Symmetrical activity of the chewing muscles and its relationship with skeletal class and body posture

OBJECTIVE

To describe the role of body posture and skeletal class in the symmetrical activity of chewing muscles.

METHODS

Descriptive study with association. Skeletal class measured by the Steiner method. Postural analysis through APECS mobile application for forward head posture and shoulder discrepancy, and surface electromyography with Biopac® device.

RESULTS

The skeletal class, forward head posture, and shoulder discrepancy presented statistical association with the symmetrical electromyographic response of digastric muscles and masseter muscles during swallowing.

DISCUSSION

This study exhibited a positive relationship between digastric muscle symmetry and skeletal class during swallowing. The compensation of the hyoid system explains these results, showing that skeletal Class III has better electromyographic balance. In contrast, masseter muscle symmetry during swallowing presented a negative relationship with skeletal class. The stabilization role that this muscle plays during swallowing explains these findings, caused by the different lengths and direction of this muscle in skeletal Class III.

Injury of the Hyoid Bone as a Rare Complication in Cervical Spine Rehabilitation: A Case Report

Neck pain is a common reason for primary care visits, and its differential diagnosis should consider various conditions. The reported incidence of hyoid bone fractures is extremely low, accounting for only 0.002% of all fractures. The most common causes of hyoid bone fractures include strangulation attempts and motor vehicle accidents. We report a case of an uncommon complication of manual therapy of the cervical spine. A 76-year-old woman complained of neck pain that worsened during speaking and swallowing, originating from a neck physiotherapy session. The otolaryngological examination revealed tenderness on the right side of the neck. Flexible nasal endoscopy demonstrated a shallow right piriform recess and asymmetry of the arytenoid cartilages. Computer tomography scan of the neck showed an isolated fracture of the right greater horn (cornu major) of the hyoid bone. The treatment was nonsurgical, with the use of a Schantz collar and pain relief drugs. Reported symptoms of hyoid bone fractures include dysphagia, odynophagia, and neck pain. In most cases of hyoid fractures, conservative management suffices, involving rest, analgesic and anti-inflammatory treatment, and neck immobilization. Surgical treatment is often necessary in the cases of fractures accompanying other injuries.

Hyoid Bone Fracture Secondary to a Blunt Neck Trauma: A Report of 2 Cases

Hyoid bone fracture unrelated to strangulation is a rare occurrence characterized by a subtle presentation. However, it may manifest as a fatal respiratory distress due to airway obstruction. We present 2 cases of hyoid bone fractures that occurred following a traffic accident in 2 male patients. Both patients presented with either a neck pain or a dysphagia. Physical examination findings were limited to neck sensibility at palpation, saliva stasis, and laryngeal congestion at the laryngeal endoscopy. In both patients, the diagnosis was confirmed through computed tomography. In the first patient, the fracture was simple and located at the body of the hyoid bone, while in the second patient, it involved the greater horn with a medial displacement of the fractured fragment. Due to the clinical presentation, we successfully treated both our patients conservatively through a 48 hour observation, analgesics, steroids, antibiotics, neck rest, and semiliquid diet. This study highlights a rare occurrence of 2 cases of hyoid bone fracture unrelated to strangulation, which emphasizes on the importance of a high clinical suspicion to make the diagnosis of this entity.

The Diversity of the Linguofacial Trunk

Background and Objectives: Typically, the external carotid artery (ECA) sends off separate anterior branches: the superior thyroid, lingual, and facial arteries. These could, however, form common trunks: thyrolinguofacial, linguofacial (LFT), or thyrolingual. Although known, the LFT variant was poorly detailed previously, and most authors just counted the variant. We aimed to demonstrate the individual anatomical possibilities of the LFT on a case-by-case basis. Materials and Methods: 150 archived angioCT files were used. After applying inclusion and exclusion criteria, 147 files of 86 males and 61 females were kept for this study. Results: In 34/147 cases, LFTs were found (23.12%). Bilateral LFTs were found in 13/34 cases (38.24%) and unilateral LFTs in 21/34 (61.76%) cases. Forty-seven LFTs were thus identified and further studied for different variables. Regarding the vertical topography of LFT origin, type 1a (suprahyoid and infragonial) was found in 28 LFTs (59.57%), type 1b (suprahyoid and gonial) was found in eight LFTs (17.02%), type 3 (suprahyoid and supragonial) was found in two LFTs (4.25%), type 2 (hyoid level of origin) in eight LFTs (17.02%), and type 3 (infrahyoid origin) in just one LFT (2.12%). Types of the initial course of the LFT were determined: type I, ascending, was found in 22/47 LFTs; type II, descending, in 12/47 LFTs; and type III, transverse, in 13/47 LFTs. Regarding the orientation of the first loop of the LFT, 23/47 LFTs had no loop, 4/47 had anterior loops, 1/47 had a posterior loop, 5/47 had superior loops, 5/47 had inferior loops, and 9/47 had medial loops. The position of the LFT relative to the ECA was classified as medial, anterior, or antero-medial. An amount of 12/47 LFTs were anterior to the ECA, 22/47 were antero-medial, 10/47 were medial, 2/47 were inferior, and 1/47 was lateral. Regarding their general morphology, 23/47 LFTs had a rectilinear course, 22/47 had loops, and 2/47 were coiled. A case-by-case presentation of results further demonstrated the diversity of the LFT. Conclusions: In conclusion, the morphology and topography of the LFT are individually specific and unpredictable. It can be anticipated case-by-case by surgeons on CT or MR angiograms.

Value of the Hyomental Distance Measured With Ultrasound in Forecasting Difficult Laryngoscopy in Newborns

PURPOSE

Preoperative evaluations of difficult airways are imperative, especially in newborns. The hyomental distance is a reliable index for predicting difficult airways in adults. However, few studies have evaluated the value of the hyomental distance for predicting difficult airways in newborns. It is unclear whether the hyomental distance forecasts a restricted or difficult view when using direct laryngoscopy. We intended to develop an effective system for predicting difficult tracheal intubation in newborns.

DESIGN

A prospective observational clinical study.

METHODS

Newborns aged 0 to 28 days undergoing oral endotracheal intubation with direct laryngoscopy for elective surgery under general anesthesia were enrolled. The hyomental distance and hyoid level tissue thickness were assessed by ultrasound. Other parameters, such as the mandibular length and sternomental distance, were also evaluated before anesthesia. The glottic structure view under laryngoscopy was graded according to the Cormack-Lehane classification. The patients with Grade 1 and 2 laryngeal views were assigned to Group E. Those with Grade 3 and 4 views were assigned to Group D.

FINDINGS

A total of 123 newborns were recruited for our study. The incidence of poor visualization of the larynx during laryngoscopy in our study was 10.6%. The multifactor logistic regression results showed that the hyomental distance was a powerful predictor of difficult laryngoscopy (OR = 0.16, 95% CI 0.03-0.74, P = .019). The curve with the highest sensitivity and specificity and the maximum area under the curve (AUC) was the hyomental distance. The receiver operating characteristic (ROC) curve for the hyomental distance suggested that the best cut-off value was less than equal to 2.74 cm, with an AUC of 0.80 (95% CI 0.64-0.95).

CONCLUSIONS

It is noninvasive and feasible to accurately measure the hyomental distance with ultrasound in newborns, and the results are reliable. We believe that the hyomental distance measured with ultrasound could be used as a marker for predicting difficult laryngoscopy in newborns.

Management of Giant Cell Tumor of the Hyoid bone- A rare Clinical Entity with Review of Literature

BACKGROUND

Giant cell tumors (GCTs) are typically found in the long bones but can also occur in the head and neck region. GCT of the larynx is a rare entity with only 42 reported cases in the international literature. Furthermore, to the best of our knowledge this is the largest laryngeal GCT reported in the literature to date. GCT of the larynx can present with dysphonia, dyspnea, and/or dysphagia and should be considered in the differential diagnosis of a neck mass.

