Infrahyoid Research Articles

Clinical significance of gross extrathyroidal extension to only the strap muscle according to tumor size in differentiated thyroid cancer: a systematic review and metaanalysis.

The presence of extrathyroidal extension (ETE) in differentiated thyroid cancer (DTC) patients is an important predictor of their prognosis. Therefore, the tumor stage of DTC is divided into extensive ETE and gross ETE only affecting the strap muscle (Gross strap muscles invasion; gSMI). However, insufficient evidence exists regarding the association of gSMI with the prognosis, especially in relation to tumor size. Related literature was searched in MEDLINE, Embase, Cochrane Library and KoreaMed. All processes were performed in accordance with PRISMA guidelines, and the process was conducted by two independent reviewers. The meta-analysis was performed using a random-effect model considering the diversity of studies. RoBANS version 2.0, an evaluation tool for non-randomized studies, was used to evaluate the quality of the selected research. Clinical data from observational studies that analyzed the relationship between the degree of ETE and prognosis were collected, and a meta-analysis was performed. Eighteen observational studies were included in this study. A subgroup analysis was performed for each outcome. The recurrence rate (odds ratio [OR]: 2.498), disease-specific mortality (risk ratio [RR]: 2.984), overall mortality (RR: 1.361) and lymph node (LN) metastasis (OR: 5.355) were significantly higher in patients with gSMI than in those with no ETE. However, in an analysis limited to tumors 4 cm or smaller, no significant difference in prognostic outcomes was seen, except for LN metastasis. gSMI has a negative impact on the prognosis; however, this correlation diminishes when the tumor size is small. Thus, a more cautious approach is warranted during the treatment process.

Ansa Cervicalis Stimulation Effects on Upper Airway Patency: A Structure-Based Analysis.

Ansa cervicalis stimulation (ACS) of the infrahyoid muscles has been proposed as a neurostimulation therapy for obstructive sleep apnea (OSA). ACS stabilizes the pharynx by pulling it caudally, but its specific effects on flow limitation caused by palatal, oropharyngeal lateral wall, tongue base, or epiglottis collapse remains unclear. To quantify the effect of ACS on collapsibility of different pharyngeal flow-limiting structures. Participants with OSA underwent bilateral ACS during drug-induced sleep endoscopy. Maximum inspiratory airflow was assessed over a range of positive airway pressures while ACS was applied. The flow-limiting structure for each breath was classified based on manometric and endoscopic findings and a linear mixed-effects model characterized their response to ACS. The influence of patient characteristics was explored with univariate models. Forty-one participants yielded 1761 breaths for analysis. On average, bilateral ACS decreased the observed pharyngeal critical closing (PCRIT) and opening (POPEN) pressures by -3.0 [95% confidence interval: [-3.6, -2.3] and -3.7 [-4.4, -3.0] cmH2O, respectively (p<0.001). During tongue base obstruction, modeled ACS effects for PCRIT and POPEN were -2.0 [-2.7, -1.4] and -3.1 [-3.8, -2.4] cmH2O, respectively (p<0.001). Greater reductions were generally observed for other flow-limiting structures. A lower apnea-hypopnea index was associated with a greater decrease in POPEN (p<0.01). Other patient characteristics, including body mass index, did not influence PCRIT or POPEN (p>0.05). Bilateral ACS decreased collapsibility of all airway flow-limiting structures. ACS generally had greater effects on palatal, oropharyngeal lateral wall, and epiglottic collapse than the tongue base.

Effect of passive jaw opening on the electromyographic activity of the temporalis, masseter, digastric, and infrahyoid muscles in healthy adults

ABSTRACT Objective To investigate the surface electromyography (EMG) activity of the temporalis, masseter, digastric, and infrahyoid muscles during passive jaw opening in healthy adults. Methods The EMG activity of the masseter, temporalis, digastric anterior belly, and infrahyoid muscles on the right side was recorded during the four jaw-opening tasks: active opening to 20 mm (AO20); active opening to 40 mm (AO40); passive opening to 40 mm with a rubber mouth prop on the right posterior teeth (POR40); and passive opening to 40 mm with a mouth prop on the left posterior teeth (POL40). Results The EMG amplitude of the digastric anterior belly and infrahyoid muscles in either POL40 or POR40 was significantly less than that in AO20 or AO40, respectively. Conclusion Passive jaw opening reduces the EMG activity of the digastric and infrahyoid muscles significantly and could help reduce the load on these muscles during prolonged mouth-opening conditions.

