OBJECTIVE: This study aims to determine the presence and morphology of triticeal cartilage (TrC) through autopsy cases and to examine its relationship with age, gender, and height, thus contributing to clinical practices and forensic perspective.
METHODS:  Our study was conducted on a total of 84 autopsy cases between the ages of 20-90 years who came to Tokat Forensic Medicine Institute. The laryngeal region was palpated to determine whether TrC was present. The dimensions of the TrC and the length of the upper horn of thyroid cartilage (UHThC) were measured with precise digital calipers, and its weight was measured with an accurate digital scale.
RESULTS: The presence of TrC was identified in 56% of the autopsy cases examined. The prevalence of TrC was higher in males (61.9%) than in females (23.1%). It was determined to be bilateral in 45% of the cases and unilateral in 11%. TrCs had a cylindrical shape in 68.2%, an oval shape in 25.8%, and a pyramidal shape in 5.8%. The average weight of TrC was 67.93 ± 33.91 mg on the right side and 72.67 ± 32.23 mg on the left. As the individual\'s height increased, the weight of TrC increased (p < 0.001). Additionally, there was a strong positive correlation between the lengths of TrC and UHThC and the individual\'s height (p < 0.001).
CONCLUSIONS: TrC may be confused with UHThC fractures. Therefore, we believe that knowledge of the presence and morphology of TrC will contribute to clinical approaches and forensic cases, especially in relation to the neck region.

OBJECTIVE: To evaluate the possible etiological factors of spontaneous pneumomediastinum and to describe a case that was unusual in its etiology: a thyroid cartilage fracture as a result of sneezing.
METHODS: Six patients (four male, two female, aged 16-82 years) were hospitalized with spontaneous pneumomediastinum diagnosed with a chest X-ray in five patients and 100% with computed tomography. Treatment was symptomatic.
RESULTS: The commonest symptoms (cough, shortness of breath, hoarseness) were in four patients. Spontaneous pneumomediastinum developed in three cases as a result of bronchospasm during an attack of bronchial asthma, in one patient after exercise, in one after fibrogastroscopy, in one after sneezing. We report a 30-year-old man who presenting subcutaneous emphysema on the neck, hoarseness, pain when swallowing, hemoptysis developed after sneezing. His computed tomography revealed a pneumomediastinum due to fistula of the fracture of the thyroid cartilage following sneezing while simultaneously obstructing both nostrils. At laryngoscopy, there was a linear hematoma in the resolution stage on the anterior wall of the larynx. He was treated conservatively and recovered rapidly. There are no previous published reports of spontaneous pneumomediastinum following fracture of the thyroid cartilage.
CONCLUSIONS: Fracture of the thyroid cartilage as a result of a sharp rapid increase in airway pressure during a sneeze with blocked nasal passages can be one of the rare causes of spontaneous pneumomediastinum. Avoid closing both nostrils at the same time when sneezing.
UNASSIGNED: Оценить возможные этиологические факторы спонтанного пневмомедиастинума и представить клиническое наблюдение перелома щитовидного хряща в результате чиханья как одну из возможных редких причин этого осложнения.
UNASSIGNED: Спонтанный пневмомедиастинум диагностирован у 6 пациентов на основании клинической картины, рентгенографии и компьютерной томографии грудной клетки. В исследование вошли 4 мужчины и 2 женщины в возрасте от 16 до 82 лет. Все пациенты успешно пролечены консервативно.
UNASSIGNED: Клинические симптомы (кашель, одышка, осиплость голоса) имелись у 4 пациентов. Спонтанный пневмомедиастинум развился в 3 случаях в результате бронхоспазма во время приступа бронхиальной астмы, у 1 пациента — после физической нагрузки, у 1 — после фиброгастроскопии, у 1 — после чиханья. Спонтанный пневмомедиастинум у всех больных диагностирован на компьютерной томографии, на рентгенограмме органов грудной клетки описан у 5 человек. У мужчины 30 лет после чиханья появились подкожная эмфизема на шее, осиплость голоса, болезненность при глотании, кровохарканье. На 2-е сутки на компьютерной томограмме органов грудной клетки выявлены пневмомедиастинум и перелом щитовидного хряща, через дефект в котором воздух поступал в средостение. При ларингоскопии на передней стенке гортани имелась линейная гематома в стадии разрешения. Проведено консервативное лечение. Подобных наблюдений в литературе нам не встретилось.
UNASSIGNED: Перелом щитовидного хряща в результате резкого быстрого повышения давления в дыхательных путях во время чиханья с зажатыми носовыми ходами может служить одной из редких причин спонтанного пневмомедиастинума. Следует избегать одновременного закрытия обеих ноздрей во время чиханья.

