Relationship between Vowel Sound Features and Pharyngeal Airway Cross-Sectional Area during Normal Breathing*

2020 ◽  
Author(s):  
Shumit Saha ◽  
Keerthana Viswanathan ◽  
Nasim Montazeri Ghahjaverestan ◽  
Azadeh Yadollahi
Keyword(s):  
Cross Sectional Area ◽  
Vowel Sound ◽  
Sectional Area ◽  
Cross Sectional ◽  
Pharyngeal Airway ◽  
Normal Breathing ◽  
Sound Features

Effect of Increasing Depth of Propofol Anesthesia on Upper Airway Configuration in Children

2003 ◽  
Vol 99 (3) ◽  
pp. 596-602 ◽  
Author(s):  
Russell G. Evans ◽  
Mark W. Crawford ◽  
Michael D. Noseworthy ◽  
Shi-Joon Yoo
Keyword(s):  
Confidence Interval ◽  
Soft Palate ◽  
Upper Airway ◽  
Magnetic Resonance Images ◽  
Cross Sectional Area ◽  
Depth Of Anesthesia ◽  
Sectional Area ◽  
Cross Sectional ◽  
Airway Narrowing ◽  
Pharyngeal Airway

Background The upper airway tends to be obstructed during anesthesia in spontaneously breathing patients. The purpose of the current study was to determine the effect of increasing depth of propofol anesthesia on airway size and configuration in children. Methods Magnetic resonance images of the upper airway were obtained in 15 children, aged 2-6 yr. Cross-sectional area, anteroposterior dimension, and transverse dimension were measured at the level of the soft palate, dorsum of the tongue, and tip of the epiglottis. Images were obtained during infusion of propofol at a rate of 50-80 microg.kg-1.min-1 and after increasing the depth of anesthesia by administering a bolus dose of propofol and increasing the infusion rate to 240 microg.kg-1.min-1. Results Overall, the cross-sectional area of the entire pharyngeal airway decreased with increasing depth of anesthesia. The reduction in cross-sectional area was greatest at the level of the epiglottis (24.5 mm2, 95% confidence interval = 16.9-32.2 mm2; P < 0.0001), intermediate at the level of the tongue (19.3 mm2, 95% confidence interval = 9.2-29.3 mm2; P < 0.0001), and least at the level of the soft palate (12.6 mm2, 95% confidence interval = 2.7-22.6 mm2; P < 0.005) in expiration and resulted predominantly from a reduction in anteroposterior dimension. The airway cross-sectional area decreased further in inspiration at the level of the epiglottis. The narrowest portion of the airway resided at the level of the soft palate or epiglottis in the majority of children. Conclusion Increasing depth of propofol anesthesia in children is associated with upper airway narrowing that occurs throughout the entire upper airway and is most pronounced in the hypopharynx at the level of the epiglottis.

Advancement of the mandible improves velopharyngeal airway patency

1995 ◽  
Vol 79 (6) ◽  
pp. 2132-2138 ◽  
Author(s):  
S. Isono ◽  
A. Tanaka ◽  
Y. Sho ◽  
A. Konno ◽  
T. Nishino
Keyword(s):  
Static Pressure ◽  
Video Recording ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Cross Sectional ◽  
Airway Patency ◽  
Pharyngeal Airway ◽  
Obstructive Sleep ◽  
Pressure Area ◽  
Nasal Pressure

The velopharynx is the most common site of obstruction in patients with obstructive sleep apnea (OSA). Advancement of the mandible effectively reverses the pharyngeal obstruction. Accordingly, we hypothesized that mandibular advancement increases cross-sectional area of several segments of the upper airway, including the velopharynx and the oropharynx. We examined the pressure-area properties of the pharyngeal airway in 13 patients with OSA. Under general anesthesia and total muscle paralysis, the pharynx was visualized with an endoscope connected to a video-recording system. During an experimentally induced apnea, we manipulated the nasal pressure from 20 cmH2O to the point of total closure at the velopharynx. The procedure was repeated after maximal forward displacement of the mandible. Measurements of the cross-sectional area at different levels of nasal pressure allowed construction of a static pressure-area relationship of the “passive pharynx,” where active neuromuscular factors are suppressed. In 12 of 13 patients with OSA, advancement of the mandible stabilized the airway by reducing the closing pressure and increasing the area at any airway pressure. Thus the maneuver shifted the static pressure-area curve of the velopharynx and the oropharynx upward in these patients. We conclude that anterior movement of the mandible widens the retropalatal airway as well as that at the base of the tongue in the passive pharynx of OSA patients.

scholarly journals Risk factors for small pharyngeal airway dimensions in preorthodontic children: A three-dimensional study

