Hyoid Displacement Research Articles

Influence of natural hyoid bone position and surgical repositioning on upper airway patency: A computational finite element modeling study.

A validated finite element model of the rabbit UA was advanced and used to simulate changes in BHP and SHR, alone and in combination. The hyoid was displaced in cranial, caudal, anterior, anterior-cranial and anterior-caudal directions from 1-4mm. Model outcomes included UA collapsibility, measured using closing pressure (Pclose), cross-sectional area (CSA) and soft tissue mechanics (displacement, stress and strain). Graded BHP increments increased Pclose for all directions, and up to 29-43% at 4mm (relative to the original BHP). Anterior-based SHR decreased Pclose (~-115% at 4mm) and increased ΔCSA (~+35% at 4mm). Cranial SHR decreased ΔPclose (-29%), minimally affecting CSA. Caudal SHR increased ΔPclose (+27%) and decreased ΔCSA (-7%). Anterior-cranial and anterior-caudal SHR produced the highest stresses and strains. SHR effects on UA outcomes were dependent on BHP, with more caudal BHPs leading to less effective surgeries. BHP (phenotype) and SHR both alter UA outcomes, with effects dependent on hyoid displacement direction and magnitude. BHP influences the effectiveness of SHR in reducing UA collapsibility. These findings provide further insights into the hyoid's role in UA patency and suggest that considering the hyoid's baseline position and surgical repositioning direction/increment may help improve hyoid surgeries for OSA treatment.

Kinematic Measurements of Swallowing by Ultrasound: A Scoping Review.

Ultrasound (US) is a non-invasive method used to study the kinematics of the swallowing function. Kinematic measurements are reported in studies evaluating swallowing using US, but there is no standardization. The aim of this scoping review was to identify and characterize the kinematic measurements of swallowing obtained by ultrasound. We followed the methodological recommendations of the Joanna Briggs Institute (JBI) and the reporting guidelines of the Preferred Reporting Items for Systematic Reviews and Meta-Analysis-extension for scoping reviews (PRISMA-ScR). The research question followed the acronym PCC (population, concept, and context). Seven databases and gray literature were searched. Studies were selected using a blind, paired, and independent method. Data were extracted using a standardized tool. There were 2591 studies and 42 were eligible. Most studies had samples of less than 30 participants and mostly included healthy young adults and older people. The swallowing tasks during the assessments were not standardized. The most commonly studied measures were hyoid displacement and tongue movement during swallowing. However, there is no consensus between studies on the definition of the measures and the procedures for ultrasound assessment, including image acquisition and analysis.

Hyoid displacement during swallowing function for completely edentulous subjects rehabilitated with mandibular implant retained overdenture

BackgroundHyoid bone is attached to the mandible, tongue, larynx, temporal bone, and cervical spine via different types of muscles or ligaments. The tongue, mandible, and hyoid system play a crucial role in swallowing function. This within subject study aimed to evaluate the impact of mandibular implant overdentures on the displacement of the hyoid bones during the swallowing process.MethodsTwenty five healthy edentulous subjects were selected for participating in the study. New complete dentures were constructed for all the participants. Subsequently two dental implants were inserted in the canine regions of the participant’s mandibular arch. In order to retain the mandibular prosthesis in place, ball attachments were incorporated into the mandibular dentures to convert them into implant overdentures. Using 10 ml of thin liquid bolus, videofluoroscopy swallowing examination was performed in three different oral conditions: without complete dentures (WCD), with complete denture (CDs), and with a mandibular implant overdenture (IODs). ANOVA with Bonferroni test was used to analyze the data in order to determine how the hyoid displacement varied throughout different oral conditions.ResultsCompared to complete dentures, mandibular implant overdentures showed a significant decrease (P < 0.05) in both anterior hyoid displacement and duration of hyoid maximum anterior excursion (DOHMAE). However, there was a non-significant difference (P > 0.05) between the two oral circumstances in terms of superior hyoid displacement or duration for hyoid maximum elevation (DOHME). There is no penetration or aspiration for both complete denture and implant overdenture oral conditions.ConclusionImplant retained overdentures have a positive effect on hyoid displacement during swallowing of thin liquid bolus consistency relative to conventional complete dentures.Trial registrationRetrospectively registered (NCT06187181) 02/1/2024.

