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

BACKGROUND: Hyoid 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. METHODS: Twenty 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. RESULTS: Compared 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. CONCLUSION: Implant retained overdentures have a positive effect on hyoid displacement during swallowing of thin liquid bolus consistency relative to conventional complete dentures. TRIAL REGISTRATION: Retrospectively registered (NCT06187181) 02/1/2024.

[Hyoid epiglottis combined with sternocleidomastoid muscle clavicle flap for repairing laryngeal defect after laryngeal trauma infection: a case report].

The initial treatment of open laryngeal trauma must be implemented immediately, with the primary focus on saving lives. However, in the later stages, various factors may cause changes in the structure and function of the larynx, which requires special attention. This article reports on the treatment process of a patient with depression who suffered from laryngeal trauma. Due to the late stage of laryngeal infection causing laryngeal defects, a hyoid epiglottis combined with sternocleidomastoid muscle clavicular flap repair was performed. Additionally, personalized functional exercise was performed, ultimately resulting in recovery.

Ultrasound Evaluation of Anterior Neck Soft-Tissue Thickness to Predict Difficult Intubation in Overweight Adult Patients Posted for Surgery under General Endotracheal Anesthesia - An Observational Study.

BACKGROUND: Ultrasonographic imaging has been recently become simple portable and non-invasive adjuvant for bedside assessment of anterior neck soft tissue thickness which when measured at different levels showed to have significant role in predicting difficult laryngoscopy. AIMS AND OBJECTIVES: Primary objective was Ultrasonographic measurement of anterior neck soft tissue thickness at 3 levels -Distance from skin to hyoid bone (DSHB) -Distance from skin to thyrohyoid membrane (DSTM) -Distance from skin to anterior commissure of vocal cord(DSAC) and to compare and correlate the findings with Cooks modification of Cormack-Lehane score in predicting difficult laryngoscopy. Secondary objective was to compare and correlate the ultrasonographic measurements with conventional airway assessment methods. MATERIALS AND METHODS: After obtaining approval from the ethical committee, 90 Patients with BMI above 25 kg /m2 was enrolled for the study. A day before the surgery a thorough Preanaesthetic evaluation and assessment of the airway is done using conventional methods. Then on the day of surgery ultrasonographic measurement of anterior neck at 3 levels was done and after inducing the patients laryngoscopy was done and Cooks modification of Cormack-Lehane score assessed. RESULTS: The optimal cut off values to predict difficult laryngoscopy was 1.26, 2 and 1.2 cms for DSHB, DSTM and DSAC respectively, and among the three skin to anterior commissure of vocal cord was observed to be best USG parameter with more area under the ROC curve. CONCLUSION: USG measurement of anterior neck soft tissue thickness can be useful in predicting difficult laryngoscopy in overweight and obese patients also it had more diagnostic accuracy than conventional methods like MMS in predicting difficult laryngoscopy.

RésuméArrière-plan L'imagerie échographique est récemment devenue un simple adjuvant portable et non invasif pour l'évaluation au lit du patient de l'épaisseur des tissus mous du cou antérieur qui, lorsqu'elle est mesurée à différents niveaux, s'est avérée avoir un rôle important dans la prédiction d'une laryngoscopie difficile. Buts et objectifs L'objectif principal était la mesure échographique de l'épaisseur des tissus mous du cou antérieur à 3 niveaux -Distance de la peau à l'os hyoïde (DSHB) -Distance de la peau à la membrane thyrohyoïdienne (DSTM) -Distance de la peau à la commissure antérieure de la corde vocale (DSAC) et pour comparer et corréler les résultats avec la modification de Cooks du score de Cormack-Lehane pour prédire une laryngoscopie difficile. L'objectif secondaire était de comparer et de corréler les mesures échographiques avec les méthodes conventionnelles d'évaluation des voies respiratoires Matériels et méthodes Après avoir obtenu l'approbation du comité d'éthique, 90 patients présentant un IMC supérieur à 25 kg/m2 ont été inclus dans l'étude. Un jour avant la chirurgie, une évaluation préanesthésique approfondie et une évaluation des voies respiratoires sont effectuées à l'aide de méthodes conventionnelles. Ensuite, le jour de la chirurgie, une mesure échographique de la partie antérieure du cou à 3 niveaux a été effectuée et après l'induction des patients, une laryngoscopie a été effectuée et la modification de Cooks du score de Cormack-Lehane a été évaluée. Résultats Les valeurs seuil optimales pour prédire une laryngoscopie difficile étaient respectivement de 1,26, 2 et 1,2 cm pour DSHB, DSTM et DSAC, et parmi les trois paramètres de la peau à la commissure antérieure de la corde vocale, il a été observé que le meilleur paramètre USG avec plus de surface sous la courbe ROC Conclusion La mesure par USG de l'épaisseur des tissus mous du cou antérieur peut être utile pour prédire une laryngoscopie difficile chez les patients en surpoids et obèses. Elle a également une plus grande précision diagnostique que les méthodes conventionnelles comme le MMS pour prédire une laryngoscopie difficile.

