CT and MR anatomy of the larynx and hypopharynx.

Imaging of the larynx and hypopharynx is frequently requested to assess the extent of neoplasms beyond the field of view of endoscopic evaluation. The combination of optical and cross-sectional imaging allows tumors to be classified according to AJCC/UICC guidelines. A thorough understanding of laryngeal and hypopharyngeal anatomy is crucial to guide the radiological eye along the possible pathways of the spread of diseases and to guide differential diagnoses. Computed tomography (CT) has been the first cross-sectional imaging technique used to evaluate the larynx and hypopharynx; its spatial resolution combined with volumetric capability and the use of injectable contrast medium made CT the working horse in the assessment of neoplastic and inflammatory diseases. In the last two decades, magnetic resonance (MR) supported CT in the most challenging cases, when the optimal contrast resolution due to the multisequence portfolio is needed to assess the neoplastic involvement of laryngeal cartilages, paraglottic space(s), and extra laryngeal spread. The aim of this paper is to give a comprehensive radiological overview of larynx and hypopharynx complex anatomy, combining in vivo images, anatomical sections, and images of ex vivo specimens.

Cone-beam computed tomography airway measurements: Can we trust them?

INTRODUCTION: Pharyngeal airway space (PAS) assessment has been used in the past for a better understanding of orthodontic and surgical outcomes; however, this analysis could be unreliable. Our objective was to evaluate possible changes in the PAS reading in the same patient from their consecutive cone-beam computed tomography (CBCT) scans. METHODS: We evaluated a total of 27 patients' CBCT scans obtained at 2 time points with the use of a standardized acquisition protocol. The mean age at T0 was 31 years (range 17-62 years) and the follow-up records (T1) were taken after 4-6 months. Dolphin Imaging software was used to measure the volumes of the nasopharynx, oropharynx, and hypopharynx. We also evaluated the craniocervical position with the use of a lateral cephalogram. RESULTS: The variables exhibited high intraclass correlation coefficients (ICCs) when measuring the same CBCT scan twice (T0 and T0). However, The ICC between the measurements performed on the first and second CBCT scans (T0 and T1) showed that the only variable with high reproducibility between the 2 scans was cranial base, with an ICC >0.97. Average differences of 682.1 mm3, 2255.3 mm3, and 517.4 mm3 were found for the nasopharynx, oropharynx, and hypopharynx, respectively. Regarding the cephalometric angles, average differences between T0 and T1 scans were 0.6°, 2.7°, and 0.4° for OPT.CVT, OPT.SN, and cranial base, respectively. CONCLUSIONS: Different CBCT exams with equal scanning and patient positioning protocols can result in different 3D PAS readings. A more careful interpretation of CBCT volumetric data to achieve adequate conclusions of the clinical outcomes is necessary.

Effects of Le Fort I Osteotomy on the Nasopharyngeal Airway-6-Month Follow-Up.

PURPOSE: The literature discussing the impact of a single Le Fort I osteotomy on nasopharyngeal airways is limited. This study assessed the volumetric changes in the nasopharyngeal airway after a single Le Fort I osteotomy and explored the correlation between these changes and 3-dimensional surgical movements of the upper jaw. MATERIALS AND METHODS: This retrospective study was conducted in 40 patients who had undergone a single Le Fort I (maxillary advancement with or without impaction) to correct Class III malocclusion with maxillary hypoplasia. Preoperative (T1) and 6-month postoperative (T2) cone-beam computed tomographic (CBCT) scans of these patients were used for analysis. Maxillary surgical movements and volumetric changes in the nasopharyngeal airway were measured. The reproducibility of the measurements was evaluated using paired t tests and intraclass correlation coefficients. The Wilcoxon test and Pearson correlation coefficient were applied to evaluate the volumetric changes in the nasopharyngeal airway space and assess the correlations of these changes to the maxillary surgical movements. RESULTS: Six patients were excluded from the study owing to major differences (>5°) in their head and neck posture between the T1 and T2 CBCT scans. The errors of the repeated measurements were insignificant (P > .05), with a high level of agreement (r = 0.99; P < .05) between the repeated digitization of the landmarks. There was a statistically significant impact of a Le Fort I osteotomy on the right maxillary sinus (decreased by 17.8%) and the lower retropalatal space (expanded by 17.3%; P < .05). The correlation between the change in airway volume and the magnitude of surgical maxillary movements was moderate (r = .4). Similarly, there was a moderate correlation between changes in the upper nasopharynx and those in the hypopharynx. CONCLUSION: The single Le Fort I osteotomy was found to increase the retroglossal airway volume. This could be important for the treatment of obstructive sleep apnea in patients with maxillary deficiency. A long-term follow-up assessment of a larger sample with a functional assessment of airway would be beneficial to confirm these findings.