Physiologic and anatomic determinants of hyoid motion during drug-induced sleep endoscopy

PurposeTo examine factors accounting for differences in hyoid motion during obstructive breathing events amongst obstructive sleep apnea (OSA) patients.MethodsThis was a prospective cohort study from June 2022 to October 2022. Patients with OSA undergoing evaluation for PAP alternative therapies with drug-induced sleep endoscopy with positive airway pressure titration (DISE-PAP). All patients underwent DISE-PAP and concurrent hyoid-focused ultrasound. DISE-PAP enabled measurement of airway physiology (flow, respiratory effort) and airway collapsibility (pharyngeal opening pressure, PhOP). Hyoid-ultrasound enabled hyoid bone movement during obstructive breathing. Respiratory effort was measured using a retro-epiglottic pressure-sensitive catheter. Hyoid position was measured using a standardized, awake, CT protocol. Regression analyses adjusted for age, race, sex, and BMI were performed to associate indices of respiratory effort and CT data with hyoid motion.ResultsOn average, the 26 patients in this cohort were older (63.9 ± 10.5 years), male (69%), overweight (29.6 ± 3.99 kg/m2), and with moderate-to-severe OSA (26.8 ± 10.4 events/hour). Greater respiratory effort was associated with increased hyoid motion (β [95% CI] = 0.034 [0.016,0.052], standardized β = 0.261,p = 0.0003). Higher hyoid position was associated with greater hyoid displacement (β [95% CI] = -0.20 [-0.38,-0.01], Standardized β = -0.57, p = 0.036).ConclusionOur data demonstrate that greater respiratory effort, higher hyoid position, and higher airway collapsibility, but not airflow, are associated with greater hyoid motion during obstructive breathing in DISE. These findings suggest that downward hyoid movement represents a compensatory response to upper airway obstruction. Further studies should investigate the vectors of hyoid motion to better understand its role in sleep-related airway collapse.

Investigating Parkinson's disease with dual high resolution pharyngeal manometry with impedance and videofluoroscopy.

To characterize pharyngeal function in people with Parkinson's Disease using both high resolution impedance manometry (HRIM) and videofluoroscopy (VFSS) and to explore correlations between VFSS and HRIM metrics. All participants received both VFSS and HRIM within 24 h-time window. A standard VFSS protocol (IDDSI 0: 1 mL, 3 mL, 20 mL, and 100 mL) was performed. A solid-state unidirectional catheter (36 pressure sensors) was used to acquire manometric data for triplicate swallows (IDDSI 0: 5 mL, 10 mL, 20 mL), quantitative swallow analysis was completed through Swallowtail™ and SwallowGateway™. Parameters were compared to published norms and statistical tests explored correlational associations (p < 0.05). Twenty-one participants (76% male; mean age 70 years, SD7.16) with mild-moderate severity PD were recruited with 73% reporting Eating Assessment Tool (EAT-10) scores ≥3 indicating swallow impairment. Compared to normal metrics, one third of participants had abnormally elevated hypopharyngeal contractile integral (HPCI), hypopharyngeal peak pressure, upper esophageal sphincter (UES) integrated relaxation pressure (UES IRP), and reduced UES maximum admittance. Five participants showed compromised swallow safety (Penetration-Aspiration Scale score ≥6). One third of participants had abnormal VFSS values for pharyngoesophageal segment (PES) opening duration, maximum PES opening distance, and maximum hyoid displacement measures. Some HRIM metrics had a strong correlation with pharyngeal VFSS measures (r > 0.60, p < 0.05). This study identifies early manometric signs of pharyngeal dysfunction in people with PD. The congruence of the VFSS and HRIM measures confirms the hypothesis of insidious early decline in swallow function in PD despite maintenance of airway safety (i.e., low aspiration rates).

Impact of sarcopenia and malnutrition on swallowing function utilizing ultrasonography in patients with acute heart failure: A retrospective cohort study

This study aimed to determine the impact of sarcopenia and nutritional risk on swallowing-related muscles by ultrasonography and dysphagia occurrence in older patients with acute heart failure (AHF) during hospitalization. Patients with AHF aged ≥65 years without dysphagia (Food Intake LEVEL Scale [FILS] score ≥9) before admission were classified into four groups at admission: robust group, sarcopenia group (Asian Working Group for Sarcopenia 2019), nutritional risk group (geriatric nutritional risk index <92), and complicated group (with both sarcopenia and nutritional risk). Swallowing function (maximal hyoid displacement, geniohyoid muscle area and brightness, and maximal tongue pressure) and FILS were investigated from the medical records. In total, 131 patients with AHF (mean age 82.8±7.1 years, 71 males) were enrolled during the study period; 33, 58, 5, and 35 were classified into the robust, sarcopenia, nutritional risk, and complicated groups, respectively. In the covariance analysis adjusted for age, sex, comorbidities, and cardiac function, the complicated group had significantly worse swallowing function than the sarcopenia and robust groups (P<0.05). In the Cox proportional hazards model, in which event occurrence was defined as the first-time FILS score of ≥9 obtained during hospitalization, the sarcopenia group (hazard ratio [HR]: 0.83, 95% confidence interval [CI]: 0.51-1.34, P=0.438) and nutritional risk group (HR: 0.77, 95% CI:0.25-2.32, P=0.637) were not significantly different, but the complicated group (HR: 0.54, 95% CI: 0.31-0.95, P=0.033) had significantly lower cumulative event rates with the robust group as the reference. Sarcopenia and nutritional risk in older patients with AHF are risk factors for decreased swallowing function.