The skull of the Turks and Caicos rock iguana, Cyclura carinata (Squamata: Iguanidae).

We provide a detailed and first description of the skull, hyoid apparatus, and trachea of the Turks and Caicos rock iguana, Cyclura carinata (Squamata: Iguanidae). Cyclura is a radiation of iguanas restricted to islands of the Caribbean Sea. Species of Cyclura have high rates of endemism, and all species are severely threatened with extinction. Our anatomical description of this threatened iguana is based on high-resolution computed tomography scans of one adult, one putative adult or near adult, and one juvenile specimen, and includes three-dimensional segmented renderings and visualizations. We discuss some observations of intraspecific and ontogenetic variation, and provide a brief comparison with specimens of another species of Cyclura and published descriptions of other iguanas. Our study provides a cranial osteological framework for Cyclura and augments the body of knowledge on iguana anatomy generally. Finally, we posit that our description and future studies may facilitate identification of fossil Cyclura, which could help understand the paleobiogeography of the genus.

Evaluation of neck ultrasound measurements as a difficult airway predictor: A prospective observational study.

This study aimed to investigate the relationship between cervical measurements and difficult airways using ultrasonographic measurements. American Society of Anesthesiologists grade I to III, male or female, 120 adult patients, undergoing elective surgery were enrolled in the study. The study involved measuring the distance of the trachea, cricoid cartilage, thyroid cartilage, vocal cord anterior commissure, and hyoid bone to the skin using a 10 to 13 MHz linear ultrasound probe in the transverse plane. Additionally, the length of the cricothyroid and thyrohyoid membranes, along with their distance from the skin, were measured using the probe in the sagittal plane. Subsequently, another experienced anesthesiologist conducted mask ventilation and intubation after the patient's induction of general anesthesia. Throughout this process, the patient was assessed for difficulties in mask ventilation, laryngoscopy, and intubation. 28 (23.3%) patients had a difficult airway. Analyzing the measurements associated with difficult airways, the most reliable predictor was the epiglottis midline-skin distance [AUC (area under the curve): 0.847, P < .001, cutoff: >19.9, sensitivity: 78.6%, specificity: 79.4%]. Additionally, other factors such as hyoid bone to skin distance, thyroid cartilage to skin distance, thyrohyoid membrane to skin distance, and vocal cord anterior commissure-skin distance were also identified as predictors for a difficult airway. The increase in the distance of the epiglottis midline, vocal cord anterior commissure, hyoid bone, thyrohyoid membrane, and thyroid cartilage to the skin at the level of the isthmus measured by ultrasonography is predictive of difficult airways. Based on our study outcomes, we assert that ultrasonographic evaluation can be used in the prediction of difficult airways.

The previously undescribed variant of the thyrohyoid muscle and its potential impact on surgical procedures.

