Geniohyoid Research Articles

Aging-associated differences between perioral and trunk muscle characteristics

The physiological and functional changes from aging affect the systemic and swallowing muscles. While ultrasound is used to examine muscle characteristics, no previous studies have examined the relationship between age and perioral and trunk muscle characteristics, including stiffness. This study aimed to investigate the relationship between age and the characteristics of perioral and trunk muscles, including quality, quantity, and stiffness, using ultrasound. A total of 215 participants were recruited for this cross-sectional study: 98 younger adults (20–64 years) and 117 older adults (≥ 65 years). Muscle characteristics were assessed along with data on age, sex, body mass index, and number of teeth. The correlation between age and muscle characteristics was examined. Multiple linear regression was performed with muscle characteristics as dependent variables and age, body mass index, and number of teeth as explanatory variables. We found that only trunk muscle stiffness was associated with age, with a stronger correlation in quality and quantity than perioral muscles. Masseter muscle quality and quantity showed a higher correlation with age than those of the geniohyoid muscle. In conclusion, characteristics of the trunk and perioral muscles exhibit differences in age-related changes, highlighting the importance of maintaining both trunk and perioral muscle activity in older adults to prevent functional decline.

Evaluation of masticatory muscles in patients with different sagittal direction skeletal anomalies by ultrasonography and ultrasonographic elastography.

The aim of this study was to evaluated the masseter, anterior digastric and geniohyoid muscles of individuals with similar growth and developmental periods but different sagittal skeletal malocclusions using ultrasonography and ultrasonographic elastography and to make interclass assessments. In this study, ultrasonography and ultrasonographic elastography records of 30 Class I individuals (17 females, 13 males), 30 Class II individuals (14 females, 16 males), and 27 Class III individuals (12 females, 15 males) in the normodivergent and growth development periodwere used. The masseter, anterior digastric, and geniohyoid muscles of individualswere examinedusing ultrasonography and ultrasonographic elastography, andcomparisons were madebetween the classes. Statistical analysis was accomplished by Mann Whitney U, One-way ANOVA, Kruskal Wallis H tests. Interclass differences were foundin ultrasonography and elastography measurements of the masseter muscle. However, no differences were observed in ultrasonography measurements of the auxiliary masticatory muscles, whereas differences were seen only in the geniohyoid muscle in elastography measurements among the classes (p<0.05). Individuals with different sagittal skeletal malocclusions during growth and development exhibited similar muscle sizes and elasticities, approximately close to each other.

The other face of facioscapulohumeral muscular dystrophy: Exploring orofacial weakness using muscle ultrasound.

One of the most distinct clinical features of facioscapulohumeral muscular dystrophy (FSHD) is facial weakness. It leads to diminished facial expression and functional impairments. Despite its clinical relevance, little else is known about orofacial muscle involvement. We therefore evaluated orofacial muscle involvement in a sizeable cohort of FSHD participants with muscle ultrasound. Muscle ultrasound images of the following orofacial muscles were scored visually and quantitatively: depressor anguli oris (DAO), orbicularis oris (OO), buccinator, temporalis, masseter, digastric, zygomaticus major and minor bilaterally, and the geniohyoid. Reliability analyses of both visual and quantitative evaluations were performed. Ultrasound results were correlated with other measures: the FSHD clinical score, facial weakness score, and facial function scale. We included 107 FSHD participants (male 54%; age 52 ± 14 years), of whom 92% showed signs of facial weakness. The reliability of visual ultrasound analysis varied widely (κ 0.0-1.0). Quantitative ultrasound reliability was high (intraclass correlation analysis ≥ 0.96). The DAO, buccinator, OO, temporalis, and zygomaticus minor muscles were affected most often (15%-39%). The digastric, geniohyoid, zygomaticus major, and masseter muscles were least often affected (<5%). The ultrasound compound score correlated weakly to moderately with other outcome measures used (ρ = 0.3-0.7). This study adds to the understanding of orofacial weakness in FSHD, confirming the involvement of the muscles of facial expression in FSHD using ultrasound. We showed that orofacial muscle ultrasound is feasible and reliable when quantitatively assessed. Future studies should evaluate orofacial muscle ultrasound longitudinally, alongside clinical and patient-reported facial weakness outcome measures, to assess their potential as outcome measures.

