Pharyngeal Structure Research Articles

Changes of pharyngeal airway structure and function in patients with skeletal class III malocclusion one year after orthognathic surgery.

This study aimed to analyze changes in the pharyngeal airway structure and function in patients with skeletal Class III malocclusion one year after orthognathic surgery. In this research, cone-beam computed tomography (CBCT) images of 30 patients (14 men and 16 women; mean age 20-30 years) with skeletal Class III malocclusion who underwent Lefort I osteotomy and bilateral sagittal split osteotomy were obtained before and one year after the surgery. Changes in pharyngeal airway structure were achieved by comparing CBCT data, and changes in function were achieved by comparing fluid dynamics models. The pharyngeal airway was analyzed by Element 3D (E3D) and the nasal airway 3D model was reconstructed. The meshing was implemented in ICEM-CFD (ANSYS, Canonsburg, PA, USA), and improved the mesh quality. The meshes were imported into Fluent (ANSYS, Canonsburg, PA, USA) to stimulate a fluid analysis. The minimal anteroposterior diameter, minimal cross-sectional area and volume of pharyngeal airway were significantly reduced after surgery. There was no significant difference in the nasopharyngeal cross-sectional area. Pharyngeal airway resistance increased significantly after surgery, wall shear stress changed little before and after surgery. The anatomic structure of pharyngeal airway changed after surgery, but the morphological change of pharyngeal airway was not significant. One year after surgery, the anatomical structure and function changed compared with those before surgery, and the changes of minimal cross-sectional area of pharyngeal airway should be considered when designing the treatment plan for the patients.

Spatial relationships of oropharyngeal structures during respiration, chewing, and swallowing.

Spatial relationships between oropharyngeal structures and their coordinated dynamics ensure proper adaptations in functions such as respiration, chewing, and swallowing. Thus, the aim of this study is to analyze spatial changes in the normal oropharynx during respiration and mastication. For this purpose, eight 7-8 months old Yucatan minipigs, four of each sex were used. X-ray fluoroscopy was recorded with the field of view focused on the oropharyngeal region. The x-ray video clips showing respiratory cycles and masticatory sequences were digitized and traced. Points to be digitized and traced were located on the soft palate, epiglottis, tongue base, and pharyngeal wall. An X-Y coordinate system was established to trace distances and directions of each structure (structural), and between structures (inter-structural) during phases of respiration, chewing stages, and swallowing episodes. During respiration, the soft palate showed the largest X-Y movements with the largest distance change (1.32 ± 0.64 mm). In contrast, distance changes in the tongue base were significantly smaller (0.32 ± 0.21 mm, p < 0.05). Notably, during chewing the tongue base and epiglottis showed major changes in distance and direction. Similarly, during swallowing the tongue base showed the largest changes (2.94 ± 1.28 mm) followed by the pharyngeal wall and epiglottis. Thus, although coordinated, each pharyngeal structure plays specific roles. Understanding of these spatial and specific dynamics in different oropharyngeal structures would provide the baseline to analyze the potential mechanisms of various swallowing and breathing disorders such as dysphagia and obstructive sleep apnea.

Analysis of the pharyngeal structure of the genus Oreochromis for species identification through geometric morphometrics in the Aguamilpa reservoir, Nayarit, Mexico

Analysis of the pharyngeal structure of the genus Oreochromis for species identification through geometric morphometrics in the Aguamilpa reservoir, Nayarit, Mexico

Improved traits of proximate composition, liver antioxidant capacity and feeding habits in diploid hybrids from female Micropterus salmoides × male Lepomis cyanellus

Improved traits of proximate composition, liver antioxidant capacity and feeding habits in diploid hybrids from female Micropterus salmoides × male Lepomis cyanellus

Pharyngeal Constrictor Dose–Volume Histogram Metrics and Patient-Reported Dysphagia in Head and Neck Radiotherapy

