Laryngeal Skeleton Research Articles

Postnatal Development of the Mouse Larynx: Negative Allometry, Age-Dependent Shape Changes, Morphological Integration, and a Size-Dependent Spectral Feature.

Purpose The larynx plays a role in swallowing, respiration, and voice production. All three functions change during ontogeny. We investigated ontogenetic shape changes using a mouse model to inform our understanding of how laryngeal form and function are integrated. We understand the characterization of developmental changes to larynx anatomy as a critical step toward using rodent models to study human vocal communication disorders. Method Contrast-enhanced micro-computed tomography image stacks were used to generate three-dimensional reconstructions of the CD-1 mouse (Mus musculus) laryngeal cartilaginous framework. Then, we quantified size and shape in four age groups: pups, weanlings, young, and old adults using a combination of landmark and linear morphometrics. We analyzed postnatal patterns of growth and shape in the laryngeal skeleton, as well as morphological integration among four laryngeal cartilages using geometric morphometric methods. Acoustic analysis of vocal patterns was employed to investigate morphological and functional integration. Results Four cartilages scaled with negative allometry on body mass. Additionally, thyroid, arytenoid, and epiglottic cartilages, but not the cricoid cartilage, showed shape change associated with developmental age. A test for modularity between the four cartilages suggests greater independence of thyroid cartilage shape, hinting at the importance of embryological origin during postnatal development. Finally, mean fundamental frequency, but not fundamental frequency range, varied predictably with size. Conclusion In a mouse model, the four main laryngeal cartilages do not develop uniformly throughout the first 12 months of life. High-dimensional shape analysis effectively quantified variation in shape across development and in relation to size, as well as clarifying patterns of covariation in shape among cartilages and possibly the ventral pouch. Supplemental Material https://doi.org/10.23641/asha.12735917.

Rediscovery of the toadlet Brachycephalus bufonoides Miranda-Ribeiro, 1920 (Anura: Brachycephalidae) with osteological and acoustic descriptions.

Brachycephalus bufonoides was described as a "variety" of B. ephippium based on two specimens which 90 years later was considered full species. Besides its brief original description, nothing else is known for this species. Herein we report the rediscovery of the pumpkin-toadlet Brachycephalus bufonoides from Nova Friburgo, State of Rio de Janeiro, the second most populous area within the Atlantic Forest in Brazil. A detailed osteological description of this species was also provided, including skull, hyolaryngeal skeleton and postcranium skeleton. The laryngeal skeleton of Brachycephalus genus was depicted for the first time. We conducted a molecular phylogenetic analysis of Brachycephalus using DNA sequences comprising two fragments of mitochondrial gene (16S). Both analysis with Bayesian inference and maximum parsimony supported the recognition of B. bufonoides as an exclusive lineage, allocated within the B. ephippium species group in B. vertebralis lineage. We improved the diagnosis and variation of the species, including more collected specimens, coloration in vivo and advertisement call description. Compared with its congeners, B. bufonoides has skin on head and dorsum with dermal hyperossification; skull with hyperossification of postorbital crests; a pair of hyperossified bulges about equidistant between postorbital crests; fourth presacral vertebra with transverse process hyperossified, ornamented and sacral diapophyses hyperossified, which can be seen externally (lineage of B. vertebralis sensu Condez et al. 2020); presence of dermal ossification as separated bulges of each vertebrae; general background color orange with different intensities of dark orange blotches on dorsum, including bordering of sacral region; absence of osteoderms and presence of warts on the dorsolateral surface of body; medium body size (SVL of adults: 12.0-14.5 mm for males and 14.7-16.3 mm for females; Table 1); rough dorsum; advertisement calls with 13 to 17 pulses; presence of pulse period modulation; and advertisement calls with notes longer than 0.2 s (0.22 to 0.31 s). Herein an important contribution for the taxonomy and systematics of this genus is provided, including a large amount of novel information for B. bufonoides from different sources (i.e., molecular, morphological variation, bioacoustic), allowing it to be included in future studies of species delimitation and relationships within Brachycephalus. Also, the discovery of this species reiterates the importance of Nova Friburgo for the conservation of the Atlantic Forest biodiversity.