The thyrohyoid muscle belongs to the infrahyoid group located in the carotid triangle. It normally originates from thyroid cartilage and inserts into hyoid bone. Quite often, it is continuous with the sternohyoid muscle. Furthermore, there are variants that have their origin in the cricoid cartilage only, however, this occurs very rarely. During anatomical dissection, a two-headed variant of this muscle was found. One head had its origin in the cricoid cartilage and the other in the thyroid cartilage. This variant of thyrohyoid had not been previously described in the available literature. Therefore, we believe that it may be referred to as the cricothyrohyoid muscle. As the thyrohyoideus is often used as a landmark during surgical procedures in the prelaryngeal area and as a muscle graft, a thorough knowledge of its anatomy and variation is extremely important. We speculate that the two-headed version of this muscle may be problematic during surgical procedures in this region, however, it may also provide more options as a muscular graft.

A Preliminary Study of Vallecular Bolus Aggregation in Healthy Swallowing of Solid Food Boluses.

OBJECTIVE: The pharyngeal swallow typically begins within 400 ms following the arrival of a liquid bolus in the pharynx. By contrast, processed food particles aggregate in the valleculae prior to swallow initiation. With solid foods, swallow reaction time (SRT), the interval between bolus passing the ramus of mandible and hyoid burst onset (HYB) can be subdivided into components of vallecular aggregation time (VAT) and the subsequent end of aggregation to hyoid burst interval (EOA-to-HYB). However, expected durations of these timing measures remain unclear. We aimed to study bolus aggregation in healthy swallowing for International Dysphagia Diet Standardisation Initiative Food Levels 5 (minced and moist [MM5]), 6 (soft and bite-sized [SB6]), and 7 (regular [RG7]). Understanding typical patterns and durations of vallecular aggregation with solids in healthy swallowing will inform the identification of impaired swallow timing in patient populations. DESIGN: Twenty healthy adults (10 males, Mage = 28 years, range: 23-55 years) swallowed two boluses each of MM5, SB6, and RG7 foods in videofluoroscopy. Blinded duplicate ratings determined bolus location at swallow onset, SRT, VAT, and EOA-to-HYB. Texture-based differences were measured using Friedman's tests. Bolus location was at/above the valleculae at swallow onset for 85% of boluses, with no differences by texture. SRT, VAT, and EOA-to-HYB did not vary by texture, with overall median values (interquartile range) of 99 ms (-66 to 743 ms) for SRT, 347 ms (66 to 891 ms) for VAT, and -132 ms (-231 to -83 ms) for EOA-to-HYB. CONCLUSIONS: These data corroborate prior evidence that it is not unusual for food particles to aggregate in the valleculae prior to swallow initiation in healthy swallowing. However, durations of vallecular aggregation are typically < 1 s in healthy adults.

A Possible Mechanism of Laryngohyoid Fractures in Hanging: A Preliminary Observation.

ABSTRACT: Fractures of the hyoid bone, particularly the greater horns, and thyroid cartilage (superior horns) are known to be associated with hanging deaths. Depending on the literature, the frequency of these fractures varies from 0% to 83%. The mechanism underlying these fractures is believed to be direct compression or indirect traction from the ligature. The relationship of these structures with the cervical spine cannot be visualized with traditional internal examination, due to obstruction by surrounding soft tissue. Postmortem computed tomography scan offers an unobscured view of the relationship of the laryngohyoid structures with the cervical spine.We aim to illustrate the phenomenon of displacement of the laryngohyoid structures associated with fractures of the horns. In our case reports, the laryngohyoid structures were displaced, not only superiorly and posteriorly, but also in 2 of the cases, by tilting, when the suspension point was at the posterior or posterolateral aspect of the neck. This displacement had caused the greater horns of the hyoid bone and superior horns of the thyroid cartilage to be approximated against the cervical spine, particularly the transverse processes. We believe that, in these circumstances, the fractures were caused by pressure of the horns of the laryngohyoid structures against the cervical spine.

Ultrasonographic analysis of the hyoid bone distance in individuals with neurogenic oropharyngeal dysphagia. / Análise ultrassonográfica da distância do osso hioide em indivíduos com disfagia orofaríngea neurogênica.