Longitudinal Analysis of Dysphagia and Factors Related to Postoperative Pneumonia in Patients Undergoing Esophagectomy for Esophageal Cancer

AbstractFew studies have quantified longitudinal changes in swallowing in patients undergoing esophagectomy for esophageal cancer. This study longitudinally analyzed the changes in the Modified Barium Swallow Study Impairment Profile (MBSImP™) scores, swallowing kinematic measurements, and swallowing-related symptoms in patients undergoing esophagectomy. We also examined the association between identified swallowing impairment and aspiration pneumonia after surgery. We included consecutive patients who underwent esophagectomy and completed laryngoscopy and videofluoroscopy before, two weeks, and three months after surgery. We analyzed physiological impairments using the MBSImP. We also assessed the swallowing kinematics on a 5 mL thickened liquid bolus at three time points. Vocal fold mobility was assessed using a laryngoscope. Repeated measures were statistically examined for longitudinal changes in swallowing function. The association between the significant changes identified after esophagectomy and aspiration pneumonia was tested. Twenty-nine patients were included in this study. Preoperative swallowing function was intact in all participants. The timing of swallowing initiation and opening of the pharyngoesophageal segment remained unchanged after surgery. Tongue base retraction and pharyngeal constriction ratio worsened two weeks after surgery but returned to baseline levels three months after surgery. Three months after surgery, hyoid displacement and vocal fold immobility did not fully recover. Aspiration pneumonia occurred in nine patients after surgery and was associated with postoperative MBSImP pharyngeal residue scores. Decreased hyoid displacement and vocal fold immobility were observed postoperatively and persisted for a long time. The postoperative pharyngeal residue was associated with pneumonia and thus should be appropriately managed after surgery.

Hyolaryngeal Movement During Normal and Effortful Swallows Determined During Ultrasonography.

This study investigated (a) the effects of the effortful swallow under two different instructions (tongue emphasis vs. pharyngeal squeezing) on hyoid displacement and hyoid-larynx approximation, (b) the association between tongue pressure and hyolaryngeal movement during normal swallowing and the effortful swallow produced with tongue emphasis, and (c) age-related differences in hyolaryngeal movement during normal and effortful swallows (tongue emphasis vs. pharyngeal squeezing) in healthy individuals. Forty healthy adults (20 younger and 20 older) swallowed their saliva as they normally do (normal swallow) and performed the effortful swallow with tongue emphasis and pharyngeal squeezing. Tongue-to-palate pressure during swallowing was measured using the Iowa Oral Performance Instrument, hyolaryngeal movement was measured using ultrasonography, and submental surface electromyography was used to track swallows. Results revealed differences in hyolaryngeal movement across swallowing types. Both types of effortful swallows showed greater hyolaryngeal movement than normal swallows. Additionally, hyolaryngeal movement was greater during the effortful swallow with tongue emphasis than the effortful swallow with pharyngeal squeezing. Age-related differences were found only in hyoid-larynx approximation during the effortful swallow with tongue emphasis (younger > older adults). Furthermore, moderate positive correlations were identified between tongue pressure and hyolaryngeal movement during normal swallows and the effortful swallow with tongue emphasis. The findings show that varying instructions of the effortful swallow affect hyolaryngeal movement differently, suggesting that clinicians may need to individualize the effortful swallow instruction according to the physiological impairments of each patient. Additionally, natural age-related changes in swallowing physiology do not seem to affect an individual's ability to perform the effortful swallow or to impact hyolaryngeal movement. Finally, the association between tongue pressure and hyolaryngeal movement during normal swallows and the effortful swallow with tongue emphasis suggests that the tongue plays a critical role in swallowing, priming subsequent swallowing events.