Head and neck radiotherapy long-term survival continues to improve and the management of long-term side-effects is moving to the forefront of patient care. Dysphagia is associated with dose to the pharyngeal constrictors and can be measured using patient-reported outcomes to evaluate its effect on quality of life. The aim of the present study was to relate pharyngeal constrictor dose-volume parameters with patient-reported outcomes to identify prognostic dose constraints. A 64-patient training cohort and a 24-patient testing cohort of oropharynx and nasopharynx cancer patients treated with curative-intent chemoradiotherapy were retrospectively examined. These patients completed the MD Anderson Dysphagia Inventory outcome survey at 12 months post-radiotherapy to evaluate late dysphagia: a composite score lower than 60 indicated dysphagia. The pharyngeal constrictor muscles were subdivided into four substructures: superior, middle, inferior and cricopharyngeal. Dose-volume histogram (DVH) metrics for each of the structure combinations were extracted. A decision tree classifier was run for each DVH metric to identify dose constraints optimising the accuracy and sensitivity of the cohort. A 60% accuracy threshold and feature selection method were used to ensure statistically significant DVH metrics were identified. These dose constraints were then validated on the 24-patient testing cohort. Existing literature dose constraints only had two dose constraints performing above 60% accuracy and sensitivity when evaluated on our training cohort. We identified two well-performing dose constraints: the pharyngeal constrictor muscle D63% < 55 Gy and the superior-middle pharyngeal constrictor combination structure V31Gy < 100%. Both dose constraints resulted in ≥73% mean accuracy and ≥80% mean sensitivity on the training and testing patient cohorts. In addition, a pharyngeal constrictor muscle mean dose <57 Gy resulted in a mean accuracy ≥74% and mean sensitivity ≥60%. Mid-dose pharyngeal constrictor muscle and substructure combination dose constraints should be used in the treatment planning process to reduce late patient-reported dysphagia.

Pharyngeal Structure and Dysphagia in Patients with Parkinson's Disease and Related Disorders.

Pharyngeal muscle changes occur in patients with Parkinson's disease and related disorders (PRD); however, the association between the structural alterations in the pharynx and the symptoms of dysphagia remains unclear. We assessed structural changes and contractile forces by measuring pharyngeal wall thickness and width. We aimed to define the pharyngeal measurements and determine their value as diagnostic tools for dysphagia.The pharyngeal wall thickness (PWT), pharyngeal width at rest (PWR), and shortest pharyngeal width at swallowing (PWS) were measured using lateral neck roentgenograms and videofluoroscopic swallowing study. We compared the PWR and PWT between the PRD and control groups using an independent t-test. The Kendall correlation test was performed on the radiological data of the pharynx (PWT, PWR and PWS), dysphagia scales (Penetration-Aspiration scale [PAS] and Dysphagia Outcome and Severity Scale [DOSS]), and Hoehn and Yahr scale (HY scale).The PWT was smaller and the PWR greater in the PRD than in the control group (p < 0.05). The dysphagia scales (PAS and DOSS) were correlated with the radiological data (PWT and PWS) and the HY scale (p < 0.05). The HY scale score also correlated with the PWT (p < 0.05). The optimal cutoff points of the PWT and PWR for predicting aspiration were 4.05 and 16.05mm in the PRD group, respectively.Using the PWT, PWR and PWS, muscle atrophy and contractile strength of the pharynx can be estimated. The combination of the PWT and PWR can be a simple indicator for predicting swallowing disorders at the bedside.

Effect of intraoperative single dose of dexamethasone on posttonsillectomy pain in children: a systematic review and meta-analysis

Background Tonsillectomy is one of the commonest operative techniques done universally. In spite of developments in anesthetic and operative procedures, posttonsillectomy pain remains a vital clinical problem. Posttonsillectomy pain is perhaps the consequence of muscle spasm caused by inflammation and irritation of the pharyngeal muscular structure. Postoperatively cases frequently have significant odynophagia, alteration of diet, and reduced activity. The recovery interval of kids frequently continues from 4 to 7 days, whereas adults might continue being symptomatic up to 2 weeks. The odynophagia may be sufficiently severe to control oral intakes, which in occasional cases can lead to dehydration needing admittance for intravenous fluids. Aim This work aimed to evaluate the consequence of intraoperative single dosage of dexamethasone on posttonsillectomy pains in kids and to verify its significance. Patients and methods A systematic review of presently accessible randomized controlled trials via a one-dose, intravenous corticoid throughout pediatric tonsillectomy has been done. Visual analog pain score information was obtained with reviewers blinded to findings. Results Seven randomized trials have been involved in posttonsillectomy pain analysis. A significant decrease in pain as determined by visual analog pain score on the first-day postoperatively was found. Conclusions A single, intraoperative dosage of dexamethasone can decrease posttonsillectomy pain on the first day postoperatively by a factor of 1 on a 10-point pain scale. As the adverse effects and price of dexamethasone dosage seem negligible, considerations of routine usage appear acceptable.