To compare the ultrasound measurement of distance from the approximation of the hyoid bone during of the maximum deglutition peak between healthy individuals and neurogenic dysphagic individuals and to verify the effect of food consistencies on the displacement of the hyoid bone. Prospective, controlled clinical study. Ultrasound recordings of the oropharyngeal deglutition were conducted in 10 adults diagnosed with oropharyngeal dysphagia and in 10 healthy adults, matched by sex and age group. A portable ultrasound model Micro ultrasound system with a microconvex transducer 5-10 MHz, coupled to a computer as well as the head stabilizer were used. The ultrasound images were recorded using the AAA software (Articulate Assistant Advanced) at a rate of 120 frames/second. Food consistencies level 0 (free volume and 5 mL) and level 4 (5 mL) were used, based on the International Dysphagia Diet Standardisation Initiative (IDSSI). The calculation of the mean and standard deviation was used for the descriptive analysis, while the repeated measures ANOVA test was used for the inferential analysis. Results showed dysphagic individuals had lower elevation of the hyoid bone marked by a longer distance from the approximation of the hyoid bone during of the maximum deglutition peak when compared to healthy individuals, regardless of the food consistency offered. It was concluded that the ultrasound measurement of distance from the approximation of the hyoid bone during of the maximum deglutition peak showed less laryngeal elevation in individuals with neurogenic oropharyngeal dysphagia when compared to healthy individuals for all food consistencies offered.

Comparar a medida ultrassonográfica de distância da aproximação do osso hioide no momento do pico máximo da deglutição entre indivíduos saudáveis e disfágicos neurogênicos e verificar o efeito das consistências do alimento no deslocamento do osso hioide. Estudo clínico prospectivo controlado. Foram realizadas avaliações ultrassonográficas da deglutição orofaríngea em 10 adultos com diagnóstico de disfagia orofaríngea e 10 adultos saudáveis, pareados por sexo e faixa etária. Para tanto, foi utilizado ultrassom portátil com transdutor microconvex 5-10 MHz, além de estabilizador de cabeça. As imagens ultrassonográficas foram gravadas pelo software Articulate Assistant Advanced a uma taxa de 120 quadros/segundo. Foram utilizadas as consistências de alimentos nível 0 (volume livre e 5 mL) e nível 4 (5 mL), conforme as recomendações do International Dysphagia Diet Standardisation Initiative. A distância foi mensurada no momento do pico máximo da deglutição entre a parte inferior do osso hioide e a inserção do músculo milo-hioideo. Cálculos de média e o desvio padrão foram utilizados na análise descritiva, enquanto o teste ANOVA de medidas repetidas foi aplicado na análise inferencial.Resultados evidenciaram que indivíduos disfágicos apresentaram menor elevação do osso hioide, marcada por maior distância da aproximação do osso hioide no momento do pico máximo da deglutição quando comparados aos indivíduos saudáveis, independentemente da consistência alimentar ofertada. Concluiu-se que a medida ultrassonográfica de distância da aproximação do osso hioide no momento do pico máximo da deglutição mostrou menor elevação laríngea em indivíduos com disfagia orofaríngea neurogênica quando comparados aos indivíduos saudáveis para todas as consistências alimentares ofertadas.

Screening of aspiration pneumonia using the modified Mallampati classification tool in older adults.

Pneumonia is a major cause of morbidity and mortality in older adults. In the aging society, screening methods for predicting aspiration pneumonia are crucial for its prevention. Changes in the oropharyngeal morphology and hyoid bone position may increase the risk of aspiration pneumonia. This multicenter study aimed to investigate a simple and effective screening method for predicting dysphagia and aspiration pneumonia. Overall, 191 older adults (aged 65 years or older) were randomly sampled using the simple random sampling technique. Oropharyngeal morphology was assessed using the modified Mallampati classification, which reflects the size of the tongue in the oropharyngeal cavity. The hyoid position was measured as the distance between the menton and laryngeal prominence to evaluate aging-related changes in the muscles of the laryngopharynx. Dysphagia was assessed using the repetitive saliva swallowing test (RSST), which measures the number of swallowing movements in 30 seconds; dysphasia is defined as less than 3 swallowing movements in 30 seconds. The aspiration signs were assessed based on history of choking or coughing reflex during eating or drinking and medical history of pneumonia. The study findings revealed that the modified Mallampati classification was significantly correlated with a medical history of pneumonia. A higher incidence of pneumonia was evident in the lower Mallampati classification, which shows the smaller size of the tongue base in the oropharyngeal cavity. The results of this study suggest that the modified Mallampati classification may be a possible screening method to predict the occurrence of pneumonia.