The Application of Ultrasound to Quantify Hyoid Motion During Drug-Induced Sleep Endoscopy.

The significance of hyoid dynamics in OSA pathophysiology remains unclear. Drug-induced sleep endoscopy (DISE) is often used for evaluating patients intolerant to positive airway pressure (PAP) therapy. We performed DISE with concurrent hyoid-focused ultrasonography to quantify hyoid dynamics during obstructive and non-obstructive breathing. A cross-sectional analysis from a prospective cohort of patients undergoing DISE with PAP titration (DISE-PAP) and hyoid-focused ultrasound was conducted. Hyoid ultrasound was performed during obstructive breathing, and non-obstructive breathing after PAP administration. Motion was quantified by generating displacement curves based on echo-tracking hyoid movement. The image analysis protocol for quantifying hyoid displacement was performed independently by two researchers, and reliability of measures was assessed. Univariate and multivariate regressions were performed for various clinical data and hyoid displacement during obstructive breathing. Twenty patients met inclusion criteria. On average, the cohort was male (75%), elderly (65.9 ± 10 years), overweight (29.3 ± 3.99 kg/m2 ), and with moderate-to-severe OSA (29.3 ± 12.5 events/h). Mean hyoid displacement during obstructive breathing was 5.81 mm (±3.48). In all patients, hyoid displacement decreased after PAP administration (-3.94 mm [95% CI: -5.10, -2.78]; p < 0.0001). Inter-rater reliability for measures of hyoid displacement was excellent. After multivariate regression, hyoid displacement at baseline was associated with higher AHI (β [95% CI] = 0.18 [0.03, 0.33], p = 0.020). During DISE, hyoid displacement is greater during obstructive breathing with significant variability amongst patients. Further, these ultrasonographic measurements had excellent intra- and inter-rater reliability. Additional, larger studies are needed to understand contributors to hyoid mobility. 4 Laryngoscope, 133:3221-3227, 2023.

Impact of Quantitative Videofluoroscopic Swallowing Measures on Clinical Interpretation and Recommendations by Speech-Language Pathologists

Quantitative measures are available for adult videofluoroscopic swallow study (VFSS) analysis but are yet to be seen routinely in clinical practice. This study explores agreement between traditional observational analysis and quantitative analysis, and the impact of analytical approaches on subsequent diagnosis and recommendations. One hundred adults referred for VFSSs with swallowing concerns were administered a standardised VFSS protocol. All VFSSs were analysed using three approaches: (1) a traditional observational analysis typically used by treating speech-language pathologists (SLPs), (2) quantitative analysis by two independent raters, and (3) binary subjective analysis by 11 independent raters. Three metrics were focussed on; pharyngeal constriction (PC), hyoid displacement (Hmax) and pharyngoesophageal segment opening (PESmax). All raters were blinded to others’ ratings. Treating SLPs using traditional observational analysis were provided with no instructions. Quantitative analysis used published Leonard and Kendall digital displacement measures. Binary subjective analysis involved rating each VFSS as normal versus impaired for the three metrics above. Treating SLPs using traditional observational analysis and quantitative analysis raters independently provided diagnostics and treatment plans. PC, Hmax and PESmax achieved fair agreement (Kappa = 0.33–0.36) between binary subjective analysis compared to substantial agreement (ICC = 0.77–0.94) for quantitative analysis. Reports of impairment were significantly lower in the traditional observational and binary subjective analyses compared with studies rated using the quantitative analysis (p < 0.05). Consequently, this resulted in significantly less rehabilitation recommendations when traditional observational analysis was used in comparison to the quantitative analysis. Quantitative measures to analyse VFSSs can be used in clinical practice producing increased inter-rater agreement and supporting more targeted rehabilitation recommendations than using a traditional observational VFSS analysis alone.

Defining Normal Sequential Swallowing Biomechanics.

