muscle CSA as the dependent variable and age, BMI, SMI, and the Eichner classification as explanatory variables. ResultsOlder men had a significant positive correlation between tongue pressure and CSA (r = 0.35, P = .031). Jaw opening force was positively correlated with geniohyoid muscle CSA (r = 0.41, P = .001) in older women. In the multiple regression analysis, age, BMI, and SMI were significantly associated with tongue CSA in men. Age was significantly and inversely associated with suprahyoid muscle CSA in both men and women. No explanatory variables were significantly associated with geniohyoid muscle CSA except age. Conclusions and ImplicationsThe tongue increased in volume, and the suprahyoid muscles underwent atrophy with age. The study results suggest that interventions to prevent dysphagia associated with aging should be tailored toward specific muscles. Direct muscle training is required for the suprahyoid muscles, whereas the maintenance of tongue muscle mass and function, as well as training for the tongue, requires attention to ensure optimal nutritional status and whole-body skeletal muscle mass.

Repetitive Peripheral Magnetic Stimulation for Strengthening of the Suprahyoid Muscles: A Randomized Controlled Trial

Head lift exercise is a widely known form of training in the rehabilitation of patients with dysphagia. This study aimed to compare muscular strength reinforcement training of the suprahyoid muscles using repetitive peripheral magnetic stimulation (rPMS) with head lift exercises in a randomized controlled trial. Twenty-four healthy adults were randomly assigned to either the magnetic stimulation group (M group) or the head lift exercise group (H group). Both groups underwent training five days a week for two weeks. The primary outcome was the cervical flexor strength, and secondary outcomes were jaw-opening force, tongue pressure, muscle fatigue of the hyoid and laryngeal muscles, displacement of the hyoid bone and opening width of the upper esophageal sphincter (UES) while swallowing 10 mL of liquid, training performance rate, and pain. No dropouts were reported during the two-week intervention period. Cervical flexor strength significantly increased solely in the M group. Tongue pressure significantly improved in both groups. There were no significant differences in the jaw-opening force, median frequency rate of the anterior belly of the digastric muscle, sternohyoid muscle, sternocleidomastoid muscle, anterior and superior hyoid bone displacement, and UES opening width in both groups. Two-week rPMS of the suprahyoid muscles increased the strength of these muscles compared with the head lift exercise during the same period.

Estimation of jaw-opening forces, energy expenditure and jaw-opening patterns in adults

ObjectivesThe aims of this study were to investigate (1) the jaw-opening forces in different stages of jaw-opening, and determine the correlation among maximum jaw-opening force, maximum jaw-opening, and parameters such as age, height, weight, and gender, (2) the energy expenditure during jaw-opening, and (3) the jaw-opening patterns in adults. DesignThis was a cross-sectional study. The sample consisted of 87 participants were recruited from Dunedin, New Zealand. Jaw-opening forces were measured using an adjustable, rigid extra-oral device connected to a 1000 N load cell. Main resultsOutcomes were highly skewed. The median (IQR) value of maximum jaw-opening was 48 mm (8 mm). The median of maximum jaw-opening force (40.0 N) was higher than jaw-opening force at maximum jaw-opening (35.2 N) (P < 0.01). The median (IQR) of the work was 1.30 J (1.28 J), ranging from 0.38 J to 4.03 J. The median of maximum jaw-opening force and work was higher in males (54.8 N; 1.22 J) than females (33.5 N; 0.74 J) (P < 0.05). Four jaw-opening force patterns (Pattern 1, 2, 3 and 4) were fitted and generated using Origin Pro software. ConclusionA wide range of variation in jaw-opening force and work was observed, and they displayed a non-parametric, highly skewed distributions. The maximum jaw-opening force did not correspond to the maximum jaw-opening. Further studies could explore the potential association among the jaw-opening force pattern, the work of jaw-opening and TMJ diseases.

Relationship between the swallowing function and jaw-opening muscle strength in elderly cerebrovascular disease patients

