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Objectives The present study aimed to evaluate the effectiveness of a newly designed jaw-retraction exercise for strengthening the geniohyoid muscle and thus improving the anterior movement of the hyoid bone during swallowing. Background Although previous studies suggest a relationship between anterior hyoid excursion and upper esophageal sphincter (UES) opening, there are currently no reports of physical exercises without the use of special equipment that can effectively improve this movement of the hyoid bone during swallowing. Materials and methods This before-after study included patients presenting to the authors' hospital with mild dysphagia (Level 5 on the Dysphagia Outcome and Severity Scale). The participants were instructed to perform a jaw-retraction exercise designed to strengthen the geniohyoid muscle. Each participant was instructed to perform two sets of the exercise daily for four weeks, with each set consisting of five repetitions. Before and after the four-week training period, videofluoroscopic swallowing studies were performed and later analysed. Results Twenty-five patients with a median age of 77 were included. The median peak anterior hyoid position before and after exercise were 129.82 and 132.74 (%C2-C4 length), respectively, and this increase was found to be significant (P = .007). The median extent of UES opening before and after exercise were 8.6 and 9.3 (mm), respectively, and this increase was also found to be significant (P = .040). Conclusion Our findings demonstrate that the jaw-retraction exercise can effectively improve the anterior movement of the hyoid bone. This exercise may be effective in individuals with oral frailty when signs of swallowing disorders are observed.

Currently, there is no established technique to directly measure extrinsic tongue muscle activation during selective hypoglossal stimulation therapy (sHNS) in patients with obstructive sleep apnea syndrome (OSAS) in a simple, non-invasive clinical setting. Ultrasound shear-wave elastography (US-SWE) enables quantitative measurement of tissue stiffness. We investigated whether US-SWE is able to detect changes in muscle stiffness of the tongue during sHNS. Patients with OSAS treated with sHNS were prospectively enrolled. A standardized US-SWE protocol was used to selectively measure tissue stiffness of the geniohyoid muscle (GH) and genioglossus (GG) muscles on the side of stimulator implantation (sGH, sGG) and on the contralateral side (nGH, nGG) without and with sHNS. Eighteen patients were included (median age = 62 years, interquartile range: 56-65, 83.3% male). Median shear-wave velocity (SWV) increased during contraction with each patient's clinically prescribed therapeutic regimen in the sGH (+19%, p = 0.020) and sGG (+81%, p0.001) and decreased during contraction in the nGH (-8%, p = 0.107) and nGG (-8%, p = 0.396). Differences in SWV during contraction were significant only on the side of stimulation (sGG +81%, sGH +19%). SWE measurements had excellent reliability as reflected by a Cronbach α value ≥0.9 for all target muscles pre- and post-contraction and an item-total correlation ≥0.5. US-SWE allows reliable measurement of SWV as an indicator of muscle stiffness of extrinsic tongue muscles. This non-invasive method provides new possibilities to distinguish and characterize responders from non-responders in hypoglossal stimulation therapy. Compared with the regular visual assessment of tongue movement, US-SWE of individual muscle groups provides a new non-invasive imaging tool in patients with OSAS.

Expiratory muscle strength training (EMST) is an exercise program designed to strengthen the muscles of expiration by increasing expiratory load during breathing exercises using either resistive or pressure threshold devices. Previous research has shown that EMST may increase submental suprahyoid muscle activity as measured with surface electromyography. The impact of EMST on submental muscles is of interest to those who treat dysphagia. The purpose of this study was to determine whether the cross-sectional area of the geniohyoid muscle changes as observed with ultrasound during a 5-week EMST program performed at 75% of maximum expiratory strength using the EMST150 device in healthy adults. Ten healthy adults participated in the 5-week program. Maximum expiratory pressure (MEP) and cross-sectional area of the geniohyoid muscle were measured weekly. Geniohyoid cross-sectional area was measured from ultrasound images recorded in the coronal plane. Repeated Measures ANOVA was used to determine whether there were significant changes among the dependent variables over the study period. Both MEP and geniohyoid area increased significantly in response to a 5-week program of EMST. EMST in healthy adults is effective at strengthening the geniohyoid muscle as reflected by significantly increased cross-sectional area measured with B-mode ultrasound. This is the first study to document weekly change in muscle morphology as a result of EMST. Increasing geniohyoid muscle mass and consequent strength through a program of EMST may be beneficial for persons with pharyngeal stage dysphagia resulting from reduced hyolaryngeal elevation, reduced laryngeal closure, or reduced UES opening.