Long-Term Survival and Regeneration Following Transplantation of 3D-Printed Biodegradable PCL Tracheal Grafts in Large-Scale Porcine Models.

Polycaprolactone (PCL) implants in large animals show great promise for tracheal transplantation. However, the longest survival time achieved to date is only about three weeks. To meet clinical application standards, it is essential to extend the survival time and ensure the complete integration and functionality of the implant. Our study investigates the use of three-dimensional (3D)-printed, biodegradable, PCL-based tracheal grafts for large-scale porcine tracheal transplantation, assessing the feasibility and early structural integrity crucial for long-term survival experiments. A biodegradable PCL tracheal graft was fabricated using a BIOX bioprinter and transplanted into large-scale porcine models. The grafts, measuring 20 × 20 × 1.5 mm, were implanted following a 2 cm circumferential resection of the porcine trachea. The experiment design was traditionally implanted in eight porcines to replace four-ring tracheal segments, only two of which survived more than three months. Data were collected on the graft construction and clinical outcomes. The 3D-printed biosynthetic grafts replicated the native organ with high fidelity. The implantations were successful, without immediate complications. At two weeks, bronchoscopy revealed significant granulation tissue around the anastomosis, which was managed with laser ablation. The presence of neocartilage, neoglands, and partial epithelialization near the anastomosis was verified in the final pathology findings. Our study demonstrates in situ regenerative tissue growth with intact cartilage following transplantation, marked by neotissue formation on the graft's exterior. The 90-day survival milestone was achieved due to innovative surgical strategies, reinforced with strap muscle attached to the distal trachea. Further improvements in graft design and granulation tissue management are essential to optimize outcomes.

Thyroid ima artery (the artery of Neubauer) - how much do we know?

Blood supply of the thyroid gland was the subject of numerous original studies, case reports and meta-analysies. The number of surgical procedures carried out on the thyroid gland significantly increases during last few decades. The cadaveric report discusses the case of a thryoidea ima artery (TIA) which originated from the brachiocephalic artery before its terminal subdivision, giving off numerous branches to the infrahyoid muscles, trachea and thyroid gland. Based on the current literature we discuss the prevalence of TIA, its embryology, and possible clinical aspects of this variation, with special attention paid to the postoperative complications.

Extrinsic Laryngeal Muscle Activity and Vocal Economy in Professionally Trained Voices During Vocal Vibrato

Summary PurposeThe purpose of the present study was to determine the extrinsic laryngeal muscle activity and vocal economy during two different singing conditions (straight-tone singing vs. vibrato singing) over a physiologically relevant singing range. MethodsThirty professional singers or voice coaches participated in the study. The participants sang a sustained /a:/ vowel for approximately 5 seconds, once in straight-tone singing conditions and once more in vibrato. The target pitches were C3, F3, A3, C4, F4, A4, and C5. Surface electromyographic (sEMG) measures were performed in the infrahyoid (IH) muscle region and the suprahyoid (SH) muscle region. Contact quotient (CQ), sound pressure level (SPL), and fundamental frequencies were measured to derive the electroglottographic-based vocal economy parameter quasi-output cost ratio (QOCR). ResultssEMG measures show that IH and SH muscles significantly increased in activity with ascending pitch. IH and SH muscle activity were significantly higher when singing in vibrato than straight-tone. Moreover, SPL also increased with ascending pitch and when sung in vibrato. CQ increased and QOCR decreased as pitch ascended but did not significantly change when sung in vibrato. ConclusionSinging higher pitches were generally associated with higher extrinsic laryngeal muscle activity and lower QOCR values. When comparing the two singing conditions, the extrinsic laryngeal muscle activity was higher during vibrato, implicating that the IH and the SH muscles may contribute to rhythmic pulsations of pitch changes. Although the QOCR value did not show significant differences between the two singing conditions, a significantly high SPL during vibrato may indicate acoustical and physiological advantages while singing in vibrato.