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

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

Intramuscular condition of swallowing-related muscles using shear-wave elastography: A preliminary study in healthy adults.

Assessing the internal condition of swallowing-related muscles and muscle strength and size is important because their deterioration may lead to dysphagia. However, there are few reports on stiffness of swallowing-related muscles measured using shear-wave elastography (SWE) and their qualitative characteristics. We measured stiffness of swallowing-related muscles using SWE to investigate the relationship between muscle stiffness and body composition as well as other relevant variables in healthy adults. Thirty healthy adults were included in this cross-sectional study. We evaluated stiffness of the genioglossus muscle (GGM) and geniohyoid muscle (GHM) using SWE. Skeletal muscle mass index, body mass index (BMI), handgrip strength, tongue pressure, and cross-sectional areas of the muscles were measured, and we determined their relationship with muscle stiffness. For muscle stiffness, the mean value for the middle GGM was 7.08 ± 1.92 kPa, that for the posterior GGM was 9.31 ± 2.68 kPa, and that for the GHM was 8.84 ± 2.15 kPa. In multiple regression analysis, with stiffness of the posterior GGM as the dependent variable, BMI (β = -.473, p = .039) was a significant negative explanatory variable. However, with the GHM stiffness as the dependent variable, BMI (β = .419, p = .033) was a significant positive explanatory variable. Stiffness of the posterior GGM was positively correlated with BMI and that of the GHM was negatively correlated with BMI. Stiffness, as measured using SWE, has the potential to capture the intramuscular characteristics of swallowing-related muscles, particularly the posterior GGM.

Reliability of ultrasound real‐time tissue elastography in evaluating swallowing‐related muscle elasticity and effects of swallowing exercises

AbstractIntroductionEvaluating swallowing function, essential for eating, is necessary to detect functional decline, enabling the provision of effective interventions. There is a growing demand for a simple method for evaluating swallowing dynamics. Conventional methods of evaluating swallowing function, such as the fibreoptic endoscopic evaluation of swallowing or videofluoroscopic swallowing study, are highly invasive and require specific equipment only available at certain hospitals, making it difficult for older adults to receive convenient evaluations. Therefore, we used ultrasound real‐time tissue elastography (RTE), a low‐invasive method, to evaluate tissue elasticity as the strain ratio (SR). This study primarily aimed to verify whether RTE can evaluate the elasticity of swallowing‐related muscles (SRMs) and determine intra‐ and inter‐rater reliabilities. The secondary aim was to investigate the effect of swallowing exercises, such as head‐lifting exercises, on SRM elasticity.MethodsIntraclass correlation coefficients for SR were calculated using ultrasound B‐mode images to determine the reliability of SRM elasticity. SRs before and after the Shaker swallowing exercise were compared using the Wilcoxon signed‐rank test.ResultsHigh ICCs for intra‐ and inter‐rater reliabilities were obtained for all targeted SRMs. SR after the Shaker exercise indicated a significant decrease in the geniohyoid muscle and both sides of the digastric muscles, whereas both sides of the masseter exhibited no changes.ConclusionRTE can be used as a novel simple and non‐invasive method for assessing and capturing differences in SRs of SRMs after light exercise. Further research may develop a relationship with swallowing function in patients with dysphagia or older individuals.

A new computed tomography-based approach to quantify swallowing muscle volume by measuring tongue muscle area in a single slice.