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.

This study aimed to determine whether geniohyoid and/or masseter muscle mass can predict the severity of dysphagia after salvage surgery for head and neck cancer. We conducted a retrospective cohort study of 45 male patients with head and neck cancer (median age, 68 years) who underwent salvage surgery. The preoperative geniohyoid and masseter muscle masses were evaluated using computed tomography and the severity of dysphagia was evaluated by Penetration Aspiration Scale (PAS), Functional Oral Intake Scale (FOIS) and Oropharyngeal swallow efficiency (OPSE). The median PAS, FOIS and OPSE scores after surgery were 7 (interquartile range [IQR] 1–8), 6 (IQR 2–7) and 95.8 (IQR 67.1–116.2), respectively. The mean geniohyoid muscle masses were 3.13 ± 0.78 cm2 and the mean masseter muscle masses were 4.37 ± 0.99 cm2, respectively. The multivariate analysis showed that the geniohyoid muscle mass was significantly associated with the PAS, FOIS and OPSE scores. Conversely, the masseter muscle mass was not significantly associated with the PAS score but was significantly associated with the FOIS and OPSE scores. Geniohyoid muscle mass may predict the severity of dysphagia after salvage surgery.

Background & Aims Ensuring adequate ventilation and oxygenation requires comprehensive knowledge and specific skills to secure the airway. We hypothesized that airway assessment using ultrasound is superior in predicting difficult laryngoscopy and aimed to compare airway ultrasound with clinical assessment to predict it. Methodology Cross sectional study on 100 adults (65 females) undergoing elective surgeries with tracheal intubation in a tertiary centre were subjected to 2 staged airway assessment, both clinical and ultrasound. Airway ultrasound parameters recorded were anteroposterior thickness of geniohyoid muscle, distance from skin to hyoid bone, thyrohyoid membrane and true vocal cords. The Cormack and Lehane (CL) grade at laryngoscopy and Intubation Difficulty Scale (IDS) scores were noted. Results were analysed using Kappa statistics. Results Neck circumference and distance from skin to epiglottis at the level of thyrohyoid membrane (DSETM) were significant predictors of difficult laryngoscopy with a cut-off value of ≥35.8 cm (33% were predicted to be difficult however only 4% cases posed difficulty in laryngoscopy) and 1.9 ± 0.3 cm respectively. Conclusion Airway ultrasound is an objective and cost-effective modality in the anaesthesiologists’ armamentarium. DSETM ≥1.90 cm differentiated between easy and difficult laryngoscopy. Ultrasonography assessment adds an incremental diagnostic value to clinical screening tests.