MyotonPRO as a new valid tool for measuring cervical muscle tension. A reliability study

Objective The main objective of this study is to test the reliability of a non-invasive objective method for the measurement of biomechanical parameters of cervicofacial muscle groups, with the purpose of diagnosis and evaluation of voice disorders’ treatments, especially focused on muscle tension dysphonia. Study design Prospective study. Methods The device used is a handheld myotonometer (MyotonPRO) that measures biomechanical and viscoelastic properties in superficial soft tissues frequency, stiffness, elasticity, relaxation time and creep. It is used in the field of medicine, sport and research. This pilot study includes 10 subjects, who have been measured in the masseter, sternocleidomastoid, orbicularis oris, semispinalis capitis, suprahyoid, infrahyoid and trapezius muscles on each side. Measurements were performed by 2 evaluators to assess inter-evaluator reliability. Subsequently, one of them repeated the measurements to assess intra-evaluator reliability. Results The results revealed good to excellent inter-rater reliability for the masseter, sternocleidomastoid, trapezius and suprahyoid muscles, with lower ICCs for the stiffness and creep properties. Intra-rater reliability was good to excellent for the masseter, sternocleidomastoid, semispinalis capitis and suprahyoid muscles. The lowest ICCs were found in the stiffness and creep properties. Conclusion The use of a myotonometer to measure the mechanical properties of selected cervical and orofacial muscles is a reliable and reproducible method. Future research is needed to establish an association between the properties of these muscles and their role in voice disorders, as well as to determine whether this tool can aid diagnosis with quantifiable and objectifiable indicators, and for monitoring and treatment efficacy.

Prognostic significance of T3b in papillary thyroid carcinoma: Appropriateness of classifying T3bN0M0 in patients aged 55years or older into stage II.

Papillary thyroid carcinoma (PTC) often extends to adjacent organs. According to the 8th Tumor-Node-Metastasis Classification, extension to the strap muscles was graded as T3b. We investigated the prognostic impact of T3b and the appropriateness of T3b in patients aged ≥55years who were classified as stage II. We enrolled 7811 patients with M0 PTC who underwent initial surgery at the Kuma Hospital (Kobe, Japan) between January 2007 and December 2016. Tumor extension was divided into T3b, T4a1 (extension to the tracheal adventitia, tracheal cartilage, esophageal muscle layer, recurrent laryngeal nerve, cricothyroid, and inferior constrictor muscles), and sT4a2 (extension to the subcutaneous soft tissues, tracheal mucosa, esophageal mucosa, internal jugular vein, brachiocephalic vein, larynx, pharynx, and sternocleidomastoid muscle). In patients ≥55years, the local recurrence-free survival (LR-FS), distant recurrence-free survival (DR-FS), and cause-specific survival (CSS) rates of T3bN0M0 were significantly poorer than those of T1/T2N0M0 but did not significantly differ from those of T3aN0M0. The LR-FS, DR-FS, and CSS rates of T3b stage II patients did not differ from those of T4a1 stage III patients but were significantly better than those of T4a2 stage III patients. T3b was an independent predictor of local recurrence and distant recurrence but not of death due to carcinoma in the multivariate analysis. In patients aged <55years with M0 PTC, T3b had no prognostic value in both analyses. T3bM0 patients are appropriate to be classified as stage II in patients ≥55years but be kept in stage I in patients <55years.

