Swallowing kinematics and submental muscles activation during a newly designed maneuver called Mouth Open Swallowing Maneuver: A comparative study.

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).

Lowered hyoid bone overlapping the thyroid cartilage in CT angiograms.

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.

Intraosseous hemangioma with aneurysmal bone cyst-like changes of the hyoid bone: Case report and literature review.

RATIONALE: Intraosseous hemangioma is a rare benign vascular tumor of the bone that can affect any body part; however, the most common site is the vertebra, followed by calvarial bones. PATIENT CONCERNS: We present a case of intraosseous hemangioma in a 23-year-old male who presented a feeling of fullness in the throat for 3 months. The hyoid bone level had a hard mass of about 5 cm. Fine needle aspiration showed 5 mL dark bloody aspirates. Magnetic resonance image showed a 5.3 cm mixed signal intensity lesion in the hyoid body. DIAGNOSIS: Histopathologic examination showed intraosseous hemangioma with aneurysmal bone cyst (ABC)-like changes in the hyoid bone. INTERVENTIONS: The mass was completely removed without significant problems. OUTCOMES: Complete mass excision and symptomatic improvements were achieved, and no subsequent relapses were observed. LESSONS: The authors experienced a case of intraosseous hemangioma with ABC-like changes. There has been no case report of intraosseous hemangioma in the hyoid bone. This case showed a spectral pattern of the ABC-like changes developing from the underlying bone tumor as a secondary change. ABC-like changes in bone tumors can mislead the diagnosis. Careful examination of the tumor is essential for the correct diagnosis of ABC or ABC-like changes.

Biomechanical and Cortical Control of Tongue Movements During Chewing and Swallowing.

Tongue function is vital for chewing and swallowing and lingual dysfunction is often associated with dysphagia. Better treatment of dysphagia depends on a better understanding of hyolingual morphology, biomechanics, and neural control in humans and animal models. Recent research has revealed significant variation among animal models in morphology of the hyoid chain and suprahyoid muscles which may be associated with variation in swallowing mechanisms. The recent deployment of XROMM (X-ray Reconstruction of Moving Morphology) to quantify 3D hyolingual kinematics has revealed new details on flexion and roll of the tongue during chewing in animal models, movements similar to those used by humans. XROMM-based studies of swallowing in macaques have falsified traditional hypotheses of mechanisms of tongue base retraction during swallowing, and literature review suggests that other animal models may employ a diversity of mechanisms of tongue base retraction. There is variation among animal models in distribution of hyolingual proprioceptors but how that might be related to lingual mechanics is unknown. In macaque monkeys, tongue kinematics-shape and movement-are strongly encoded in neural activity in orofacial primary motor cortex, giving optimism for development of brain-machine interfaces for assisting recovery of lingual function after stroke. However, more research on hyolingual biomechanics and control is needed for technologies interfacing the nervous system with the hyolingual apparatus to become a reality.

Gender differences in the upper airway, craniofacial morphological and polysomnographic parameters in patients with obstructive sleep apnoea.

BACKGROUND: Obstructive sleep apnoea (OSA) is a common sleep disorder characterized by repetitive episodes of upper airway collapse during sleep associated with arousals with or without oxygen desaturation. OBJECTIVE: This study aims to assess and analyse the morphological and neurological factors associated with obstructive sleep apnoea using polysomnography study data and two-dimensional cephalometric analysis of airway and skeletal parameters and their correlation in the patients with varying severities of obstructive sleep apnoea. METHODS: This study included 892 patients who underwent a complete work up, including a thorough history, clinical examination, standard polysomnography study and 2D cephalometric analysis to diagnose obstructive sleep apnoea. This study divided the participants into two groups based on the AHI score from the PSG study: AHI < 15 and AHI > 15 groups. The groups were further divided into male and female groups to study the prevalence of OSA. The analysis involved 13 cephalometric parameters: Seven linear and six angular measurements. The airway parameters measured in this study were minimum posterior airway space (PAS_min), hyoid bone to the mandibular plane (H_MNP) and soft palate length (SPL). All the subjects in this study underwent a standard overnight polysomnography study at the sleep centre in Samsung Medical Center. RESULTS: A total of 892 adult participants (M: F = 727:165, mean age: 50.6 ± 13.2 years and age range: 18-85 years). AHI >15 group was significantly older with higher BMI, NC and WC compared to the AHI < 15 groups in both male and female groups. There was statistical significance observed in N1, N3, AI, ODI, lowest saturation (%) and apnoea max length between the groups (p < .001). The arousal index (AI), especially the respiratory arousal index was considerably higher in the male group. There were significantly higher values in all the PSG parameters in the male group. In the airway parameters, hyoid bone position and soft palate length showed significant differences (p < .001), whereas the PAS did not show any differences (p = .225) between the AHI <15 and AHI >15 groups. The overall skeletal cephalometric parameters showed no significant differences between the groups, whereas the gonial angle and AB to mandibular plane angle showed significant differences in the female group (p = .028, p = .041 respectively). CONCLUSION: The partial correlation of cephalometric parameters with AHI showed a stronger correlation between the H_MNP and AHI in both men and women. The position of the hyoid bone and the soft palate length influences the progression of OSA, especially in male patients. This study found no direct association between the minimum PAS and varying severities of OSA in men and women. We speculate that more than the craniofacial morphological factors such as the sagittal and vertical position of the maxilla and the mandible, the position of the hyoid bone might be more responsible for the severity of OSA.