Laryngeal framework surgery

Laryngeal framework surgery is defined as surgical procedures performed on the laryngeal skeleton and the insertion of muscles to correct vocal fold positioning and tension. Its main objective is to improve the voice without directly intervening in the vocal folds. The European Society of Laryngology proposed in 2000 a classification and nomenclature of these surgeries according to their purpose. Such standardization has divided these procedures into four groups: Approximation laryngoplasty, Expansion laryngoplasty, Relaxation laryngoplasty, and Tensioning laryngoplasty. Indications, techniques, and complications of each procedure will be described in this review.

Emergent Reconstruction of Laryngeal Penetrating Neck Injury: A Case Report

Objective: This paper aims to describe an unconventional surgical procedure performed in a case of penetrating neck injury involving the larynx.
 Methods:
 Design: Case Report
 Setting: Tertiary Government Hospital
 Population: One
 Results: A 38-year-old man sustained a hacking laceration to the anterior neck that extended into the hypopharyngeal area, transecting the thyroid cartilage. After pre-emptive tracheostomy, the patient was referred to otorhinolaryngology – head and neck surgery due to the extensive hypopharyngeal injury. Neck exploration performed to control bleeders confirmed a Schaefer-Fuhrman Classification Group 3 penetrating neck injury. Anastomotic reconstruction of the hypopharynx, transected thyroid cartilage and strap muscles was attempted using absorbable sutures with post-operative re-establishment of structural continuity and documentation of full bilateral vocal fold mobility. The patient was about to be discharged home with a tracheotomy and nasogastric tube when he suddenly deteriorated and expired on the eighth post-operative day.
 Conclusion: Our technique might be utilized in cases where urgent reconstruction of laryngeal structures is considered despite serious damage to the laryngeal skeleton, and may provide a temporary surgical option for similar cases in an emergent setting. However, we cannot recommend it as a routine standard on the basis of one case.
 Keywords: larynx; penetrating neck injury; vocal cord; reconstruction, neck exploration

Using micro-computed tomography to examine the larynx in cases of suspected strangulation\u2014a comparison of case findings and control images

The examination of strangulation is one of the most challenging causes of death diagnoses encountered in forensic pathology. The injuries are often subtle and difficult to detect, especially in cases that lack superficial marks. Fractures of the laryngeal skeleton are commonly regarded as evidence of strangulation but these can be too subtle to be detected during autopsy. Micro-CT is a novel imaging technique that achieves a spatial resolution 1 μm or less which lends itself to the examination of small and delicate structures such as the larynx. However, there is little information to date regarding the appearance of the larynx at this scale, thus complicating the interpretation of the micro-CT images. This study therefore uses micro-CT to examine ten larynges from strangulation deaths and to compare them to nineteen samples from donor individuals in order to distinguish between naturally occurring features and actual trauma. It was found that there are several features which mimic damage in the donor group. Using associated case information, initial trends and patterns of different strangulation methods were established.

Multidetector CT of Laryngeal Injuries: Principles of Injury Recognition.

Blunt laryngeal trauma is associated with high morbidity and mortality. However, owing to their relatively rare occurrence, laryngeal injuries may be missed or underdiagnosed. Even subtle abnormalities at multidetector CT may correspond to significant functional abnormalities. It is important to understand normal CT laryngeal anatomy and develop a systematic review of the cervical soft tissues and laryngeal skeleton in patients who undergo screening CT cervical spine or other neck examinations in the setting of trauma, such as CT angiography. Multidetector CT findings of the normal larynx are reviewed, and blunt laryngeal injuries including soft-tissue edema, hematoma, mucosal lacerations, cartilage fracture, cricoarytenoid dislocation, and vocal fold paralysis are presented. The radiologist plays an important role in diagnosis and may be the first to identify laryngeal injuries that are not evident at physical examination. This article reviews normal laryngeal anatomy, presents various blunt laryngeal injuries at multidetector CT with case examples, discusses the role of multidetector CT in acute management, and describes pitfalls of diagnosis. ©RSNA, 2019.

Calcified Triticeous Cartilage Detected on Digital Panoramic Radiographs in a Sample of Lebanese Population.