In this study, we aimed to clarify the relationship between the swallowing function and the jaw-opening force after cerebrovascular disease. Elderly patients with a history of cerebrovascular disease with swallowing disability were enrolled in the present study. The swallowing function was evaluated using the Dysphagia Severity Scale (DSS), and the jaw-opening force was measured using Jaw-Opening Sthenometer (TK2014). The correlation between the DSS and jaw-opening force was analyzed using Spearman's correlation coefficient. Patients were also classified into three groups according to the DSS: normal, dysphagia, and aspiration groups. The jaw-opening forces of the three groups were compared using the Kruskal-Wallis test. Fifty-two patients (27 women, average age 78.8±8.2 years) were recruited. A significant negative correlation was found between the patient age and jaw-opening force in all subjects (r=-0.362, p=0.008) as well as in men (r=-0.548, p=0.005). A significant positive correlation was found between the DSS and jaw-opening force in all subjects (r=0.560, p=0.000) and in both men (r=0.636, p=0.001) and women (r=0.587, p=0.001). The jaw-opening force of the aspiration group was significantly lower than that of the normal group in all subjects (p=0.006), as well as in men (p=0.024) and women (p=0.015). The DSS and jaw-opening force may have a significant positive correlation. Furthermore, it was shown that the jaw-opening force of the aspiration group was significantly lower than that of the normal-swallowing group.

Relationship between jaw-opening force and neck circumference in healthy older individuals.

In recent years, the relationships of arm circumference and calf circumference with swallowing function have been reported. However, the efficacy of using the neck circumference, which is closer to the swallowing-related muscles, has never been verified. Jaw-opening force, an indicator of suprahyoid muscle strength, is known to be useful for screening for dysphagia. The aim of the present study was to identify the relationships between neck circumference and swallowing-related muscle strength, and to clarify the association between these variables in older individuals. A total of 104 healthy, independent older individuals, aged ≥65 years (36 men, 68 women, mean age 71.5 ± 4.5 years, range 65-83 years), participated in the study. Neck circumference, arm circumference, calf circumference, jaw-opening force and repetitive saliva swallowing test scores were measured. Multiple regression analysis was carried out to determine the relationship between neck circumference and jaw-opening force, between neck circumference and repetitive saliva swallowing test score, and to identify variables affecting jaw-opening force and neck circumference. The participants' mean body mass index was 22.8 ± 2.9 (range 15.8-32.4). Sex and neck circumference, but not arm or calf circumference, were significant independent factors related to jaw-opening force. Independent factors affecting neck circumference were sex, body mass index, jaw-opening force and arm circumference, but not repetitive saliva swallowing test score. In healthy older individuals, neck circumference was more strongly related to jaw-opening force than were arm or calf circumference. This suggested that neck circumference could be useful for evaluating swallowing-related muscle strength non-invasively and easily. Geriatr Gerontol Int 2019; 19: 330-334.

Relationship between the nutritional state of elderly people in need of support or nursing care and jaw-opening force and tongue pressure.

[Purpose] We hypothesized that an association exists between the nutritional state of elderly people and the deterioration in the swallowing function associated with sarcopenia, which is reflected by the strength of the tongue and suprahyoid muscles. Therefore, we conducted a comparative study of the nutritional state and swallowing muscle strength. [Participants and Methods] The participants in this study were 25 elderly people in need of support or nursing care, situated at a geriatric health service facility, who were able to understand instructions and ate three meals per day orally. We evaluated the strength of the tongue muscles using a tongue pressure measurement device and the strength of the suprahyoid muscles by measuring the jaw-opening force. The nutritional state was evaluated using the Mini Nutritional Assessment. [Results] There was a significant correlation between the Mini Nutritional Assessment score and the jaw-opening force. Conversely, no correlation was found between the Mini Nutritional Assessment score and the tongue pressure. [Conclusion] The significant correlation between the Mini Nutritional Assessment score and the jaw-opening force suggests that the strength of the suprahyoid muscles, which reflects the swallowing function and jaw-opening force, deteriorates with age and is affected by the nutritional state. This suggests that the nutritional state could be an important indicator for the evaluation of the swallowing function.

Relationship between swallowing muscles and trunk muscle mass in healthy elderly individuals: A cross-sectional study

Background and objectiveA decrease of swallowing muscle strength causes dysphagia, and a relationship between swallowing muscle strength and appendicular muscle mass has been reported. Moreover, the effect of trunk retention function on swallowing function has been clinically recognized. However, the relationship between trunk muscle mass and swallowing muscle strength is unclear. We aimed to clarify the association between these variables in elderly individuals. MethodsSubjects were 118 healthy community-dwelling individuals aged ≥65 years (men: 37, women: 81). We measured total muscle mass, grip strength, jaw-opening force, tongue pressure, cross-sectional area (CSA) of the geniohyoid muscle, and tongue muscle thickness. The appendicular skeletal muscle mass index (ASMI) and trunk muscle mass index (TMI) were calculated based on the appendicular skeletal muscle mass and trunk muscle mass, and corrected by height squared. Multiple regression analysis was performed with jaw-opening force and tongue pressure as dependent variables and with age, sex, grip strength, ASMI, TMI, CSA of the geniohyoid muscle, and tongue muscle thickness as independent variables. ResultsSignificant explanatory factors for jaw-opening force were sex (p = 0.002) and TMI (p = 0.003). Significant explanatory factors for tongue pressure were aging (p = 0.001), tongue muscle thickness (p = 0.027), and TMI (p = 0.033). ConclusionsUntil now, the relationship between swallowing muscles and whole body muscle mass has been reported using ASMI as the indicator of whole body muscle mass. This study suggests that TMI may be used as a highly relevant indicator of swallowing muscles rather than ASMI.