Medicare volume and reimbursement trends in lingual and hyoid procedures for obstructive sleep apnea.

OBJECTIVES: This study aims to analyze utilization and reimbursement trends in lingual and hyoid surgery for obstructive sleep apnea (OSA). METHODS: Annual retrospective data on lingual and hyoid OSA surgeries was obtained from the 2000-2021 Medicare Part B National Summary Datafiles. Current Procedural Terminology (CPT) codes utilized included 21,685 (hyoid myotomy and suspension [HMS]), 41,512 (tongue base suspension [TBS]), 41,530 (radiofrequency ablation of the tongue [RFT]) and 42,870 (lingual tonsillectomy [LT]). RESULTS: The number of lingual and hyoid OSA surgeries rose 2777 % from 121 in 2000 to 3481 in 2015, before falling 82.9 % to 594 in 2021. Accordingly, Medicare payments rose 17,899 % from an inflation-adjusted $46,958 in 2000 to $8.45 million in 2015, before falling drastically to $341,011 in 2021. As the number of HMSs (2000: 91; 2015: 84; 2021: 165), TBS (2009: 48; 2015: 31; 2021: 16), and LTs (2000: 121; 2015: 261; 2021: 234) only experienced modest changes in utilization, this change was largely driven by RFT (2009: 340; 2015: 3105; 2021: 179). Average Medicare payments for RFT rose from $1110 in 2009 to $2994 in 2015, before falling drastically to $737 in 2021. CONCLUSION: Lingual and hyoid surgery for OSA has overall fallen in utilization among the Medicare population from 2000 to 2021. However, there was a brief spike in usage, peaking in 2015, driven by the adoption (and then quick dismissal) of RFT. The rise and fall in RFT use coincide with the rise and fall in reimbursement.

Effect of bolus property on swallowing dynamics in patients with dysphagia.

BACKGROUND: Modification of foods or liquids is commonly administered as part of dysphagia treatment. However, no consensus exists on the parameters for defining texture-modified food for patients with dysphagia. OBJECTIVES: The aim of this study was to evaluate the effect of food/liquid material on swallowing physiology in patients with dysphagia and to discuss the optimal food choice for direct swallowing therapy. MATERIALS AND METHODS: A total of 140 patients underwent a videofluoroscopic swallowing study using three test foods/liquids: 3 mL of mildly thick liquid (Thick liquid), jelly made of agar and polysaccharide (Jelly) and jelly made of pectin (Reset gel). Outcome measures of videofluoroscopic images, bolus transit time and hyoid movements were compared. RESULTS: The frequency of chewing movements was highest for Jelly, followed by Reset gel and Thick liquid. While the probability of oral residue was the highest for Reset gel, pharyngeal residue after swallowing was high for Thick liquid as compared to Jelly and Reset gel. Oral transit time and pharyngeal transit time for Thick liquid were significantly smaller than that for Jelly and Reset gel. Pharyngeal delay time was significantly smaller for Thick liquid than that for Jelly and Reset gel. There was no difference in hyoid elevation time and hyoid movement time among the conditions. CONCLUSION: Mildly thick liquid material may be optimal for patients with primarily oral motor function impairment and jelly, such as Reset gel, may be more suitable for patients with primarily pharyngeal motor function impairment or oral and pharyngeal coordinative motor function decline.

Consideration of Hyoid Variability in the Diagnostic Workup of Fishbone Foreign Body Aspiration.