Visual evaluation of the larynx and hypopharynx during esophagogastroduodenoscopy: a safety and feasibility study.

BACKGROUND: The larynx and hypopharynx are common sites for head and neck cancer, which shares many risk factors with upper digestive tract disease. Patient survival with malignancies depends on stage at the time of diagnosis. Endoscopic screening of the hypopharynx is neither routinely performed in clinical practice nor has it been evaluated in a formal study. METHODS: This is a prospective pilot study of patients undergoing routine EGD. Demographic data were collected from patients prior to the procedure. All patients in the study underwent an EGD and prior to performing the standard portion of the EGD procedure, the endoscopist evaluated the larynx and hypopharynx with both white light endoscopy (WLE) and narrow band imaging (NBI). Details of the procedure, including ability to see all anatomic structures, time spent, complications, and findings, were recorded. RESULTS: A total of 111 patients were included in the study. The exam of the laryngopharynx was completed in 87% of patients (97/111). Reasons for incomplete exam included intubated patients (2/14), inadequate sedation (9/14), and inability to see the entire hypopharynx (3/14). The mean time of the WLE was 20.2 s, while the NBI evaluation took 15.6 s for a mean and 35.8 s for the entire exam of the larynx and hypopharynx. Minor procedural complications occurred in 3/11 (2.7%) of the patients and included hypotension, tachycardia, and hypoxia. There were 6 patients who had hypopharyngeal abnormalities seen on both WLE and NBI (5.4%) and were subsequently referred to otolaryngology. Of the six referrals, one patient had a vocal cord biopsy showing leukoplakia, while the others were deemed normal anatomic variants. CONCLUSIONS: Evaluation of the hypopharynx can be accomplished by gastrointestinal endoscopists at the time of EGD in the vast majority of patients in a safe manner while adding only about 35 s to the overall exam time.

3D analysis of upper airway morphology related to obstructive sleep apnea severity.

BACKGROUND: Obstructive sleep apnea (OSA) is the most common sleep-related breathing disorder characterized by repetitive collapse of the upper airway during sleep. However, little evidence is available on the differences between the sub-regions of the upper airway morphology and OSA severity. Since orthodontists frequently perform cone beam computed tomography (CBCT) in the neck area, we aimed to investigate the relationship and the differences between upper airway morphology and OSA severity using CBCT. MATERIALS AND METHODS: The medical records, CBCT imaging of 21 OSA patients diagnosed by polysomnography, and the apnea-hypopnea index (AHI) results were included to classify OSA severity as mild, moderate, or severe. The minimum cross-sectional areas (MCA) and volumes of the upper pharyngeal airway boundaries in four sub-regions: nasopharynx, retropalatal, retroglossal, and hypopharynx were measured. Dolphin Imaging software was used for upper airway segmentation. The correlation coefficient (r), one-way ANOVA, and the least significant difference post hoc multiple comparison test were applied to fulfill the objectives. RESULTS: A statistically significant relationship was found between the MCA of the nasopharynx and the AHI (r = -0.473, P < 0.05). Furthermore, a difference was found between mild and moderate and moderate and severe OSA severity in the MCA results of the retroglossal region (P < 0.05). However, no relationship was found between the upper airway volume and OSA severity. CONCLUSIONS: MCA was moderately negatively correlated to AHI only in the nasopharynx subregion. Moderate OSA presented significantly less MCA than mild and severe OSA only in the oropharynx and retroglossal subregions.

Effects of open mouth and rubber dam on upper airway patency and breathing.