2016 ◽  
Vol 87 (1) ◽  
pp. 138-146 ◽  
Author(s):  
Seerone Anandarajah ◽  
Raahib Dudhia ◽  
Andrew Sandham ◽  
Liselotte Sonnesen
Keyword(s):  
Skeletal Maturity ◽  
Three Dimensional ◽  
Cross Sectional Area ◽  
Craniofacial Morphology ◽  
Sectional Area ◽  
Cross Sectional ◽  
Pharyngeal Airway ◽  
And Gender ◽  
Relevant Factors ◽  
Airway Dimensions

ABSTRACT Objective: To analyze which parameters, gathered from standard orthodontic diagnostic material, were most relevant for identifying small pharyngeal airway dimensions in preorthodontic children. Materials and Methods: The sample was composed of 105 cone beam computed tomography scans of healthy preorthodontic children (44 boys, 61 girls; mean age, 10.7 ± 2.4 years). Airway volume and minimal cross-sectional area were three-dimensionally assessed. Cephalometric features and skeletal maturity were assessed on generated two-dimensional cephalograms. Associations were analyzed and adjusted for age, gender, and skeletal maturity by multiple regression analyses. Results: Airway volume and minimal cross-sectional area were significantly smaller in prepubertal children (P < .001, P < .05, respectively) and positively associated with age (P < .001, P < .01, respectively). After adjustment of age, skeletal maturity and gender significant associations were found between pharyngeal airway dimensions and craniofacial morphology. Airway volume was positively associated with maxillary and mandibular width (P < .01; P < .001, respectively) and anterior face height (P < .05; P < .05, respectively). Minimal cross-sectional area was positively associated with maxillary and mandibular width (P < .01; P < .001, respectively) and negatively associated with sagittal jaw relationship (AnPg, P < .05). Mandibular width and age were the most relevant factors for airway volume (r2 = 0.36). Mandibular width and sagittal jaw relationship were the most relevant factors for minimal cross-sectional area (r2 = 0.16). Conclusion: Pharyngeal airway dimensions were significantly associated with age, skeletal maturity, and craniofacial morphology in all three planes. Children with a reduced mandibular width and increased sagittal jaw relationship are particularly at risk of having small pharyngeal airway dimensions.

Effect of Head Posture on Airflow and Pressure Behavior of Human Upper Airway During Snoring

2020 ◽  
Author(s):  
Junshi Wang ◽  
Pan Han ◽  
Ruixuan Tang ◽  
Hong Tang ◽  
Younghoon Kwon ◽  
...  
Keyword(s):  
Upper Airway ◽  
Cross Sectional Area ◽  
High Speed Photography ◽  
Sectional Area ◽  
Cross Sectional ◽  
Head Posture ◽  
Pressure Behavior ◽  
Pharyngeal Airway ◽  
Aerodynamic Pressure ◽  
Airway Model

Abstract Snoring is a common breathing disorder during sleep. It is hypothesized that head posture during sleep could change the bending angle and the cross-sectional area of the airway, which could cause changes in airflow and aerodynamic pressure during sleep. In this work, an experiment-driven computational study was conducted to examine the aerodynamics and pressure behavior in human upper airway during snoring. An anatomically accurate human upper airway model associated with a dynamic uvula was reconstructed from human magnetic resonance image (MRI) and high-speed photography. The airway bending at different head posture and the corresponding change in airway cross-sectional area are modeled based on measurements from literature. An immersed-boundary-method (IBM)-based direct numerical simulation (DNS) flow solver was adopted to simulate the corresponding unsteady flows of the bent airway model in all their complexity. Analyses were performed on vortex dynamics and pressure fluctuations in the pharyngeal airway. It was found that the vortex formation and aerodynamic pressure were significantly affected by the airway bending. A head-neck junction extension posture tends to facilitate the airflow through the upper human airway. Fast Fourier transformation (FFT) analysis of the pressure time history revealed the existence of higher order harmonics of base frequency with significant pressure amplitudes and energy intensities. The results of this study help better understand the pathology of snoring under the influence of head posture from an aerodynamic perspective.

scholarly journals The use of SPHARM-PDM and mean latitude axis to evaluate airway changes

2016 ◽  
Vol 86 (6) ◽  
pp. 943-948 ◽  
Author(s):  
Tung Nguyen ◽  
Ceib Phillips ◽  
Beatriz Paniagua
Keyword(s):  
Shape Change ◽  
Imaging Techniques ◽  
Cross Sectional Area ◽  
Cone Beam ◽  
Imaging Method ◽  
Sectional Area ◽  
Volume Changes ◽  
Cross Sectional ◽  
Pharyngeal Airway ◽  
Bilateral Sagittal Split Osteotomy