Objective – of the work is to clarify the sources of germs and find out the chronological sequence of morphogenesis of the muscular structures of the suprahyoid triangles of the anterior cervical region in the embryonic and prefetal periods of human ontogenesis.Material and methods. 25 series of consecutive histological sections of human embryos and prefetuses aged from 5 till 12 weeks of development (6.0-80.0 mm parietal-coccygeal length (PCL)) using a complex methods of morphological examination (anthropometry, morphometry, microscopy, three-dimensional computer reconstruction and statistical analysis) were studied.Results. The rudiment of digastric muscle was first detected in 7-week-old prefetuses (15.5-16.0 mm PCL). The medial surface of Meckel’s cartilage is the site of attachment of the superior belly of the digastric muscle. At the 12th week of intrauterine development, the digastric muscle finally acquires its definitive attachment to the internal surface of the body of mandible. The rudiment of the mylohyoid muscle was first detected in 6-week-old embryos (10.0-12.0 mm PCL). The place of its attachment begins near the mental symphysis, the attachment of the muscle to the anlage of the hyoid bone was detected only at the end of the 7th week of intrauterine development (prefetuses 19.0-20.0 mm PCL). The anlage of the geniohyoid muscle was first determined in the 6-week-old human embryos. In prefetuses of 15.5- 40.0 mm PCL, geniohyoid muscle begins on the medial surface of Meckel’s cartilage, and from the 12th week of intrauterine development (prefetuses 75.0-77.0 mm PCL), the muscle attachment is localized on the internal surface of the body of mandible. The genioglossus muscle is found on the internal and caudal surfaces of Mekel’s cartilage, but from the middle of the 12th week of intrauterine development the site of its attachment moves to the medial-caudal surface of the body of mandible.Conclusions. 1. The anlages of all muscles that delimit the boundaries of the suprahyoid triangles of the neck were identified at the beginning of the 7 th week of intrauterine development (prefetuses 15.5-16.0 mm PCL). 2. The suprahyoid muscles attach to the medial surface of Meckel’s cartilage, but during the 8-11th weeks of intrauterine development, the attachment sites gradually move to the bony edges of the mandible, which cover Meckel’s cartilage. 3. In the prenatal period of development, bundles of the mylohyoid muscle leave the anterior region of the mental symphysis free. 4. In human prefetuses, only the geniohyoid and mylohyoid muscles were attached to the hyoid bone.

We investigated the associations about the mass of geniohyoid and tongue muscle and the maximum tongue pressure in patients with sarcopenic dysphagia using ultrasonography. Cross sectional study. 5 hospitals including 3 acute and 2 rehabilitation hospitals and 1 older facility. 36 inpatients with sarcopenic dysphagia. Ultrasonography was performed for geniohyoid muscle and tongue. The area for geniohyoid and tongue muscles in sagittal plane and the mean brightness level (0–255) in the muscle area were calculated. Maximum tongue pressure as strength of swallowing muscle were investigated. Partial correlation coefficient and multiple regression analysis adjusting for age and sex were performed. The mean age was 81.1 ± 7.9. Men were 23. The mean BMI was 19.0 ± 4.1. The mean maximum tongue pressure was 21.3 ± 9.3 kPa. The mean cross sectional area for geniohyoid muscles was 140 ± 47 mm2. The mean brightness for geniohyoid muscle was 18.6 ± 9.0. The mean cross sectional area for tongue muscles was 1664.1 ± 386.0 mm2. The mean brightness for tongue muscles was 34.1 ± 10.6. There was a significant positive correlation between area of geniohyoid muscle and maximum tongue pressure (r = 0.38, p = 0.04). Geniohyoid muscle area was an explanatory factor for maximum tongue pressure (p = 0.012) and tongue muscle area (p = 0.031) in multivariate analysis. Geniohyoid muscle mass was an independent explanatory factor for maximum tongue pressure and tongue muscle mass.

We experienced a malnourished 62‐year‐old male patient with Wallenberg syndrome whose swallowing‐related muscle mass was shown to improve on ultrasound following aggressive nutritional therapy used to improve malnutrition. Dysphagia improved from no oral intake at admission to regular oral intake at discharge by aggressive rehabilitation nutrition. Rate increases in body weight, skeletal muscle index, and coronal cross‐section of geniohyoid muscle area assessed by ultrasound during the 131 days of hospitalization were 15%, 21%, and 33%, respectively. Aggressive nutritional therapy, aimed at improving malnutrition, can improve swallowing‐related muscle mass. Ultrasonography of the swallowing‐related muscles over time is useful in assessing dysphagia., We experienced a malnourished 62‐year‐old male patient with Wallenberg syndrome whose swallowing‐related muscle mass was shown to improve on ultrasound following aggressive nutritional therapy used to improve malnutrition. Dysphagia improved from no oral intake at admission to regular oral intake at discharge by aggressive rehabilitation nutrition. Rate increases in body weight, skeletal muscle index, and coronal cross‐section of geniohyoid muscle area assessed by ultrasound during the 131 days of hospitalization were 15%, 21%, and 33%, respectively.

