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.

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.
OBJECTIVE: 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.
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.
CONCLUSIONS: 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.

OBJECTIVE: The vertical level of carotid bifurcation (CB) is commonly indicated at the superior margin of the thyroid cartilage. Few studies observed the CB vertical topography. It was aimed at studying the vertical location of the CB as referred to vertebral and anterior cervical landmarks.
METHODS: An archived lot of 147 computed tomography angiograms was documented for the vertical level of CB referred to vertebral and anterior cervical landmarks. The topography of the CB in relation to anterior landmarks was classified into seven types: (1) at the superior margin of the thyroid cartilage; (2) between the hyoid and the thyroid cartilage; (3) at the hyoid level; (4) between the hyoid and mandible; (5) subgonial or supragonial CB; (6) lower cervical level; (7) intrathoracic.
RESULTS: The most common locations of CB were at C3 (27.21%), C3/C4 (26.19%) and C4 (25.51%). Bilateral symmetry of CB was found in 51.7%, except for C2 and C5/C6. Type 7 was not found, type 3 occurred in 39.12%, type 2 in 24.49%, type 1 in 13.95%, type 4 in 13.61%, type 5 in 6.12%, and type 6 in 2.72% (294 CBs). Bilateral symmetry of anterior types was found in 59.86%. Statistically significant correlations were found between sex and both left and right types and vertebral levels of CB.
CONCLUSIONS: The vertical topography of the CB is highly variable and has sex-related specificity. This detail should be included in the teaching of anatomy. Surgeons and interventionists should better document the carotid anatomy on a case-by-case basis.

UNASSIGNED: 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.
UNASSIGNED: 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.
UNASSIGNED: 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.

UNASSIGNED: The objective was to study the effect of orthodontic therapy regarding the position of the hyoid bone and upper airways in nighty-one 6-21 year-old Caucasian patients with normoclussion.
UNASSIGNED: Nineteen variables were analyzed by teleradiography. The differences were analyzed with the ANOVA test of repeated measures with an intra-group factor for two occasions.
UNASSIGNED: The statistical analysis revealed a greater influence on the variables Hy-MP (12.3 vs 14.2), Hps-C3 (25.2 vs 28.1), Hpi-C3 (28.8 vs 35.5), H°-C3 (14.4 vs 12.7), Hps-Rg (36.0 vs 42.7), Hpi-Rg (34.1 vs 39.7), USP (16.2 vs 20.2), MPP (12.9 vs 14.8), C3P (10.6 vs 12.8), PNS-Ba (43.5 vs 66.5), PtV-Ad (12.0 vs 17.1) and PtM-Ba (33.9 vs 35.9), and Ad2-SO (24.16 vs 20.87).
UNASSIGNED: Significant differences were observed between most of the airway and hyoid bone variables before and after orthodontic treatment in our Spanish pediatric population, especially in the nasopharynx.

The aim of this study was to design a new maneuver called the Mouth Open Swallowing Maneuver (MOSM), and to compare swallowing kinematics and submental muscles activation (SMA) between MOSM and two current approaches used in dysphagia rehabilitation. Fifty healthy volunteers were asked to perform three repetitions of dry swallowing (DS) (control task), the MOSM, the Mendelsohn Maneuver (MM), and the Tongue-Hold Maneuver (THM) during videofluoroscopic swallowing study accompanied with simultaneous SMA recording. Swallowing kinematics were measured by frame-by-frame analysis on hyolaryngeal movement using ImageJ. Swallowing with maximum hyolaryngeal movement and SMA during these tasks was used for comparative analysis. Vertical movement of the hyoid during the MOSM was significantly greater than those observed during the DS and the THM (p<0.001, p<0.001). Horizontal movement of the hyoid during DS and the THM was significantly greater than that observed during the MM (p = 0.001, p = 0.001). Vertical movement of the larynx during the MOSM was significantly greater than those observed during DS, MM, and THM (p<0.001). There was no significant difference between tasks in horizontal movement of the larynx (p = 0.785). SMA during the THM was significantly greater than that observed during MOSM (p = 0.002). No significant difference was found between other tasks in terms of SMA (p>0.05). The MOSM as a newly designed maneuver was significantly superior to other maneuvers in increasing vertical hyolaryngeal movement. The THM has as much effect on hyolaryngeal movement as the MM. In this study, the MOSM was shown to be effective in increasing hyolaryngeal movement. ClinicalTrials.gov Protocol Registration and Results System (PRS); the clinical trial registration number (NCT05579041).