Measuring the swallowing muscle mass with volume measurements is complex and time intensive; therefore, it is not used in clinical practice. However, it can be clinically relevant, for instance, in the case of sarcopenic dysphagia. The aim of the study was to develop a feasible and clinically applicable method to measure swallowing muscle mass. Data from 10 head and neck cancer patients were collected from the Oncological Life Study data-biobank of the University Medical Center Groningen. The pharyngeal constrictor, genioglossus, mylohyoid and geniohyoid complex muscles, as well as the tongue complex muscles, were delineated manually on routinely performed head and neck computed tomography scans. Axial and sagittal planes were used for volume and area measurements, respectively. Muscle density measurements were performed with and without Hounsfield unit thresholding. Correlations were assessed by Pearson correlation coefficients, and interobserver reliability was measured using intra-class correlation coefficients (ICCs). Significant differences were observed between sagittal area measurements with and without Hounsfield unit thresholds for pharyngeal constrictor, tongue complex and the sum of the swallowing muscles (t>6; P-value<0.001). Stronger correlations emerged without Hounsfield unit thresholding. Strong positive and significant correlations were found between the total swallowing muscle mass volume and the sagittal area of the tongue complex muscles (r=0.87, P-value<0.05) and the sum of the sagittal areas of the pharyngeal constrictor and tongue complex muscles (r=0.85, P-value<0.05). The use of the Hounsfield unit threshold weakened correlations. Interobserver reliability was assessed and found to be fair to good for the pharyngeal constrictor muscle (ICC=0.68, P-value<0.05), excellent for the tongue complex muscles (ICC=0.98, P-value<0.05) and excellent for the total swallowing muscle area (ICC=0.96, P-value<0.05). Single-slice delineation of the sagittal area of tongue complex muscle and pharyngeal constrictor muscle is a promising, fast, simple and clinically applicable method for measuring the total volume of the swallowing muscle mass in head and neck cancer patients without Hounsfield unit thresholding. These advancements and findings would help in the early and accurate diagnosis of definitive sarcopenic dysphagia.

Preoperative geniohyoid muscle mass in esophageal cancer patients is associated with swallowing function after esophagectomy.

Dysphagia often develops after esophagectomy. The geniohyoid muscle is involved in swallowing movements, but its significance in esophagectomy patients remains unclear. We investigated the relationship of preoperative geniohyoid muscle mass with post-esophagectomy swallowing function. We retrospectively analyzed 114 patients who underwent esophagectomy and gastric conduit reconstruction for esophageal malignancy. We evaluated preoperative geniohyoid muscle sagittal cross-sectional areas (cm2) using computed tomography. Median values for each sex were considered as cutoff values. Dysphagia severity was assessed using the Penetration-Aspiration Scale (PAS) during video-fluoroscopic swallowing studies performed 7-10 days postoperatively. The cross-sectional area was significantly larger in males than in females (3.2 ± 0.7 vs. 2.4 ± 0.5, p < 0.01: median in males: 3.2 cm2, and in females: 2.3 cm2). These values were used to define high and low cross-sectional area groups. The cross-sectional area correlated positively with grip strength (correlation coefficient (CC) = 0.530) and skeletal muscle index (CC = 0.541). Transthyretin levels (22.4 ± 6.8 vs. 25.4 ± 5.5, p = 0.03) and cross-sectional area (2.6 ± 0.7 vs. 3.2 ± 0.8, p < 0.01) were significantly lower in patients with (PAS score ≥6; 20%) than in those without aspiration during fluoroscopic swallowing studies. Recurrent laryngeal nerve palsy was significantly more frequent in those with than in those without aspiration during fluoroscopic studies (22% vs. 5%, p = 0.03). In the multivariate analysis, low cross-sectional area and recurrent laryngeal nerve palsy were both independent risk factors for aspiration during swallowing studies (odds ratio = 3.6, p = 0.03 and odds ratio = 6.6, p = 0.02, respectively). Preoperative geniohyoid muscle mass, evaluated using neck computed tomography, can predict dysphagia after esophagectomy.

The feasibility of visualizing and quantifying muscle changes in postoperative oral cancer patients using Quantitative Muscle Ultrasound (QMUS)