The activities of the suprahyoid muscles have been reported to be induced by tongue muscle contraction. The purpose of this research was to investigate whether tongue-strengthening exercises using a device cause hypertrophy of the geniohyoid muscle in healthy adults. Seven healthy young adults (3 men and 4 women, 21.0 ± 1.3 years old) received 8-week tongue muscle training with the JMS Tongue Pressure Measuring Device. The participants were instructed to press the anterior tongue against the hard palate 30 times in each session, three sessions a day, and 3 days a week. The exercise intensity was set to 60% of maximum tongue pressure in the first week, and to 80% of maximum tongue pressure for the remaining period. The training effect was evaluated by measuring (1) maximum tongue pressure value with the JMS Tongue Pressure Measuring Device, and (2) the area at rest, shortening amount, and contraction ratio of the geniohyoid muscle using ultrasonic imaging. After the 8-week training program, the maximum tongue pressure increased significantly from 44.9 to 61.6 kPa. The area of the geniohyoid muscle at rest also increased significantly from 2.3 to 2.6 cm2 after the program. There were no significant differences in the shortening amounts and the contraction ratios of the geniohyoid muscle between the values before and after the program. The tongue-strengthening exercise was useful to increase the muscle power of the geniohyoid, as well as the tongue muscles, in healthy young adults.

Comparative myo-architectural anatomical studies were adopted on both sexes of twelve apparently healthy adults of cattle, buffalo and camel. The study was aimed to describe the architectural orientation of the extrinsic lingual muscles for each species. As well as statistical data between the tongue and extrinsic lingual muscles. The work declared the properties of potent tongue which allowed the cattle and buffalo to perform their behavioral prehension of food. The study described the extrinsic lingual muscles and spotted a light on the role of the geniohyoid muscle on the tongue. The work concluded that the tongue of cattle was stronger than that of buffalo while both were able to depend on their tongue for food prehension. On the other hand, the tongue of camel was found to be adapted for intraoral function.

Objectives To investigate age-related changes in the intramuscular adipose tissue (IAT) of the tongue and geniohyoid muscle (GHM) and associated factors. Design Exploratory cross-sectional study. Setting and participants This study included 89 participants recruited from a health survey, which included 38 younger adults (age range, 20–63 years) and 51 older adults (age range, 65–87 years). Measurements 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. Results 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. Conclusion 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.

BACKGROUND Sarcopenia is a common disease in the elderly. Although extensive research has been conducted on muscle mass and quality assessment tools, there are still certain drawbacks preventing their universal use. AIM The aim of this study was the evaluation of the thickness of head, neck, upper and lower limb muscles measured with ultrasonography, as a potential predictory tool in sarcopenia. DESIGN Prediction study. SETTING The Outpatient Sarcopenia Clinic of the Rehabilitation Department of the University Hospital of Patras. POPULATION Ninety-four individuals (27 men and 67 women) with a mean age of 75.6 years (SD=6.6), referred for sarcopenia screening, participated in this study. METHODS The muscle thickness was measured with transverse and longitudinal ultrasound scans bilaterally. RESULTS The thickness of the geniohyoid and medial head of gastrocnemius muscle in all ultrasound sections, and the thickness of the rectus femoris and vastus intermedius muscle, in specific sections, was found to be significantly decreased in patients with sarcopenia (P

Aim: Jaw-opening strength is an indicator of swallowing function including hyoid bone elevation. Geniohyoid muscles play an important role during hyoid bone elevation. This study aimed to investigate whether geniohyoid muscle thickness and echo intensity measured by ultrasonography were related to jaw-opening strength.Material and methods: Sixty-eight participants (39 men) with an average age of 77±7.7 years were recruited from a functional training health care facility. We measured muscle thickness and echo intensity of the geniohyoid muscle on transverse ultrasound images.Results: Age, calf circumference, grip strength, muscle thickness and echo intensity were significantly associated with jaw-opening strength in univariate analyses. After adjusting for grip strength in multiple regression analysis, geniohyoid muscle thickness and echo intensity were significantly associated with jaw-opening strength (β=0.29 for muscle thickness, β=−0.26 for echo intensity).Conclusions: There was a positive correlation between geniohyoid muscle thickness and jaw-opening strength; echo intensity negatively correlated with jaw-opening strength. Ultrasound evaluation of geniohyoid muscle status provides important information about maintaining jaw-opening strength.