OBJECTIVES: Rubber dams increase the quality and safety of dental treatment. However, the condition of a rubber dam over an open mouth may also obstruct the route for respiration. We tested whether an open mouth with or without a rubber dam would affect upper airway patency and breathing pattern. MATERIALS AND METHODS: Twenty young healthy volunteers were imaged with a magnetic resonance (MR) system under three conditions: mouth closed, mouth open, and rubber dam with mouth open. Respiration was concurrently monitored with plethysmography. MRI slices of the upper airway were obtained at 5-mm thicknesses, and the size of the cross-sectional area of the upper airway was measured by image analysis software. Respiratory cycle duration and tidal volume were also measured with digital signal analysis software. RESULTS: The volume of the upper airway became significantly decreased with the mouth open. Analysis of each cross-sectional area of the upper airway revealed that while the oropharyngeal area was significantly narrower with an open mouth, the retropalatal and hypopharyngeal areas were not affected. Placing a rubber dam had no additional influence on upper airway patency but was seen to significantly shorten mean respiratory duration and decrease tidal volume. CONCLUSIONS: Open mouth position plays the largest role in decreased upper airway patency, and open mouth position with a rubber dam may further disrupt breathing pattern. CLINICAL RELEVANCE: Breathing pattern may become deteriorated by airway obstruction during dental treatments requiring a rubber dam.

Pharyngeal airway protective reflexes are triggered before the maximum volume of fluid that the hypopharynx can safely hold is exceeded.

Aerodigestive reflexes triggered by pharyngeal stimulation can protect the airways by clearing fluid from the pharynx. The objective of this study was to determine the relationship between the maximum capacity of fluid that can safely dwell in the hypopharynx [hypopharyngeal safe volume (HPSV)] before spilling into the larynx and the threshold volumes required to trigger pharyngoglottal closure reflex (PGCR), pharyngo-upper esophageal sphincter contractile reflex (PUCR), and reflexive pharyngeal swallow (RPS). Twenty-five healthy volunteers (mean age 24 yr, 8 males) were studied in the semi-inclined supine position. PGCR, PUCR, and RPS were elicited using techniques of concurrent upper esophageal sphincter manometry and pharyngo-laryngoscopy. The hypopharynx was then anesthetized to abolish RPS. HPSV was determined by infusing water in the pharynx, and perfusion was stopped when the infusate reached the superior margin of the interarytenoid fold. The threshold volumes for triggering PGCR, PUCR, and RPS by slow and rapid injections before pharyngeal anesthesia were 0.18 ± 0.02 and 0.09 ± 0.02 ml; 0.20 ± 0.020 and 0.13 ± 0.04 ml; and 0.61 ± 0.04 and 0.4 ± 0.06 ml, respectively. All of the above volumes were significantly smaller than the HPSV (0.70 ± 0.06 ml, P < 0.01) except for the threshold volume to elicit RPS during slow perfusion, which was not significantly different (P = 0.23). We conclude that pharyngeal aerodigestive reflexes are triggered by both slow and rapid pharyngeal perfusion of water at significantly smaller volumes than the maximum capacity of the hypopharynx to safely hold contents without spilling into the airway. These reflexes thereby aid in prevention of aspiration.

A rare bimuscular conglomeration gluteopiriformis case report.

The present paper reports a rare anomalous muscle in the gluteal region, which appears to be a conglomeration of gluteus maximus and piriformis muscles. The muscle was proximally attached to the gluteus maximus and distally merged with the piriformis muscle. The innervation of the anomalous muscle was derived from the inferior gluteal nerve. Recognition of such a muscle variant may facilitate early clinical diagnosis and treatment of patients with symptoms of piriformis syndrome or sciatica of unexplained etiology. Contraction of such an anomalous muscle could lead to altered biomechanics of the piriformis and the gluteus maximus. Such a rare muscle, which morphologically resembles the piriformis and developmentally appears to be a part of gluteus maximus could be a challenging puzzle for the present day surgeon and radiologist.

An anatomical study of the anterior wall of the hypopharyngeal and the cervical esophageal junction.