PurposeQuantitative muscle ultrasound (QMUS) is a patient friendly tool for examining orofacial muscles. Resection of tissue can have an effect on the architecture and function of these muscles. The aim of this study is to investigate the feasibility of visualizing and quantifying muscle changes in postoperative oral cancer patients and to relate the findings to tumor and patient characteristics.MethodsAdult patients with a resected first primary pT1 or T2 oral squamous cell carcinoma, at least one year post operatively, where included. Ultrasound data were collected of the geniohyoid muscle, digastric muscles, masseter muscle, transverse muscle and genioglossus muscle. Ultrasound images were labeled as clearly visible, questionable or unclear. Of the clear muscles, echogenicity and muscle thickness were measured.Results37 patients were included. The masseter muscle was clearly visible in all ultrasound images, both intrinsic tongue muscles had the lowest visibility (45.9%). There was a significant correlation between visibility and tumor localization for the genioglossus (p = 0.029). Age correlated with the visibility of the genioglossus muscle, BMI with the genioglossus and transverse muscles. Echogenicity and muscle thickness of the clearly identified muscles did not differ from normative values.ConclusionQMUS of orofacial muscles is feasible in postoperative oral cancer patients with relatively small tumor sizes. Tongue resections negatively affected the visibility of the two intrinsic tongue muscles. These preliminary results for particular muscles indicate that the use of ultrasound might be promising in oral cancer patients to help determine targeted goals in post-operative rehabilitation.

Evidence for peripheral and central actions of codeine to dysregulate swallowing in the anesthetized cat

Systemic administration of opioids has been associated with aspiration and swallow dysfunction in humans. We speculated that systemic administration of codeine would induce dysfunctional swallowing and that this effect would have a peripheral component. Experiments were conducted in spontaneously breathing, anesthetized cats. The animals were tracheotomized and electromyogram (EMG) electrodes were placed in upper airway and chest wall respiratory muscles for recording swallow related motor activity. The animals were allocated into three groups: vagal intact (VI), cervical vagotomy (CVx), and supra-nodose ganglion vagotomy (SNGx). A dose response to intravenous codeine was performed in each animal. Swallowing was elicited by injection of 3 mL of water into the oropharynx. The number of swallows after vehicle was significantly higher in the VI group than in SNGx. Codeine had no significant effect on the number of swallows induced by water in any of the groups. However, the magnitudes of water swallow-related EMGs of the thyropharyngeus muscle were significantly increased in the VI and CVx groups by 2–4 fold in a dose-related manner. In the CVx group, the geniohyoid muscle EMG during water swallows was significantly increased. There was a significant dose-related increase in spontaneous swallowing in each group from codeine. The spontaneous swallow number at the 10 mg/kg dose of codeine was significantly larger in the CVx group than that in the SNGx group. During water-evoked swallows, intravenous codeine increased upper airway motor drive in a dose-related manner, consistent with dysregulation. The data support the existence of both central and peripheral actions of codeine on spontaneous swallowing. At the highest dose of codeine, the reduced spontaneous swallow number in the SNGx group relative to CVx is consistent with a peripheral excitatory action of codeine either on pharyngeal/laryngeal receptors or in the nodose ganglion itself. The higher number of swallows in the CVx group than the VI group supports disinhibition of this behavior by elimination of inhibitory vagal sensory afferents.

Assessing the oral and suprahyoid muscles in healthy adults using muscle ultrasound to inform the swallowing process: a proof-of-concept study

The oral and suprahyoid muscles are responsible for movements of swallowing. Our study aimed to determine the reproducibility of static and dynamic measurements of these muscles using bedside ultrasound equipment. Forty healthy participants were recruited prospectively. Primary outcomes were evaluation of mass measurements of the anterior bellies of the digastric, mylohyoid, geniohyoid and tongue in B-mode ultrasound. Secondary outcomes were evaluation of geniohyoid muscle layer thickness and function using M-mode. Muscle mass measurements demonstrated little within-participant variability. Coefficient of Variance (CoV) across muscles were: anterior belly digastric (5.0%), mylohyoid (8.7%), geniohyoid (5.0%) and tongue (3.2%). A relationship between sex (r2 = 0.131 p = 0.022) was demonstrated for the geniohyoid muscle, with males having higher transverse Cross Sectional Area (CSA) (14.3 ± 3.6 mm vs. 11.9 ± 2.5 mm, p = 0.002). Tongue size was correlated with weight (r2 = 0.356, p = 0.001), height (r2 = 0.156, p = 0.012) and sex (r2 = 0.196, p = 0.004). Resting thickness of the geniohyoid muscle layer changed with increasing bolus sizes (f = 3.898, p = 0.026). Velocity increased with bolus size (p = < 0.001, F = 8.974). However swallow time and slope distance did not, potentially influenced by higher coefficients of variation. Oral and suprahyoid muscle mass are easily assessed using bedside ultrasound. Ultrasound may provide new information about muscle mass and function during swallowing.