Background: The relationships between muscle fiber-type expression and the ratio between pyruvate dehydrogenase kinase (Pdk)-1 and hypoxia inducible factor (Hif)-1α was investigated using Hif-1α heterozygous knockout (“Het”) mice. Because Pdk-1/Hif-1α ratio changes could alter skeletal muscle phenotypes following brief sustained hypoxia as demonstrated earlier, we aimed to examine if the genetically down-regulated Hif-1α level influences skeletal muscle phenotypes in an intermittent hypoxic (IH) condition. This query is important because upper airway dilating muscles in patients with obstructive sleep apnea who frequently exposed to IH conditions tend to have an increased Type II fibers with increased Hif-1α levels. Methods: Here, we examined whether Pdk-1/Hif-1 ratios play a role in Het Hif-1α KO mice when exposed to brief IH (altering ambient oxygen levels between 10.3% and 20.8% every 240s). We performed single fiber analysis and Western blots on the harvested geniohyoid (GH) muscle after IH treatment for 5h. Results: Wild-type (WT) GH muscles in mice contain muscle fibers composed of myosin heavy chain (MyHC) IIa and MyHC IIa/IIb proteins, as opposed to the GH muscle in Het mice expressing MyHC IIa, IIa/IIb as well as IIb (p

Aim The aim of this study was to investigate digastric muscle mass and intensity between no sarcopenic dysphagia and sarcopenic dysphagia. Methods Patients aged ≥65 years were enrolled. According to the diagnostic algorithm for sarcopenic dysphagia, the patients were divided into two groups, no sarcopenic dysphagia and sarcopenic dysphagia. Handgrip strength, gait speed, skeletal muscle mass, tongue pressure, Mini Nutritional Assessment-Short Form and Food Intake LEVEL Scale were investigated. Digastric muscle mass and intensity were examined by ultrasonography. Univariate and multivariate analyses were performed to analyze two groups. Multivariate logistic regression analysis was performed to determine independent factors for the presence of sarcopenic dysphagia. To estimate the accuracy of diagnosing sarcopenic dysphagia, a receiver operating characteristic curve analysis was performed for digastric muscle mass and intensity. Results Forty-five patients (mean ± SD, 84.3 ± 7.8 years, 22 men, 23 women) including 19 no sarcopenic dysphagia and 26 sarcopenic dysphagia were examined. In sarcopenic dysphagia, lower BMI, Food Intake LEVEL Scale, Mini Nutritional Assessment-Short Form and smaller muscle mass and greater muscle intensity were found compared with no sarcopenic dysphagia. In multivariate logistic regression analysis, digastric muscle mass and intensity were identified as independent factors for sarcopenic dysphagia. The cut-off value of muscle mass was 75.1 mm2 (area under curve: 0.731, sensitivity: 0.692, specificity: 0.737) and muscle intensity was 27.8 (area under curve: 0.823, sensitivity: 0.923, specificity: 0.632). Conclusions Digastric muscle mass was smaller and muscle intensity was greater in sarcopenic dysphagia than no sarcopenic dysphagia. Ultrasonography of digastric muscle, as well as the tongue and geniohyoid muscle, is useful. Geriatr Gerontol Int ••; ••: ••-•• Geriatr Gerontol Int 2020; ••: ••-••.

