Deglutition anatomy

The glossopharyngeal nerve is a complicated and mixed nerve including sensory, motor, parasympathetic, and visceral fibers. It mediates taste, salivation, and swallowing. The low cranial nerves, including IXth, Xth, and XIth, are closely related, sharing some nuclei in the brainstem. The glossopharyngeal nerve arises from the spinal trigeminal nucleus and tract, solitary tract and nucleus, nucleus ambiguous, and inferior salivatory nucleus in the brainstem. There are communicating branches forming a neural anastomotic network between low cranial nerves...

BACKGROUND AND PURPOSE: Auto-contouring of complex anatomy in computed tomography (CT) scans is a highly anticipated solution to many problems in radiotherapy. In this study, artificial intelligence (AI)-based auto-contouring models were clinically validated for lymph node levels and structures of swallowing and chewing in the head and neck. MATERIALS AND METHODS: CT scans of 145 head and neck radiotherapy patients were retrospectively curated. One cohort (n = 47) was used to analyze seven lymph node levels and the other (n = 98) used to analyze 17 swallowing and chewing structures...

Although the epiglottis plays a vital role in deglutition, histological studies of the epiglottis and surrounding ligaments associated with swallowing dysfunction are limited. Therefore, we performed histological observations to clarify age-related changes in the morphological characteristics of the epiglottis and surrounding structures. Tissue samples comprising the epiglottis and surrounding structures were collected from corpses that were both orally fed and tube-fed during their lifetimes. Following hematoxylin and eosin, Elastica Van Gieson, and immunohistochemical staining procedures, the chondrocytes, connective tissue, and glandular tissue were observed under the epiglottis epithelium, and intervening adipose tissue was observed in the surrounding area...

The effects of head and neck alignment and pharyngeal anatomy on epiglottic inversion remain unclear. This study investigated the factors involved in epiglottic inversion, including head and neck alignment and pharyngeal anatomy, in patients with dysphagia. Patients with a chief complaint of dysphagia and who underwent videofluoroscopic swallowing study at our hospital from January to July 2022 were enrolled. They were divided into three groups based on the degree of epiglottic inversion as the complete-inversion (CI), partial-inversion (PI), and non-inversion group (NI) groups...

The restoration of speech, deglutition, mastication, and respiration in patients with bimaxillary resection involving the maxillae, hard and soft palates, and paranasal sinuses poses a significant challenge. This clinical report describes the prosthodontic management of a patient with bilateral maxillectomy caused due to post-COVID-19 mucormycosis. A patient-specific implants (PSI) that matched the remnants of the zygoma complex was designed to improve the patient's severely impaired speech and swallowing. The patient's postsurgical anatomy was first visualized using three-dimensional computed tomography data...

The larynx serves as the gateway between the upper and lower respiratory tracts and is involved in the tasks of phonation, deglutition, and airway protection. Familiarity with the complex anatomy of the larynx is critical for detecting and characterizing disease in the region, especially in cancer staging. In this article, we review the anatomy of the larynx and cervical trachea, including an overview of their cartilages, supporting tissues, muscles, mucosal spaces, neurovascular supply, and lymphatics, followed by correlation to the clinically relevant anatomic sites of the larynx...

Preservation of laryngeal functions after supraglottic laryngectomy depends on both the extent of surgical resection and the type of reconstruction. Any reconstructive modality faces the challenges of preserving voice and swallow function due to the complex and dynamic anatomy of the larynx. In this report, we present a case in which the entire affected unilateral supraglottis and piriform sinus were functionally reconstructed using a triple chimeric superficial circumflex iliac artery perforator (SCIP) free flap...

Several reconstructive methods have been reported to restore the continuity of the aerodigestive tract following resection of pharyngeal and hypopharyngeal cancers. However, high complication rates have been reported after voice prosthesis insertion. In this setting, the ileocolon free flap (ICFF) offers a tubularized flap for reconstruction of the hypopharynx while providing a natural phonation tube. Herein, we systematically reviewed the current evidence on the use of the ICFF for reconstruction of the aerodigestive tract...

Abandoned harbour seal pups (Phoca vitulina) are frequently recovered by rehabilitation centres and often require intensive nursing, gavage feeding and swallowing rehabilitation prior to anticipated release. Seal upper aerodigestive tract (UAT) histology descriptions relevant to deglutition are limited, impacting advances in rehabilitation practice. Therefore, we examined the histological characteristics of the harbour seal UAT to understand species-specific functional anatomy and characterize adaptations. To this end, we conducted gross dissections, compiled measurements and reviewed histologic features of the UAT structures of 14 pre-weaned harbour seal pups that died due to natural causes or were humanely euthanized...

Epiglottic retroversion is difficult to explain anatomically. One reason is inadequate structural identification of the ligaments in the submucosal tissue anterior to the epiglottis (pre-epiglottic space, PES). Although studies have shown that tongue root movement plays a role in epiglottic retroversion, few morphological reports have investigated the attachment of the lingual muscles to the epiglottis. This study reconstructed the fiber structure of the PES by comprehensively analyzing fiber alignment in the PES focusing on the hyoepiglottic ligament, which runs between the lingual muscles and the epiglottis...