Objective:Triticeous cartilage is a small ovoid structure belonging to the laryngeal skeleton. When calcified, it becomes visible on panoramic radiographs and be mistaken for a carotid artery calcification (CAC) associated with cerebrovascular accidents. This study aimed to estimate the prevalence of calcified triticeous cartilage (CTC) detected by means of digital panoramic radiographs in a sample of Lebanese population.Materials and Methods:Digital panoramic radiographs of 500 Lebanese adult patients (281 females and 219 males) with a mean age of 47.9 years were included in this study and examined for CTC. The IBM® SPSS® for Windows version 20.0 (SPSS, Chicago, IL, USA) was used to carry out statistical analysis of the data collected.Results:Nearly 10.6% (53 out of 500) of the radiographs examined presented CTC. Of all the calcifications, 11 were on the right side, 5 on the left side, and 37 were bilateral. The cases detected belonged to 31 females and 22 males with an average age of 55.6 years (ranging from 24 to 85 years). Chi-square test did not show any statistical connection between gender and CTC, while Spearman's correlation analysis showed low positive correlation with age (r = 0.146).Conclusion:CTC can be detected on panoramic radiographs taken in daily dental practice; its identification is essential to avoid misdiagnosis with other calcifications in the neck region closely related to life-threatening risks such as CAC.

Unsuspected Hyoid Bone Fracture Following a Sport Laryngeal Trauma

A years old man sustained a fracture of the hyoid bone following closed neck injury while weight lifting in the gym Though commonly occurring in association of other neck fractures of the laryngeal skeleton the fracture was isolated Isolated hyoid bone fractures resulting from trauma other than strangulation are very rare and occur more frequently in young men more than in women These fractures are usually managed conservatively with good results as indeed our case was

Triticeous Cartilage CT Imaging Characteristics, Prevalence, Extent, and Distribution of Ossification.

The triticeous cartilage is a small ovoid cartilaginous structure variably present as a component of the laryngeal skeleton. This structure has received scant attention in the literature and has yet to be described adequately on cross-sectional imaging. Retrospective study in a tertiary medical center. We investigated triticeous cartilage prevalence in a large population utilizing computed tomography images. The cases of all patients with computed tomography angiography images of the neck from October 1, 2013, to September 31, 2014, were examined. A total of 663 patients were included in this study (age: range, 18-97 years; mean ± SD, 65 ± 15 years), 58.4% men and 41.6% women. The presence of a triticeal cartilage and its site, number, and degree of ossification were recorded. A total of 53.1% of patients had at least 1 triticeous cartilage (352 of 663). Prevalence was 57.4% (222 of 387) among men and 47.1% (130 of 276) among women. The presence of bilateral triticeous cartilages was more common than unilateral (63.1%, 222 of 352). A minority of patients (4.5%, 16 of 352) had a cartilaginous triticeous with no appreciable ossification, and more than half (54.0%, 190 of 352) had mild triticeal ossification. Moderate ossification was found in 34.9% of patients (123 of 352) and marked ossification in 6.5% (23 of 352). The presence of a triticeous cartilage is common and of variable appearance. As the clinical and surgical significance of this anatomic structure may be misinterpreted, it is important for imaging interpreters to be familiar with this seldom-recognized anatomic structure and recognize its variable appearance on cross-sectional imaging to avoid a misdiagnosis.

The triticeous cartilage - redefining of morphology, prevalence and function.

Triticeous cartilage is a small cartilaginous component of the laryngeal skeleton. This cartilage, located in posterior end of the thyrohyoid ligament, presents in different shapes. Radiological studies indicate clinical and anatomical importance of the triticeous cartilage but these studies have limited information due to inadequate inspection method. Computed tomographic angiography is able to evaluate the triticeous cartilage with using three-dimensional images in more detail. The aim of this study is to describe prevalence and morphological properties of the triticeous cartilage. We examined computed tomographic angiography images of 746 patients (368 women, 378 men) retrospectively. Shapes, calcification degrees, volumes, lengths and wideness of the triticeous cartilage were evaluated by OsiriX-Lite software. According to our results, triticeous cartilage presents common in the examined population (68.1%). The prevalence of the triticeous cartilage was higher in men than in women. We also found that the degree of calcification was not related with age and gender. Clinical importance of the triticeous cartilage is that it could be misdiagnosed with atherosclerosis in common carotid artery because the triticeous cartilage is located almost at same level as the bifurcation of the common carotid artery. Therefore, clinicians should be aware about the triticeous cartilage.