OBJECTIVE: The upper esophageal sphincter plays a significant role by forming a physical barrier at the junction of the hypopharynx and the cervical esophagus. As few studies have focused on the ventral aspect of this junction, the contribution of the anterior wall of the cervical esophagus to upper esophageal sphincter function remains unknown. The purpose of this study was to examine the muscle fibers' arrangement at the junction, especially of those forming its anterior wall. METHODS: Thirteen specimens from 13 Japanese cadavers were analyzed. Six specimens were dissected macroscopically, while the remaining seven were examined histologically. RESULTS: The outer longitudinal layer of the proximal esophagus was well-developed anterolaterally. The uppermost fibers of the inner circular layer of the esophagus ascended longitudinally. The anterolateral part of the outer longitudinal layer and the uppermost region of the inner circular layer were continuous with the median tendinous band, in turn reaching superior to the cricoid cartilage. Histological analysis showed that the tendinous band was also continuous with the superior part of the perichondrium of the cricoid cartilage and with the aponeurosis of the transverse and oblique arytenoids. CONCLUSION: The well-developed anterolateral region of the outer longitudinal layer and the uppermost fibers of the inner circular layer were continuous with the median tendinous band, which reached superior to the cricoid cartilage. The contraction of the proximal esophagus may result in protrusion of the anteromedian esophageal wall into the lumen, thereby supporting the closure of the upper esophageal sphincter.

Cricoid pressure results in compression of the postcricoid hypopharynx: the esophageal position is irrelevant.

BACKGROUND: Sellick described cricoid pressure (CP) as pinching the esophagus between the cricoid ring and the cervical spine. A recent report noted that with the application of CP, the esophagus moved laterally more than 90% of the time, questioning the efficacy of this maneuver. We designed this study to accurately define the anatomy of the Sellick maneuver and to investigate its efficacy. METHODS: Twenty-four nonsedated adult volunteers underwent neck magnetic resonance imaging with and without CP. Measurements were made of the postcricoid hypopharynx, airway compression, and lateral displacement of the cricoid ring during the application of CP. The relevant anatomy was reviewed. RESULTS: The hypopharynx, not the esophagus, is what lies behind the cricoid ring and is compressed by CP. The distal hypopharynx, the portion of the alimentary canal at the cricoid level, was fixed with respect to the cricoid ring and not mobile. With CP, the mean anterioposterior diameter of the hypopharynx was reduced by 35% and the lumen likely obliterated, and this compression was maintained even when the cricoid ring was lateral to the vertebral body. CONCLUSIONS: The location and movement of the esophagus is irrelevant to the efficiency of the Sellick's maneuver (CP) in regard to prevention of gastric regurgitation into the pharynx. The hypopharynx and cricoid ring move together as an anatomic unit. This relationship is essential to the efficacy and reliability of Sellick's maneuver. The magnetic resonance images show that compression of the alimentary tract occurs with midline and lateral displacement of the cricoid cartilage relative to the underlying vertebral body.

Ultrastructure features of the surface of the gills and the lower pharyngeal jaw of the Tilapia Zilli, redbelly tilapia (Coptodon Zillii, Gervais, 1848).

The present investigation was designed to describe the surface ultrastructure of the gill system of tilapia Zilli. The gill system is formed from four gill arches and each gill arch carries a row of gill filaments on its convex border and two rows of the gill rakers on its concave border. The quadrilateral interbranchial septum has elevated part at the level of the third gill arch. By SEM observations, the gill arch was divided into three regions: rostral, middle and caudal region. The caudal region contained two characteristic structures: oval leaf-like structure and rounded-shaped structure. Each oval leaf-like structure carried two lateral rows of the triangular pointed spines separated by a median groove. All surfaces of gill arches, rakers and filaments were covered with a mosaic of the polygonal pavement cells, in addition to the opening of chloride cells and mucous cells. The gill arch and gill raker had only one appearance of taste buds named type I. Meanwhile, the filaments contained two types of different appearance of the taste buds named: type I and type II. Type I was the main common and similar to that present in gill arch and raker and characterized by its blunt end, while type II had hair-like structures that projected from the volcano-shaped depression. The gill rakers were formed from central axis surrounded by two lateral lobulated regions which carry pointed spines, taste buds and the opening of chloride cells. The surface of triangular lower pharyngeal jaw carries numerous teeth-like papillae which originated from the socket-like depression.

Can anatomical assessment of hypopharyngolarynx in awake patients predict obstructive sleep apnea?