Impact of Varying Transcutaneous Electrical Stimulation Pulse Frequency on Swallow Timing Measures in Healthy Adults.

The impaired swallow timing subsequent to dysphagia or aging can potentially endanger swallowing safety and efficiency. Preliminary evidence has suggested that transcutaneous electrical stimulation (TES) may have the potential to affect swallow timing. However, limited knowledge exists regarding which TES parameters can optimize swallow timing. Pulse frequency is one of the primary TES parameters that can affect the quality of muscle contraction. Yet, no clear information exists regarding how changing pulse frequency impacts the timing of swallowing events. This study aimed to investigate the varying effects of submental TES pulse frequency on swallowing events during and post-15-min TES administration. Twenty-six healthy individuals between the ages of 20 and 54 participated in this study and were assigned to high pulse frequency (HPF) (80 Hz) or low pulse frequency (LPF) (30 Hz) groups. Videofluoroscopic swallowing study (VFSS) was used to record swallowing. Three trials of 10 mL pureed mixed with barium sulfate were presented under three different conditions, including pre-TES, during TES, and post-TES, in which measures were taken following 15 min of TES delivery. The swallow timing events that were measured in each condition were time to maximum hyoid elevation, time to maximum laryngeal elevation, laryngeal vestibule closure reaction time (LVCrt), laryngeal vestibule closure duration (LVCd), time to maximum pharyngeal constriction, and pharyngoesophageal segment (PES) opening duration. No significant pulse frequency effect was found on any swallow timing measures during or after 15 min of TES. Both protocols decreased the duration of some swallowing events during TES including time to maximum hyoid elevation [p < 0.017, ηp2 = 0.185], LVCrt [p < 0.032, ηp2 = 0.158], and time to maximum pharyngeal constriction [p < 0.034, ηp2 = 0.155]. None of the significant TES effects were continued when TES ceased after 15 min. Overall, both protocols have comparable immediate effects on shortening the duration of some swallowing events during TES. Future clinical trials should examine whether these physiologic timing changes can lead to safer and more efficient swallows in patients with dysphagia.

Sex estimation from the hyoid bone measurements in an adult Eastern Turkish population using 3D CT images, discriminant function analysis, support vector machines, and artificial neural networks☆.

The hyoid bone is one of the bones in the human body that shows sexual dimorphism. The anthropological and anthropometric characteristics that determine sexual dimorphism are influenced by demographic differences. The aim of this study was to investigate the rate of sexual dimorphism of the hyoid bone in the adult Eastern Turkish population from the examination of the 3D computed tomography images of 240 patients, using discriminant function analysis (DFA), support vector machines (SVM), and artificial neural networks (ANN). These evaluations were based on eight hyoid measurements that have been frequently used in previous CT studies. The results showed that all eight measurements were higher in males than in females (p = 0.000). It was determined that sex could be estimated accurately at up to 93.3 % using DFA, 93.8 % using SVM and 95.4 % using ANN. The maximum accuracy rate achieved to 94.2 % in males using SVM, and 95.8 % in females using ANN. These high rates of sexual dimorphism found using DFA, SVM, and ANN in this study indicate that characteristics of the hyoid bone can be utilized to determine sex in the Eastern Turkish population.