Reliability of Measuring Geniohyoid Cross-Sectional Area with B-Mode Ultrasound.

B-mode ultrasound is a safe noninvasive procedure that has been used to characterize aspects of the oropharyngeal swallow. The submental suprahyoid muscles are often investigated with ultrasound because of their contributions to hyolaryngeal elevation. There are several techniques for positioning the ultrasound transducer in the coronal plane, however, there is limited research on how reliability of measurement of the cross-sectional area (CSA) of the geniohyoid differs across transducer placement technique. This study examined three methods of transducer placement in the coronal plane by two examiners to determine the reliability of measurement of CSA of the geniohyoid muscle. Forty healthy adults participated in the study. Each participant's geniohyoid muscles were imaged using B-mode ultrasound under three transducer placement conditions in the coronal plane by two examiners. Geniohyoid CSA was measured from each ultrasound image. A three-way mixed-methods ANOVA was used to determine whether there were significant differences in geniohyoid CSA among transducer position conditions, trials, and examiners. There were significant differences among the transducer placement conditions, indicating that each condition was measuring a different portion of the muscle. There were no significant differences among repeated trials nor between examiners within each method of transducer placement. All three conditions of transducer placement were reliable at measuring geniohyoid CSA across trials and examiners. This study emphasizes the need for consistency of placement, whichever method is selected. It also highlights the need for researchers to provide a precise description of methods for positioning the transducer so that placement is reproducible.

Influence of Microinjection of Kynurenic acid into the Pre-Botzinger Complex on Swallowing in the Cat

Recent evidence supports the involvement of the pre-BÖtzinger complex (pre-BOT) in spatiotemporal features of swallowing and swallowing-breathing coordination in mice. We hypothesized that pharmacological disruption of glutamate neurotransmission in this brainstem region would perturb the swallow motor pattern in anesthetized cats. Electromyograms (EMGs) of upper airway muscles were recorded in anesthetized, spontaneously breathing cats (n=5). Swallowing was induced by injection of 3 cc of water into the oropharynx. Multi-barrel micropipettes were employed to inject artificial cerebrospinal fluid or kynurenic acid (KYN; 50 mM, 44±3 nL per injection) bilaterally into the region of the pre-BOT. Microinjection sites were confirmed histologically by detection of fluorescent beads that were suspended in the microinjectate. Blocking glutamate-related neuronal excitation by bilateral microinjections of the nonspecific glutamate receptor antagonist kynurenic acid had no effect on the number of swallows induced by water injection (control 2.3±0.3; KYN 3.0±0.7; P&lt;0.32). Swallow durations were significantly increased following microinjections of KYN from 691±54 ms to 812±81 ms (p&lt;0.04). KYN significantly reduced the magnitudes of geniohyoid (control 97±3 % of median; Kyn 47±12% of control median, p&lt;0.02), thyrohyoid (control 100±3% of median; KYN 69±8% of control median, p&lt;0.01), and posterior cricoarytenoid (control 103±2% of median; KYN 74±8% of control median, p&lt;0.04) muscle EMGs during swallowing. There was no significant effect of microinjection of KYN on the magnitudes of thyroartytenoid, mylohyoid, or thyropharyngeus electromyograms during swallowing. The results suggest that disruption of glutamate neurotransmission in the preBOT has preferential effects consistent with actions on motor drive to hypoglossal and ventrolateral motoneuron pools that participate in swallowing. Lengthening of swallow duration induced by KYN supports a role for the preBOT in modulating the excitability of the swallow oscillatory circuit. NIH HL163008; NIH HL 131716; HL 155721. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Tongue exercise-induced plasticity in upper airway EMG activity in a model of hypoglossal motor neuron loss