Little is known about the physiology of a common fluid ingestion pattern-sequential swallowing. This study investigated sequential swallowing biomechanics in healthy adults. Archival normative videofluoroscopic swallow studies were analyzed for hyolaryngeal complex (HLC) patterning and biomechanical measures from the first 2 swallows of a 90-mL thin liquid sequential swallow task. The effects of age, sex, HLC type, and swallow order were explored. Eighty-eight participants were included in the primary analyses as they performed sequential swallows. HLC Type I (airway opens, epiglottis approaches baseline) and Type II (airway remains closed, epiglottis remains inverted) most commonly occurred (47% each), followed by Type III (mixed, 6%). Age was significantly associated with Type II and longer hypopharyngeal transit, total pharyngeal transit (TPT), swallow reaction time (SRT), and duration to maximum hyoid elevation. Males demonstrated significantly greater maximum hyoid displacement (Hmax) and longer duration of maximum hyoid displacement. Significantly larger maximum hyoid-to-larynx approximation was linked to the first swallow, while the subsequent swallow had significantly longer oropharyngeal transit, TPT, and SRT. Secondary analyses included an additional 91 participants who performed a series of discrete swallows for the same swallow task. Type II had significantly greater Hmax than Type I and series of discrete swallows. Sequential swallowing biomechanics differ from discrete swallows, and normal variance exists among healthy adults. In vulnerable populations, sequential swallowing may challenge swallow coordination and airway protection. Normative data allow comparison to dysphagic populations. Systematic efforts are needed to further standardize a definition for sequential swallowing.

Bolus Clearance Ratio Elevated in Patients With Neurogenic Dysphagia Compared With Healthy Adults: A Measure of Pharyngeal Efficiency.

Postswallow pharyngeal residue is a risk factor for aspiration, implies swallowing inefficiency, and increases the work of eating. The Bolus Clearance Ratio (BCR) is a derived metric that relates quantities of bolus material observed in the pharynx at two different points: before and after a swallow. The ratio provides a percentage estimate of bolus clearance. In healthy adults, mean BCR is < .05; that is, less than 5% of an ingested bolus is retained in the pharynx. The aim of this study was to compare BCR measures from patients referred for videofluoroscopic swallow studies with concerns related to stroke (n = 100) or other neurological conditions (n = 131, including Parkinson's disease and dementia) with BCRs for 139 healthy adults across the age range. BCR for a 20 ml of thin liquid barium bolus was measured. Additional metrics included age, penetration-aspiration scale (PAS) score, and quantitative measures of timing and displacement. Correlations were explored between BCR and pharyngeal constriction ratio (PCR), pharyngoesophageal segment opening (PESmax), maximum hyoid displacement (HMax), and total pharyngeal transit time (TPT). BCR values for patients with stroke (Mdn = 9%, interquartile range [IQR]: 19%, range: 0%-73%) and other neurological conditions (Mdn = 9%, IQR: 16%, range: 0%-96%) were significantly higher than in healthy norms (Mdn = 2%, IQR: 4%, range: 0%-16%, p < .001). BCR was significantly correlated with age (R s = .23, p < .01), TPT (R s = .20, p < .01), PCR (R s = .55, p < .01), PESmax (R s = -.17, p < .01), HMax (R s = -.16, p < .01), and PAS (R s = .38, p < .01). BCR was elevated in patients with neurogenic dysphagia in comparison with healthy norms and was significantly associated with increased aspiration severity (i.e., PAS). BCR was also correlated with pharyngeal timing and displacement parameters, with the strongest correlation with pharyngeal constriction-a measure of pharyngeal strength. The BCR offers clinicians a simple, quantitative measure of bolus residue and, therefore, pharyngeal efficiency and may be used to assess change in patients over time and with treatment.

Longitudinal Analysis of Swallowing Displacement Kinematics After Oropharyngeal Cancer Treatment.

Quantitative swallowing displacement kinematics evolve in patients treated for oropharyngeal squamous cell carcinoma (OPSCC). We aimed to longitudinally assess these measurements and correlate them with functional swallowing outcomes. A retrospective review was conducted on patients with OPSCC treated with definitive (chemo)radiation ([C]RT) or surgery with adjuvant (chemo)radiation (S-[C]RT) who completed at least two videofluoroscopic swallow studies (VFSS). Longitudinal analysis was accomplished via mixed-effects logistic regression for the Functional Oral Intake Scale (FOIS), and Penetration Aspiration Scale (PAS), and mixed-effects linear regression for kinematic measures. Spearman's correlation was conducted between changes in FOIS/PAS and kinematic measures. Ninety-seven patients (76 males; mean age 61) completed 245 VFSS studies. A total of 94% had human papillomavirus (HPV)/p16 positive OPSCC and 74% were T0-T2. Sixty-four patients underwent [C]RT while 33 patients underwent S-[C]RT. After treatment, posterior pharyngeal wall at hold (PPWhold) increased 3.2 standard deviation (SD) between 0 and 6 months (p < 0.001), then decreased 2.2 SD between 6 and 12 months (p < 0.001) and did not return to baseline. Hyoid-to-larynx (HL) (p=0.046) and maximal hyoid displacement (Hmax) + HL (p=0.042) increased between 6 and 12 months. Hmax (p=0.020) and Hmax + HL (p < 0.001) decreased between 12-24 months beyond baseline values. The decrease in HL and increase in PPWhold (p < 0.05) correlated with an increase in PAS. From baseline, increased pharyngeal constriction ratio correlated with decreased FOIS and PPWhold (p < 0.05). Quantitative swallowing kinematic measures can effectively track changes in swallowing physiology. Increased PPWhold and restricted hyolaryngeal movement were seen in patients with OPSCC after treatment and correlated with a change in swallowing outcome, emphasizing the need for serial VFSS monitoring and targeted intervention. 3 Laryngoscope, 133:1339-1348, 2023.