Purpose To clarify the effect of geniohyoid (GH) muscle morphology and related function on masticatory ability using a decision-tree analysis. Materials and methods A total of 103 participants were enrolled. A cross-sectional area (CSA) of the GH muscle, neck circumference, body mass index, tongue pressure, jaw opening strength, and masticatory ability score were measured. The CSA of the GH muscle was selected as an independent variable for the first layer of the decision tree, with masticatory score as the dependent variable. Results and conclusion These data suggest that the CSA of the GH muscle may have a large impact on the masticatory ability score when evaluating masticatory ability.

Background Sarcopenic dysphagia is characterized by difficulty swallowing due to a loss of whole-body skeletal and swallowing muscle mass and function. However, no study has reported on swallowing muscle mass and quality in patients with sarcopenic dysphagia. Objective To compare the differences in swallowing muscle mass and quality between sarcopenic and nonsarcopenic dysphagia. Method A cross-sectional study was performed in 55 older patients, who had been recommended to undergo dysphagia assessment and/or rehabilitation. Sarcopenic dysphagia was diagnosed using a diagnostic algorithm for sarcopenic dysphagia. The thickness and area of tongue muscle and geniohyoid muscle (coronal plane and sagittal plane), and the echo-intensity of the tongue and geniohyoid muscles were examined by ultrasound. Results The study participants included 31 males and 24 females (mean age of 82 ± 7 years), with 14 having possible sarcopenic dysphagia, 22 probable sarcopenic dysphagia, and 19 without sarcopenic dysphagia. The group with sarcopenic dysphagia had a significantly lower cross-sectional area and area of brightness of the tongue muscle than that observed in the group without sarcopenic dysphagia. The most specific factor for identifying the presence of sarcopenic dysphagia was tongue muscle area (sensitivity, 0.389; specificity, 0.947; cut-off value, 1536.0), while the factor with the highest sensitivity was geniohyoid muscle area brightness in sagittal sections (sensitivity, 0.806; specificity, 0.632; cut-off value, 20.1). Multivariate logistic regression analysis showed that the area of the tongue muscle and its area of brightness were independent risk factors for sarcopenic dysphagia. However, geniohyoid sagittal muscle area and area of brightness showed no significant independent association with sarcopenic dysphagia. Conclusion Tongue muscle mass in patients with sarcopenic dysphagia was smaller than that in patients without the condition. Sarcopenic dysphagia was also associated with increased intensity of the tongue muscle.

OBJECTIVES/HYPOTHESIS Ultrasonography is an emerging clinical tool to study the dysfunction of swallowing muscles. This was the first sonographic study to assess the relationship between suprahyoid muscle contraction, hyoid bone displacement, and penetration-aspiration status (PAS) during swallowing in nasopharyngeal carcinoma (NPC) patients treated with radiotherapy (RT). The study also aimed to establish reliability data for the sonographic technique described. STUDY DESIGN Cross-sectional study. METHODS Geniohyoid muscle contraction was quantified using brightness-mode ultrasonography in this study of 40 post-RT NPC patients. A series of physiological parameters and PAS were measured using videofluoroscopy. RESULTS Intra- and inter-rater agreement values ranged from 0.75 to 0.96 across various sonographic measurements. Percentage increase in the cross-sectional area of the geniohyoid muscle correlated with anterior (r = 0.42, P

Background: Early detection and treatment to sarcopenia and presbyphagia are needed to address the problems experienced by an aging population. Objective: We aimed to clarify morphological changes in the geniohyoid (GH) muscle and associated aging-related factors, and to examine if changes in the GH muscle predict reduced swallowing function. Materials and Methods: 103 participants (57 women and 46 men, mean age 59.4 ± 19.5 years) were recruited. GH muscle cross-sectional area (CSA) and contraction velocity were measured using ultrasonography. Body height and weight, neck circumference, body mass index, remaining teeth number, occluding teeth number, tongue pressure, and jaw-opening strength were measured. Swallowing function was evaluated using the swallowing screening assessment questionnaire and by measuring swallowing sound duration. Results: GH muscle CSA significantly affected age, gender, body height and weight, neck circumference, remaining teeth number, occluding teeth number, tongue pressure, jaw-opening strength, duration of swallowing sounds, and GH muscle velocity. Covariance structure analysis showed that GH muscle CSA directly influenced swallowing sound duration. Conclusion: Morphological changes in the GH muscle are predictive of decline in swallowing function.