PATIENT AND METHODS

A38-year-old man presented with complaints of mass in the neck with dysphonia and dysphagia. On clinical examination,there was huge spherical swelling extending from submental region till sternal notch with overlying normal skin. Computed tomography (CT) neck revealed a 20 × 15.7 cm mass centered on the hyoid bone, which was further diagnosed by histopathology as giant cell tumour on biopsy. The patient was counselled on treatment options and it was decided to proceed with a surgical approach. The patient consented to and successfully underwent en-bloc excision of mass with hyoid bone. Histopathology report revealed GCT of Hyoid bone.Currently the patient has no evidence of disease at 25 months follow-up, has an optimal voice, and is on regular follow -up with us.

DISCUSSION AND CONCLUSION

GCTs of the larynx have a good prognosis and can be treated successfully through complete resection of the tumor, negating the need for adjunctive therapy such as radiation, chemotherapy or denosumab therapy.

Hyoid bone compression‑induced carotid dissecting aneurysm: A case report

Bony structures around the carotid artery, such as the styloid process and the hyoid bone, can cause dissection, compression, plaque formation and plaque rupture of the carotid artery. The present study aimed to present a novel case of hyoid bone elongation causing dissecting aneurysm of the carotid artery. However, the patient had no permanent neurologic symptoms. An 80-year-old man presented with right hemiparesis for >5 h despite preventive therapy with antiplatelets and statins. Magnetic resonance imaging revealed acute infarction in the left parietal lobe. Contrast-enhanced computed tomography revealed two cysts with some calcification located at the bifurcation of the right internal carotid artery (ICA) and the right greater horn of the hyoid bone adjacent to the right ICA. A color duplex scan of the carotid vessels confirmed the relationship between dissecting aneurysm and the hyoid bone. In conclusion, greater attention should be paid to the bony structures around the carotid artery.

Assessment of Posterior Pharyngeal Airway Changes After Orthognathic Surgery Using Barium Sulfate

INTRODUCTION

 Obstructive sleep apnea (OSA), caused by airway narrowing, is likely to occur if the mandibular plane to hyoid distance is greater than 15.4 mm and the posterior airway space (PAS) is less than 11 mm. OSA may be caused by mandibular deficit, bimaxillary retrusion, increased lower facial height, extended soft palate, a large tongue base, and a posteroinferiorly positioned hyoid bone. Snoring and drowsiness during exercise are symptoms of OSA, which is a risk factor for high blood pressure, heart disease, and stroke, and these can result in car crashes. However, orthognathic surgery can improve dental occlusion and aesthetics by adjusting facial bone position, shape, and size. When bones move, the position and tension of soft tissues change. These novel soft tissue interactions, especially when anteroposterior, change the face's appearance and PAS dimensions. This study uses barium sulfate paste to enhance lateral cephalograms before and after orthognathic surgery to assess posterior pharyngeal airway changes.

MATERIALS AND METHODS

 Barium sulfate was mixed with water to make a paste for the tongue's dorsum. A preoperative digital lateral cephalogram was obtained, and a postoperative evaluation was conducted six weeks after the procedure. In the cephalostat, the Frankfort horizontal and median planes were aligned parallel to the floor, and a radiograph was taken after the breathing cycle to standardize the hyoid bone location. Preoperative lateral cephalogram analysis using Burstone's hard tissue landmarks confirmed skeletal class II or III deformities. First, the narrowest part of the posterior pharyngeal airway was measured. Second, the narrowest portion between the soft palate and posterior pharyngeal wall parallel to the Frankfort horizontal plane was measured preoperatively, and the procedure was repeated six weeks postop.

RESULTS

 Complexity characterizes the pharyngeal airway, which, along with the surrounding structures, facilitates the bodily functions of eating, talking, and breathing. The pharyngeal airway is located behind the nose, mouth, and larynx, and adjusting the jaws changes the size and structure of the pharyngeal airway and surrounding soft tissues, which may affect breathing. A statistically significant change is detected in the posterior palatal and posterior lingual airways after different orthognathic operations. After the mandible is moved forward, both the posterior palatal and posterior lingual airways enlarge. Furthermore, the soft palate exhibits slight decreases in length, thickness, and angle. Additionally, there is an anterosuperior displacement of the hyoid bone. Following maxillary superior impaction, mandibular autorotation is seen in a counterclockwise direction, which has the same result as that of mandibular advancement.

CONCLUSION

 It is essential to consider these soft tissue changes when planning orthognathic procedures, as alterations in the pharyngeal airway may impact the patient's postoperative breathing and overall health. Patients with OSA or those at risk of developing it should be closely evaluated and managed appropriately during the surgical planning process.

Craniofacial Phenotype in Obstructive Sleep Apnea and Its Impact on Positive Airway Pressure (PAP) Adherence

Positive airway pressure (PAP) is an important treatment tool for patients with moderate and severe obstructive sleep apnea (OSA), and adherence to PAP significantly affects treatment outcomes. Disease severity, adverse effects, and psychosocial factors are known to predict medication adherence. Cephalometric parameters have been reported to positively correlate with upper airway collapse. However, research on the correlation between these cephalometric parameters and PAP adherence remains insufficient. This study aimed to identify this relationship. This study included 185 patients with OSA who were prescribed PAP. Polysomnography (PSG) was performed to diagnose OSA, and paranasal sinus computed tomography (PNS CT) was performed to check for comorbidities of the upper airway. In addition, cephalometric parameters such as the hyoid-posterior nasal spine (H-PNS), posterior nasal spine-mandibular plane (PNS-MP), and hyoid-mandibular plane (H-MP) were measured in the midsagittal and axial CT views. Adherence was evaluated 3-12 months after the PAP prescription. A total of 136 patients were PAP-adherent, and 49 were nonadherent. There were more males in the adherent group and a higher average height in the adherent group. The PSG results showed that the apnea-hypopnea index (AHI), respiratory disturbance index (RDI), oxygen desaturation index (ODI), arousal index (AI), rapid eye movement (REM) AHI, and supine AHI were significantly higher, and the lowest oxygen saturation was lower in the adherent group. In the analysis of covariance (ANCOVA) model adjusted for sex and height, among the cephalometric parameters, H-MP was significantly longer in the adherent group (p = 0.027), and H-PNS showed a longer tendency (p = 0.074). In the logistic regression analysis model, the odds ratio (OR) and 95% confidence intervals (95% CI) of adherence and severe OSA in the third tertile compared to the first tertile of H-MP were 2.93 (1.25-6.86) and 4.00 (1.87-8.56). In the case of H-PNS, they were 2.58 (1.14-5.81) and 4.86 (2.24-10.54), respectively. This study concluded that an inferiorly placed hyoid bone in adult patients is associated with PAP adherence and disease severity.

Quantitative approach to analyze hyoid bone movement during swallowing by ultrasound: an integrative review

PURPOSE

To synthesize the scientific knowledge on which measurements of hyoid bone movement during swallowing are obtained by ultrasonography and how to extract these measures.

RESEARCH STRATEGIES

The PECO question and combinations of descriptors and keywords were formulated in the electronic databases Medline/PubMed, EMBASE, Web of Science, Scopus and Lilacs.

SELECTION CRITERIA

Articles that used ultrasonography to analyze measurements of hyoid bone movement during swallowing were included, regardless of language, year of publication, or presence of deglutition disorders.

DATA ANALYSIS

The included articles were analyzed for: year, study site, study design, population, sample size, equipment used, transducer positioning, measurements obtained, method of extraction, and reliability of measurements.

RESULTS

Twenty-six articles met the eligibility criteria. The most frequent measurement was hyoid movement maximum amplitude, followed by time and velocity. There was great variability in the study population, equipment used, positioning of the transducer and method of extraction of the measurements. Thus, it was not possible to find a standard model to extract the measures. The level of reliability was investigated in only eight articles.

CONCLUSION

Amplitude, time and velocity are the measures of hyoid bone movement during swallowing that can be obtained by ultrasonography. There is no standardization on how to extract these measurements.