Gross morphology and topographical relationships of the hyobranchial apparatus and laryngeal cartilages in the ostrich (Struthio camelus)

AbstractThe ostrich hyobranchial apparatus consists of the centrally positioned paraglossalia and basiurohyale and paired caudo‐lateral elements (horns), each consisting of the ceratobranchiale and epibranchiale. The paraglossalia lie within the tongue parenchyma and consist of paired, flat, caudo‐laterally directed cartilages joined rostrally. The basiurohyale forms a single dorso‐ventrally flattened unit composed of an octagonal‐shaped body from which extend rostral (the rostral process) and caudal (the urohyale) projections. The laryngeal skeleton consists of cricoid, procricoid and paired arytenoid cartilages. The large ring‐shaped cricoid cartilage displays a body and paired wings which articulate with each other and with the procricoid. The blunt, ossified, rostral projection of the cricoid and the scalloped nature of the arytenoid cartilages are unique to the ostrich. The procricoid is a single structure which links the paired arytenoids and wings of the cricoid. The hyobranchial apparatus is firmly attached to the tongue parenchyma and to the larynx and proximal trachea. In contrast to previous reports in this species, the horns of the hyobranchial apparatus are not related to the skull. Ossification of the body of the basihyale, the ceratobranchials and the rostral process and body of the cricoid cartilage of the larynx lends stability to these structures.

Self-Induced Vomiting as a Probable Mechanism of an Isolated Hyoid Bone Fracture

Fractures of the laryngeal skeleton (hyoid bone and thyroid horns) are an important finding in a forensic autopsy because they are almost always caused by significant trauma and often are relevant in determining the cause and manner of death. In the forensic setting, these injuries are seen in some hangings and more frequently in manual strangulation. Less common mechanisms include direct blows, "choke holds," and hyperextension of the neck. We present a case of a 37-year-old woman who died of complications of acute ethanol intoxication. The case involves an incidental hyoid bone fracture unrelated to the cause of death as well as facial petechiae. After review of all of the medical records, autopsy findings and scene/police investigations-the key findings of facial petechial hemorrhages and hyoid bone fracture are best attributed to the mechanism of self-induced vomiting. This case emphasizes the importance of synthesizing autopsy findings with the patient's medical and social history to avoid unnecessary investigation or prosecution. This is the second known case of this novel mechanism of hyoid bone fracture in the medical literature and the first in the forensic literature.

Transoral robotic surgery total laryngectomy

has been reported with feasibility trials andpromising initial data. The combination of the two proce-dures, supraglottic and hypopharyngeal TORS resection,can be adapted to perform a TORS total laryngectomy(TORS-TL). In the past, TORS-TL has been met with skep-tical criticism as to its ultimate clinical benefit. Conversely,the authors suggest that the minimally invasive TORSapproach offers significant benefits toward improvingpatient recuperation and the avoidance of substantial post-operative morbidity. However, such benefits can only bedemonstrated following repeated clinical experience. It isthe purpose of this report to describe the surgical protocolutilized by the authors to encourage further application andstudy of this promising surgical advancement.

Validation of Imaging with Pathology in Laryngeal Cancer: Accuracy of the Registration Methodology