Background and Objectives: This study examined how a history of thyroid surgery impacts the precision of cricothyroid membrane (CTM) identification through palpation (validated by ultrasound) in female patients visiting the operating room for surgeries unrelated to neck procedures. Materials and Methods: This prospective observational cohort study enrolled adult female patients undergoing elective non-neck surgery, dividing them into control (no thyroid surgery history; n = 40) and experimental (with thyroid surgery history; n = 40) groups. CTM identification was performed by palpation and confirmed via ultrasound. Results: There were no significant differences between two groups in the demographic characteristics of the patients. The success rate and accuracy of CTM identification through palpation were significantly higher in the control group compared to the experimental group (90% vs. 42.5%, respectively; p < 0.001). For female patients with a history of thyroid surgery, the sensitivity of successful CTM palpation was 42.5%, and the specificity was 10%. These figures are based on the calculated true positives (17), false positives (36), true negatives (4), and false negatives (23). Conclusions: Thyroid surgery history in female patients may hinder the accurate palpation-based identification of the CTM, suggesting a need for enhanced clinical practices and considerations during airway management training.

OBJECTIVE: Thyroid cartilage (TC) calcifications may impact surgical planning and clinical management. However, few studies to date have implemented virtual reality (VR) to evaluate these calcifications. This study assessed the feasibility of evaluating TC calcifications in various regions and measuring their volumes through VR models generated from computed tomography scans. We also investigated age and gender-related differences in calcification patterns.
METHODS: Ninety-two participants were categorized into younger, middle-aged, and older age groups. Calcification patterns (degree in Hounsfield units and volume of calcification in cm3) in different TC regions were identified by VR analysis, which enabled comparisons between age groups and genders.
RESULTS: Significant differences in calcification patterns were observed between males and females, particularly in the middle right, middle left, bottom left, and vertex regions. Age-related differences in the vertex region showed increased calcification in the older age group.
CONCLUSIONS: This study points to the contribution of VR in the evaluation of complex anatomical structures. The findings revealed significant gender and age patterns in TC calcification. These insights can inform surgical planning and highlight the potential of using VR to gain a better understanding of TC calcification clinically.

OBJECTIVE: Ultrasound-guided superior laryngeal nerve (SLN) block is a practical and painless approach to avoid the hemodynamic stress response during endotracheal intubation and relieve sore throat after laryngeal surgery. The main purpose of this study was to establish an optimal dosage of local anesthetic when performing SLN block to help anesthetists balance analgesia and side effects.
METHODS: Twenty fresh larynx specimens were obtained immediately after resection and then injected with 2-, 3-, 4-, or 5- mL of a lidocaine-blue dye mixture at bilateral SLN puncture sites. Superficial areas of deposited blue dye were measured. Dye leakage and surrounding dyed tissue were recorded. Another 40 patients were included in the ultrasound investigation. Distances between the internal branch of the SLN (iSLN) and adjacent structures were calculated.
RESULTS: The dye spread area was greater with the administration of larger doses, especially to the visceral space. A 2- or 3-mL injection of local anesthetic was sufficient to infiltrate the SLN gap. A higher incidence of dye leaking out of the thyrohyoid membrane and anterior epiglottis space was observed; furthermore, there was substantially more dyed hyoid/thyroid cartilage with 4 and 5 mL of injected dye mixture than 2 mL. There was no significant difference between the specimen and ultrasound measurements of for length of iSLN-adjacent structures.
CONCLUSIONS: In the Chinese population, 2- or 3- mL of local anesthetic is a safe dose during SLN block. A larger volume could overflow from the cavity to cause complications. The thyrohyoid membrane combined with the superior laryngeal artery is a reliable target for positioning the iSLN during ultrasound-guided regional anesthesia.