[Internal carotid artery stenosis with repeated ischemic stroke recurrence due to mechanical stimulation by the hyoid bone and thyroid cartilage: a case report]

We present a case of internal carotid artery (ICA) stenosis caused by mechanical stimulation by the hyoid bone (HB) and thyroid cartilage (TC). A 78-year-old man with a history of right ICA stenting four years previously was admitted for abrupt onset of dysarthria and left hemiparesis and diagnosed with ischemic stroke by magnetic resonance imaging. Three-dimensional computed tomographic angiography revealed internal carotid in-stent restenosis. Furthermore, the HB and TC contacted with the right ICA. Treatment involved antiplatelet therapy, partial HB and TC resection, and carotid artery restenting. Posttreatmently, the ICA was restored and stenosis improved. Since restenosis may occur posttreatmently in patients with carotid artery stenosis caused by mechanical stimulation of the HB and TC, it is necessary to consider treatments including not only carotid artery stenting but also partial bone structures resection and carotid endarterectomy.

A meta-analytic review of the frequency and patterning of laryngohyoid and cervical fractures in cases of suicide by hanging

The frequency and distribution of fractures are commonly utilized to assist in interpreting the manner of death. In cases of alleged suicide by hanging, however, the evidence base for the frequency and patterning of laryngohyoid and cervical vertebrae fractures resulting from such blunt force traumatic events is limited and so fractures cannot be reliably used to assist in interpreting the manner. Using meta-analytic techniques, this study aimed to estimate frequency and distribution of fractures in the context of relevant intrinsic and extrinsic variables. A systematic review of the literature identified 20 studies with relevant data (8523 cases of suicide by hanging). Meta-analyses identified the frequency and distribution of fractures present and how fracture frequency was affected by the subgroups of age, sex, completeness of suspension, ligature knot position and study design. Results indicated that fracture frequency was variable, there was no unique patterning, and high levels of heterogeneity were present in all variable sub-groups. Age was the only subgroup to show differences. Findings suggest that neck fracture frequency is inconsistent and cannot be predicted by the chosen variables. Subsequently, neck fractures in isolation should not be given weight in medico-legal interpretations of a hanging death as suicidal.

Vertical Levels of the Occipital Artery Origin

Background and Objectives. The occipital artery (OA) is a posterior branch of the external carotid artery (ECA). The origin of the OA is commonly referred to a single landmark. We hypothesized that the origin of the OA could be variable as referred to the hyoid bone and the gonial angle. We thus aimed at patterning the vertical topographic possibilities of the OA origin. Materials and Methods. One hundred archived computed tomography angiograms were randomly selected, inclusion and exclusion criteria were applied, and 90 files were kept (53 males, 37 females). The cases were documented bilaterally for different levels of origin of the OA origin: type 1-infrahyoid; type 2-hyoid; 3-infragonial; 4-gonial; 5-supragonial; 6-origin from the internal carotid artery (ICA). Results. The incidence of unilateral types in the 180 OAs was: type 1-1.11%, type 2-5.56%, type 3-40.56%, type 4-28.33%, type 5-23.33% and type 6, ICA origin of the OA-1.11%. There was found a significant association between the location of the left and right origins of the OAs (Pearson Chi2 = 59.18, p < 0.001), which suggests the presence of a strong symmetry of the origins. Bilateral symmetry of the vertical types of the OA origin was observed in 56.67% of cases; in 43.33% there was bilateral asymmetry. Conclusions. The ICA origin of the OA is an extremely rare variant. For surgical planning or prior to endovascular approaches the topography of the OA origin should be carefully documented, as it may be located from an infrahyoid to a supragonial level.

Ultrasound Guided Measurement of Anterior Neck Tissue for the Prediction of Difficult Airway: A Prospective Observational Study

Objectives

To determine that ultrasound (US) measurements of anterior neck soft tissue thickness at hyoid bone, thyrohyoid membrane, and anterior commissure levels can be used to predict difficult laryngoscopy.

Materials & Methods

The present study included 100 patients of age group 18-60 years undergoing elective surgery under general anaesthesia. It was a prospective observational study which included patients with ASA physical status I and II. Excluded patients were with facial and neck deformities, neck trauma, or those undergoing surgery of the larynx, epiglottis and pharynx. Comparison analysis was performed using t-test for continuous variables and chi-square or Fisher exact test for non-continuous variables. Correlation analysis performed using Pearson test.

Results

There were 39 out of 100 patients categorised as difficult laryngoscopy. Thickness at hyoid bone (DSHB), thyrohyoid membrane (DSEM) and anterior commissure (DSAC), MMS (modified Mallampati score), and BMI (body mass index) were greater in the difficult laryngoscopy group (p < 0.001). TMD (thyromental distance) was less in the difficult laryngoscopy group (p < 0.001). There was a strong positive correlation between DSEM and DSAC (r = 0.784). Moderate positive correlation was between DSEM and DSHB (r = 0.559), DSEM and MMS(r=0.437). The area under curve (AUC) of DSHB, DSEM, DSAC, TMD and MMS is >0.7. The optimal cut-off values for DSEM, DSHB, DSAC and TMD were 1.34 cm, 0.98 cm, 1.68 cm and 6.59 cm, respectively, in predicting difficult airway.

Conclusion

Ultrasound measurement of soft tissue thickness at hyoid bone, thyrohyoid membrane, and anterior commissure of vocal cord are good independent predictors for difficult laryngoscopy. When combined with traditional screening tests it improves the ability to predict difficult laryngoscopy.

Topography of the Anatomical Landmarks of Carotid Bifurcation and Clinical Significance

OBJECTIVE

Carotid bifurcation (CB) and its terminal branches are the most common sites of atherosclerotic plaques. In surgical treatment, these plaques can be reached by an endarterectomy technique. The success of the technique can be achieved with good anatomical knowledge of these arteries and their relationships with surrounding structures.

MATERIALS AND METHODS

The study was performed retrospectively on archived images of patients with computed tomography angiography (CTA). Two hundred forty-seven patients who met the criteria were included in this study. Three-dimensional (3D) reconstructions of two-dimensional CTA images were made automatically using the open-source software Horos v.4.0.0. The distance between the transverse plane passing through the bifurcation point (BP) and the defined planes of the surrounding structures was evaluated.

RESULTS

CB was observed below the mastoid process, gonion point, and hyoid bone. CB was observed above the thyroid cartilage. Carotid bifurcation was seen at 15 levels in total, the lowest in the upper 1/3 of the C6 vertebral body and the highest in the lower 1/3 of the C2 vertebral body. In all cases, the most common level was the C3 lower level.

CONCLUSION

All these values, which emerged as a result of the study, provide general information about the topography of the CB according to the neighboring structures. Estimating the location of the CB according to the gonion and hyoid bone will give a more accurate result. The vertebral level on the right side increased in direct proportion to age; there was no similar relationship on the left side. It is necessary to be aware of these anatomical variations in order to prevent various iatrogenic complications.

Changes in hyoid bone and tongue position in Class I subjects after orthodontic treatment with rapid palatal expander

OBJECTIVE

To evaluate the effects of the rapid palatal expander (RPE) on the hyoid bone and tongue position in skeletal Class I patients, compared to control groups.

METHODS

Eighty-four Class I subjects, aged 6-14, were selected. Among these, 28 patients were treated with RPE, 28 with function-generating bite (FGB) appliance, and 28 were untreated. Lateral cephalograms taken before (T0) and after (T1) treatment were retrieved. Changes in the hyoid bone and tongue position were evaluated, and the area above the tongue was measured.

RESULTS

No significant difference in the hyoid and tongue posture was observed across the groups. However, there were significant differences for HC3 (distance from H-point to the third cervical vertebrae), H2H (distance from H-point to SN plane), and TT-Eb (tongue length) between T0 and T1 in all groups.

CONCLUSION

The results suggest that hyoid bone and tongue position changes were related to growth rather than treatment.

Lateral Cephalometric Analytical Uses for Temporomandibular Joint Disorders: The Importance of Cervical Posture and Hyoid Position

The temporomandibular joint disorder (TMD) is a syndrome that affects the masticatory muscles and temporomandibular joint (TMJ). Its pathophysiology is not yet fully known. Cephalometric analysis is used for routine evaluation regarding orthodontic treatment and other purposes. The aim of this study was to assess if using cephalometric analysis and TMJ conservative therapy to evaluate the hyoid bone position and the cervical posture reduced symptoms in adults with TMDs compared to no intervention. The authors conducted a systematic review of the literature (PubMed, Cochrane, Web of Science, Scopus, and Embase) for clinical studies of TMDs with conservative treatment and lateral cephalometric analysis of the hyoid and cervical posture. To assess the risk of bias for non-randomized clinical trials ROBINS-I tool was used. Out of 137 studies found, 6 remained to be included. Most of them found a link between TMD and lateral cephalometric analysis, but there was a high risk of bias. This review found a possible link between TMDs, the neck and cervical posture. There is a benefit reported regarding the use of the lateral cephalometry as a treatment, but more extensive prospective randomized clinical trials are necessary to be able to draw definitive conclusions.