OBJECTIVES/HYPOTHESIS: To assess the relationships between laryngeal and hypopharyngeal morphology and obstructive sleep apnea-hypopnea syndrome (OSAHS) in awake patients. STUDY DESIGN: Prospective study. METHODS: Awake flexible fiberoptic laryngoscopy and sleep studies were performed in 80 patients for snoring or OSAHS suspicion. Endoscopic videos were reviewed by two examiners to assess morphological characteristics of hypopharynx and larynx using a standardized examination of appearance, shape and position of epiglottis, shape of retropharyngeal-epiglottic aerospace (RPEA), modified Cormack-Lehane score, and length ratios of the hypopharynx and epiglottis. The multivariate logistic regression model was used to assess independent predictors of moderate/severe OSAHS. RESULTS: The interrater agreements were moderate for epiglottis appearance (κ = 0.52), epiglottis form (κ = 0.66), and epiglottis position (κ = 0.49), but fair for the shape of RPEA (κ = 0.26) and modified Cormack-Lehane scoring (κ = 0.38). The presence of a mega-epiglottis was significantly correlated with the severity of OSAHS (P < .05). By multivariate logistic regression analysis, independent predictors of moderate/severe obstructive sleep apnea were mega-epiglottis (adjusted odds ratio [aOR]: = 4.78, 95% confidence interval [CI]: 1.23-18.56, P = .024), modified Cormack-Lehane score of 2 (aOR: 15.3, 95% CI: 1.8-130.3, P = .012), or modified Cormack-Lehane score of 3 (aOR: 10.03, 95% CI: 1.3-78.2, P = .03) and aging (aOR = 1.07, 95% CI: 1.01-1.14, P = .025). CONCLUSIONS: Routine flexible fiberoptic laryngoscopy performed by otorhinolaryngologists in awake patients may help to detect some predictors of OSAHS such as presence of mega-epiglottis, and modified Cormack-Lehane score of 2 or more. Investigation of sleep disorders should be proposed in these patients. LEVEL OF EVIDENCE: 2 Laryngoscope, 129:2782-2788, 2019.

Imaging of the larynx and hypopharynx.

The purpose of this article is to review currently used imaging protocols for the evaluation of pathologic conditions of the larynx and hypopharynx, to describe key anatomic structures in the larynx and hypopharynx that are relevant to tumor spread and to discuss the clinical role of Computed Tomography (CT), Magnetic Resonance Imaging (MRI) and PET CT in the pretherapeutic workup and posttherapeutic follow-up of patients with squamous cell carcinoma of this region. A detailed discussion of the characteristic neoplastic submucosal invasion patterns, including extension to the preepiglottic space, paraglottic space and laryngeal cartilages and the implications of imaging for tumor staging and treatment planning is provided. The present article also reviews less common tumors of this region, such as chondrosarcoma, lymphoma, minor salivary gland tumors and lipoma. As the majority of non-neoplastic conditions do not require imaging the role of CT and MRI is discussed in some particular situations, such as to delineate cysts and laryngoceles, abscess formation in inflammatory conditions, to evaluate laryngeal and hypopharyngeal involvement in granulomatous and autoimmune diseases, and to evaluate the extent of laryngeal fractures due to severe blunt trauma.

Measuring Hypopharyngeal Gland Acinus Size in Honey Bee (Apis mellifera) Workers.

The nurse hypopharyngeal glands produce the protein fraction of the worker and royal jelly that is fed to developing larvae and queens. These paired glands that are located in the head of the bee are highly sensitive to the quantity and quality of pollen and pollen substitutes that the nurse bee consumes. The glands get smaller when nurses are fed deficient diets and are large when they are fed complete diets. Because nurse hypopharyngeal gland size is a robust indicator of nurse nutrition, it is essential that those studying honey bee nutrition know how to measure these glands. Here, we provide detailed methods for dissecting, staining, imaging, and measuring nurse bee hypopharyngeal glands. We present comparisons of unstained and stained tissue and data that were used to study the impact of pollen on gland size. This method has been used to test how diet impacts hypopharyngeal gland size but has further use for understanding the role of these glands in hive health.

Accuracy of objective parameters in acute epiglottitis diagnosis: A case-control study.