Comparative analysis of growth performance, pharyngeal teeth and intestinal traits in F1 hybrids of female Megalobrama amblycephala × male Culter mongolicus

Aquaculture provides approximately 78% of the fish consumed by humans in China. However, the characters of fish cultivars have different deficiencies, and degradation is serious. Less improved varieties of fish are still an important factor restricting the development of aquaculture in China. Interspecific hybridization is an effective method for producing hybrid varieties with desirable traits. In this study, diploid hybrids (BM, 2 n = 48) of blunt snout bream ( Megalobrama amblycephala ♀, 2 n = 48, BSB) × Mongolian culter ( Culter mongolicus ♂, MC, 2 n = 48) were obtained by intergeneric crossing. To investigate whether these hybrids have heterobeltiosis, the growth performance, pharyngeal teeth and intestinal traits of BM hybrids were compared with those of their parents (BSB and MC). The average weight of BM hybrids (97.01 ± 27.52 g) was significantly greater ( P < 0.05) than that of MC (68.04 ± 12.64 g) and similar to that of BSB (99.33 ± 16.72 g) at 1 year of age; the average weight of BM hybrids (990.49 ± 149.21 g) was significantly greater ( P < 0.05) than that of both BSB (895.12 ± 135.38 g) and MC (625.81 ± 81.83 g) at 2 years of age. The pharyngeal tooth structure and intestinal traits of BM hybrids were similar to those of BSB, indicating that BM hybrids were biased toward herbivory. This is the first report of a diploid hybrid with a growth advantage and herbivory produced by crossing female BSB and male MC. The new hybrid offspring have great significance in aquatic applications. • Diploid hybrids were produced by crossing of female Megalobrama amblycephala and male Culter mongolicus . • The produced diploid hybrids grows faster than parents. • The produced diploid hybrids were biased toward herbivory.

Investigations into Early Larval Feeding Practices for the Tiger Barb Puntigrus tetrazona

Abstract The Tiger Barb Puntigrus tetrazona is one of the highest trade volume freshwater species in the ornamental fish industry. Culture of larval Tiger Barb is largely dependent on live feeds at first feeding and throughout early life stages, leading to increased cost relative to the use of commercially produced microparticulate diets (MDs). Potential for the successful culture of Tiger Barb by using MDs from first feeding was evaluated here, with a focus on the physiological characteristics that limit digestive capacity in larval cyprinids, as well as the hypothetical benefit of including feed attractants in formulated larval feeds. Comparable growth and survival were achieved for the first 14 d of feeding with one of three MDs when compared to feeding with brine shrimp Artemia spp. Histological preparation revealed evidence for a fully functional pharyngeal jaw structure, including pharyngeal teeth and a pharyngeal pad, from 6 d posthatch, which coincided with first feeding. The masticatory function of these structures likely facilitated the breakdown and subsequent utilization of the relatively complex macronutrients that are characteristic of MDs. Inclusion of top-coated potential attractants (tryptophan, taurine, trimethylglycine betaine, or a mix of the three) with the most successful MD from the original trial failed to induce an increased feeding response, as evidenced by the observation of similar feeding incidence, total larval protein content, and tryptic enzyme activity relative to a negative control MD without added attractants. The results of this research suggest that the successful culture of larval Tiger Barb is possible with the use of commercially available MDs, potentially leading to cost savings and increased resilience of producers in the ornamental aquaculture industry.

Volumetric magnetic resonance imaging analysis of multilevel upper airway surgery effects on pharyngeal structure.