Organismal form constrains the evolution of complex lever systems in Neotropical cichlid four-bar linkages.

The diversification of functional traits may be limited by the intrinsic constraints of organismal form (i.e., constructional constraints), owing to the differential investment in different anatomical structures. In this study, we test whether overall organismal form impacts the evolution of shape and function in complex lever systems. We examined the relationship between four-bar shape and overall head shape in two four-bar linkage systems: the oral-jaw and hyoid-neurocranium systems in Neotropical cichlids. We also investigated the strength of form-function mapping in these four-bar linkages and the impact of constraining head shape on these correlations. We quantified the shape of the head and two four-bar linkages using geometric morphometrics and compared these with the kinematic transmission coefficient of each linkage system. The shapes of both linkages were strongly correlated with their mechanical properties, and head shape appears to constrain the shape of both four-bar linkages. Head shape induced greater integration between the two linkages, was associated with stronger form-function correlations and higher rates of evolution in biomechanically important features. Head shape constraints may also contribute to a weak but significant trade-off in linkage kinematics. Elongation of the head and body, in particular, appears to minimize the impact of this trade-off, possibly through maximizing anterior-posterior space availability. However, the strength of relationships between shape and function, and the impact of head shape differed between the two linkages, with the hyoid four-bar in general showing stronger form-function relationships despite being more independent from head shape constraints.

Assessment of Soft Tissue, Airway Dimension and Hyoid Bone Position in Class II Patients Treated by PowerScope Class 2 Corrector.

AIM: This study aims to assess the changes in the soft tissue, pharyngeal airway dimensions, and hyoid bone position in patients treated with PowerScope Class 2 corrector to correct the skeletal Class II pattern. MATERIALS AND METHODS: This study was conducted on a sample of 20 cases diagnosed with Class II malocclusion. The lateral cephalograms were taken before (T1) and after functional appliance therapy (T2) and were traced. The outcomes were compared for the mean changes in soft tissue, airway way dimension, and hyoid bone position. The paired t-test was used for the data comparisons wherein p < 0.05 was kept for statistical significance. RESULTS: The mean values before and after treatment for H angle, mentolabial angle, lower lip E-line, upper lip S-line, lower lip S-line, and lip strain were 19.88 ± 2.77 vs 17.13 ± 1.659, 94.09 ± 12.164 vs 101.75 ± 11.28, -2.47 ± 1.213 vs -1.38 ± 0.976, 3.99 ± 0.19 vs 2.64 ± 0.32, 9.01 ± 0.247 vs 9.43 ± 0.238, 10.24 ± 0.510 vs 10.64 ± 0.52, respectively, which were statistically significant (p < 0.05). All airway spaces (except for lower pharyngeal space) and hyoid bone parameters were significantly improved posttreatment. CONCLUSION: The facial convexity, upper E-line, Z-angle, nasolabial angle, and lower pharyngeal space did not show statistically significant changes. The rest of the soft tissue parameters, oropharyngeal air spaces, and hyoid positioning measured in the study showed significant improvement after treatment with the PowerScope appliance in Class II patients. CLINICAL SIGNIFICANCE: Class II malocclusion is the most common dental anomaly with a high degree of prevalence in the population. This study will help the clinician in understanding the improvement of soft tissue, airway dimension, and hyoid bone position changes on treatment with a fixed functional appliance for the correction of Class II cases, thereby ensuring the greater success of orthodontic therapy in the future.

Tratamento cirúrgico do cisto epidermóide situado anteriormente ao osso hióide: relato de caso / The surgery treatament of epidermoid cyst situated anteriorly to the hyoid bone: case report / Tratamiento quirúrgico del quiste epidermoide situado anterior al hueso hioides: reporte de um caso