Motor neuron diseases (MNDs) are a group of neuromuscular disorders in which motor neurons (MNs) required for activities of daily living are lost. Patients with MNDs often develop swallowing and breathing dysfunction due to pathology of the hypoglossal (XII) axis ( e.g., XII lower motor neurons, LMNs). These co-dependent, vital functions require reciprocal roles of the tongue during swallowing, and impaired control and coordination of these opposing behaviors can lead to aspiration pneumonia and respiratory failure. Due to a lack of research, available treatments for patients with MNDs are largely palliative, and there is a critical need for therapies targeting the preservation of upper airway function and coordination. The extensive tongue muscle weakness in patients with MNDs suggests a potential role for therapeutic exercise, but suffcient evidence is lacking to conclude if tongue exercise is beneficial or harmful. A barrier in studying the impact of XII LMN degeneration and developing therapies to improve swallowing and breathing function/coordination has been the lack of an appropriate model. We therefore developed a novel rodent model of XII LMN loss using intralingual injections of cholera toxin B conjugated to saporin (CTB-SAP), which has tongue motility and swallowing deficits that are mitigated by a high-repetition/low resistance tongue exercise paradigm for muscle growth. Here, we simultaneously studied upper airway (geniohyoid) and diaphragm EMG activity with swallowing ( via videofluoroscopy swallow studies; VFSS) and breathing ( via plethysmography) to discern whether CTB-SAP induced XII LMN loss results in upper airway deficits and discoordination of swallowing and breathing functions. We hypothesized that geniohyoid (not diaphragm) EMG activity would be decreased and swallow-breathing coordination would be altered in unanesthetized and spontaneously breathing CTB-SAP rats vs. controls, and that tongue exercise would mitigate these deficits. Using custom-made headcap implants, we embedded EMG electrodes into the geniohyoid and diaphragm muscles in adult male rats prior to intralingual injection of CTB-SAP or control (CTB unconjugated to SAP) and studied chronic EMG activity during VFSS or during plethysmography studies +/- tongue exercise (N=4-6/group). Our preliminary findings show decreased geniohyoid (but not diaphragm) EMG activity as well as swallow/breathing discoordination that appears to be reversed with tongue exercise in CTB-SAP rats vs. controls. In conclusion, tongue exercise appears to enhance XII axis plasticity to improve upper airway function and coordination in the face of XII LMN degeneration. Studies are now underway to understand the underlying mechanism of tongue exercise-induced neuroplasticity, which may help guide future translational studies in patients with MNDs. R01 HL153612 and Phi Zeta. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Using Sequence Analyses to Quantitatively Measure Oropharyngeal Swallowing Temporality in Point-of-Care Ultrasound Examinations: A Pilot Study.

(1) Background: Swallowing is a complex process that comprises well-timed control of oropharyngeal and laryngeal structures to achieve airway protection and swallowing efficiency. To understand its temporality, previous research adopted adherence measures and revealed obligatory pairs in healthy swallows and the effect of aging and bolus type on the variability of event timing and order. This study aimed to (i) propose a systemic conceptualization of swallowing physiology, (ii) apply sequence analyses, a set of information-theoretic and bioinformatic methods, to quantify and characterize swallowing temporality, and (iii) investigate the effect of aging and dysphagia on the quantified variables using sequence analyses measures. (2) Method: Forty-three participants (17 young adults, 15 older adults, and 11 dysphagic adults) underwent B-mode ultrasound swallowing examinations at the mid-sagittal plane of the submental region. The onset, maximum, and offset states of hyoid bone displacement, geniohyoid muscle contraction, and tongue base retraction were identified and sorted to form sequences which were analyzed using an inventory of sequence analytic techniques; namely, overlap coefficients, Shannon entropy, and longest common subsequence algorithms. (3) Results: The concurrency of movement sequence was found to be significantly impacted by aging and dysphagia. Swallowing sequence variability was also found to be reduced with age and the presence of dysphagia (H(2) = 52.253, p < 0.001, η2 = 0.260). Four obligatory sequences were identified, and high adherence was also indicated in two previously reported pairs. These results provided preliminary support for the validity of sequence analyses for quantifying swallowing sequence temporality. (4) Conclusions: A systemic conceptualization of human deglutition permits a multi-level quantitative analysis of swallowing physiology. Sequence analyses are a set of promising quantitative measurement techniques for point-of-care ultrasound (POCUS) swallowing examinations and outcome measures for swallowing rehabilitation and evaluation of associated physiological conditions, such as sarcopenia. Findings in the current study revealed physiological differences among healthy young, healthy older, and dysphagic adults. They also helped lay the groundwork for future AI-assisted dysphagia assessment and outcome measures using POCUSs. Arguably, the proposed conceptualization and analyses are also modality-independent measures that can potentially be generalized for other instrumental swallowing assessment modalities.