Lateral neck radiography is often used as a screening tool in emergency departments for suspected acute epiglottitis. The qualitative radiographic signs have been mainly used. The aim of this study was to evaluate the accuracy of objective radiographic parameters to aid diagnosis of acute epiglottitis.Patients who were diagnosed with acute epiglottitis from January 2006 to December 2016 were included in this case-control study. Control subjects with normal lateral neck radiograph findings were included at a 1:4 ratio during the same period. The clinical findings of the patients were assessed from electronic medical records and radiographs were interpreted by a board-certified radiologist and a board-certified emergency medicine physician. The widths of the 3rd cervical vertebral body, epiglottis base (EWB), epiglottis tip (EWT), aryepiglottic fold (AFW), and hypopharynx, as well as the dimensions of the retropharyngeal and retrotracheal soft tissues, were retrospectively measured. The sensitivity, specificity, and receiver operating characteristic (ROC) curves were analyzed for the measured parameters, and cutoff values were determined to predict acute epiglottitis. The predictive cutoff values of radiologic parameters were evaluated using 5-fold cross-validation.A total 260 epiglottitis patients and 1166 controls were included in the study. In the ROC curve analysis, the EWB had an area under the ROC curve (AUROC) of 0.99 for a cutoff value of 5.02 mm (sensitivity, 96.2%; specificity, 98.2%). The EWT had an AUROC of 0.97 for a cutoff value of 4.84 mm (sensitivity, 91.2%; specificity, 97.3%). The AFW had an AUROC of 0.88 for a cutoff value of 6.59 mm (sensitivity, 86.5%; specificity, 78.8%). The 5-fold cross-validation achieved AUROCs of 0.97 for EWB, 0.94 for EWT, and 0.83 for AFW.The objective radiographic parameters in lateral neck radiography may be useful in diagnosing acute epiglottitis. Further prospective studies may be warranted to evaluate the diagnostic performance in actual clinical practice.

How does open-mouth breathing influence upper airway anatomy?

OBJECTIVES/HYPOTHESIS: Open-mouth breathing during sleep may increase the severity of obstructive sleep apnea (OSA) and complicate nasal continuous positive airway pressure (CPAP) therapy in patients with OSA. The aim of this study was to assess the effect of open-mouth breathing on upper airway anatomy using lateral cephalometry and fiberoptic nasopharyngoscopy. STUDY DESIGN: This was a cross-sectional study. METHODS: Lateral cephalometry and fiberoptic nasopharyngoscopy were carried out on 28 subjects with a mean age of 36.7 years. We compared the effect of the mouth being open or closed on the results in lateral cephalometry (pharyngeal length, distance between the mandible and hyoid bone [MP-H], angles from the sella-nasion to mandibular points A and B [SNA, SNB, respectively], retropalatal, retroglossal, and hypopharyngeal distance) and fiberoptic nasopharyngoscopy (retropalatal and retroglossal cross-sectional area). RESULTS: On lateral cephalometric measurements, retropalatal distance (P = .000), retroglossal distance (P = .000), and MP-H (P = .002) were lower with mouth open, and pharyngeal length (P = .000) was greater. However, there were no significant differences in SNA and hypopharyngeal distance. On fiberoptic nasopharyngoscopy, retropalatal (P = .005) and retroglossal (P = .000) cross-sectional areas were significantly reduced with the mouth open. CONCLUSIONS: Open-mouth breathing is associated with reduction of the retropalatal and retroglossal areas, lengthening of the pharynx and shortening of the MP-H in the upper airway. We suggest that knowledge of these anatomic changes improves our understanding of the increase of OSA severity and the low adherence to nasal CPAP therapy in mouth breathers.

Upper airway volume segmentation analysis using cine MRI findings in children with tracheostomy tubes.