Oral support for patients with severe motor and intellectual disabilities

BACKGROUND

Oral support during feeding was clinically provided to patients with severe motor and intellectual disabilities (SMID) for the prevention of dysphasia. The present study investigated the advantages of oral support anatomically and functionally.

METHODS

A videofluoroscopic swallowing study was conducted on nine patients with SMID (age = 5-41 years; mean age = 15.0; four males, five females) and 24 healthy adults (age = 26-67 years; mean age = 44.3; 16 males, eight females). The movements of the hyoid bone and mandible during pharyngeal swallowing were tracked, and the pharyngeal residues were evaluated. The temporal and spatial features of the movements were compared between patients with and without oral support as well as healthy adults.

RESULTS

The mandible moved downward earlier and showed larger displacement in the patients with SMID. The patients also had insufficient anterior displacement of the hyoid, which was associated with the pharyngeal residue. This displacement was enhanced, and the pharyngeal residue decreased with oral support.

CONCLUSIONS

Oral support to hold the mandible successfully improved hyoid excursion and reduced pharyngeal residue during swallowing, which is a simple and reliable strategy for the prevention of dysphasia in patients with SMID.

Age-related changes in the hyoid bone: An autopsy-based radiological analysis

Forensic age estimation is a crucial aspect of the biological profile of unidentified cadavers. The utility of age-related changes of hyoid bone fusion in forensic age estimation has not been explored much in the past. These age-related changes can be visualised in both the living and the dead using conventional radiography. These changes can assist medico-legal professionals and forensic anthropologists in the identification of unknown deceased, especially when the cadaver is mutilated or charred or when the other well-established indicators of skeletal and dental maturity are absent. The aims of this study were to evaluate age-related changes in the hyoid bone and to ascertain whether these changes may be utilised for age estimation in forensic examinations. The hyoid bone was carefully dissected using a standard procedure from 75 cadavers during post-mortem examination. The hyoid bone was radiographed, and the bone was replaced in the body cavity before the post-mortem examination was completed. Hyoid bone fusion was studied by using a standard grading method. Spearman's correlation coefficient was calculated between the fusion scores and chronological age to assess their relationship. Box and whisker plots of fusion stage-wise age distribution were constructed to demonstrate the gradual linear relationship between hyoid bone fusion and the chronological age of the study participants. The present study concludes that hyoid bone fusion is an indicator of the chronological age of an individual and can be used in conjunction with other methods of age estimation such as the skeletal and dental age.

[Study of morphometric parameters of the hyoid bone]

THE OBJECTIVE OF THE WORK

Is to study the morphological and morphometric variations of the hyoid bone in the population of the Tver region. One hundred adult hyoid bone samples were taken from 63 males and 37 females. Morphological and morphometric variations of the hyoid bone were determined. Six types of hyoid bone were identified: U-shaped - 25 bones (25%); H-shaped - 3 bones (3%); B-shaped - 48 bones (48%); D-shaped - 14 bones (14%); V-shaped - 2 bones (2%); HK-shaped - 8 bones (8%). The width, length, and the largest transverse axis were 42.44; 36.49, and 35.6 mm, respectively. Morphological differences of the hyoid bones of the Tver region population compared to other populations were found. Anatomical variations and dimensions of the hyoid bone are important for practical forensic medicine.

Hyo-Mental Angle and Distance: An Important Adjunct in Airway Assessment of Adult Mucopolysaccharidosis

Background: Mucopolysaccharidosis (MPS) is a rare congenital lysosomal storage disorder with complex airways. High anterior larynx is assessed by thyromental distance (TMD) nasendoscopy. A simpler method to assess this hyoid bone is described. The distance between the central-hyoid and symphysis of the mandible (hyo-mental distance; HMD) and inclination of this line to the horizontal axis (hyo-mental angle; HMA) in neutrally positioned patients is investigated. Methods: HMA, HMD in MPS, and non-MPS were compared, and their correlation with height and weight were assessed. Results: 50 adult MPS patients (M = 32, F = 18, age range = 19–66 years; mean BMI = 26.8 kg/m²) of MPS I, II, III, IV, and VI were compared with 50 non-MPS (M = 25, F = 25; age range = 22–84 years; mean BMI = 26.5 kg/m²). Mean HMA in MPS was 25.72° (−10 to +50) versus 2.42° (−35 to +28) in non-MPS. Mean HMD was 46.5 (25.7–66) millimeters in MPS versus 41.8 (27–60.3) in non-MPS. HMA versus height and weight showed a moderate correlation (r = −0.4, p < 0.05) in MPS and no significant correlation (r < 0.4, p > 0.05) in non-MPS. HMD versus height and weight showed no correlation (r < 0.4, p > 0.05) in both groups. Conclusions: HMA seems more acute in MPS despite nearly the same HMD as non-MPS, signifying a high larynx, which may be missed by TMD.

Jaw-retraction exercise increases anterior hyoid excursion during swallowing in older adults with mild dysphagia

OBJECTIVES

The present study aimed to evaluate the effectiveness of a newly designed jaw-retraction exercise for strengthening the geniohyoid muscle and thus improving the anterior movement of the hyoid bone during swallowing.

BACKGROUND

Although previous studies suggest a relationship between anterior hyoid excursion and upper esophageal sphincter (UES) opening, there are currently no reports of physical exercises without the use of special equipment that can effectively improve this movement of the hyoid bone during swallowing.

MATERIALS AND METHODS

This before-after study included patients presenting to the authors' hospital with mild dysphagia (Level 5 on the Dysphagia Outcome and Severity Scale). The participants were instructed to perform a jaw-retraction exercise designed to strengthen the geniohyoid muscle. Each participant was instructed to perform two sets of the exercise daily for four weeks, with each set consisting of five repetitions. Before and after the four-week training period, videofluoroscopic swallowing studies were performed and later analysed.

RESULTS

Twenty-five patients with a median age of 77 were included. The median peak anterior hyoid position before and after exercise were 129.82 and 132.74 (%C2-C4 length), respectively, and this increase was found to be significant (P = .007). The median extent of UES opening before and after exercise were 8.6 and 9.3 (mm), respectively, and this increase was also found to be significant (P = .040).

CONCLUSION

Our findings demonstrate that the jaw-retraction exercise can effectively improve the anterior movement of the hyoid bone. This exercise may be effective in individuals with oral frailty when signs of swallowing disorders are observed.

Hyoid Elongation May Be a Rare Cause of Recurrent Ischemic Stroke in Youth-A Case Report and Literature Review

The investigation for etiology of ischemic stroke in young adults remains a diagnostic challenge. Hyoid bone–related carotid injury is a rare and under-recognized cause of ischemic stroke, without established guidelines. We describe a case of recurrent ischemic stroke in a young patient presumably attributed to an impingement of the carotid artery by an elongated hyoid bone, and present other cases reported in the literature. Based on the imaging study as well as the lack of other findings, we attributed recurrent neurovascular events to the repetitive mechanical stimulation by the elongated hyoid bone that caused a vessel wall injury with subsequent thrombus and embolus. Given repeated recurrence under antiplatelet treatment, anticoagulation was added. The following 2-year follow-up showed no new neurologic events or any other complaints. Among the young, a broad spectrum of possibilities should be considered and we call attention to this infrequent etiology of ischemic stroke.