UNASSIGNED: Non-traumatic rupture or other injuries to the larynx are very rare disorder. According to the published series, there are only 15 cases reported with such kind of injury to the larynx. Despite the rarity of the non-traumatic larynx fracture, it is important to elucidate adequate management for the patients with such emergency. The aim of the study is to demonstrate the features of clinical manifestations, examination, and surgical treatment of a case of spontaneous longitudinal rupture of the thyroid cartilage.
METHODS: A 54-year-old male patient presented with chief complaints of pain in the front surface of the neck, difficulty swallowing and breathing during physical exertion, hyperemia of the skin on the front surface of the neck, and the presence of subcutaneous emphysema. 20 h after the onset of the symptoms, the patient reported breathing difficulties that appeared during physical exertion, and the patient walked to the hospital. Computed tomography revealed a longitudinal rupture of the thyroid cartilage, emphysema of the neck, and the presence of air in the anterior-upper mediastinum. The defect of the ruptured thyroid cartilage was treated by suturing as well as by myoplasty using sternocleidomastoid muscle.
UNASSIGNED: Our case report is in line with others, showing that patient with spontaneous rupture of the thyroid cartilage is the surgical emergency. Our approach of using myoplasty was not presented before.
CONCLUSIONS: This case report adds evidence and knowledge about such rare disorders as spontaneous rupture the thyroid cartilage rupture. It is useful to apply the technique of myoplasty with sternocleidomastoid muscle flaps, ensuring reliable sealing of the damaged area reducing the risk of failure, and inflammatory complications, and supporting neck functions in the postoperative period.

BACKGROUND: The ventral enclosure of the thyroid cartilage by a collapsed hyoid bone (CHB) is poorly encountered in previous research. It was aimed to observe whether or not these malformations could be found and detailed anatomically in a consistent lot of computed tomography (CT) files.
METHODS: Two hundred archived CT angiograms were explicitly observed for the CHB anatomical variant.
RESULTS: Different possibilities of CHB were found in 6/200 cases, five males and one female. The symmetrical overlap of the thyroid cartilage by the hyoid body was found in one male case. In three cases, two males and one female, there was asymmetrical overlapping due to tilted hyoid bones. In one male case with such asymmetrical CHD, an ossified anterior longitudinal ligament was noted: the tips of the superior horns of the thyroid cartilage reached lateral to it, thus being retropharyngeal. A different male case had a lowered hyoid with a greater horn fused to the superior horn of the thyroid cartilage, with an interposed ossified triticeal cartilage. In the last male case, the right greater horn collapsed laterally to an ossified triticeal cartilage fused with the thyroid cartilage\'s superior horn.
CONCLUSIONS: The CHB is an undeniable anatomical possibility of an atavism that alters conventional anatomical and surgical landmarks. Different anatomical components of the hyoid bone can descend uni- or bilaterally.