Fishbone foreign body (FFB) can lodge in the upper respiratory or gastrointestinal tracts and frequently cause discomfort. While FFBs are common, variations in the hyoid may present radiographically similarly. The authors present a case in which a 32-year-old woman presented with pain in the right neck with a globus sensation after eating fish. Examination, including flexible fiberoptic laryngoscopy, did not reveal a foreign body. Given the patients' persistent symptoms, a noncontrast computed tomography was performed, demonstrating a radiopaque body superior to the right lateral hyoid bone, consistent with FFB. Direct examination under anesthesia was performed, and no FFB was noted. A reassessment of the imaging suggested a likely aberrant hyoid bone. The authors report this case to remind clinicians that while rare, aberrant hyoid variants may mimic FFB. The authors also review the imaging findings of aberrant hyoid variants in this report, as recognition of hyoid variability can mitigate unnecessary intervention.

Muscle Tension Dysphagia: An Expanded Investigation of Clinical Presentations and Swallowing Kinematics.

PURPOSE: This study retrospectively examined patient-reported symptoms, quality of life, and swallowing kinematics in individuals with presumed muscle tension dysphagia (MTDg). METHOD: Twenty-six individuals met the inclusion criteria. Data were gathered from patient-reported outcome measures (PROs), symptomology, clinician reports of palpation, and hyolaryngeal and hyoid movements measured on a 20-ml thin liquid bolus during videofluoroscopic swallowing studies. RESULTS: All PROs were outside of typical limits, except for the Voice Handicap Index-10. Mean hyoid excursion was 1.52 cm (SD = 0.46, range: 0.76-2.43), and hyolaryngeal excursion was 0.77 cm (SD = 0.44, range: -0.42-1.68). A minority of participants (4%-19%) demonstrated atypical hyoid and/or hyolaryngeal excursion compared to the available normative reference value sets. CONCLUSIONS: Individuals demonstrated abnormalities in the clinical evaluation of the areas of palpation and reported perilaryngeal discomfort and symptoms of laryngeal hyperresponsiveness, with a negative impact on their quality of life across various PROs. Atypical hyoid and/or hyolaryngeal excursion during swallowing was rare when compared to available normative reference values. The clinical evaluation of MTDg may be enhanced by including components related to muscle tension and laryngeal hyperresponsiveness in order to differentiate MTDg from idiopathic functional dysphagia and lead the patient to the otolaryngology/speech-language pathology clinic for intervention and management.

The Thyrohyoid Muscle: A Crucial Player in Deglutition and Vocalization / El Músculo Tirohioideo: Un Actor Crucial en la Deglución y la Vocalización

SUMMARY: The thyrohyoid muscle is one of the four infrahyoid muscles. Its role in vocalization and deglutition could be often overlooked, despite its crucial participation in these processes. Unlike other infrahyoid muscles, the thyrohyoid muscle receives innervation from the first cervical spinal nerves which contributes to its unique function. Its primary action involves hyolaryngeal elevation during swallowing, contributing to the opening of the upper esophageal sphincter. In conjunction with other muscles, it also protects the airway and facilitates the passage of food into the esophagus. Variations in the muscle's thickness may exist, and its function can be influenced by chewing habits. Weakened muscles involved in swallowing are often associated with dysphagia, a common complication in stroke and brain-injured patients. Advanced imaging techniques and sleep studies have provided insights into the dynamics and frequency of swallowing. This review explores the anatomic structures, function in action, diagnosis and clinical implications of this muscle. Overall, understanding the significance of the thyrohyoid muscle enhances our comprehension of the intricate interplay of laryngeal muscles during vocalization and deglutition.