Human Hyoid Descent is Adaptive rather than Maladaptive for Swallowing Performance: An Experimental and Computational Argument

PurposeDistinctive features of the human supralaryngeal vocal tract have been argued to be adaptive for speech and maladaptive for swallowing. However, this maladaptive hypothesis has not been thoroughly tested and in fact is refuted by studies of normal human feeding physiology. This study validates a computational model of hyolingual biomechanics derived from an previously validated experimental nonhuman primate model system and examines how changes in hyolingual and craniofacial morphology over the course of human evolution and ontogeny affect hyolingual biomechanics during swallowing. In particular, we examine superoanterior excursion of the hyoid, which is often reduced in human patients with dysphagia and therefore used here as a surrogate for swallowing performance.MethodsA computational model of hyolingual range of motion during swallowing in Macaca mulatta was developed in R using in vivo data. Model outputs were compared against in vivo macaque data to determine the model's goodness of fit using a receiver operating characteristics (ROC) curve; model predictive power was estimated using the area under the ROC curve. Several aspects of macaque craniofacial and hyoid morphology were then altered towards the human condition with consequent adjustments made to muscle lengths, and the model calculated hyoid displacement during swallowing for each condition. A model was considered viable if its range of motion included a target of hyoid excursion derived from in vivo macaque and human data.ResultsThe macaque model had a sensitivity of 0.79, specificity of 0.82, and accuracy of 88% compared to in vivo data. A humanoid model predicts hyoid excursion within normal limits of healthy humans. Altering macaque morphology to approach the human condition by lowering the hyoid and making the symphysis vertical had little effect on model performance. Isolated shortening of the mandible significantly decreased hyoid excursion unless the symphysis was also made more vertical. Moreover, as the model was made more humanoid, both hyoid descent and physiologically maximal muscle shortening were necessary to approximate target hyoid excursion.ConclusionsHyoid descent—which is commonly assumed to be detrimental to swallowing—may actually maintain swallowing performance as the human face has shortened in recent evolutionary history. Moreover, because mandibular morphology affects suprahyoid muscle length, selective pressure to maintain swallowing performance may have resulted in the emergence of humanity’s characteristic vertical mandibular symphysis. Geometric constraints require human suprahyoid muscles to perform at their physiological limits when the hyoid is descended. Such extreme performance requirements may leave humans vulnerable to dysphagia not because of airway morphology alone but because of physiologic constraints.

Automated assessment of hyoid movement during normal swallow using ultrasound.