O cisto epidermóide (CE) é uma má formação cística de desenvolvimento incomum. Ocorre mais comumente na linha média do assoalho da boca, ocasionalmente localiza-se lateralmente ou em outros sítios. A etiologia do CE ainda é incerta, mas acredita-se que esteja associado a remanentes do ectoderma durante a fusão do primeiro e segundo arcos branquiais. A lesão cresce lentamente sem provocar dor, apresentando-se como massa de consistência semelhante à de borracha ou à massa de pão. Seu diagnóstico se dá por meio de exame clínico e exames complementares de imagem como tomografia computadorizada, ressonância magnética e/ou ultrassonografia, entretanto somente com o exame histopatológico é possível um diagnóstico definitivo. A excisão cirúrgica do cisto é o tratamento de escolha. Quando o diagnóstico é precoce e a intervenção correta, o índice de recidiva torna-se raro. Diante da raridade de casos na região maxilo facial e a dificuldade relacionada ao diagnóstico, o presente trabalho tem como objetivos descrever a ocorrência do cisto epidermóide bem como seu diagnóstico através de exame histopatológico/exames de imagem, tratamento cirúrgico e contribuir com a literatura já existente por meio de um relato de caso que foi diagnosticado no Serviço de Patologia Bucal da Universidade de Gurupi, campus Gurupi/TO.

Epidermoid cysts (EC) is an unusually developing cystic malformation that occurs most frequently in the midline of the floor of the mouth, occasionally located laterally or elsewhere. The etiology of the (EC) still uncertain, but it is believed to be associated with remnants of the ectoderm during the fusion of the first and second branchial arches. The lesion grows slowly without causing pain, presenting itself as a mass with a consistency like of rubber or bread dough. Diagnosis of (EC) is made through complementary imaging tests such as computed tomography, magnetic resonance imaging and/or ultrasound, only histopathological examination it is possible to obtain a definitive diagnosis. Surgical excision of cyst is the treatment of choice. When the diagnosis is made early and the intervention is correct, the recurrence rate is rare. Given the rarity of cases in the maxillofacial region and the difficulty related to diagnosis, this study aims to describe epidermoid cysts occurrence and your diagnostic through of histopathologic/imagine exams, surgical treatment and contribute to the existing literature, through a review and description of a clinical case that was diagnosed at the Oral Pathology Outpatient Clinic at the Faculty of Dentistry - University of Gurupi - UNIRG. Gurupi -Tocantins. Brazil.

El quiste epidermoide (CE) es una malformación quística de desarrollo infrecuente. Ocurre más comúnmente en la línea media del piso de la boca, ocasionalmente se localiza lateralmente o en otra parte. La etiología de la FB aún es incierta, pero se cree que está asociada con restos del ectodermo durante la fusión del primer y segundo arcos branquiales. La lesión crece lentamente sin causar dolor, apareciendo como una masa con una consistencia similar a la de la goma o la masa de pan. Su diagnóstico se realiza a través del examen clínico y pruebas de imagen complementarias como tomografía computarizada, resonancia magnética y/o ultrasonografía, sin embargo, solo con el examen histopatológico es posible un diagnóstico defi nitivo. La escisión quirúrgica del quiste es el tratamiento de elección. Cuando el diagnóstico es temprano y la intervención es correcta, la tasa de recurrencia se vuelve rara. Dada la rareza de los casos en la región maxilofacial y la difi cultad relacionada con el diagnóstico, el presente trabajo tiene como objetivo describir la ocurrencia del quiste epidermoide así como su diagnóstico a través del examen histopatológico/pruebas de imagen, tratamiento quirúrgico y contribuir a la literatura existente a través de un reporte de caso que fue diagnosticado en el Servicio de Patología Oral de la Universidad de Gurupi, campus Gurupi/TO.

Effect of premolar extraction and anchorage type for orthodontic space closure on upper airway dimensions and position of hyoid bone in adults: a retrospective cephalometric assessment.

Background: This study aimed to assess the effect of premolar extraction and anchorage type for orthodontic space closure on upper airway dimensions and position of hyoid bone in adults by cephalometric assessment. Methods: This retrospective study was conducted on 142 cephalograms of patients who underwent orthodontic treatment with premolar extraction in four groups of (I) 40 class I patients with bimaxillary protrusion and maximum anchorage, (II) 40 class I patients with moderate crowding and anchorage, (III) 40 class II patients with maximum anchorage, and (IV) 22 skeletal class III patients with maximum anchorage. The dimensions of the nasopharynx, velopharynx, oropharynx, and hypopharynx, and hyoid bone position were assessed on pre- and postoperative lateral cephalograms using AudaxCeph v6.1.4.3951 software. Data were analyzed by the Chi-square test, paired t-test, and Pearson's correlation test (alpha = 0.05). Results: A significant reduction in oropharyngeal, velopharyngeal, and hypopharyngeal airway dimensions was noted in groups I, III, and IV (P < 0.001), which was correlated with the magnitude of retraction of upper and lower incisors (r = 0.6 - 0.8). In group II, a significant increase was observed in oropharyngeal and velopharyngeal dimensions (P < 0.001). A significant increase in nasopharyngeal dimensions occurred in all groups (P < 0.001). Also, in groups I and III, the position of hyoid bone changed downwards and backwards, which was correlated with reduction in airway dimensions (r = 0.4 - 0.6). Conclusion: According to the present results, extraction orthodontic treatment affects upper airway dimensions and hyoid bone position. Maximum anchorage decreases airway dimensions while moderate anchorage increases airway dimensions.