The Sleep Apnea Multilevel Surgery (SAMS) trial found that modified uvulopalatopharyngoplasty with tonsillectomy (if tonsils present) combined with radiofrequency tongue ablation reduced obstructive sleep apnea (OSA) severity and daytime sleepiness in moderate-severe OSA. This study aimed to investigate mechanisms of effect on apnea-hypopnea index (AHI) reduction by assessing changes in upper airway volumes (airway space, soft palate, tongue, and intra-tongue fat). This is a case series analysis of 43 participants of 51 randomized to the surgical arm of the SAMS trial who underwent repeat magnetic resonance imaging (MRI). Upper airway volume, length, and cross-sectional area, soft palate and tongue volumes, and tongue fat were measured. Relationships between changes in anatomical structures and AHI were assessed. The participant sample was predominantly male (79%); mean ± SD age 42.7 ± 13.3 years, body mass index 30.8 ± 4.1 kg/m2, and AHI 47.0 ± 22.3 events/hour. There were no, or minor, overall volumetric changes in the airway, soft palate, total tongue, or tongue fat volume. Post-surgery there was an increase in the minimum cross-sectional area by 0.1 cm2 (95% confidence interval 0.04-0.2 cm2) in the pharyngeal airway, but not statistically significant on corrected analysis. There was no association between anatomical changes and AHI improvement. This contemporary multilevel upper airway surgery has been shown to be an effective OSA treatment. The current anatomical investigation suggests there are not significant post-operative volumetric changes associated with OSA improvement 6-month post-surgery. This suggests that effect on OSA improvement is achieved without notable deformation of airway volume. Reduced need for neuromuscular compensation during wake following anatomical improvement via surgery could explain the lack of measurable volume change. Further research to understand the mechanisms of action of multilevel surgery is required. This manuscript presents a planned image analysis of participants randomized to the surgical arm or the clinical trial multilevel airway surgery in patients with moderate-severe obstructive sleep apnea (OSA) who have failed medical management to assess change in OSA events and daytime sleepiness. https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=266019&isReview=true%20Australian%20New%20Zealand%20Clinical%20Trials%20Registry%20ACTRN12514000338662, prospectively registered on March 31, 2014.

Study on the structural changes of pharyngeal cavity after bariatric surgery in obese patients with obstructive sleep apnea

Objective:To study whether and how bariatric surgery changes the structure of the pharyngeal cavity in obese patients with obstructive sleep apnea（OSA）. Methods:Forty-two patients who underwent laparoscopic sleeve gastrectomy were recruited. Morphological indicators（BMI, neck and waist circumference）, PSG and acoustic pharyngometry indicators were evaluated pre-operatively and 3, 6, and 12 months post-operatively. Results:All indicators including morphology, pharyngeal cavity structure and OSA severity changed significantly after surgery. Among them, BMI, neck circumference, waist circumference and AHI value were significantly reduced（P<0.001）, while pharyngeal cavity volume, pharynx volume, oropharyngeal junction area, glottis area and LSaO2 increased significantly（P<0.001）. The results of multiple comparisons showed that BMI, neck and waist circumference decreased significantly in the first 6 months, and no further decline occurred during 6 to 12 months postoperatively. The decrease in AHI and LSaO2 mainly occurred within the first 3 months postoperatively, while there was no statistically significant difference in these two indicatiors between 3 months vs. 6 months, 6 months vs. 12 months postoperatively. The area of the oropharyngeal junction increased significantly within 0 to 3 months after surgery, while the volume of the pharyngeal cavity and the area of the glottis increased at 6 months and 12 months after surgery. Conclusion:Bariatric surgery can significantly reduce body weight and reduce fat accumulation in the neck. It can also enlarge the volume and cross-sectional area of the pharyngeal cavity, and improve upper airway obstruction, therefore reduce the symptoms of sleep apnea in obese patients with OSA to a certain extent.

A deep cascaded segmentation of obstructive sleep apnea-relevant organs from sagittal spine MRI

PurposeThe main purpose of this work was to develop an efficient approach for segmentation of structures that are relevant for diagnosis and treatment of obstructive sleep apnea syndrome (OSAS), namely pharynx, tongue, and soft palate, from mid-sagittal magnetic resonance imaging (MR) data. This framework will be applied to big data acquired within an on-going epidemiological study from a general population.MethodsA deep cascaded framework for subsequent segmentation of pharynx, tongue, and soft palate is presented. The pharyngeal structure was segmented first, since the airway was clearly visible in the T1-weighted sequence. Thereafter, it was used as an anatomical landmark for tongue location. Finally, the soft palate region was extracted using segmented tongue and pharynx structures and used as input for a deep network. In each segmentation step, a UNet-like architecture was applied.ResultsThe result assessment was performed qualitatively by comparing the region boundaries obtained from the expert to the framework results and quantitatively using the standard Dice coefficient metric. Additionally, cross-validation was applied to ensure that the framework performance did not depend on the specific selection of the validation set. The average Dice coefficients on the test set were 0.89pm 0.03, 0.87pm 0.02, and 0.79pm 0.08 for tongue, pharynx, and soft palate tissues, respectively. The results were similar to other approaches and consistent with expert readings.ConclusionDue to high speed and efficiency, the framework will be applied for big epidemiological data with thousands of participants acquired within the Study of Health in Pomerania as well as other epidemiological studies to provide information on the anatomical structures and aspects that constitute important risk factors to the OSAS development.