The Mandibular and Hyoid Arches-From Molecular Patterning to Shaping Bone and Cartilage

The mandibular and hyoid arches collectively make up the facial skeleton, also known as the viscerocranium. Although all three germ layers come together to assemble the pharyngeal arches, the majority of tissue within viscerocranial skeletal components differentiates from the neural crest. Since nearly one third of all birth defects in humans affect the craniofacial region, it is important to understand how signalling pathways and transcription factors govern the embryogenesis and skeletogenesis of the viscerocranium. This review focuses on mouse and zebrafish models of craniofacial development. We highlight gene regulatory networks directing the patterning and osteochondrogenesis of the mandibular and hyoid arches that are actually conserved among all gnathostomes. The first part of this review describes the anatomy and development of mandibular and hyoid arches in both species. The second part analyses cell signalling and transcription factors that ensure the specificity of individual structures along the anatomical axes. The third part discusses the genes and molecules that control the formation of bone and cartilage within mandibular and hyoid arches and how dysregulation of molecular signalling influences the development of skeletal components of the viscerocranium. In conclusion, we notice that mandibular malformations in humans and mice often co-occur with hyoid malformations and pinpoint the similar molecular machinery controlling the development of mandibular and hyoid arches.

Hyoid Bone Tracking in a Videofluoroscopic Swallowing Study Using a Deep-Learning-Based Segmentation Network

Kinematic analysis of the hyoid bone in a videofluorosopic swallowing study (VFSS) is important for assessing dysphagia. However, calibrating the hyoid bone movement is time-consuming, and its reliability shows wide variation. Computer-assisted analysis has been studied to improve the efficiency and accuracy of hyoid bone identification and tracking, but its performance is limited. In this study, we aimed to design a robust network that can track hyoid bone movement automatically without human intervention. Using 69,389 frames from 197 VFSS files as the data set, a deep learning model for detection and trajectory prediction was constructed and trained by the BiFPN-U-Net(T) network. The present model showed improved performance when compared with the previous models: an area under the curve (AUC) of 0.998 for pixelwise accuracy, an accuracy of object detection of 99.5%, and a Dice similarity of 90.9%. The bounding box detection performance for the hyoid bone and reference objects was superior to that of other models, with a mean average precision of 95.9%. The estimation of the distance of hyoid bone movement also showed higher accuracy. The deep learning model proposed in this study could be used to detect and track the hyoid bone more efficiently and accurately in VFSS analysis.

Automatic Hyoid Bone Tracking in Real-Time Ultrasound Swallowing Videos Using Deep Learning Based and Correlation Filter Based Trackers

(1) Background: Ultrasound provides a radiation-free and portable method for assessing swallowing. Hyoid bone locations and displacements are often used as important indicators for the evaluation of swallowing disorders. However, this requires clinicians to spend a great deal of time reviewing the ultrasound images. (2) Methods: In this study, we applied tracking algorithms based on deep learning and correlation filters to detect hyoid locations in ultrasound videos collected during swallowing. Fifty videos were collected from 10 young, healthy subjects for training, evaluation, and testing of the trackers. (3) Results: The best performing deep learning algorithm, Fully-Convolutional Siamese Networks (SiamFC), proved to have reliable performance in getting accurate hyoid bone locations from each frame of the swallowing ultrasound videos. While having a real-time frame rate (175 fps) when running on an RTX 2060, SiamFC also achieved a precision of 98.9% at the threshold of 10 pixels (3.25 mm) and 80.5% at the threshold of 5 pixels (1.63 mm). The tracker's root-mean-square error and average error were 3.9 pixels (1.27 mm) and 3.3 pixels (1.07 mm), respectively. (4) Conclusions: Our results pave the way for real-time automatic tracking of the hyoid bone in ultrasound videos for swallowing assessment.

Large thyroglossal duct cyst of the neck mimicking cervical cystic lymphangioma in a neonate: a case report

Thyroglossal duct cyst (TGDC) is a congenital neck malformation, with a rate of approximately 7% in paediatric patients. TGDC is rarely detected in infants aged younger than 1 year. Even though TGDC is histologically benign, it is associated with preterm delivery or sudden infant death due to airway obstruction, with a mortality rate of 30% to 40%. We report a rare case of a neonate who presented with a large left lateral neck mass. At 7 to 8 months of gestation, magnetic resonance imaging of the foetal neck showed that there was a high possibility of a cervical cystic lymphangioma. The patient had normal vital signs and was afebrile. She was immediately transferred to our Ear, Nose, and Throat Department for further diagnosis and treatment. A computed tomography scan confirmed a large cystic mass that was positioned against a thyroglossal duct. Excision of the mass in the left neck was performed under general anaesthesia without resecting part of the hyoid bone. A histopathological examination confirmed the diagnosis of a TGDC. Follow-up at 1 year showed no recurrence.

Cephalometric evaluation of hyoid bone position in subjects with different vertical dental patterns

Objective

This study investigated the relationship between hyoid position and vertical dental dimensions (overbite), and the influence of gender on the location of this bone.

Methods

One hundred and seventy-four standardized lateral cephalometric radiographs were randomly selected from a pool of radiographs of patients seeking orthodontic treatment with ages ranging from 10 to 58 years. The subjects were divided into three groups according to their vertical dental dimensions (overbite) into reduced, normal, and increased overbite groups. The hyoid bone position was determined by four horizontal linear and three vertical linear line measurements. Associations between the position of the bone and different vertical dental patterns were analyzed using ANOVA and Tukey's multiple comparison analysis.

Results

There was a progressive increase in the horizontal linear position of the hyoid bone parameters across the groups from the reduced through normal to increase overbite. Similarly, a statistical reduction in the vertical linear positions of the hyoid bone parameters was found across the groups from reduced overbite through normal overbite to increased overbite (P < 0.05). The vertical linear hyoid bone positions were located higher in the male than in female subjects. Tukey's multiple comparison analysis showed a highly statistically significant difference in the vertical linear hyoid bone positions between reduced and normal overbite groups and between reduced and increased overbite groups.

Conclusion

The hyoid bone was positioned more antero-inferiorly and more postero-superiorly in subjects with reduced overbite and increased overbite, respectively.

Growth and sexual dimorphism of the hyoid bone and its relationship to the mandible from birth to 19 years: A three-dimensional computed tomography study

The hyoid bone and the hyomandibular complex subserve the functions of respiration, deglutition, and speech. This study quantified the growth of the hyoid bone and the hyomandibular relationships in males and females from birth to 19 years. Using 97 computed tomography (CT) scans, from a previous study (Kelly et al., 2017) on mandibular growth from 49 individuals (16 with longitudinal scans), landmarks were placed on 3D CT models and used to calculate four distance, and three angular measurements. A general increase in growth trend was observed in hyoid bone linear measurements-length, width, and depth-as well as relational mandible-to-hyoid distance, throughout the developmental ages examined in both males and females, with most variables having larger measurements for females up to age 10 years. A general decrease in all three angular measurements was observed in both males and females up to approximately age 12 years, at which time male angular measurements gradually increased with significant sexual dimorphism emerging after age 15 years. As expected, postpubertal males had greater hyoid angle than females; they also had greater hyoid angle of inclination than mandible body inclination (with inclination relative to the anterior-posterior nasal plane), likely related to hyo-laryngeal descent. This study contributes to normative data on hyoid bone and hyomandibular relational growth in typically developing individuals and provides a baseline against which structural and functional influences on anatomic growth may be examined by clinical disciplines that address the aerodigestive and speech functions, as well as the fields of anatomy, forensics, and anthropology.

Melanoma metastatic to the hyoid bone

Metastatic melanoma may be included in the differential diagnosis of hyoid masses in patients with a history of melanoma. Hyoid resection is well tolerated and of diagnostic and therapeutic benefit in patients with tumors metastatic to the hyoid bone.

Changes in the upper airway, hyoid bone and craniofacial morphology between patients treated with headgear activator and Herbst appliance: A retrospective study on lateral cephalometry

Background

The present study compared the treatment changes in the upper airway, hyoid bone position and craniofacial morphology between two groups of children with skeletal class II malocclusion treated with the headgear activator (HGA) and Herbst appliance (Herbst).

Setting and sample population

Orthodontic population from the Faculty of Dentistry of the University of Hong Kong.