Biomimetic intruder tip design for horizontal penetration into a granular pile.

In nature, woodpeckers peck trees with no reported brain injury. A highly functional system comprising a hyoid bone, smooth skull, straight pointed beak with varying lengths of upper and lower beak bones, and rhamphotheca is one of the adaptations that enable efficient pecking. Soil penetration is an energy-intensive procedure used in civil infrastructure applications and is often followed by pushing, impact driving, and digging. This study uses discrete element modeling to evaluate the effect of woodpecker beak mimetic intruder tip design with wedge offsets on lift and drag forces during horizontal penetration into granular piles. The findings show that the wedge offsets of the intruder have a negligible effect on drag forces. By contrast, lift forces can be manipulated by adjusting the top and bottom offsets of the intruder, which can be used to guide the intruder upward, downwards, or horizontally. Furthermore, as the width of the intruder increased, the lift and drag forces also increased.

Pre-mandibular pharyngeal pouches in early non-teleost fish embryos.

The vertebrate pharynx is a key embryonic structure with crucial importance for the metameric organization of the head and face. The pharynx is primarily built upon progressive formation of paired pharyngeal pouches that typically develop in post-oral (mandibular, hyoid and branchial) domains. However, in the early embryos of non-teleost fishes, we have previously identified pharyngeal pouch-like outpocketings also in the pre-oral domain of the cranial endoderm. This pre-oral gut (POG) forms by early pouching of the primitive gut cavity, followed by the sequential formation of typical (post-oral) pharyngeal pouches. Here, we tested the pharyngeal nature of the POG by analysing expression patterns of selected core pharyngeal regulatory network genes in bichir and sturgeon embryos. Our comparison revealed generally shared expression patterns, including Shh, Pax9, Tbx1, Eya1, Six1, Ripply3 or Fgf8, between early POG and post-oral pharyngeal pouches. POG thus shares pharyngeal pouch-like morphogenesis and a gene expression profile with pharyngeal pouches and can be regarded as a pre-mandibular pharyngeal pouch. We further suggest that pre-mandibular pharyngeal pouches represent a plesiomorphic vertebrate trait inherited from our ancestor's pharyngeal metameric organization, which is incorporated in the early formation of the pre-chordal plate of vertebrate embryos.

Comparison of invisalign mandibular advancement and twin-block on upper airway and hyoid bone position improvements for skeletal class II children: a retrospective study.

BACKGROUND: This study is to evaluate and compare the improvement of upper airway morphology and hyoid bone position in children with Class II mandibular retrusion treated with Invisalign mandibular advancement (MA) and Twin-Block (TB) appliances, utilizing cone beam computed tomography (CBCT). METHODS: 32 children aged between 8 and 11.5 years old were included in this study, with an average age of 10.2 years old. These children were divided into two groups, MA and TB, with 16 children in each group. Changes in upper airway morphology and hyoid bone position before and after treatment were analyzed using CBCT. RESULTS: (1) Changes in upper airway before and after treatment: the oropharynx volume (Or-V), the oropharynx minimum cross-sectional area (Or-mCSA), the hypopharynx volume (Hy-V), and the hypopharynx minimum cross-sectional area (Hy-mCSA) in both the MA and TB groups increased after treatment, and the differences were statistically significant (P < 0.05) compared to pre-treatment status. (2) Changes in hyoid bone position before and after treatment: The distances between H point and third cervical vertebra (H-C3), H point and pogonion (H-RGN), H point and mandibular plane (H-MP), H point and Frankfort horizontal plane (H-FH), H and S point (H-S), and H point and palatal plane (H-PP) in both the MA and TB groups increased after treatment, and the differences were statistically significant (P < 0.05). CONCLUSION: Both MA and TB appliances effectively improved the structural narrowness of the upper airway and reduced respiratory resistance, thus improving breath quality. However, MA showed more effectiveness in improving the narrowest part of the hypopharynx compared to TB. Both appliances also promoted anterior downward movement of the hyoid bone, which opens the upper airway of the oropharynx and hypopharynx and helps the upper airway morphology return to normal range.