A consideration of factors affecting palliative oral appliance effectiveness for obstructive sleep apnea: a scoping review.

This scoping review allows physicians, researchers, and others interested in obstructive sleep apnea to consider effectiveness of oral appliances (OAs). The intent is to improve understanding of OA effectiveness by considering morphologic interaction in patients with obstructive sleep apnea. Morphologic and biomechanical criteria for positional alterations of the mandible assessed success rates of OA appliances. Searches of databases (Medline, PubMed, The Cochrane Library, EBSCO) using terms: OA treatment effectiveness and positive and/or negative outcome predictors. Craniofacial predictors of OAs and obstructive sleep apnea biomechanical factors of anatomical traits associated with OA effectiveness were included. Databases searched radiographic cephalometric imaging for morphology/phenotypes and apnea-hypopnea index responses. Articles were excluded if title or abstract was not relevant or a case report. If the analysis did not report mean or standard deviation for apnea-hypoxia index, it was excluded. No language, age, or sex restrictions were applied. Analysis of 135 articles included in searched literature indicated alterations in musculature and pharyngeal airway structure through OA use. These alterations were individually unpredictable with wide variability 61.81% ± 12.29 (apnea-hypoxia index mean ± standard deviation). Morphologic variations as predictors were typically weak and idiosyncratic. Biomechanical factors and wide variations in the metrics of appliance application were unclear, identifying gaps in knowledge and practice of OAs. An integrated basis to identify morphologic and biomechanical elements of phenotypic expressions of sleep-disordered breathing in the design and application of OAs is needed. Current knowledge is heterogeneous and shows high variability. Identification of subgroups of patients with obstructive sleep apnea responding to OAs is needed.

Flow-Identified Site of Collapse During Drug-Induced Sleep Endoscopy: Feasibility and Preliminary Results

Flow-Identified Site of Collapse During Drug-Induced Sleep Endoscopy: Feasibility and Preliminary Results

Spatiotemporal remodeling of embryonic aortic arch: stress distribution, microstructure, and vascular growth in silico.

The microstructure for mature vessels has been investigated in detail, while there is limited information about the embryonic stages, in spite of their importance in the prognosis of congenital heart defects. It is hypothesized that the embryonic vasculature represents a disorganized but dynamic soft tissue, which rapidly evolves toward a specialized multi-cellular vascular structure under mechanical loading. Here the microstructural evolution process of the embryonic pharyngeal aortic arch structure was simulated using an in ovo validated long-term growth and remodeling computational model, implemented as an in-house FEBio plug-in. Optical coherence tomography-guided servo-null pressure measurements are assignedas boundary conditions through the critical embryonic stages. The accumulation of key microstructural constituents was recorded through zoom confocal microscopy for all six embryonic arch arteriessimultaneously. The total amount and the radial variation slope of the collagen along the arch wall thickness in different archtypes and for different embryonic times, with different dimension scales, were normalized and compared statistically. The arch growth model shows that the stress levels around the lumen boundary increase from [Formula: see text] (Stage 18) to a level higher than [Formula: see text] (Stage 24), depending on matrix constituent production rates, while the homeostatic strain level is kept constant. The statistical tests show that although the total collagen levels differentiate among bilateral positions of the same arch, the shape coefficient of the matrix microstructural gradient changes with embryonic time, proving radial localization, in accordance with numerical model results. In vivo cell number (DAPI) and vascular endothelial growth factor distributions followed similar trends.