Age-related declines in the swallowing muscle strength of men and women aged 20–89 years: A cross-sectional study on tongue pressure and jaw-opening force in 980 subjects

Swallowing muscle strength weakens with aging. Although numerous studies have investigated tongue pressure (TP) changes with age, studies on jaw-opening force (JOF), an indicator of suprahyoid muscle strength, are lacking. We investigated differences between age-related declines in TP and JOF in a cross-sectional study of 980 healthy and independent participants (379 men, 601 women) without dysphagia. Hand grip strength (HGS), TP, and JOF were compared among decade-based age groups in multiple comparison analyses with post-hoc tests and effect size calculated. Participants were divided into adult (20 s–50 s) and elderly groups (60 s–80 s); within each group, Pearson correlations between age and muscle strength indices were evaluated. TP started to significantly decline in the 60 s and 50 s for men and women (p < .01, medium effect size and p < .05, small effect size, respectively); HGS also declined at these ages (men: p < .01, women: p < .01, medium effect size). JOF started to significantly decline in men in their 80 s (p < .01, large effect size), but remained unchanged in women. In the elderly group, all measurements declined with age more sharply in men (HGS: r = −0.56, TP: r = −0.63, JOF: r = −0.13) than in women (HGS: r = −0.38, TP: r = −0.49, JOF: r = −0.003). TP declined more steeply than did JOF. Thus, the age related-decline in TP was similar to that of the HGS, but not the JOF. The results reveal that different patterns exist in the age-related decline in swallowing muscle strength, and suggest that maintenance of JOF might contribute to safe swallowing in healthy elderly individuals.

Estimation of jaw-opening forces in adults.

To estimate maximum jaw-opening forces in healthy participants of diverse ancestry and to estimate whether opening forces are associated with sex, age and anthropometric parameters such as height, weight and BMI. One hundred and forty-nine participants aged 20-60years with overall good oral and general health. Exclusion criteria included myofascial or neck pain, symptomatic temporomandibular joint disorders (TMD), current orthodontic treatment or the absence of a natural dentition. Jaw-opening forces were measured with an adjustable rigid extra-oral device connected to a 1000N load cell. Seven attempts were recorded, with 10seconds interval. Median force values were obtained after discarding the first and last attempt. The height and weight of each participant were measured and recorded, alongside age, sex and ethnicity. Men had greater maximum opening force median values than women (P<.001). Median (IQR) values for women were 41.16N (30.44) and 79.00N for men (63.86). Jaw-opening force values were poorly associated with biological and anthropometric parameters. In this study, which included a large sample of participants of broad age range and from a demographically diverse background, jaw-opening force values were greater in males than in females; however, force values were poorly associated with biological and anthropometric parameters. Future studies should explore the potential of this method as a screening tool for TMJ disorders and other conditions.

The relationship between jaw-opening force and the cross-sectional area of the suprahyoid muscles in healthy elderly.

We conducted a clinical cross-sectional study to examine the relationship between jaw-opening force and the cross-sectional area of the suprahyoid muscles and whole skeletal muscle mass. Subjects were healthy 39 males and 51 females without dysphagia and sarcopenia, aged 65years and older. Jaw-opening force was measured three times using a jaw-opening sthenometer; the maximum of these three was taken as the measurement value. The cross-sectional area of the geniohyoid and anterior belly of the digastric muscles were evaluated using ultrasonography. The skeletal muscle mass index, gait speed and grip strength were evaluated according to the diagnostic criteria of the Asian Working Group for Sarcopenia. For each sex, a multiple regression analysis determined the factors that affect jaw-opening force. Jaw-opening force was associated with the cross-sectional area of the geniohyoid muscle in males (regression coefficient [β]=0.441, 95% confidence interval [CI]=14.28-56.09) and females (β=0.28, 95% CI=3.10-54.57). Furthermore, in females only, jaw-opening force was associated with the skeletal muscle mass index (β=0.40, 95% CI=3.67-17.81). In contrast, jaw-opening force was not associated with the cross-sectional area of the anterior belly of the digastric muscle in either sex. In healthy elderly males and females, jaw-opening force was positively associated with the cross-sectional area of the geniohyoid muscle. However, the jaw-opening force was positively associated with the skeletal muscle mass index only in females.