The roar of Rancho La Brea? Comparative anatomy of modern and fossil felid hyoid bones.

Animal vocalization is broadly recognized as ecologically and evolutionarily important. In mammals, hyoid elements may influence vocalization repertoires because the hyoid apparatus anchors vocal tissues, and its morphology can be associated with variation in surrounding soft-tissue vocal anatomy. Thus, fossil hyoid morphology has the potential to shed light on vocalizations in extinct taxa. Yet, we know little about the hyoid morphology of extinct species because hyoid elements are rare in the fossil record. An exception is found in the Rancho La Brea tar pits in Los Angeles, California, where enough hyoids have been preserved to allow for quantitative analyses. The La Brea Tar Pits and Museum houses one of the largest and most diverse collections of carnivore fossils, including hyoid elements from the extinct felids Smilodon fatalis and Panthera atrox. Here, we found that extant members of Felinae (purring cats) and Panthera (roaring cats) showed characteristic differences in hyoid size and shape that suggest possible functional relationships with vocalization. The two extinct taxa had larger and more robust hyoids than extant felids, potentially reflecting the ability to produce lower frequency vocalizations as well as more substantial muscles associated with swallowing and respiration. Based on the shape of the hyoid elements, Panthera atrox resembled roaring cats, while Smilodon fatalis was quite variable and, contrary to suggestions from previous research, more similar overall to purring felids. Thus P. atrox may have roared and S. fatalis may have produced vocalizations similar to extant purring cats but at a lower frequency. Due to the confounding of vocalization repertoire and phylogenetic history in extant Felidae, we cannot distinguish between morphological signals related to vocalization behavior and those related to shared evolutionary history unrelated to vocalization.

Three-dimensional evaluation of upper pharyngeal airway, hyoid bone, and craniocervical changes following stabilization splint therapy in adult patients with temporomandibular joint disorders and mandibular deviation: A retrospective study.

OBJECTIVE: This study aimed primarily to analyze the three-dimensional (3D) changes in the pharyngeal airway (PA), and secondarily, the hyoid bone (HB) and the craniocervical (CC) following stabilization splint (SS) therapy in adult patients with temporomandibular joint disorders (TMD) and mandibular deviation (MD). METHODS: Thirty-five adult patients with TMD and MD, who were treated using SS with a mean age of 25.14 ± 6.11 years, were enrolled in this retrospective clinical study. Pre- and post-therapeutic cone-beam computed tomography (CBCT) scans were analyzed. PA dimension,nasopharyngeal, oropharyngeal, hypopharyngeal, sub-hypopharyngeal, and total pharyngeal airway spaces were measured in surface area, volume, minimum constricted area (MCA) and width, HB position, and CC posture were analyzed three-dimensionally using InVivo 6.0.3 and Dolphin 11.95 software. Wilcoxon rank-sum or Paired t-test was conducted, and P < 0.05 was considered significant. RESULTS: SS therapy was administered for a period of 9.49 ± 4.02 months. The oropharyngeal airway space showed a significant decrease in sagittal width. The hypopharyngeal surface area, volume, MCA, and sagittal width decreased significantly. In terms of HB, hyoid-mandibular plane (H-MP), retrognathia-third vertebra's most inferior-anterior (RGN-C3ia), and retrognathia-Sella (RGN-S) distances significantly decreased. The Nasion-Sella line and the line that passes through C2ip to the odontoid process posterior tangent (NSL-OPT) angle in CC posture also decreased significantly. CONCLUSION: SS therapy in TMD patients with MD mainly results in narrowing of the hypopharyngeal region, no change in HB position and improvement in head posture. These results undoubtedly assist in diagnosis and treatment of clinical conditions.

Three-dimensional evaluation of alveolar bone and pharyngeal airway dimensions after mandibular dentition distalization in patients with Class III malocclusion: a retrospective study.