Comparison of upper airway obstruction during zolpidem-induced sleep and propofol-induced sleep in patients with obstructive sleep apnea: a pilot study

Drug-induced sleep endoscopy (DISE) using propofol is commonly used to identify the pharyngeal structure involved in collapse among patients with obstructive sleep apnea. DISE has never been compared with zolpidem-induced sleep endoscopy. We hypothesized that propofol at recommended sedation levels does not influence upper airway collapsibility nor the frequency of multilevel pharyngeal collapse as compared with zolpidem-induced sleep. Twenty-one patients with obstructive sleep apnea underwent polysomnography and sleep endoscopy during zolpidem-induced sleep and during DISE with propofol. A propofol target-controlled infusion was titrated to achieve a bispectral index between 50 and 70. Airway collapsibility was estimated and compared in both conditions by peak inspiratory flow and the magnitude of negative effort dependence. Respiratory drive was estimated by the difference between end-expiratory and peak-negative inspiratory pharyngeal pressure (driving pressure). Site and configuration of pharyngeal collapse during zolpidem-induced sleep and DISE with propofol were compared. The frequency of multilevel collapse during zolpidem-induced sleep was similar to that observed during DISE with propofol (72% vs 86%, respectively; difference: 14%; 95% confidence interval: -12% to 40%; P = .453). The endoscopic classification of pharyngeal collapse during both conditions were similar. Peak inspiratory flow, respiratory drive (effect size: 0.05 and 0.03, respectively), and negative effort dependence (difference: -6%; 95% confidence interval: -16% to 4%) were also similar in both procedures. In this pilot study, recommended propofol doses did not significantly increase multilevel pharyngeal collapse or affect upper airway collapsibility and respiratory drive as compared with zolpidem-induced sleep. Registry: clinicaltrials.gov; Name: Natural and Drug Sleep Endoscopy; URL: https://clinicaltrials.gov/ct2/show/study/NCT03004014; Identifier: NCT03004014.

The Efficacy of Nasal Surgery on Pharyngeal Airway

Background and Objectives Nasal surgery is known to improve the quality of life in patients with obstructive sleep apnea; however, its effect on the airway structure is little known. This study attempted to identify the impact of nasal surgery on the pharyngeal airway structure. Subjects and Method We enrolled in the study patients who underwent nasal surgery from July 2015 to March 2018 due to nasal obstruction with severe snoring or sleep apnea. Patients with palate surgery or previous history of airway surgery were excluded. Demographic factors, symptoms regarding nasal obstruction, sleep study, preoperative cephalometry, and postoperative 3-month cephalometry were taken into account and analyzed. We also performed a subgroup analysis according to the severity of sleep apnea. Results Sixty-three patients were enrolled in this study. Soft palate thickness showed no significant change. Pre and postoperative soft palate thickness were 10.82±3.00 and 11.11±3.35 (p=0.261), respectively. However, the pharyngeal airway space was enlarged via nasal surgery from 12.05±3.35 to 13.04±3.35 (p=0.006), respectively. The subgroup analysis showed that the pharyngeal airway was mainly enlarged in the patients with lower Apnea-Hypopnea Index (AHI). Conclusion Although nasal surgery does not reduce soft palate thickness, it can enlarge the pharyngeal airway space. The effect of surgery would be more prominent in patients with AHI of lower than 15 event/hour (p=0.005) as nasal surgery alone does not affect the pharyngeal airway of patients with AHI greater than 15. Key words: Cephalometry ㆍ Nasal surgery ㆍ Obstructive sleep apnea ㆍ Pharynx ㆍ Snoring

Anthropometric and acoustic pharyngometric parameters in sleep-disordered breathing due to structural pharyngeal alterations