Background: Descending necrotizing mediastinitis is a potentially fatal polymicrobial infection that often leads to dysphagia after treatment. Such dysphagia is likely the result of fibrosis and scarring from inflammatory changes in the fascial space. A case is presented in which the mechanism of dysphagia was verified using two-dimensional analysis of the muscle lengths of the suprahyoid and infrahyoid muscles. Case: A 57-year-old woman presented with a hyoid and laryngeal movement disorder with pharyngeal residue secondary to descending necrotizing mediastinitis. To treat this disorder, the chin-down maneuver was performed, and it immediately improved hyoid and laryngeal elevation and reduced pharyngeal residue at the epiglottic valleculae and pyriform sinus. Analysis of the mechanism of these improvements revealed that combined head and neck flexion, compared with neck flexion, decreased the distance between the origin and insertion (DOI) of the sternohyoid muscle (SM) and increased the muscle contraction rate and the maximum contraction duration of the geniohyoid muscle (GM) during swallowing. Discussion: In the present case, the patient had restrictions in extension of the SM that applied resistance to GM contraction. Compensation of this condition was achieved by combined head and neck flexion, which decreased the DOI of the SM, thereby improving the contractile function of the GM.

Background Sarcopenia in the oral region, including the tongue, leads to declined swallowing function and dysphagia. Muscle mass and strength, and motor function in the oral region have not been examined together, and the relationship between generalised and oral sarcopenia remains unclear. Objective(s) The purpose of this study is to clarify the relationship between generalised sarcopenia and oral sarcopenia in the elderly in order to facilitate the establishment of a method for assessing oral sarcopenia. Methods A total of 54 elderly persons participated in this study. We examined the skeletal muscle mass index (SMI), grip strength (GS) and walking speed (WS) as the index of generalised sarcopenia, and the cross-sectional area of the geniohyoid muscle (CSG), tongue pressure (TP) and oral diadochokinesis (ODK) as the index of oral sarcopenia. Results We found a moderate correlation between CSG and SMI, a weak correlation between GS and TP, and a moderate correlation between WS and ODK. CSG, TP and ODK were significantly smaller in the sarcopenia group than in the non-sarcopenia group. By multiple regression analysis, SMI and TP were significantly associated with CSG. ODK, BMI and CSG were significantly associated with TP. WS and SMI were significantly associated with ODK. Conclusion CSG, TP and ODK were confirmed as endpoints of oral sarcopenia. All endpoints of oral sarcopenia were influenced by those of generalised sarcopenia.

Background: The relationships between muscle fiber-type expression and the ratio between pyruvate dehydrogenase kinase (Pdk)-1 and hypoxia inducible factor (Hif)-1α was investigated using Hif-1α heterozygous knockout ("Het") mice. Because Pdk-1/Hif-1α ratio changes could alter skeletal muscle phenotypes following brief sustained hypoxia as demonstrated earlier, we aimed to examine if the genetically down-regulated Hif-1α level influences skeletal muscle phenotypes in an intermittent hypoxic (IH) condition. This query is important because upper airway dilating muscles in patients with obstructive sleep apnea who frequently exposed to IH conditions tend to have an increased Type II fibers with increased Hif-1α levels. Methods: Here, we examined whether Pdk-1/Hif-1 ratios play a role in Het Hif-1α KO mice when exposed to brief IH (altering ambient oxygen levels between 10.3% and 20.8% every 240s). We performed single fiber analysis and Western blots on the harvested geniohyoid (GH) muscle after IH treatment for 5h. Results: Wild-type (WT) GH muscles in mice contain muscle fibers composed of myosin heavy chain (MyHC) IIa and MyHC IIa/IIb proteins, as opposed to the GH muscle in Het mice expressing MyHC IIa, IIa/IIb as well as IIb (pRead Complete Article at ijSciences: V82019062102 AND DOI: http://dx.doi.org/10.18483/ijSci.2102