To investigate the feasibility and accuracy of an automated method to validate gross tumor volume (GTV) delineations with pathology, in laryngeal and hypopharyngeal cancer. High resolution CT (CTHR), MRI, and positron emission tomography (PET) scans were obtained from 16 patients before total laryngectomy. The GTV was delineated in each imaging modality, separately. The laryngectomy specimen was fixed with formaldehyde, embedded in a block of agarose, sliced transversely in 3-mm thick slices, photographed, and whole-mount hematoxylin-eosin stained sections were obtained. Tumor tissue was delineated in the hematoxylin-eosin sections by a pathologist. A landmark based registration was performed to register the hematoxylin-eosin sections to the thick-slice photos. Using the thick-slice photos, an automatic 3D reconstruction of the specimen was performed. The CTHR was automatically and rigidly registered to the 3D-specimen. The MRI and the PET were rigidly registered to the 3D-specimen using the CTHR as intermediate. The accuracy of the pathology-imaging registration and the specimen deformation and shrinkage were assessed. The tumor delineation inaccuracies were assessed as the distance between the surfaces of the imaging based GTVs and the gold standard delineation (based on the hematoxylin-eosin sections). The tumor delineation inaccuracies were finally compared with the registration errors, to estimate the limits of the validation of the GTV delineations with our registration method. Good agreement was observed between anatomical landmarks in the 3D-specimen and in the in vivo images. Limited deformations and shrinkage (3 ± 1%) were found inside the cartilage skeleton. However, deformations were observed outside the skeleton, particularly in the epiglottis. The root mean squared error of the registration between the 3D-specimen and the CT, MRI and PET was on average 1.5, 3.0, and 3.3 mm, respectively, in the cartilage skeleton. The GTVs delineated based on the hematoxylin-eosin sections, CT, MRI, and PET generated a mean volume of 7.2, 14.9, 18.3, and 9.8 mL, respectively. The tumor coverage by the CT, MRI, and PET delineation was on average 85%, 88%, and 77%, respectively. The tumor delineation inaccuracies exceeded the registration error for 62%, 38%, and 37% of the GTV surface points, for CT, MRI, and PET, respectively. Validation of GTV delineation with pathology is feasible with an average overall accuracy below 3.5 mm inside the laryngeal skeleton. The tumor delineation inaccuracies were larger than the registration error; therefore, an accurate histological validation of anatomical and functional imaging techniques for GTV delineation is possible, in laryngeal and hypopharyngeal cancer patients.

Relation between PGS Invasion and LN Metastasis in SCPL

Objective: Transglottic cancer invading PGS is characteristically known to show a high incidence of laryngeal skeleton invasion and cervical metastasis. The objective was to determine the role of paraglottic space (PGS) invasion in lymph node metastasis in patients undergoing supracricoid partial laryngectomy (SCPL). Method: We retrospectively reviewed the clinical and pathological data of 98 patients who were diagnosed with glottis laryngeal carcinoma and underwent SCPL. We examined the relationship between PGS invasion and clinicopathological factors such as age, gender, tumor stage, vocal cord mobility, anterior commissure invasion, thyroid cartilage invasion, and subglottic extension. Results: The PGS invasion rate was 60.2% (59/98). Significant correlations were found between PGS invasion and cervical lymph node metastasis ( P = .022). Fifteen of the 59 patients (25.4 %) with the PGS invasion had cervical lymph node metastasis, whereas only 3 of the 39 patients (7.7%) without any evidence of PGS invasion had lymph node metastasis. There was also a significant correlation of PGS invasion with T stage ( P = .008), vocal cord mobility ( P = .001), and subglottic extension ( P = .014). Patients with no evidence of PGS invasion may have a survival benefit even without statistical significance ( P = .118). Conclusion: PGS invasion was found to be significantly related to the presence of cervical lymph node metastasis, which suggests that could be used to predict the presence of lymph node metastasis and to determine operative extent and prognosis in patients undergoing SCPL.

Validation of Imaging With Pathology in Laryngeal Cancer: Accuracy of the Registration Methodology

To investigate the feasibility and accuracy of an automated method to validate gross tumor volume (GTV) delineations with pathology in laryngeal and hypopharyngeal cancer. High-resolution computed tomography (CT(HR)), magnetic resonance imaging (MRI), and positron emission tomography (PET) scans were obtained from 10 patients before total laryngectomy. The GTV was delineated separately in each imaging modality. The laryngectomy specimen was sliced transversely in 3-mm-thick slices, and whole-mount hematoxylin-eosin stained (H&E) sections were obtained. A pathologist delineated tumor tissue in the H&E sections (GTV(PATH)). An automatic three-dimensional (3D) reconstruction of the specimen was performed, and the CT(HR), MRI, and PET were semiautomatically and rigidly registered to the 3D specimen. The accuracy of the pathology-imaging registration and the specimen deformation and shrinkage were assessed. The tumor delineation inaccuracies were compared with the registration errors. Good agreement was observed between anatomical landmarks in the 3D specimen and in the invivo images. Limited deformations and shrinkage (3% ± 1%) were found inside the cartilage skeleton. The root mean squared error of the registration between the 3D specimen and the CT, MRI, and PET was on average 1.5, 3.0, and 3.3 mm, respectively, in the cartilage skeleton. The GTV(PATH) volume was 7.2 mL, on average. The GTVs based on CT, MRI, and PET generated a mean volume of 14.9, 18.3, and 9.8 mL and covered the GTV(PATH) by 85%, 88%, and 77%, respectively. The tumor delineation inaccuracies exceeded the registration error in all the imaging modalities. Validation of GTV delineations with pathology is feasible with an average overall accuracy below 3.5 mm inside the laryngeal skeleton. The tumor delineation inaccuracies were larger than the registration error. Therefore, an accurate histological validation of anatomical and functional imaging techniques for GTV delineation is possible in laryngeal cancer patients.