INTRODUCTION : Sleep-disordered breathing is a medico-social problem of rising importance worldwide. There are various clinical forms of sleep apnea such as obstructive sleep apnea (OSA) and central sleep apnea as well as snoring. Recently, there have been considerable advances in the diagnosis of OSA and snoring. А IМ : This study aimed at applying the method of acoustic pharyngometry for the diagnosis of pharyngeal alterations in subjects with sleep-disordered breathing within a preventive otorhinolaryngological programme in the city of Varna for the first time in Bulgaria. MATERIALS AND METHODS : Between January 1, 2016 and August 31, 2019, screening for sleep-disordered breathing was performed among 100 subjects, 62 males at a mean age of 48.82±11.45 years and 38 females at a mean age of 52.42±16.54 years in the Division of Otorhinolaryngology, St. Anna Hospital of Varna. Clinical inspections, anterior rhinoscopy, pharyngoscopy, indirect laryngoscopy, acoustic rhinometry, as well as acoustic pharyngometry by means of Eccovision ® acoustic pharyngometer were used. The t -test for independent variables and the correlation analysis were applied for statistical data processing. RESULTS : The acoustic pharyngometry identified several pharyngeal alterations. There were statistically significant changes of the anthropometric parameters (body mass index, neck circumference and adjusted neck circumference) and pharyngometric ones (pharyngeal cavity and vocal tract lengths and volumes) between males and females. There were statistically significant positive and negative correlations between the values of these parameters. CONCLUSION : Within the complex otorhinolaryngological examination of the pharyngeal structure and function in the subjects suspected for sleep-disordered breathing, acoustic pharyngometry could play an irreplaceable role as a cost-effective tool.

Egg and Larval Morphology of Culicoides sonorensis (Diptera: Ceratopogonidae).

The egg and larval instars (L1-L4) of Culicoides sonorensis Wirth and Jones are described. Average (range) of body lengths of a laboratory colony (Van Ryn) were 0.45 (0.43-0.48) mm for eggs, 0.72 (0.39-0.92) mm for L1, 1.8 (1.3-2.2) mm for L2, 3.6 (2.2-5.0) mm for L3, and 5.9 (5.0-6.9) mm for L4. Head capsule lengths were 0.067 (0.064-0.070) mm for L1, 0.100 (0.094-0.110) for L2, 0.157 (0.144-0.168) for L3, and 0.316 (0.300-0.324) mm for L4. Wild and colony L4 larvae differed in many standard metrics such as head length or width, but head ratios and pharyngeal armature measurements were comparable. Standard external and internal features of the head capsule are described. Scanning electron microscope photos revealed pharyngeal armature structure was similar for L2-L4. The pharyngeal armature and piercing mandibles suggest a generalist feeder and opportunistic predator. Egg ansullae were randomly distributed (as opposed to rows in most other Culicoides spp.) and averaged 1.98 ansullae per 25 µm2 of egg surface. Ansullae were widened and porous apically, averaging 1.29 microns long, 0.65 µm at the base, and 1.06 µm at the apex. Only the L1 had a proleg, structurally complex, and featuring five rows of posteriorily directed, shorter spines (1-3 µm long) and 8-10 setae 18 µm long with hooked tips. On terrestrial mud, this proleg was used for surface crawling, and the L1 navigated dry conditions better than the more aquatic L2-L4 stages. Eggs are laid above waterline, and the L1 proleg is probably an advantage in terrestrial surface movement.

Airflow Shape Is Associated With the Pharyngeal Structure Causing OSA

OSA results from the collapse of different pharyngeal structures (soft palate, tongue, lateral walls, and epiglottis). The structure involved in collapse has been shown to impact non-CPAP OSA treatment. Different inspiratory airflow shapes are also observed among patients with OSA. We hypothesized that inspiratory flow shape reflects the underlying pharyngeal structure involved in airway collapse. Subjects with OSA were studied with a pediatric endoscope and simultaneous nasal flow and pharyngeal pressure recordings during natural sleep. The mechanism causing collapse was classified as tongue-related, isolated palatal, lateral walls, or epiglottis. Flow shape was classified according to the degree of negative effort dependence (NED), defined as the percent reduction in inspiratory flow from peak to plateau. Thirty-one subjects with OSA (mean apnea-hypopnea index score ± SD, 54 ± 27 events/h) who were 50 ± 9 years of age were studied. NED was associated with the structure causing collapse (P< .001). Tongue-related obstruction (n= 13) was associated with a smallamount of NED (median, 19; interquartile range [IQR], 14%-25%). Moderate NED was found among subjects with isolated palatal collapse (median, 45; IQR, 39%-52%; n= 8) andlateral wall collapse (median, 50; IQR, 44%-64%; n= 8). The epiglottis was associated with severe NED (median, 89; IQR, 78%-91%) and abrupt discontinuities in inspiratory flow (n= 9). Inspiratory flow shape is influenced by the pharyngeal structure causing collapse. Flow shape analysis may be used as a noninvasive tool to help determine the pharyngeal structure causing collapse.