Cutoff value of the geniohyoid muscle mass to identify sarcopenic dysphagia by ultrasonography.

Determining the strength and area of the swallowing muscles is important in patients with sarcopenic dysphagia. Although the normative data on the strength of the swallowing muscles have been reported, those of the area of the geniohyoid muscle are poorly investigated. We investigated the cross-sectional area of the geniohyoid muscle in Japanese subjects without dysphagia using ultrasonography to determine the normative and cut-off values. 142 subjects without dysphagia were included. The older group (age ≥ 65years) included 36 (women 27/men 9) subjects, and the younger group (age ≤ 39years) included 106 (women 54/men 52) subjects. The cross-sectional area of the geniohyoid muscle was measured by ultrasound. The mean of the younger group-2 standard deviation (SD) was calculated and used as a cut-off value for low swallowing muscle mass. The mean (SD) of the area of the geniohyoid muscle of each group was as follows: older women group 167.2 (32.6) mm2, older men group 193.2 (49.5) mm2, younger women group 247.3 (37.4) mm2, younger men group 313.1 (59.2) mm2. The mean 2SD of the geniohyoid muscle area in the younger women group was 172.5mm2 and in the younger men group 194.7mm2. We found that the cut-off value of the ultrasonographic cross-sectional area of the geniohyoid muscle was 172.5mm2 for women and 194.7mm2 for men. These values could be used as cut-off values for the mass of the geniohyoid muscle to identify patients with sarcopenic dysphagia.

Chemoradiation to the submental muscles alters hyoid movement during swallowing in a rat model.

Hyolaryngeal dysfunction is a commonly reported swallowing problem after chemoradiation treatment for head and neck cancer. The displacement of the hyolaryngeal complex during swallowing protects the airway and assists in opening the upper esophageal sphincter. Activation of the submental muscles, specifically the mylohyoid and geniohyoid muscles, is thought to facilitate movement of the hyoid. The purpose of this study was to determine if targeted radiation to the submental muscles given concurrently with chemotherapy alters hyolaryngeal displacement 1 mo after treatment. We hypothesized that chemoradiation treatment would result in abnormal patterns of hyoid movement compared with controls. Furthermore, we propose that these changes are associated with alterations in bolus size and discoordination of the jaw during drinking. Eighteen rats underwent either chemoradiation, radiation, or no treatment. Radiation treatment was targeted to submental muscles using a clinical linear accelerator given in 12 fractions of 4 Gy (3 days per week). Cycles of 1 mg/kg of cisplatin were administered concurrently each week of radiation. One month posttreatment, videofluoroscopy swallow studies (VFSS) were performed in self-drinking rats using a fluoroscope customized with a high-speed camera. The hyoid, jaw, and hard palate were tracked during swallowing from VFSS. Hyoid kinematics were analyzed from the start to the end of hyoid movement, and parameters were compared with bolus size and jaw movement. Significant differences in hyoid retraction parameters were found postchemoradiation. Alterations in the trajectory of hyoid motion during swallowing were observed. The findings demonstrate early changes in hyoid motion during swallowing associated with chemoradiation treatment.NEW & NOTEWORTHY Chemoradiation treatment for head and neck cancer can cause functional impairments in swallowing, which can adversely affect quality of life. This study provides new evidence that chemoradiation targeted to the submental muscles provokes early adaptations in hyoid movement during swallowing, which correlate with changes in bolus size. We also demonstrate a method for tracking the hyoid during swallowing in a rat model of chemoradiation injury.