Methods

Thirty‐four skeletal class II patients treated with the HGA (17 patients, mean age 10.6 ± 1.5 years) and the Herbst (17 patients, mean age 11.0 ± 1.4 years) were matched for sex, age, overjet, skeletal class and mandibular divergence. The patients received lateral cephalometric radiographs (LCRs) at the beginning of treatment (T₁), after treatment (T₂) and at follow‐up (T₃). In the HGA group, patients underwent LCRs 7 months before the beginning of treatment (T₀), which were used as growth reference for intra‐group comparison. Paired Student's t tests were used for intra‐ and inter‐group comparisons (α = .05).

Results

Treatment changes (T₂‐T₁) did not differ significantly between the groups. However, at follow‐up (T₃‐T₁) the Herbst group showed a smaller increase than the HGA group in the vertical position of the hyoid bone relative to the Frankfort plane (P = .013) and mandibular plane (P = .013).

Conclusions

There were no significant differences in the upper airway, hyoid bone position and craniofacial morphology between the groups at the end of treatment. However, the Herbst may provide better long‐term control of the vertical position of the hyoid bone than the HGA in children with skeletal class II malocclusion.

Microstructure of the hyoid bone based on micro-computed tomography findings

In this study, micro-CT was used to observe the microscopic anatomy of the hyoid bone, examine the variation of the trabecular bone inside the hyoid bone, and investigate the internal structure of the hyoid bone.A total of 22 hyoid bones were scanned using micro-CT. The changes in the internal bone trabeculae were assessed with 3D reconstructions, and the fine anatomical structure of the hyoid bone was further analyzed.Micro-CT images showed the microstructure of various parts of the hyoid bone. There were significant differences in total volume, bone volume, bone area, bone density, and volume fraction between the body and greater horns of the hyoid bone (P < .05), but no significant differences in the ratio of bone area/volume and bone surface density were found between the body and greater horns of the hyoid bone (P > .05). In addition, significant differences in the trabecular bone measurements, bone trabecular connectivity, and Euler number were found between the body and greater horns of the hyoid bone (P < .05). Other parameters, including bone trabecular thickness, number of trabecular bones, bone trabecular structure model index, and anisotropy of bone trabeculae, did not differ between the body and greater horns of the hyoid bone (P > .05). There was noticeably ossified healing at the joint between the body and greater horns of the hyoid bone.Micro-CT can adequately display the internal structure of the hyoid bone. The identified bone structure may help clarify the physiological function of the hyoid bone. The present findings provide a theoretical basis for further studies aimed at pathological changes due to hyoid injury in clinical and forensic medicine.

Effects of resistive jaw opening exercise in stroke patients with dysphagia: A double- blind, randomized controlled study

BACKGROUND

The resistive jaw opening exercise (RJOE) was suggested as a potential remedial treatment for patients with dysphagia. However, clinical evidence is insufficient.

OBJECTIVE

To investigate the effect of RJOE on hyoid bone movement, aspiration, and oral intake level in stroke patients with dysphagia.

METHODS

Forty stroke patients with dysphagia were randomly allocated into either the experimental group (n= 20) or placebo group (n= 20). The experimental group performed RJOE using a portable device, while the placebo group performed RJOE using a sham device with fewer loads. Intervention was conducted 5 times a week for 4 weeks. Hyoid bone movement was analyzed by two-dimensional analysis of anterior and superior motion based on a videofluoroscopic swallowing study. Aspiration was assessed using a penetration-aspiration scale (PAS), and oral intake level was assessed using the functional oral intake scale (FOIS).

RESULTS

Both groups showed statistically significant differences in hyoid movement, PAS, and FOIS scale (p< 0.05). However, after the intervention, there was no significant difference between the two groups except for the liquid type of PAS. Effect sizes (Cohen's d) were 0.9 and 0.7, 0.6 and 0.6, and 1.1 for the anterior and superior movement of the hyoid bone, semisolid and liquid type of PAS, and FOIS scale respectively.

CONCLUSIONS

This study suggests that RJOE helps in hyoid movement, aspiration reduction, and oral intake in patients with dysphagia after stroke.

Comparison of 2 types of therapeutic exercise: jaw opening exercise and head lift exercise for dysphagic stroke: A pilot study

The aim of this study was to investigate the effect of the jaw opening exercise (JOE) on the thickness of the suprahyoid muscle and hyoid bone movement compared with the head lift exercise (HLE) in patients with dysphagia after strokeThis study recruited 30 patients with dysphagia after stroke. The JOE group performed a JOE using a resistance bar. The HLE group performed the traditional HLE. The total intervention duration was 6 weeks. We measured the thickness of the digastric and mylohyoid muscles using ultrasound. Two-dimensional motion analysis of the hyoid bone was performed using Image J software. The Borg rating of the perceived exertion scale was used to assess the intensity level of physical activity during the 2 exercises.Both groups showed a significant increase in the thickness of the digastric and mylohyoid muscles (P < .05). Hyoid bone motion was significantly increased in the anterior and superior movement in both groups (P < .05). After the intervention, there was no significant difference between the 2 groups. The Borg rating of perceived exertion scale for the JOE group was significantly lower than that of the HLE group (P < .05).In conclusion, this study demonstrated that the JOE and the HLE had similar effects with respect to increasing suprahyoid muscle thickness and improving hyoid bone movement. However, the JOE required less perceived exertion than the HLE.

[Analysis of 54 cases of thyroglossal duct cyst resection with hyoid bone preservation]

Objective:To investigate the efficacy, complications and recurrence rate of thyroglossal duct cyst resection with hyoid preservation in children. Method:Fifty-four children with thyroglossal duct cyst underwent cervical color Doppler ultrasound, CT and/or MRI before operation to make a definite diagnosis.Hyoid-preserving thyroglossal cyst resection was performed in all children.In 51 cases, the cyst wall was close to the hyoid bone, and the thin layer of the hyoid bone surface was removed, while the other 3 cases had no definite association with hyoid bone, only cysts and branches were resected.In the cases where the cyst was close to the hyoid bone, fistula tissue was found in the suprahyoid muscle group in 4 cases, which were carefully separated and excised. Result:All patients had no complications after operation, and the incision healed in the first stage. Postoperative pathology: 51 cases were thyroglossal duct cysts and 3 cases were epidermoid cysts.Follow-up for 1 years to 3 years showed that only 1 case had recurrence（2.0%,1/51）. Conclusion:Postoperative recurrence of thyroid hyoid cysts does not depend on whether the hyoid bone is removed, but on the residue of its branches.The significance of hyoid bone preservation is to narrow the scope of operation, reduce trauma and complications, and avoid the impact of hyoid bone loss on vocal and swallowing function.

Evaluation of pharyngeal airway dimensions and hyoid bone position according to craniofacial growth pattern

OBJECTIVE

To compare pharyngeal airway dimensions and hyoid bone position in different craniofacial growth patterns.

METHODS

In total, 611 patients divided into 9 subgroups were compared according to malocclusion classification and vertical growth pattern, and these subgroups were compared in terms of pharyngeal airway and hyoid measurements. A two-way ANOVA test was used to compare the findings of the subgroups.

RESULTS

No significant difference was found for the pharyngeal measurements between the groups (p>0.05). The vertical airway length (PNS-Ep) was significantly shorter in the Class III malocclusion group (p<0.05) and in the hypodivergent group (p<0.05). No statistically significant difference was found between any subgroups in any measurements of the position of the hyoid bone (p>0.05).

CONCLUSION

The pharyngeal airway dimensions and hyoid bone position are similar among individuals in the sagittal direction. The vertical airway length is significantly shorter in Class III and hypodivergent individuals.

Simple bone cyst of the hyoid: A radiological diagnosis and follow-up

Simple bone cyst (SBC), also known as unicameral bone cyst, is a benign, fluid-filled cystic lesion that mainly appears in the long bones of young patients. Simple bone cysts are considered dysplastic or reactive lesions of bone. The most common locations for SBCs are the proximal humerus and femur. Lesions may occasionally be found in the jawbones. Simple bone cysts often have no clinical impact and are usually detected during routine radiographic examinations unless a gross pathologic fracture occurs. When symptoms develop, they may include mild pain, local tenderness and swelling. Computed tomography (CT) scans demonstrate a central, well-defined, mildly expansile or non-expansile, thin-walled lytic lesion, with little or no marginal sclerosis. Magnetic resonance imaging (MRI) usually confirms the cystic nature of the lesion by showing its fluid content. Cystic masses in the hyoid bone are very rare. Here we report an asymptomatic SBC in the hyoid bone, incidentally discovered in a cone-beam computed tomography (CBCT) examination, which appears to be the 2nd reported case.