Residual effect of sequential 4-channel neuromuscular electrical stimulation evaluated by high-resolution manometry

BackgroundHigh-resolution manometry (HRM) can quantify swallowing pathophysiology to evaluate the status of the pharynx. Sequential 4-channel neuromuscular electrical stimulation (NMES) was recently developed based on the normal contractile sequences of swallowing-related muscles. This study aimed to examine the effects of sequential 4-channel NMES for compensatory application during swallowing and to observe the residual effects after the application of NMES using HRM.ResultsSequential 4-channel NMES significantly improved the HRM parameters, with respect to the maximal pressure and area of the velopharynx (VP), maximal pressure and area of the mesopharynx (MP), and upper esophageal sphincter (UES) activation and nadir duration. Furthermore, the improvement in the pressure and area variables of the VP and MP showed a tendency to maintain even when measured after NMES, but there are no significant differences.ConclusionsThe present study suggests that the sequential 4-channel NMES application of the suprahyoid and infrahyoid muscles during swallowing improves the pressure, area, and time variables of the oropharynx, as measured by HRM, and it is likely that the effects may persist even after stimulation.Trial Registration Clinicaltrials.gov, registration number: NCT02718963 (initial release: 03/20/2016, actual study completion date: 06/24/2016, last release: 10/20/2020).

Reconstruction of Defects After Oral Cancer Surgery With the Superior Thyroid Artery Perforator Flap.

The superior thyroid artery perforator flap (STAPF) was previously presented as a type of locoregional pedicled flap for lateral facial and temple defects. In this study, we aimed to present our clinical experience with this flap for the reconstruction of soft tissue defects after oral cancer surgery. From February 2019 to December 2022, 24 patients with oral cancers at the School and Hospital of Stomatology,Peking University were included. Among these patients, 10 had cancers located in the tongue, five in the cheek inside the oral cavity, three in the lower gingiva, two in the upper gingiva, two in the floor of the mouth, and two in the palate. All patients were treated with extended tumor resection, neck dissection, and STAPFs to reconstruct the soft tissue defects. The details of the flap, including the flap size, venous flow, vascular pedicle length, the attatched muscle, and operation time were evaluated. The dimensions of the flap skin paddle ranged from 3 cm × 5 cm to 6 × 14 cm. Fourteen patients had a closely concomitant superior thyroid vein perforator. Ten patients had non-closely concomitant superior thyroid veins perforators which retrograde external jugular vein. The vascular pedicle length ranged from 5 to 9 cm. The infrahyoid muscle group or sternocleidomastoid muscle was included in the flaps in three patients. A total of 23/24 flaps were successful. The STAPF is a viable reconstructive option for patients with oral cancers. It has the advantages of being robust, being thin, short operation time, and minor donor site complications. 4 Laryngoscope, 2024.

Parathyroid Adenoma Orientation for Gland Embryologic Origin on Ultrasonography

Accurate preoperative localization is critical to success in targeted parathyroidectomy for primary hyperparathyroidism. To determine if the association between the long axis of a parathyroid adenoma (PTA) candidate and strap musculature on sagittal ultrasonography (US) can be used to predict the embryologic origin of the gland. This diagnostic study was performed using the Stanford Research Repository. Patients 18 years or older with primary hyperparathyroidism who underwent parathyroidectomy between January 2009 and October 2021 were considered. Additional inclusion criteria were having clear sagittal view of the adenoma candidate on US, confirmation of the gland of origin intraoperatively, and confirmation of hypercellular parathyroid on final pathology. Data were analyzed from October 2021 to June 2022. B-mode US and surgical parathyroidectomy. The index test was using US to measure the angle between the long axis of an adenoma candidate and the strap musculature in the sagittal plane. This angle was used to test whether inferior and superior PTAs could be accurately assigned. The hypothesis was formulated prior to data collection. A total of 426 patients (mean [range] age, 61.1 [20-96] years; 316 [74.2%] female) with 442 adenomas met inclusion criteria. Of the 442 adenomas, 314 (71.0%) had measurable angles, of which 204 (46.2%) were assigned a superior origin, 238 (53.8%) were assigned an inferior origin, and 128 (29%) were indeterminate. Of the surgically identified superior PTAs, 144 (70.6%) had a definable angle, and of the surgically identified inferior PTAs, 170 (71.4%) had a definable angle. The receiver operating characteristic analysis found 94° as the optimized angle for differentiating true negatives from true positives, with an overall sensitivity of 74% and specificity of 72%. This supported using 90° as a break point for US review. True positives were considered superior adenomas with an angle greater than 90°; true negatives were inferior adenomas with an angle less than 90°. Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of angulation analysis for determining PTA origin were 72.2% (95% CI, 64.9%-79.5%), 73.5% (95% CI, 66.9%-80.1%), 69.8% (95% CI, 62.5%-77.1%), 75.8% (95% CI, 69.3%-82.3%), and 72.9%, respectively. A subgroup analysis of 426 adenomas using the posterior carotid artery border on transverse US as a surrogate for predicting gland origin showed the following for sensitivity, specificity, positive predictive value, negative predictive value, and accuracy: 49.5% (95% CI, 42.6%-56.4%), 82.3% (95% CI, 77.3%-87.3%), 71.4% (95% CI, 63.9%-78.9%), 64.6% (95% CI, 59.1%-70.1%), and 66.9%, respectively. This diagnostic study showed that PTA angulation on sagittal plane US can be used to predict gland of origin and guide surgery. The relationship between adenoma and posterior carotid artery border on transverse US can also be used to predict gland origin. These easy-to-apply US-based tests can be used in conjunction with other imaging modalities to guide targeted parathyroidectomy.