Background Vagus nerve stimulation is a palliative treatment for patients with refractory epilepsy; however, the misplacement of electrodes may cause complications and thus needs to be avoided. Methods We herein report an intraoperative monitoring technique to prevent the misplacement of electrodes. Endotracheal tube electrodes were inserted to record electromyographic activity from the vocal cords and identify the vagus nerve. Electromyography electrodes were placed on the sternomastoid muscle, sternohyoid muscle, geniohyoid muscle, and trapezius muscle to record muscle activities innervated by the ansa cervicalis. The vagus nerve and ansa cervicalis were electrically stimulated during surgery, and electromyography of the vocal cords and muscles innervated by the ansa cervicalis was recorded. The threshold of vagus nerve activation ranged between 0.05 and 0.75 mA. Results The vagus nerve was successfully identified and differentiated from the nerve root of the ansa cervicalis using this technique. Conclusions Intraoperative monitoring of the vagus nerve and ansa cervicalis is useful for safe and effective vagus nerve stimulation.

BACKGROUND Mastication is a complicated task that involves the teeth and perioral muscles, such as the tongue and lip. Previous studies have shown correlations between masticatory performance and perioral muscle strength (eg tongue pressure) and between masticatory performance and occlusal forces. OBJECTIVE To investigate the relationships between masticatory performance and perioral muscle characteristics. METHODS Forty-nine healthy young subjects (men: 24 and women: 25) with Eichner classification group A were included in this cross-sectional study. Age, body weight, masticatory performance, masseter muscle thickness, masseter muscle echo intensity, cross-sectional area of geniohyoid muscle, geniohyoid muscle echo intensity, tongue thickness (TT) and tongue echo intensity were assessed. Masticatory performance was evaluated using a colour-changeable chewing gum. The thickness and echo intensity of the masseter muscle, geniohyoid muscle and tongue were observed using an ultrasonic diagnostic apparatus. Stepwise multiple regression analysis was conducted to examine relationships between perioral muscle characteristics and masticatory performance. RESULTS Tongue thickness (P

IntroductionDespite the use of quantitative neuromuscular monitoring together with the administration of reversal drugs (neostigmine or sugammadex), the incidence of residual neuromuscular blockade defined as a train-of-four ratio (TOFr) 0.9 cannot ensure adequate recovery of neuromuscular function when T1 height is not recovered completely. Thus, a mathematical correction of TOFr needs to be applied because the return of a normal TOFr can precede the return of a normal T1 twitch height. On the other hand, different muscles have different sensitivities to neuromuscular blockade agents; thus, complete recovery of one specific muscle group does not represent complete recovery of all other muscles. Therefore, our study aims to assess the muscle strength recovery of respiratory-related muscle groups by ultrasound and evaluate global strength using handgrip dynamometry in the early postoperative period when TOFr=0.9 and corrected TOFr (cTOFr)=0.9 with comparison of neostigmine versus sugammadex as reversal drugs.Methods and analysisThis study will be a prospective, single-blinded, randomised controlled trial involving 60 patients with American Society of Anesthesiologists physical status I–II and aged between 18 and 65 years, who will undergo microlaryngeal surgery. We will assess geniohyoid muscle, parasternal intercostal muscle, diaphragm, abdominal wall muscle and handgrip strength at four time points: before anaesthesia, TOFr=0.9, cTOFr=0.9 and 30 min after admission to the post anaesthesia care unit. Our primary objective will be to compare the effects of neostigmine and sugammadex on the recovery of muscle strength of different muscle groups in the early postoperative period when TOFr=0.9 and cTOFr=0.9. The secondary objective will be to observe the difference of muscle strength between the time points of TOFr=0.9 and cTOFr=0.9 to find out the clinical significance of cTOFr >0.9.Ethics and disseminationThe protocol was reviewed and approved by the Ethics Committee of The First Affiliated Hospital, Sun Yat-sen University. The findings will be disseminated to the public through peer-reviewed scientific journals.Trial registration numberChiCTR2000033832.