OBJECTIVE: The purpose of this study is to evaluate the airway dynamics of the upper airway as depicted on cine MRI in children with tracheotomy tubes during two states of airflow through the upper airway. MATERIALS AND METHODS: Sagittal fast gradient echo cine MR images of the supra-glottic airway were obtained with a 1.5T MRI scanner on seven children with tracheotomy tubes. Two sets of images were obtained with either the tubes capped or uncapped. The findings of the cine MRI were retrospectively reviewed. Volume segmentation of the cine images to compare the airway volume change over time (mean volume, standard deviation, normalized range, and coefficient of variance) was performed for the capped and uncapped tubes in both the nasopharynx and hypopharynx (Signed Rank Test). RESULTS: Graphical representation of the airway volume over time demonstrates a qualitative increased fluctuation in patients with the tracheotomy tube capped as compared to uncapped in both the nasopharyngeal and hypopharyngeal regions of interest. In the nasopharynx, the mean airway volume (capped 2.72 mL, uncapped 2.09 mL, p = 0.0313), the airway volume standard deviation (capped 0.42 mL, uncapped 0.20 mL, p = 0.0156), and the airway volume range (capped 2.10 mL, uncapped 1.09 mL, p = 0.0156) were significantly larger in the capped group of patients. In the hypopharynx, the airway volume standard deviation (capped 1.54 mL, uncapped 0.67 mL, p = 0.0156), and the airway volume range (capped 6.44 mL, uncapped 2.93 mL, p = 0.0156) were significantly larger in the capped tubes. The coefficient of variance (capped 0.37, uncapped 0.26, p = 0.0469) and the normalized range (capped 1.52, uncapped 1.09, p = 0.0313) were significantly larger in the capped tubes. CONCLUSION: There is a statistically significant change in airway dynamics in children with tracheotomy tubes when breathing via the airway as compared to breathing via the tracheotomy tube.

Nutritional support during radiotherapy for head and neck cancer: the role of prophylactic feeding tube placement.

Significant weight loss and resultant malnutrition in patients undergoing radiotherapy for head and neck carcinomas are recognized and preventable clinical concerns. Morbidity related to weight loss during treatment may include dehydration, hospitalization, compromised treatment efficacy, and reduced quality of life and may impact survival. Malnutrition effects on wound healing may prolong recovery following treatment and increase the risk of morbidity for those undergoing subsequent salvage surgery. Multiple interventions have been implemented to help ameliorate the impact of treatment on weight loss and nutritional status, including the use of percutaneous endoscopic gastrostomy (PEG) tubes. The value of prophylactic PEG tube placement at treatment initiation increasingly is being recognized, and evidence suggests that patients experience better outcomes. Criteria for patient selection have not been defined completely, and a great deal of variation in clinical practice exists, contributing to underuse of this supportive intervention. According to a literature review, patients who require therapeutic PEG tube placement in response to significant weight loss during treatment suffer greater morbidity than patients who receive PEG tubes prophylactically. Understanding patient-, tumor-, and treatment-related risk factors to systematically identify patients most likely to benefit from prophylactic PEG tube placement is an important aspect of nursing care.

Hypopharynx in termites: Morphological and functional aspects.

The hypopharynx morphology in workers, pseudergates, and soldiers was described in six families of Isoptera using scanning electronic microscopy. This is the first comparative study to detail the hypopharynx among different species of termites, and included 4 one-piece type (OP) and 9 multiple-pieces type termites (MP). The results showed different arrangements of the hypopharynx trichomes, with fewer of these structures in the frontal region of the hypopharynx in pseudergates and soldiers of OP termites. These characteristics did not apply to Serritermes serrifer, since its pseudergates displayed a large quantity of trichomes on the frontal surface. This species may not resemble other OP termites because it does not live inside a piece of wood, but rather are inquilines inside Cornitermes spp. nests. Similar morphology of this mouthpart was observed in the different species of MP termites, with workers exhibiting many unidirectional trichomes on the frontal surface and soldiers presenting fewer of these trichomes. The morphology of the hypopharynx seems to reflect the lifestyle of these species, because MP termites are able to exploit external water sources. Since different arrangements of hypopharynx trichomes are used for water intake via capillary action, the present data reinforce the soldiers' dependence on workers to obtain water and food through the process of trophallaxis. Three different types of sensilla were observed on the lateral region of the hypopharynx: chaetica, basiconica and campaniformia. Chaetica act as chemoreceptors, while basiconica and campaniformia are mechanoreceptors, used in feeding and environmental perception. Better understanding of hypopharynx morphology permits the inference of ecological habits among OP and MP termites, and reflects the physiological differences between workers and soldiers.