Oral Reconstruction with Locoregional Flaps after Cancer Ablation: A Systematic Review of the Literature.

Introduction: The planning of oral reconstruction after tumor resection is a pivotal point for head and neck surgeons. It is mandatory to consider two aspects: the size of the surgical defect and the complexity of the oral cavity as an anatomical region. We offer a review of the literature that focuses on four types of locoregional flaps that can be profitably used for such reconstruction: infrahyoid (IF), nasolabial (NF), platysma (PF), and submental (SF). Methods: The study was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. This systematic review was carried out according to the PICOS acronym through a comprehensive electronic search on PubMed/MEDLINE, Cochrane Library, and Google Scholar databases. For each selected article, we extrapolated eight main parameters, of which all mean values were compared through an ANOVA test. The dimensions of the oral defects were referred to as "small" (<7 cm2), "medium" (7-50 cm2), or "large" (>50 cm2). Results: A total of 139 articles were selected with a total of 5898 patients. The mean ages for each type of flap were not statistically significant (p = 0.30, p > 0.05). Seven sublocations of oral defects were reported: The most common was the tongue (2003 [34.0%] patients), followed by the floor of the mouth (1786 [30.4%]), buccal mucosa (981 [16.6%]), cheek (422 [7.2%]), hard palate (302 [5.1%]), alveolar ridge (217 [3.7%]), and retromolar trigone (187 [3.2%]). The defects were mainly medium-sized (4507 [76.4%] patients), and fewer were small-sized (1056 [17.9%]) or large-sized (335 [5.7%]). Complications were noted, the most frequent of which was flap necrosis, seen in 0.57% of cases. The functional and esthetical results were mainly positive. Conclusions: Locoregional flaps represent a good alternative in medium-sized defects as well as a fairly good alternative in small- and large-sized defects when other options are ruled out.

Unusual anatomical variants of infrahyoid muscles - case report.

Anatomical anomalies of neck muscles are rarely observed and usually comprise variations of digastric and omohyoid muscles. Neck muscles' abnormalities might be correlated with embryological development and are observed in individuals with aneuploidies such as Edward's syndrome (18-trisomy) or Down syndrome (21-trisomy). Some infrahyoid muscles are important landmarks during surgery, therefore their anatomical variations of these muscles are related to higher risk of surgical complications. Herein, we present a rare case of infrahyoid muscles anomalies found during routine dissection of male cadaver. Redundant muscle bellies of sternohyoid muscle (sternohyoid azygos muscle), presence of levator glandulae thyroideae and also one hypoplastic superior belly of the omohyoid muscle were observed. Presence of muscle fibers within found structures was confirmed using Masson's trichrome staining method.