OBJECTIVE: The potential relationship between impacted mandibular third molar and lingual bone thickness was investigated by quantitative measurement of lingual bone thickness, and a three-dimensional visualization model of lingual bone was established.
METHODS: Image data of 200 cases of mandibular impacted third molar were collected from the database of Hefei Stomatological Hospital. Thickness measurement and three-dimensional reconstruction of lingual bone at different measurement sites were performed by Simplant Pro software. Statistical analysis was performed using SPSS 22.0 software package, and the comparison of lingual thickness at different measurement sites was performed using rank sum test. Whether the thickness of bone plate was \"high-risk type\" was taken as the result variable, different related factors were analyzed by logistic regression.
RESULTS: The lingual bone at the middle point of the root of the third molar was the thinnest. Multiple teeth, mesio-inclined and dial-inclined teeth, and Class Ⅱ and Ⅲ impacted teeth had thin lingual bone(P＜0.05). The mesial and distal inclines were observed, and the lingual bone was thin in the root apical region of the teeth in Class Ⅱ and Class Ⅲ(P＜0.05). In the lower impacted teeth, the thin lingual bone at the central crown site was more likely to be found in Class Ⅲ teeth(P＜0.05).
CONCLUSIONS: The thickness of lingual bone was related to the number of impacted tooth roots, tilt direction and impacted type. In the extraction of impacted teeth, the above factors should be considered, and the injury of lingual nerve, lingual bone and surrounding soft tissue should be vigilant.

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.
CONCLUSIONS: 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.

The aim of this study was to investigate the measures of displacement, time and velocity of hyoid bone movement in female thyroidectomy patients. Fifty-eight ultrasound videos of 29 women during swallowing were analyzed. The sample was divided into experimental group (EG), composed of 12 women following total or partial thyroidectomy; and control group (CG) of 17 healthy women. The kinematic measures of displacement, time and velocity of hyoid bone displacement were tracked during swallowing of 10 ml of liquid (water) and 10 ml of thickened liquid (honey) in both groups for comparisons. Additional analysis included bolus consistency effect and relationship with clinical characteristics. Ultrasound videos were analyzed according to a standardized protocol using ImageJ software. Displacement, time and velocity of hyoid movement during swallowing of 10 ml of liquid or thickened liquid were not statistically different between female thyroidectomy patients and healthy women. There is no bolus consistency effect on kinematic measures in both groups, but among thyroidectomy patients, velocity of hyoid bone movement is significantly faster in those with swallowing complaints.

UNASSIGNED: Abnormalities of the hyoid bone are associated with impairment of oropharyngeal functions including feeding, swallowing, and breathing. Few studies have characterized anatomic abnormalities of the hyoid in patients with Robin sequence (RS), e.g. a less mineralized and voluminous hyoid. The purpose of this study was to compare normal hyoid bone morphology and hyoid bone morphology in children with isolated RS.
UNASSIGNED: Three-dimensional (3D) reconstructions of the hyoid bone were obtained from CT-imaging of children with RS and unaffected controls. A 3D morphable model was constructed using Principal Component Analysis (PCA). Partial least squares - Discriminant Analysis (PLS-DA) and multivariate analysis of variance (MANOVA) were used to characterize and compare hyoid shape differences between patients with RS and an age-matched control group.
UNASSIGNED: The study included 23 subjects with RS (mean age 9.8 ± 10.3 months) and 46 age-matched control samples. A less voluminous hyoid was observed for the RS group with a larger lateral divergence of the greater horns compared to controls (MANOVA, p-value<0.001). The first shape variable from the PLS-DA model showed a significant correlation for the observed variance between the two groups (Spearman R = -0.56, p-value<0.001). The control samples and 151 CT-scans of subjects up to age 4 years were used to create a 3D morphable model of normal hyoid shape variation (n = 197, mean age 22.1 ± 13.1 months). For the normal 3D morphable model, a high degree of allometric shape variation was observed along the first principal component.
UNASSIGNED: The 3D morphable models provide a comprehensive and quantitative description of variation in normal hyoid bone morphology, and allow detection of distinct differences between patients with isolated RS and controls.