The study was conducted to quantify laryngeal cartilage matrix composition and to investigate its relationship with cartilage shape in a mouse model. A sample of 30 mice (CD-1 mouse, Mus musculus) from five age groups (postnatal Days 2, 21, 90, 365, and 720) were used. Three-dimensional mouse laryngeal thyroid cartilage reconstructions were generated from contrast-enhanced micro-computed tomography (CT) image stacks. Cartilage matrix composition was estimated as Hounsfield units (HU). HU were determined by overlaying 3D reconstructions as masks on micro-CT image stacks and then measuring the attenuation. Cartilage shape was quantified with landmarks placed on the surface of the thyroid cartilage. Shape differences between the five age groups were analyzed using geometric morphometrics and multiparametric analysis of landmarks. The relationship between HU and shape was investigated with correlational analyses. Among five age groups, HU became higher in older animals. The shape of the thyroid cartilage changes with age throughout the entire life of a mouse. The changes in shape were not synchronized with changes in cartilage matrix composition. The thyroid cartilage of young and old M. musculus larynx showed a homogenous mineralization pattern. High-resolution contrast-enhanced micro-CT imaging makes the mouse larynx accessible for analysis of genetic and environmental factors affecting shape and matrix composition.

BACKGROUND: Large neck circumference and displacement of the trachea due to pathology increase the risk of failed identification of the cricothyroid membrane and cricothyroidotomy. We investigated whether ultrasound aids in the successful identification of the cricothyroid membrane in a model of an obese neck with midline deviation of the trachea.
METHODS: We developed silicone neck models that were suitable for both palpation and ultrasonography and where the trachea deviated laterally from the midline to either side. After reading a book chapter and participating in a 25-minute lecture and a 15- to 23-minute hands-on demonstration and rehearsal of ultrasonography for identification of the cricothyroid membrane, anesthesiologists and anesthesiology residents randomly performed identification with either ultrasound or palpation on 1 of 2 neck models.
RESULTS: We included 57 participants, of whom 29 and 28 were randomized to palpation and ultrasound, respectively. Correct identification of the cricothyroid membrane was achieved by 21 (75.0%) vs 1 (3.5%) of participants in the ultrasound versus palpation groups (risk ratio [RR], 21.8 [95% confidence interval {CI}, 3.1-151.0]). The tracheal midline position in the sagittal plane was identified correctly by 24 (85.7%) vs 16 (55.2%) of participants in the ultrasound versus palpation groups (RR, 1.6 [95% CI, 1.1-2.2]).
CONCLUSIONS: Identification of the cricothyroid membrane in a model of an obese neck with midline deviation of the trachea was more often successful with ultrasound compared to palpation. Our study supports the potential use of ultrasound before induction of anesthesia and airway management in this group of patients, and it may even be applied in emergency situations when ultrasound is readily available. Further studies in human subjects should be conducted.

The feasibility and reliability of trans-thyroid cartilage EMG recording method (TCERM) during intraoperative monitoring (IONM) of the recurrent laryngeal nerve (RLN) in thyroid surgery have been established. This study compared two different recording electrode placements on the ipsi-lateral and contra-lateral lamina of the thyroid cartilage (TC).
Fifty consecutive patients undergoing total thyroidectomy with 100 RLNs at risk were enrolled. Two paired subdermal needle electrodes were inserted into the subperichondrium of the bilateral TC lamina to record electromyography (EMG) signals. The channel leads from the TC electrodes were connected to the patient interface with two different modes. In A-mode, the electrode leads were placed ipsi-laterally, and channel 1 monitored the left RLN and channel 2 monitored the right RLN respectively. In B-mode, the electrode leads were placed contra-laterally, and channels 1 and 2 simultaneously monitored the same side of the RLN. The amplitudes of four EMG signals (V1-R1-R2-V2) recorded by A-mode and B-mode were compared.
All EMG amplitudes of V1-R1-R2-V2 signals recorded with B-mode were all above 500μV and significantly higher than those with A-mode (p<0.001). No false loss of signal, electrode dislodgement, or needle-related complications were noted during IONM. Postoperatively, all patients had symmetrical vocal cord movement. Lower EMG amplitudes were observed in older and male patients. Histopathology and laterality showed no significant differences in EMG amplitude.
During using TCERM in thyroid surgery, the recording electrodes should be placed contra-laterally on the TC lamina. This approach ensures high and stable EMG signals, which are important for high-quality IONM of the RLN.