Superior Thyroid Artery Originating from the Ascending Pharyngeal Artery

Background: The superior thyroid artery generally originates from the anterior surface of the external carotid artery. The superior thyroid artery originating from the ascending pharyngeal artery is an extremely rare anatomic variation. Nevertheless, some variations in the origin of the superior thyroid artery have been reported in the literature. Such knowledge is important during neck surgeries such as thyroidectomy and radical neck dissection. Here we report the first case of a superior thyroid artery arising from the ascending pharyngeal artery. Case report: During a routine dissection on the neck, a superior thyroid artery originating from the ascending pharyngeal artery was observed on the right side, in a 37-year-old male cadaver. The superior thyroid artery had two segments, a superior (or horizontal) segment and an inferior (or vertical) segment. The superior segment passed posterior to the linguofacial trunk. The inferior segment passed posterior to the superior laryngeal artery and an artery that went to the infrahyoid muscles. These last two arteries came directly from the external carotid artery. The superior thyroid artery terminated in two branches (one lateral and one medial) 6 mm above the superior pole of the right thyroid lobe. Conclusion: The origin of the superior thyroid artery from the ascending pharyngeal artery is an extremely rare anatomical variation. A thorough knowledge of the variations in origin of the superior thyroid artery is decisive for head and neck surgeries.

Four-layer technique for tracheostomy scar treatment.

One important complication of the tracheostomy procedure is the depressed scar left after the tube is removed. A depressed tracheostomy scar can be aesthetically and functionally unacceptable. Tracheostomy scar treatment aims to fill lost soft tissue volume and correct tracheal skin tug. There are various techniques described to manage post-tracheostomy scars, including the use of autologous tissue or allogenic material and the creation of muscle flaps. In this article, the authors introduce a surgical method using four layers: the scar, the strap muscles, the platysma muscle, and the skin. This procedure has been used in two patients with depressed scar after prolonged tracheostomy placement. The tracheal tug was eliminated in each patient, and an imperceptible cutaneous scar remained. In each case, patient satisfaction was complete. The authors recommend this technique as a simple and effective method of closure for these troublesome tracheostomy scars.

Revision of the Retracted Posttracheostomy Scar by Anatomical Restoration; Four Layer Closure

AbstractMost tracheostomy scars are depressive and adherent to the underlying trachea, which causes up and down movement when swallowing. This tracheocutaneous tethering causes discomfort, pain, dysphagia, and bad appearance. A tracheocutaneous fistula may be accompanied. Here, we present a new method for reconstructing a tracheostomy scar deformity with tracheocutaneous tethering: layer-by-layer restoration of the anatomical structure with a subcutaneous fat tissue blanket. The scar tissue was fully excised, with the associated skin and subcutaneous tissue. The bilateral strap muscles around the scar were dissected proximally and distally and approximated to the midline, secured without tension. Bilateral platysma muscle flaps cover them firmly. The subcutaneous tissue around the incision margin, which included the superficial cervical fascia was elevated to form a fat blanket, closed transversely. The skin was closed after confirming the absence of retraction upon swallowing. From 2010 to 2018, 10 patients with tracheocutaneous tethering and one patient with tracheocutaneous fistula underwent surgery. All patients were functionally and aesthetically satisfied with the results. The only complication was a hypertrophic scar in one patient, which was managed with a triamcinolone injection. An anatomical layer-by-layer restoration with a fat blanket provided consistent, satisfying results for correcting tracheostomy scar deformities without using additional tissue. This simple method was effective for reconstructing tracheocutaneous tethering.

The Characterization of Normal Male and Female Voice from Surface Electromyographic Parameters.

Currently, there is no consensus on the characterization of the human voice. The objective of the present study is to describe the myoelectric behavior of the extrinsic musculature of the larynx in 146 people with normal voice (Spanish speakers), aged between 20 and 50 years old. Different vocal tasks were recorded using a surface electromyograph (SEMG). In all vocal tasks, it was observed that women had higher activation (µV) in the suprahyoid and sternocleidomastoid muscles than men, while men had higher activation in the infrahyoid muscles. SEMG is a valid procedure to help define normal vocal characteristics in the studied population, providing reference values during clinical examination. However, it is necessary to adopt a universal system of assessment tasks and standardized measurement techniques to allow for comparisons with future studies.