BackgroundThe potential for using ultrasound by speech and language therapists (SLTs) as an adjunct clinical tool to assess swallowing function has received increased attention during the COVID‐19 pandemic, with a recent review highlighting the need for further research on normative data, objective measurement, elicitation protocol and training. The dynamic movement of the hyoid, visible in ultrasound, is crucial in facilitating bolus transition and protection of the airway during a swallow and has shown promise as a biomarker of swallowing function.AimsTo examine the kinematics of the hyoid during a swallow using ultrasound imaging and to relate the patterns to the different stages of a normal swallow. To evaluate the accuracy and robustness of two different automatic hyoid tracking methods relative to manual hyoid position estimation.Methods & ProceduresUltrasound data recorded from 15 healthy participants swallowing a 10 ml water bolus delivered by cup or spoon were analysed. The movement of the hyoid was tracked using manually marked frame‐to‐frame positions, automated hyoid shadow tracking and deep neural net (DNN) tracking. Hyoid displacement along the horizontal image axis (HxD) was charted throughout a swallow, and the maximum horizontal displacement (HxD max) and maximum hyoid velocity (HxV max) along the same axis were automatically calculated.Outcomes & ResultsThe HxD and HxV of 10 ml swallows are similar to values reported in the literature. The trajectory of the hyoid movement and its location at significant swallow event time points showed increased hyoid displacement towards the peak of the swallow. Using an interclass correlation coefficient, HxD max and HxV max values derived from the DNN tracker and shadow tracker are shown to be in high agreement and moderate agreement, respectively, when compared with values derived from manual tracking.Conclusions & ImplicationsThe similarity of the hyoid tracking results using ultrasound to previous reports based on different instrumental tools supports the possibility of using hyoid movement as a measure of swallowing function in ultrasound. The use of machine learning to automatically track the hyoid movement potentially provides a reliable and efficient way to quantify swallowing function. These findings contribute towards improving the clinical utility of ultrasound as a swallowing assessment tool. Further research on both normative and clinical populations is needed to validate hyoid movement metrics as a means of differentiating normal and abnormal swallows and to verify the reliability of automatic tracking.WHAT THIS PAPER ADDSWhat is already known on this subject There is growing interest in the use of ultrasound as an adjunct tool for assessing swallowing function. However, there is currently insufficient knowledge about the patterning and timing of lingual and hyoid movement in a typical swallow. We know that movement of the hyoid plays an essential role in bolus transition and airway protection. However, manual tracking of hyoid movement is time‐consuming and restricts the extent of large‐scale normative studies. What this study adds We show that hyoid movement can be tracked automatically, providing measurable continuous positional data. Measurements derived from this objective data are comparable with similar measures previously reported using videofluoroscopy and of the two automatic trackers assessed, the DNN approach demonstrates better robustness and higher agreement with manually derived measures. Using this kinematic data, hyoid movement can be related to different stages of swallowing. Clinical implications of this study This study contributes towards our understanding of the kinematics of a typical swallow by evaluating an automated hyoid tracking method, paving the way for future studies of typical and disordered swallow. The challenges of image acquisition highlight issues to be considered when establishing clinical protocols. The application of machine learning enhances the utility of ultrasound swallowing assessment by reducing the labour required and permitting a wider range of hyoid measurements. Further research in normative and clinical populations is facilitated by automatic data extraction allowing the validity of prospective hyoid measures in differentiating different types of swallows to be rigorously assessed.

Hyoid displacement patterns in healthy swallowing.

ABSTRACTObjective To describe the patterns of displacement of the hyoid bone in healthy individuals, considering their displacements during swallowing of different consistencies.Methods Two hundred one swallowing videofluoroscopy exams of 67 adult and elderly individuals without swallowing disorders were analyzed. Descriptive analysis was performed to identify and describe the patterns of displacement of the hyoid bone.Results Seven types of displacement of the hyoid bone were found: H1 (horizontal), H2 (short vertical and long horizontal), H3 (vertical and diagonal to upper), H4 (long vertical and short horizontal), H5 (vertical), H6 (diagonal), and H7 (brief). The standards were maintained in different consistencies. The most frequent pattern of displacement was type H2. The distribution of the types of displacement of the hyoid was different among men and women.Conclusion Seven patterns of displacement of the hyoid bone during swallowing of normal adults and older people have been described. The most frequent pattern of displacement was horizontal, with variations in distribution between men and women. The displacement pattern was maintained during the swallowing of the three different consistencies (thin, pasty and solid liquid).

Cervical Vertebral Height Approximates Hyoid Displacement in Videofluoroscopic Images of Healthy Adults.

Clinicians and researchers commonly judge the completeness of hyoid displacement from videofluoroscopic swallow study (VFSS) videos. Judgments made during the clinical exam are often subjective, and post-examination analysis reduces the measure's immediate value. This study aimed to determine the validity and feasibility of a visual, anatomically scaled benchmark for judging complete hyoid displacement during a VFSS. The third and fourth cervical vertebral bodies (C3 and C4) lie at roughly the same vertical position as the hyoid body and are strongly correlated with patient height. We hypothesized that anterior and superior displacement of the hyoid bone would approximate the height of one C3 or C4 body during safe swallows. Trained raters marked points of interest on C3, C4, and the hyoid body on 1414 swallows of adult patients with suspected dysphagia (n = 195) and 50 swallows of age-matched healthy participants (n = 17), and rated Penetration Aspiration Scale scores. Results indicated that the mean displacements of the hyoid bone were greater than one C3 unit in the superior direction for all swallows from patient and healthy participants, though significantly and clinically greater in healthy participant swallows (p < .001, d > .8). The mean anterior and superior displacements from patient and healthy participant swallows were greater than one C4 unit. Results show preliminary evidence that use of the C3 and/or C4 anatomic scalars can add interpretive value to the immediate judgment of hyoid displacement during the conduct of a clinical VFSS examination.