Hyoid Bone Metastasis in Patients With Lung Adenocarcinoma: A Case Report

OBJECTIVE

Hyoid bone metastasis from lung adenocarcinoma is exceedingly rare. This study aims to provide an experience to clinicians in the differential diagnosis of hyoid tumors and discusses its possible source.

METHODS AND RESULTS

We report a 68-year-old male patient having hyoid bone metastasis from lung adenocarcinoma. The initial symptom of the hyoid bone metastasis was neck pain exacerbated by swallowing. The hyoid bone mass was resected based on comprehensive analysis including whole-body bone imaging and pathologic analysis of the hyoid bone mass. The adenocarcinoma of hyoid was identified as a metastatic lesion of lung adenocarcinoma. The patient recovered well and the anterior cervical pain was significantly alleviated after surgery and the patient underwent corresponding chemotherapy.

CONCLUSION

In patients with hyoid metastasis of lung adenocarcinoma, surgical resection may reduce the pain in anterior cervical after full consideration of physical condition.

Effect of suprahyoid muscles on mouth opening with and without lateral pterygoid muscle: 3D inverse dynamic model analysis

Objective: To evaluate the contribution of suprahyoid muscles to mouth opening in different hyoid bone positions.Methods: The jaw-opening and closing movements were imposed on the 3D inverse dynamic jaw model with and without the lateral pterygoid muscle (LPM). The activation of the muscles was evaluated for eight different positions of the hyoid bone.Results: The muscles with 100% activation provided maximum mouth opening (MMO). When the hyoid bone was replaced, the muscles could achieve MMO at the 135º, 180º, and 225º points with the LPM. Mouth opening was estimated to be 36.8 mm in the absence of the LPM. A jaw opening greater than 36.8 mm was seen when the hyoid bone was repositioned at the 90º, 180º, and 135º points.Discussion: The contribution of suprahyoid muscles to mouth opening varies in different hyoid bone positions, with the inferior and anterior positions having a positive impact.

Dynamic Internal Jugular Vein Compression by Hypertrophic Hyoid Bone: Management and Outcomes

Extracranial osseous compression of the internal jugular vein (IJV) is exceedingly rare. The clinical manifestations of IJV obstruction are very heterogeneous and subtle, and arriving at a diagnosis can be challenging. We describe a case of dynamic IJV compression in a 40-year-old male with progressive, positional, ill-defined right periorbital and neck pain associated with photosensitivity. Imaging showed a hypertrophic right hyoid bone; computed tomography venogram (CTV) with challenging maneuvers demonstrated dynamic compression of the ipsilateral IJV by a hypertrophied hyoid bone and thyroid cartilage. The patient underwent decompression of the right jugular vein which resulted in the resolution of his symptoms. The clinical manifestations of extracranial IJV impingement are variable and diagnostically challenging. Disturbances in extracranial IJV outflow is a diagnosis of exclusion and could be responsible for atypical facial pain in a select group of patients. This entity should be considered in the differential of atypical facial, especially when symptoms tend to be positional.

Asymmetry of the Accessory Anterior Digastric Muscle Bellies: The Clinical Significance in Facial and Neck Surgery

The anterior digastric muscle belly (ADMB) may present significant variations of substantial surgical importance. We present an unusual complex bilateral asymmetry of an accessory ADMB found when dissecting the submental area in a 72-year-old Greek male cadaver. A rare variant was recognized in the submental area constituted by a combination of bilateral asymmetry of the ADMB with unilateral absence of the intermediate tendon. The complex variant caused an obvious morphological asymmetry in the submental area. Such muscular variations may alter the surgical approach to the submental region. Clinicians involved in the treatment of this area should be aware of any possible variant, particularly when dealing with neck mass patients.

Evaluation of the change in the tongue posture and in the hyoid bone position after Twin Block appliance therapy in skeletal class II subjects

BACKGROUND

The tongue is posteriorly postured in a retrognathic mandible, and Twin Block appliance (TBA) therapy places the tongue and the hyoid bone in a favorable position to eliminate the risk of causing respiratory obstruction.

OBJECTIVES

The aim of this study was to evaluate the change in the tongue posture and in the hyoid bone position after TBA therapy.

MATERIAL AND METHODS

This cross-sectional study was conducted using the pre-functional (PF1), postfunctional (PF2) and post-treatment (PT) cephalograms of 30 growing subjects. The tongue posture at 6 distances and the hyoid bone position with 4 parameters were digitally measured using the Rogan-Delft View Pro-X® software. A digital vernier caliper was used to determine the inter-canine and inter-molar widths on the dental casts. The Wilcoxon signed-rank test was used to compare the PF1 and PF2 values, and the PF1 and PT values.

RESULTS

The comparison of the PF1 and PF2 values showed significant differences in the tongue posture at distances 1-5. In the case of the hyoid bone, only the linear distance from the sella (S) to the most anterior point on the hyoid bone (H) - the SH distance - revealed a significant difference (p < 0.01). The change in the tongue posture and in the hyoid bone position achieved at the PF2 stage remained stable at the PT stage. Significant differences occurred in the PF1 and PF2 maxillary and mandibular inter-canine and inter-molar widths (p = 0.01 and p = 0.04, and p < 0.01 and p = 0.02), respectively.

CONCLUSIONS

Twin Block appliance therapy resulted in the advancement of the mandible with a lowered posturing of the tongue. The hyoid bone was displaced inferiorly after TBA therapy, whereas the angular position of the hyoid bone remained unchanged.

Relations between mandible-only advancement surgery, the extent of the posterior airway space, and the position of the hyoid bone in Class II patients: a three-dimensional analysis

The objective of the present study was to evaluate the relation between mandibular advancement, the three-dimensional extent of the posterior airway space (PAS), and the position of the hyoid bone, using cone-beam computed tomography (CT). Twenty-eight Class II patients (21 women (mean (SD) age 29 (9) years) and seven men (mean (SD) age 23 (6) years)), who had had mandibular-only advancement surgery (Obwegeser-Dal Pont) were included in the study. In each case, cone-beam CT scans were taken one week before and six months after operation, and a retrospective analysis made of the alterations of several airway variables (volume, mean cross-sectional area, and diameter) and the three-dimensional extent of mandibular and hyoid movement, by using IPlan® cranial software. A linear regression was also done to correlate mandibular advancement, the movement of the hyoid bone, and airway variables. There were significant postoperative increases in all volumetric PAS variables, and in most diametric and spherical variables (p<0.05). There was also a significant linear relation between forward displacement of the mandible and the movement of the hyoid bone (p<0.05). These results show that mandible-only advancement surgery causes an increase in most dimensions of the PAS. This intervention can be assumed to reduce airway resistance and therefore might be a suitable treatment option for patients with obstructive sleep apnoea syndrome.

Thyroid cartilage loci and hyoid bone analysis using a video fluoroscopic swallowing study (VFSS)

INTRODUCTION

Hyoid bone movement can be useful for diagnosing oropharyngeal dysphagia. In most clinical settings, the movement can be evaluated by a video fluoroscopic swallowing study (VFSS) that induces radiation exposure. In contrast with the hyoid bone, the thyroid cartilage is easily seen through the anterior neck surface. We hypothesized that the movement of thyroid cartilage correlates with hyoid bone movement in various axis and can be used as a parameter to evaluate swallowing. The purpose of this study was to investigate whether thyroid cartilage and hyoid bone movement were correlated and to collect basic data to determine if thyroid cartilage can be used as a parameter to evaluate swallowing.

METHODS

A total of 25 subjects were included, and the VFSS image with normal swallowing function was collected retrospectively. The VFSS image was analyzed by specially developed semi-automatic software. Laryngeal prominence and anterior-superior margins of the hyoid were automatically extracted during swallowing. Two-point sets of the loci during swallowing were obtained in all VFSS frames. The X-coordinates showed an anterior-posterior axis, and the Y-coordinates showed a superior-inferior axis. Pearson correlation coefficients for each X- and Y-coordinate component were computed.