El músculo tirohioideo es uno de los cuatro músculos infrahioideos. A menudo podría pasarse por alto su papel en la vocalización y la deglución, a pesar de su participación crucial en estos procesos. A diferencia de otros músculos infrahioideos, el músculo tirohioideo recibe inervación de los primeros nervios espinales cervicales, lo que contribuye a su función única. Su acción principal implica la elevación hiolaríngea durante la deglución, contribuyendo a la apertura del esfínter esofágico superior. Junto con otros músculos, también protege las vías respiratorias y facilita el paso de los alimentos al esófago. Pueden existir variaciones en el grosor del músculo y su función puede verse influenciada por los hábitos de masticación. Los músculos debilitados involucrados en la deglución a menudo se asocian con disfagia, una complicación común en pacientes con accidente cerebrovascular y lesión cerebral. Las técnicas de imagen avanzadas y los estudios del sueño han proporcionado información sobre la dinámica y la frecuencia de la deglución. Esta revisión explora las estructuras anatómicas, la función en acción, el diagnóstico y las implicaciones clínicas de este músculo. En general, comprender la importancia del músculo tirohioideo mejora nuestra comprensión de la intrincada interacción de los músculos laríngeos durante la vocalización y la deglución.

Growing stylohyoideus muscle insertion to the hyoid bone with special reference to its topographical relation to the intermediate tendon of digastricus muscle: A histological study using human fetuses.

BACKGROUND: In adults, the intermediate tendon of digastricus muscle usually runs along the medial or lateral side of the stylohyoideus muscle insertion. To provide a better understanding of the variations, we examined the topographical anatomy of the muscle and tendon in fetuses. METHODS: We examined histological sections from six early-term, 26 mid-term and six near-term fetuses (approximately 8-9, 12-18 weeks and 25-33 weeks). RESULTS: At early-term, an initial sheath of intermediate tendon of digastricus muscle received the stylohyoideus muscle at the superior aspect. The muscle and tendon was distant from the hyoid. At mid-term, near the insertion to the hyoid greater horn, the stylohyoideus muscle consistently surrounded more than 2/3 of the intermediate tendon circumference. In contrast, we found no near-term specimen in which the stylohyoideus muscle surrounded the intermediate tendon. The multilayered tendon sheath was fully developed until near-term and connected to the body of hyoid by an intermuscular septum between the thyrohyoideus muscle and one or two of suprahyoid muscles. Therefore, the hyoid insertion of the styloglossus muscle was a transient morphology at mid-term. CONCLUSION: The stylohyoideus muscle insertion was appeared to move from the tendon sheath to the hyoid greater horn and, until near-term, return to the tendon sheath. A fascia connecting the tendon sheath to the body of hyoid was strengthened by the suprahyoid and infrahyoid muscles. The latter muscles seemed to regulate fixation/relaxation of the intermediate tendon to the hyoid. The stylohyoideus muscle slips sandwiching the intermediate tendon might be a rare morphology.

Adverse events associated with device assisted hyoid and tongue base suspension for obstructive sleep apnea.

PURPOSE: Hyoid and tongue base suspension may treat obstructive sleep apnea (OSA). This study summarizes device-related adverse events associated with the AIRvance and AIRLIFT systems used for hyoid and tongue base suspension. MATERIALS AND METHODS: The U.S. Food and Drug Administration's Manufacturer and User Facility Device Experience (MAUDE) database was queried for reports describing adverse events associated with hyoid or tongue base suspension from January 2012 to December 2022. RESULTS: 77 adverse events were identified. When performed separately, adverse events were equally as common with hyoid suspension as with tongue base suspension. More complications occurred postoperatively (51 [66.2 %]) than intraoperatively (26 [33.8 %]). The most reported adverse events were infection (23 [29.9 %]), broken screw (15 [19.5 %]), pain or discomfort (10 [13.0 %]), suture rupture (8 [10.4 %]), and dislodged screw (7 [9.1 %]). 10 infections required drainage or debridement; 12 required device explantation. CONCLUSIONS: The present study is the largest and most longitudinal review of adverse events associated with hyoid and tongue base suspension. Infection was the most common adverse event, and may require device explantation. While adverse events were most frequently attributed to device malfunction, broken screw, suture rupture, and broken needle were often attributed to operator error due to application of excessive force. Surgeon training to increase familiarity with hyoid and tongue base suspension may reduce adverse events caused by operator error. The MAUDE database is limited as a passive surveillance system. Standardized reporting may improve understanding of associated adverse events, enabling better informed comparisons between surgical treatment options for OSA.

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.