The mammalian respiratory and digestive tracts are configured to enable simultaneous function of both systems, while preventing accidental choking on food. This protection is critical in mysticetes (baleen whales), especially as feeding involves large pressures and potential inundation of water. Dissections were performed on 43 specimens representing 8 mysticete species: fin, blue, sei, minke, humpback, gray, right, and pygmy right whales. 36 specimens were necropsied as whole carcasses, 5 were obtained as whole heads, 2 were whole fetuses...

The Modified Barium Swallow Study (MBSS) is a videofluoroscopic examination of the anatomy and physiology involved in swallowing. Like other fluoroscopic examinations, the MBSS uses ionizing radiation with related radiation risks. Thus, the procedures and protocols related to MBSSs must balance the benefit of the diagnostic information gained with the risk of radiation exposure. This requires complex decision-making for any given clinician but becomes complicated due to the interprofessional nature of conducting MBSSs, namely the direct involvement of both the speech-language pathologist and radiologist with indirect involvement of the medical physicist and the referring physician...

Dysphagia results from diverse and distinct etiologies. The pathway from anatomy and physiology to clinical diagnosis is complex and hierarchical. Our approach in this paper is to show the linkages from the underlying anatomy and physiology to the clinical presentation. In particular, the terms performance, function, behavior, and physiology are often used interchangeably, which we argue is an obstacle to clear discussion of mechanism of pathophysiology. We use examples from pediatric populations to highlight the importance of understanding anatomy and physiology to inform clinical practice...

Systemic sclerosis is a connective tissue disease that presents with significant gastrointestinal involvement, commonly in the esophagus. Dysphagia is a common clinical manifestation of systemic sclerosis and is strongly related to esophageal dysmotility. However, there are multiple other contributing factors in each step in the physiology of swallowing that may contribute to development of severe dysphagia. The oral phase of swallowing may be disrupted by poor mastication due to microstomia and poor dentition, as well as by xerostomia...

The external carotid artery (ECA) commonly ascends in the retromandibular fossa and bifurcates posteromedial to the neck of the mandible into the maxillary (MA) and superficial temporal (STA) arteries. In its course in the neck, the ECA gives off the superior thyroid, lingual (LA), facial (FA), ascending pharyngeal (APA), occipital (OA) and posterior auricular (PAA) arteries. When the computed tomography angiograms of a 65-year-old male were evaluated, extremely rare anatomical variations of both ECAs were found...

PURPOSE: The soft palate (SP) has a complex anatomy and physiology. Reconstruction after tumour resection is a challenge, and procedures that only restore bulk don't give good results. We aim to present a new technique for the in-setting and the functional outcomes. METHODS: We retrospectively included in a monocentric retrospective cohort study every patient with a first diagnosis of a soft palate squamous cell carcinoma (SPSCC), who underwent a tumoral resection with a free flap reconstruction, from February 2013 to July 2017...

Considering Suidae Familie as a perfect and viable experimental biomedical model for research applied to human medicine, it has been sought to describe the comparative anatomy of the digastric and the stylohyoid muscles between boars and domestic swine. Heads of Sus scrofa scrofa and Sus scrofa domesticus were dissected. The digastric muscle presented only one muscle belly as anatomical component of a tendinous origin in the jugular process of the occipital bone, and muscle insertion in the midventral edge of the caudal two thirds of the body of the mandible...

This White Paper by the European Society for Swallowing Disorders (ESSD) reports on the current state of screening and non-instrumental assessment for dysphagia in adults. An overview is provided on the measures that are available, and how to select screening tools and assessments. Emphasis is placed on different types of screening, patient-reported measures, assessment of anatomy and physiology of the swallowing act, and clinical swallowing evaluation. Many screening and non-instrumental assessments are available for evaluating dysphagia in adults; however, their use may not be warranted due to poor diagnostic performance or lacking robust psychometric properties...

The hyoid bone and the hyomandibular complex subserve the functions of respiration, deglutition, and speech. This study quantified the growth of the hyoid bone and the hyomandibular relationships in males and females from birth to 19 years. Using 97 computed tomography (CT) scans, from a previous study on mandibular growth from 49 individuals (16 with longitudinal scans; Kelly et al., 2017), landmarks were placed on 3D CT models and used to calculate four distance, and three angular measurements. A general increase in growth trend was observed in hyoid bone linear measurements -length, width, and depth- as well as relational mandible-to-hyoid distance, throughout the developmental ages examined in both males and females, with most variables having larger measurements for females up to age 10 years...

The mechanisms responsible for aspiration are relatively unknown in patients recovering from acute respiratory failure (ARF) who required mechanical ventilation. Though many conditions may contribute to swallowing dysfunction, alterations in laryngeal structure and swallowing function likely play a role in the development of aspiration. At four university-based tertiary medical centers, we conducted a prospective cohort study of ARF patients who required intensive care and mechanical ventilation for at least 48 h...