BACKGROUND: To three-dimensionally evaluate changes of the alveolar bone around the mandibular anterior teeth and pharyngeal airway dimensions in adults with Class III malocclusion before and after orthodontic treatment of mandibular dentition distalization. METHODS: In this retrospective study, cone-beam computed tomography (CBCT) scans of 20 patients with Class III malocclusion who underwent mandibular dentition distalization were obtained both before and after treatment. Three-dimensional changes of the thickness and vertical marginal bone levels around mandibular incisors and canines were assessed and compared. And airway volumes of the palato-, glosso-, laryngopharynx and the minimum axial area were measured and compared before and after treatment. RESULTS: A significant decrease of lingual bone thickness of mandibular incisors, partial labial and lingual bone thickness of canines were observed (P < 0.05). The reduction in root length of incisors and canines, labial and lingual vertical marginal bone levels were significant after orthodontic treatment. No significant correlations between mandibular dentition distalization and pharyngeal airway dimensions were observed. CONCLUSIONS: Mandibular dentition distalization could result in the loss of alveolar bone around anterior teeth in Class III malocclusion, especially for the cervical marginal bone. Pharyngeal airway dimensions were not affected to a high extent after distalization. TRIAL REGISTRATION: Retrospctively registered.

The Carotid-Hyoid Topography Is Variable.

Background and Objectives: The carotid bifurcation (CB) is presented in most anatomy textbooks as having a unique location at the upper margin of the thyroid cartilage. Although a number of case reports have provided evidence of the possibility of carotid artery location either lateral or medial to the greater hyoid horn, these reports have not established specific anatomic possibilities and prevalences. Materials and Methods: We retrospectively analysed a batch of 147 CT angiograms for 12 types of carotid-hyoid relationships and classified the bilateral combination possibilities of these types. Results: In 168/294 sides there were no carotid-hyoid relationships. Type I, external carotid artery (ECA) medial to the greater horn of the hyoid bone (GHHB), was observed in 0.34%; type II, internal carotid artery (ICA) medial to GHHB, in 0.34%; type III, ICA and ECA medial to GHHB, in 1.02%; type IV, common carotid artery (CCA) medial to GHHB, in 1.02%; type V, CB medial to GHHB, in 0.34%; type VI, ECA lateral to GHHB, in 20.41%; type VII, ICA lateral to GHHB, was not recorded; type VIII, ECA and ICA lateral to GHHB, in 3.74%; type IX, CCA lateral to GHHB, in 8.5%; type X, CB lateral to GHHB, in 6.46%; type XI, ECA lateral and ICA medial to GHHB, in 0.34%; and type XII, ICA lateral and ECA medial to GHHB, in 0.34%. Bilateral symmetry was found in 70.74% of cases, including the null types without carotid-hyoid relationships as well as types IV, VI, VIII, IX, and X. There was a highly significant association between the left and right variants of the carotid-hyoid relationship. Conclusions: Mechanical compression of the hyoid bone on the carotid arteries has various undesirable effects on the ICA and cerebral circulation. Underlying these are several variational anatomical patterns of carotid-hyoid relationships, which can be accurately documented on CT angiograms. A case-by-case anatomical study is better than assuming the carotid anatomy learned from textbooks.

Pharyngeal airway subdivisions in 3-dimensional analysis: Differences between anterior and posterior anatomic boundaries.

INTRODUCTION: This study aimed to evaluate if there were differences between anterior and posterior anatomic boundaries used for the 3-dimensional determination of pharyngeal airway. METHODS: The sample included 150 cone-beam computed tomography scans from healthy patients divided according to (1) age: 6-11, 12-16, and ≥16 years; (2) sex: female and male; (3) anteroposterior skeletal pattern: Class I, II, and III; (4) vertical pattern: brachyfacial, mesofacial, and dolichofacial; and (5) craniocervical inclination (CCI): natural head posture, head flexion, and head extension. Anatomic regions were created to determine the correspondences between structures anteriorly and posteriorly to the pharyngeal airway. RESULTS: The location of the epiglottis, vallecula, hyoid, C2, and C3 were statistically different according to the CCI, and the location of vallecula, C3, and C4 were different according to sex. However, no statistically significant differences were observed between the frequencies of anterior and posterior anatomic region locations among age and different anteroposterior and vertical skeletal patterns. Posterior landmarks tend to be located below the anterior ones; consequently, the anatomic subregion they define will also be located below. CONCLUSIONS: Anterior and posterior structures and vertical and anteroposterior skeletal patterns may determine upper airway limits regardless of age. However, the studies must be paired according to sex, and CCI must be standardized.