Extraskeletal Giant Cell Tumor of the Larynx: Case Report and Review of the Literature

Giant cell tumors of the larynx typically arise within the laryngeal skeleton. We report a case of a laryngeal tumor in a 29-year-old man that clearly originated outside the laryngeal cartilage. It was identified as a soft-tissue giant cell tumor. To the best of our knowledge, an extraskeletal laryngeal giant cell tumor has not been previously reported.

Pseudarthroses of the cornu of the thyroid cartilage

Objective Injuries to the cartilaginous larynx are rare disorders that usually undergo good spontaneous healing and rarely require surgery. Study Design Case series with chart review from patients with pseudarthrosis of the cornu of the thyroid cartilage. Setting ENT department of a level I trauma center. Subjects and Methods We examined the medical records of seven patients treated for impaired healing of the cornu of the thyroid cartilage at a level I trauma center between 1997 and 2009. Results Seven patients were treated as a result of impaired healing of injuries to the cornu of the thyroid cartilage caused by trivial trauma (e.g., car accidents). The principal symptom was odynophagia. Computed tomography was used to confirm the diagnosis. Treatment involved resecting the cornu of the thyroid cartilage. Histology showed a hypertrophic pseudarthrosis at the base of the cornu. All patients were free of symptoms 10 days after resection. Conclusion Pseudarthrosis of the cornu of the thyroid cartilage is a previously undescribed condition. Pseudarthrosis of the laryngeal skeleton should be excluded in patients with odynophagia.

First Report of Intralaminar Tumorlike Lipomatous Lesions of the Thyroid Cartilage

We present two cases of tumorlike lipomatous lesions in the thyroid cartilage. Both presented as circumscribed tumors by ultrasonography and were identified accidentally. Two tumorlike lesions were identified in two different patients. Additionally, computed tomography and magnetic resonance imaging scans of the laryngeal skeleton were performed. Surgery was performed in one patient, and the lesion was excised. Histopathology revealed fatty tissue with several foci of hematopoietic cells. This is the first report of intralaminar tumorlike lipomatous lesions in the thyroid cartilage. These should be included in the differential diagnoses of primary cartilaginous lesions of the laryngeal skeleton.

Morphology and histology of the larynx of the common toad Rhinella arenarum (Hensel, 1867) (Anura, Bufonidae)

AbstractThe structure of the larynx of the toad Rhinella arenarum was exhaustively studied. The laryngeal skeleton consists of three bilaterally symmetrical cartilages: the cricoid and two arytenoids. Internally, each half‐larynx has an anterior and a posterior chamber. The first chamber is delimited by the epithelium covering the arytenoid cartilage and the anterior membrane. The latter consists of fibro‐elastic tissue and contains blood capillaries that, judging by their location and distribution, might serve to maintain vocal cord turgidity. At the level of the cricoid cartilage, two structures are reported here for the first time: the posterodorsal and the anteroventral processes. Both processes are associated with the insertion of the posterior membrane. A cartilaginous rod is located at the free margin of the posterior membrane. This rod appears to support the membrane when the air flows. The distal portion of the larynx communicates with the proximal region of the lung. The epithelium of the laryngeal mucosa contains ciliated cells, goblet cells, secretory cells with short microvilli and neuroendocrine cells immunopositive to PGP 9.5. The results obtained in this study provide new information about the internal organization of the larynx in anurans, which could serve as additional morphological characters for phylogenetic relationships.