RESULTS

X- and Y-coordinates of the thyroid cartilage and hyoid bones in all subjects showed movement in similar patterns, although each subject's movement differed. Pearson correlation coefficients of X- and Y-coordinate components of all subjects ranged from 0.611 to 0.981, which indicated that thyroid cartilage and hyoid bone movement was strongly correlated in anterior-posterior and superior-inferior axes, respectively.

CONCLUSION

We analyzed thyroid cartilage and hyoid bone movement using a specifically developed semi-automatic software and concluded that the movement of thyroid cartilage and hyoid bone was strongly correlated in anterior-posterior and superior-inferior axes, respectively, during swallowing. The present study implies that analysis of thyroid cartilage movement can be used as a parameter for swallowing evaluation.

Temporal characteristics of laryngeal penetration and aspiration in stroke patients

BACKGROUND

Despite the importance of understanding penetration-aspiration (PA) in patients with stroke, the pathophysiology of PA remains unclear.

OBJECTIVES

This study aimed to investigate the temporal characteristics of PA in post-stroke patients in terms of the timing of the PA event and hyolaryngeal incoordination.

METHODS

Fifty-eight swallows (38 stroke patients), showing PA when swallowing a thin liquid, were included. The timing of PA was classified kinematically as before or during the swallow. The movement sequence of vertical laryngeal elevation, horizontal hyoid excursion, and epiglottic rotation were compared with healthy controls. Spatiotemporal measurements, videofluoroscopic dysphagia scale parameters were compared between subgroups.

RESULTS

Thirteen swallows (22.4%) were classified as PA before the swallow and 45 were classified as PA during the swallow (77.6%). Among the PA during the swallow, 26 (57.8%) swallows exhibited abnormal sequences of hyolaryngeal movements and 19 (42.2%) swallows showed normal sequences of hyolaryngeal movements compared with healthy controls. The onset time of horizontal hyoid excursion (P = 0.028), the time to maximal horizontal hyoid excursion (P = 0.010), and maximal epiglottic rotation (P = 0.030) were significantly more delayed in the PA during the swallow group than in the PA before the swallow group. In the swallows with abnormal sequential movements, the onset of horizontal hyoid excursion occurred significantly later than the onset of epiglottic rotation (P < 0.001). Pyriform sinus residue was observed significantly more often in the swallows with abnormal sequences (P = 0.030) than in the swallows with normal sequences.

CONCLUSIONS

The timing of PA can be classified as before and during the swallow with significantly different temporal characteristics. The horizontal movement of hyoid is the most important factor associated with the pathophysiology of PA in stroke patients.

Anterior cervical pain syndrome: Risk factors, variations in hyolaryngeal anatomy, and treatments

OBJECTIVE

Anterior cervical pain syndromes (ACPS) are a poorly understood entity associated with lateral neck discomfort when talking, chewing, or yawning, and with occasional excruciating pain and dysphagia. This investigation aims to describe patients with ACPS presenting symptoms and treatments.

STUDY DESIGN

Retrospective chart review of all patients with ACPS presenting to a tertiary care laryngology practice in 1 year.

METHODS

All patients diagnosed with ACPS for 1 year were reviewed. Patient gender, age, body mass index (BMI), and pain triggers were documented. The hyolaryngeal complex was measured on computed tomography (CT) scans of the neck. Treatments were recorded.

RESULTS

Nine patients were diagnosed with an ACPS in a 1-year period. Sixty-seven percent were female with an average age of 47.3 years ± 16.6. The average BMI of a patient with ACPS was 24.8 ± 3.69. The most common symptom was point tenderness at the lateral aspect of the hyoid or superior cornu of the thyroid cartilage (89%). Pain triggers included speaking (67%), head turn (56%), chewing (44%), yawning (56%), and swallowing (56%). On CT imaging, eight of nine patients had abnormalities of the hyoid bone or the superior cornu of the thyroid cartilage, correlating 100% with point tenderness location. Treatments include physical therapy (33%), steroid injection (44%), lidocaine injection (22%), and surgical intervention (56%).

CONCLUSION

ACPS is a frustrating condition for patients and physicians. Evaluation of anterior cervical pain with point tenderness should include imaging measurement of the thyrohyoid complex. Effective treatments include local steroid injection and surgical resection of the abnormal structure.

LEVEL OF EVIDENCE

4 Laryngoscope, 130:702-705, 2020.

Changes in position of the hyoid bone and volume of the pharyngeal airway after mandibular setback: three-dimensional analysis

Important aspects of orthognathic surgery are the effects of skeletal movement and changes in the position of the hyoid bone, tongue, soft palate, and dimensions of the pharyngeal airway. Our aims were to evaluate the 3-dimensional changes in the pharyngeal airway and in the position of the hyoid bone after mandibular setback in 30 patients who were diagnosed with mandibular prognathism and were treated by intraoral vertical ramus osteotomy (IVRO). Three-dimensional cone-beam computed tomographic (CT) images were obtained preoperatively, one month postoperatively, and one year postoperatively. The total pharyngeal volume decreased between the preoperative state and one month and one year afterwards. The hyoid bone had moved 2.0mm posteriorly and 3.15mm superiorly by one month postoperatively. The position of the hyoid bone was affected by changes in posterior and superior movement of the B point at one month (r=0.44, p=0.015 and R=0.63, p=0.000, respectively) and also by superior movement of the B point at one year (r=0.57, p=-0.001). There was an advantageous relation between posterior positional changes in the B point (mandibular setback), and volumetric changes in the hypopharyngeal and total pharyngeal airway, so maxillofacial surgeons should consider the reduction in airway when planning excessive mandibular setback.

Comparison of hyoid bone positions and pharyngeal airway dimensions in different body mass index percentile adolescent subjects

OBJECTIVE

Increased body mass index (BMI) is a growing problem worldwide and can affect medical conditions through morphological structures. The purpose of this study was to examine the hyoid bone position and pharyngeal airway dimensions on the sagittal section in different BMI percentile adolescent subjects.

METHODS

Fifty-five adolescent patients were subdivided into three groups, considering their BMI percentiles: Normal-weight (16 subjects), overweight (20 subjects), and obese (19 subjects). A total of 13 linear and angular parameters of head posture angle, pharyngeal airway dimensions, and hyoid bone positions were investigated on 55 lateral cephalometric radiographs.

RESULTS

Except for one hyoid bone measurement (RGN-H), there was no significant difference among groups. The RGN-H distances of obese and overweight adolescent subjects were higher than normal-weight adolescent subjects.

CONCLUSION

Obese, overweight, and normal-weight adolescent subjects were likely to have similar hyoid bone position and pharyngeal airway dimensions.

Sonographic assessment of swallowing in irradiated nasopharyngeal carcinoma patients

Objectives/Hypothesis

Ultrasonography is an emerging clinical tool to study the dysfunction of swallowing muscles. This was the first sonographic study to assess the relationship between suprahyoid muscle contraction, hyoid bone displacement, and penetration‐aspiration status (PAS) during swallowing in nasopharyngeal carcinoma (NPC) patients treated with radiotherapy (RT). The study also aimed to establish reliability data for the sonographic technique described.

Study Design

Cross‐sectional study.

Methods

Geniohyoid muscle contraction was quantified using brightness‐mode ultrasonography in this study of 40 post‐RT NPC patients. A series of physiological parameters and PAS were measured using videofluoroscopy.

Results

Intra‐ and inter‐rater agreement values ranged from 0.75 to 0.96 across various sonographic measurements. Percentage increase in the cross‐sectional area of the geniohyoid muscle correlated with anterior (r = 0.42, P < .05) but not superior (r = 0.27, P = .09) hyoid displacement. Anterior hyoid displacement and pharyngeal constriction ratio were significantly associated with PAS score.

Conclusions

Sonographic measurement of suprahyoid muscles provides valuable information on muscle function and is potentially a useful clinical tool in swallowing assessment. Further research is needed to refine the role of this examination in dysphagia.

Level of Evidence

2b. Laryngoscope, 2552–2559, 2018