A modified pull-through approach with a pedicled bone flap for oral and oropharyngeal cancer resection: a feasibility study

PurposeCompromised swallowing, speaking, and local complications are the major disadvantages of established approaches to the posterior tongue and oropharynx. The mandibular split involves an esthetically unpleasant bipartition of the lower lip and is prone to bony non-union or sequestration. The conventional pull-through technique on the other hand lacks the secure reattachment of the lingually released soft tissues.MethodsThe feasibility of a new modified pull-through approach was tested on three anatomical specimens. CAD/CAM cutting guides were used to design a retentive bone flap to properly refixate the genioglossus and geniohyoid muscles after the procedure. The radiographic assessment and treatment planning was performed on 12 cadavers. The entire procedure was tested surgically via dissection in three of those cases. This procedure was then applied in a clinical case.ResultsPrecise repositioning and dynamic compression of bony segments was possible reproducibly and without injury to adjacent structures. In all dissected cases, a median lingual foramen was found and in two cases vessels entering it could be dissected Radiologic anatomical landmarks were sufficient in all 12 cases to perform the clinical planning procedure. Clinically, the osteotomized segment demonstrated good blood supply and plateless repositioning was verified postoperatively via cone beam scan.ConclusionThe method presented is safe and easy to perform. Individual cutting guides improve the safety and accuracy of the procedure, potentially eliminating the need for osteosynthesis. We provide the anatomical and radiologic basis for clinical evaluation of this pedicled bone flap procedure and present the clinical application of this modified pull-through approach.

A Novel Exercise to Improve Suprahyoid Muscle Area and Intensity as Evaluated by Ultrasonography.

Insufficient suprahyoid muscle strength with poor opening of the upper esophageal sphincter can cause dysphagia. This study investigated whether an exercise of the suprahyoid muscle, named forehead exercise for suprahyoid muscles (FESM, "Enge-Odeko-Taiso" in Japanese), improves the geniohyoid muscle area and intensity using ultrasonography. Sixty-four participants (15 men and 49 women, 82.8 ± 6.0years) living independently with no symptoms of swallowing difficulties were enrolled. The participants were divided into the FESM and the control group. The FESM is an isometric exercise involving repetitions of looking into the navel as if the chin is pulled back with little neck motion using a hand pushed against the forehead for resistance. This exercise is performed five times in 10 courses a day (total 50 times) for 8weeks. Participants in the control group did not conduct any exercises. Body mass index, hand grip strength, gait speed, calf circumference, Mini Nutritional Assessment short-form, eating assessment tool, repetitive saliva swallowing test (RSST), and Food Intake LEVEL Scale scores were examined. The ultrasonographic geniohyoid muscle area, intensity, and RSST were investigated before and after the program. In the FESM group, the geniohyoid muscle area increased from 2.24 to 2.52cm2 (P < 0.05), intensity decreased from 34.6 to 32.0 (P < 0.05), and the median RSST increased from 5 to 6 (P < 0.05) significantly. Conversely, no significant differences were observed in the control group. The FESM was effective to increase the area and decrease the intensity of the geniohyoid muscle and may improve swallowing function.

Morphological and functional changes of the geniohyoid muscle in elderly patients after hip fracture surgery: Comparison of ultrasound images with a focus on swallowing function.

The purpose of this study was to clarify, using ultrasound imaging, (1) whether the area and contraction of GH change in elderly patients after hip fracture surgery and (2) whether the changes in the area and contraction of GH are related to decline in swallowing function. The participants were 21 female patients over 65 years of age who underwent hip fracture surgery. The patients were divided into two groups based on the results of swallowing assessment by water drinking: One with normal swallowing function (NSF) and the other with suspected decline in swallowing function (DSF). Sagittal cross-sectional area (SA) of GH at rest and the shortening rate (SR) of GH upon contraction during swallowing were compared at two time points: immediately and 2 weeks after surgery. Wilcoxon signed-rank test was used for intra-group comparisons, and Mann-Whitney U-test was used for between-group comparisons. SA of GH decreased significantly at 2 weeks after surgery in both groups, regardless of their swallowing function. In the intra-group comparison, SR significantly decreased (worsened) only in DSF group. SR at 2 weeks after surgery was significantly higher in NSF than in the DSF. In the inter-group comparison, DSF showed a significantly smaller (worse) change of SR than NSF in 2 weeks after surgery. Decrease in muscle mass, or atrophy, of GH observed in both NSF and DSF, did not coincide with the post-operative change in GH contraction of the two groups. The results suggest the importance of continuous swallowing assessment in the elderly individuals during their perioperative period.