SEMG as complementary tool for VFSS: A synchronized study in patients with neurogenic oropharyngeal dysphagia

The neurogenic oropharyngeal dysphagia is a prevalent functional swallowing disorder resulting from neurological causes. The conventional diagnosis involves ionizing radiation in Videofluoroscopy Swallowing Studies (VFSS). Surface electromyography (sEMG) offers a non-invasive alternative by recording muscle activity. This research compares bolus passage timing through anatomical structures using VFSS and sEMG-related activation times. Fifty confirmed oropharyngeal dysphagia patients underwent synchronized VFSS and sEMG, evaluating muscle groups during cracker and fluid ingestion. sEMG revealed activation patterns in masseters, suprahyoid, and infrahyoid muscles, occurring before bolus passage through the mandibular line and concluding near the upper esophageal sphincter complex. sEMG identified differences in dysphagia severity (EAT-10 score), age, and diagnosis, contrasting VFSS results. Results indicate potential complementarity between sEMG and VFSS for dysphagia screening, diagnosis, and monitoring.

Iatrogenic Full-length Rupture of Posterior Trachea: A Multidsciplinary Management

Iatrogenic trachealis muscle rupture (ITR) following elective intubation is a potentially fatal complication with a low incidence of 0.05-0.37%. Tears involving the whole length has not been reported. We report a case of a 26-year-old lady with seropositive rheumatoid arthritis who underwent total thyroidectomy for Hashimoto Thyroiditis. Intraoperatively, a complete linear trachealis muscle rupture from the carina to the first tracheal ring was diagnosed by the Otorhinolaryngology (ORL) team by tracheoscopy through the endotracheal tube (ETT). Unlike the common presentation of subcutaneous emphysema or pneumomediastinum, the surgeon noticed the ETT cuff in the left operative field. Initial repair of the lateral defect was performed immediately by opposing the sternocleidomastoid muscle to the adjacent infrahyoid muscles. However, serial computed tomography and flexible tracheoscopy showed complete tear of the trachealis muscle with presence of pneumomediastinum and dynamic changes of the injury. We illustrate a concerted effort of multidisciplinary teams of ORL, Cardiothoracic Surgery, Intensivist, Anaesthetist, Radiologist and Speech Therapist in the steps of management which involved series of tracheoscopy and imaging prior to extubation. In view of extensive trachealis muscle tear with hemodynamically stable patient, conservative management was opted for this patient as it outweighs the benefit of the surgery. We include the outpatient management until the patient’s trachea fully healed 6 months after the injury. The management is compared to the management review in the literature. This case has taught multiple new important lessons in the management of challenging tracheal rupture in a patient.International Journal of Human and Health Sciences Supplementary Issue 01: 2024 Page: S54

Tongue pressure and maxillofacial muscle activities during swallowing in patients with mandibular prognathism.

Coordination among lip, cheek and tongue movements during swallowing in patients with mandibular prognathism remains unclear. This study aimed to identify the temporal sequences of tongue pressure and maxillofacial muscle activities during swallowing in patients with mandibular prognathism and compared characteristics with those of healthy volunteers. Seven patients with mandibular prognathism (mandibular prognathism group) and 25 healthy volunteers with individual normal occlusion (control group) were recruited. Tongue pressures and masseter, orbicularis oris, mentalis and supra- and infrahyoid muscle activities while swallowing gel were measured simultaneously using a sensor sheet system with five measurement points and surface electromyography, respectively. Onset time, offset time and durations of tongue pressure and muscle activities were analysed. In the mandibular prognathism group, tongue pressure was often produced first in more peripheral parts of the palate. Offset of tongue pressure in the posteromedian and peripheral parts of the palate and maxillofacial muscle activities except for orbicularis oris were delayed. Duration of tongue pressure in the anteromedian part of the palate was significantly shorter and durations of masseter, mentalis and suprahyoid muscle activities were significantly longer. Times to onset of orbicularis oris and suprahyoid muscle activities based on first onset of tongue pressure were significantly shorter. These results suggest that patients with mandibular prognathism may exhibit specific patterns of tongue pressure production and maxillofacial muscle activities during swallowing.