Can grip strength and/or walking speed be simple indicators of the deterioration in tongue pressure and jaw opening force in older individuals?

Swallowing-related muscle strength decreases due to sarcopenia, and older people are at risk for sarcopenia and the resultant dysphagia. However, no studies have assessed the direct relationships between whole-body strength and swallowing-related muscles. Therefore, this study investigates the relationships between decreased whole-body strength, which is easily evaluated, and swallowing-related muscle strength. A total of 197 elderly individuals (97 men aged 78.5±6.6years and 100 women aged 77.8±6.2years) were enrolled. Grip strength, walking speed, tongue pressure and jaw opening force were measured, and the effects of age and the relationships between whole-body strength and swallowing-related muscle strength were investigated. With respect to age-related changes, tongue pressure, jaw opening force, grip strength and walking speed decreased with age in men and women. The relationships between whole-body strength and swallowing-related muscle strength were analysed, with age used as the control variable. Among men, tongue pressure was correlated with grip strength and walking speed, whereas jaw opening force was correlated with grip strength. Among women, neither tongue pressure nor jaw opening force was correlated with grip strength or walking speed. There was a sex-based difference in the correlations between whole-body strength and swallowing-related muscle strength. Among men, swallowing-related muscle strength was correlated with whole-body strength, and grip strength could thus serve as a simple indicator for swallowing-related muscle strength. Decreased swallowing-related muscle strength can be inferred in cases involving male patients for whom decreased grip strength is measured during physical examination or is otherwise suggested (eg, by an inability to open plastic bottles).

Relationship between jaw opening force and hyoid bone dynamics in healthy elderly subjects

PurposeThis study aimed to examine the relationship between jaw opening force and hyoid bone dynamics and resting position in elderly individuals based on gender.Subjects and methodsSubjects were 36 healthy elderly individuals aged ≥65 years without dysphagia (16 men and 20 women; mean age 75.5 years, range 65–88 years). Videofluorographic images during the swallowing of 10 mL of 40% (w/v) barium sulfate were obtained and the degrees of anterior, superior, and hypotenuse displacements of the hyoid bone and maximum/resting hyoid position were evaluated. Jaw opening force was measured three times using a jaw opening force sthenometer; the mean of these three measurements was used for analysis.ResultsIn men, there was a positive correlation between jaw opening force and resting hyoid position and negative correlations among all the degrees of anterior, superior, and hypotenuse displacements of the hyoid bone. In women, there was no statistically significant correlation between jaw opening force and any of the measurement items. There was no statistically significant correlation between jaw opening force and maximum hyoid position in either men or women.ConclusionOur findings suggest that low jaw opening force leads to low resting hyoid position only in elderly men, and a lower hyoid position in healthy elderly men results in a larger total amount of hyoid displacement during swallowing. Moreover, a maximum hyoid position in healthy individuals of either gender does not differ depending on their jaw opening force.

Effects of aging and sarcopenia on tongue pressure and jaw-opening force.

Aging and sarcopenia reduce not only body strength, but also the strength of swallowing muscles. We examined how aging and sarcopenia affect tongue pressure and jaw-opening force. A total of 97 older adults (97 men, mean age 78.5 ± 6.6 years; 100 women, mean age 77.8 ± 6.2 years) were enrolled. Classification of sarcopenia was based on the Criteria of Asian Working Group for Sarcopenia. To investigate which variable between aging and sarcopenia was a significant independent variable on tongue pressure and jaw-opening force, multivariate linear regression analysis was carried out. The mean tongue pressure was 26.3 ± 7.8 kPa in men and 24.6 ± 7.2 kPa in women. The mean jaw-opening force was 6.3 ± 1.6 kg in men and 5.2 ± 1.3 kg in women. Tongue pressure in men, aging and sarcopenia were significant independent variables, whereas only sarcopenia was a significant independent variable in women. Jaw-opening force in men and sarcopenia were significant independent variables, whereas neither aging nor sarcopenia were significant independent variables in women. We found different characteristics in the effects of aging and sarcopenia based on site and sex. We suggested that aging decreased tongue pressure more than jaw-opening force, and affected men more than women. Sarcopenia affected tongue pressure and jaw-opening force, with the exception of jaw-opening force in women. Considering these characteristics is useful to predict the decline of swallowing function, and provide appropriate interventions preventing dysphagia. Geriatr Gerontol Int 2017; 17: 295-301.