Swallowing kinematic analysis might be helpful in predicting aspiration and pyriform sinus stasis

Aspiration due to dysphagia can lead to aspiration, which negatively impacts a patient’s overall prognosis. Clinically, videofluoroscopic swallow study (VFSS) is considered the gold-standard instrument to determine physiological impairments of swallowing. According to previously published literature, kinematic analyses of VFSS might provide further information regarding aspiration detection. In this study, 449 files of VFSS studies from 232 patients were divided into three groups: normal, aspiration, and pyriform sinus stasis. Kinematic analyses and between-group comparison were conducted. Significant between-group differences were noted among parameters of anterior hyoid displacement, maximal hyoid displacement, and average velocity of hyoid movement. No significant difference was detected in superior hyoid displacement. Furthermore, receiver-operating characteristic (ROC) analyses of anterior hyoid displacement, velocity of anterior hyoid displacement, and average velocity of maximal hyoid displacement showed acceptable predictability for detecting aspiration. Using 33.0 mm/s as a cutoff value of average velocity of maximal hyoid displacement, the sensitivity of detecting the presence of aspiration was near 90%. The investigators therefore propose that the average velocity of maximal hyoid displacement may serve as a potential screening tool to detect aspiration.

A computational model of upper airway respiratory function with muscular coupling

A two dimensional finite element model of upper airway respiratory function was developed emphasizing the effects of dilator muscular activation on the human retro-lingual airway. The model utilized an upright mid-sagittal computed tomography of the human head and neck to reconstruct relevant structures of the tongue, mandible, and the hyoid-related soft tissues, along with the retro-lingual airway. The reconstructed geometry was divided into fluid and solid domains and discretized into finite element (FE) meshes used for the computational model. Three cases were investigated: standing position; supine position; and supine position coupled with dilator muscle activation. Computations were performed for the inspiration stage of the breathing cycle, utilizing a fluid-structure interaction (FSI) method to couple structural deformation with airflow dynamics. The spatio-temporal deformation of the structures surrounding the airway wall were predicted to be in general agreement with known changes from upright to supine posture on luminal opening, as well as the distribution of airflow. The model effectively captured the effects of muscular stimulation on the upper airway anatomical changes, the flow characteristics relevant to airway reduction in the supine position and airway enlargement with muscle activation. The smallest airway opening in the retro-lingual section is predicted to occur at the epiglottic region in all the three cases considered, an unexpected vulnerable location of airway obstruction. The model also predicted that hyoid displacement would be associated with recovery from airway collapse. This information may be useful for building more complex models relevant to mechanisms and clinical interventions for obstructive sleep apnea.

Automatic Estimation of Laryngeal Vestibule Closure Duration Using High- Resolution Cervical Auscultation Signals.

Safe swallowing requires adequate protection of the airway to prevent swallowed materials from entering the trachea or lungs (i.e., aspiration). Laryngeal vestibule closure (LVC) is the first line of defense against swallowed materials entering the airway. Absent LVC or mistimed/ shortened closure duration can lead to aspiration, adverse medical consequences, and even death. LVC mechanisms can be judged commonly through the videofluoroscopic swallowing study; however, this type of instrumentation exposes patients to radiation and is not available or acceptable to all patients. There is growing interest in noninvasive methods to assess/monitor swallow physiology. In this study, we hypothesized that our noninvasive sensor- based system, which has been shown to accurately track hyoid displacement and upper esophageal sphincter opening duration during swallowing, could predict laryngeal vestibule status, including the onset of LVC and the onset of laryngeal vestibule reopening, in real time and estimate the closure duration with a comparable degree of accuracy as trained human raters. The sensor-based system used in this study is high-resolution cervical auscultation (HRCA). Advanced machine learning techniques enable HRCA signal analysis through feature extraction and complex algorithms. A deep learning model was developed with a data set of 588 swallows from 120 patients with suspected dysphagia and further tested on 45 swallows from 16 healthy participants. The new technique achieved an overall mean accuracy of 74.90% and 75.48% for the two data sets, respectively, in distinguishing LVC status. Closure duration ratios between automated and gold-standard human judgment of LVC duration were 1.13 for the patient data set and 0.93 for the healthy participant data set. This study found that HRCA signal analysis using advanced machine learning techniques can effectively predict laryngeal vestibule status (closure or opening) and further estimate LVC duration. HRCA is potentially a noninvasive tool to estimate LVC duration for diagnostic and biofeedback purposes without X-ray imaging.