ABSTRACT Objective: To introduce new 3-D imaging techniques to characterize shape and volume changes of the oropharyngeal space after bilateral sagittal split osteotomy (BSSO) advancement. Materials and Methods: Longitudinal cone-beam computed tomography (CBCT) scans were obtained for 20 patients undergoing BSSO advancement at three time points (T1 = presurgery, T2 = splint removal, and T3 = 1 year after surgery). Segmentation of the airway was performed using the following boundaries: hard palate/posterior nasal spine superiorly and lower border of C3 to the base of the epiglottis inferiorly. For shape measurements, point-based correspondent models and mean latitude axis were obtained for all the data using SPHARM-PDM software. All 3-D correspondent models were rigidly registered using Procrustes alignment. Absolute distance maps and corresponding vector maps were calculated to show shape and vector differences between each correspondent point. Mean latitude axis is a new imaging method to calculate minimum cross-sectional areas along the long axis of the airway independent of head position/alignment. Results: The airway volume increased (P < .01) after BSSO advancement (2973.9 mm3 ± 27882.0) and was stable (−439.9 mm3 ± 3308.8) 1 year post-op. 3-D color maps and semitransparency overlays showed more lateral than anteroposterior expansion of the airway after BSSO advancement. Mean latitude axis was used to measure minimum cross-sectional area, showing a statistically significant increase (52.7 mm2 ± 46.7) (P < .01) after surgery and remained stable (−10.3 mm2 ± 43.3) 1 year after surgery. Conclusions: SPHARM-PDM and mean latitude axis are useful tools to assess airway shape change. BSSO advancement produces a significant increase in pharyngeal airway volume and minimum cross-sectional area. The airway space increased more transversely than anteroposteriorly.

COMPUTATIONAL FLUID DYNAMICS MODELING OF PHARYNGEAL AIRWAY RESISTANCE BASED ON CONE-BEAM COMPUTED TOMOGRAPHY

2019 ◽  
Vol 19 (06) ◽  
pp. 1950045
Author(s):  
THYAGASEELY SHEELA PREMARAJ ◽  
SIYEONG JU ◽  
SUNDARALINGAM PREMARAJ ◽  
SUNG K. KIM ◽  
LINXIA GU
Keyword(s):  
Fluid Dynamic ◽  
Cross Sectional Area ◽  
Post Treatment ◽  
Cone Beam ◽  
Sectional Area ◽  
Cross Sectional ◽  
Airway Patency ◽  
Pharyngeal Airway ◽  
Splint Therapy ◽  
Percentage Area

Background: Oral appliances for treating patients with sleep related disorders such as snoring and disturbed sleep could alter the morphology of the pharyngeal airway and thus its flow dynamics as well as airway patency. Splint therapy, i.e., positioning the mandibular condyles in centric relation (CR) with maxillary anterior guided orthotics (MAGO), with regard to pharyngeal airway patency, is causing increased attention. The goal of this work is to quantitatively examine the fluid dynamic changes within the pharyngeal airway when the mandible is positioned in CR and its association with airway patency. Materials and Methods: Patient-specific computational fluid dynamics models were reconstructed from pre- and post- treatment high-resolution cone-beam computed tomography images for two patients who had undergone MAGO therapy. The minimal cross-sectional area and total volume of the pharyngeal airway were measured in the pre- and post-treatment for a total of four models. These two subjects were chosen out of 18 patients based on the airway volume changes in pre- and post-treatment. Subject 1 had a dramatic increase in the airway volume, whereas subject 2 kept a similar airway volume following the therapy. Both subjects anecdotally reported improvement in snoring, breathing and overall sleep quality. Results: We examined three parameters, i.e., the classically defined resistance of airway in terms of pressure drop, the minimal cross-sectional area, and the pharyngeal airway volume. We also proposed a new fluid dynamic parameter: the percentage area of higher vorticity, to be correlated with the clinical efficacy of the appliance for airway patency. All four parameters could be used as index factors for subject 1 to explain the measurable clinical outcomes and the subjective report regarding quality of breathing, snoring cessation, and improvement in sleep of the patient. But only the minimal cross-sectional area and percentage area of higher vorticity could explain the clinical observations and subjective outcome in subject 2 who reported similar effects after the treatment. Conclusion: Splint therapy expanded the minimal cross-sectional area in both subjects, but did not necessarily influence the pharyngeal airway volume. The airway shape changed in terms of the percentage area of higher vorticity and the minimal cross-sectional area. Further studies are needed to assess the clinical efficacy of MAGO in reducing or eliminating the sleep-related breathing difficulties and snoring.

scholarly journals Sitting Posture Decreases Collapsibility of the Passive Pharynx in Anesthetized Paralyzed Patients with Obstructive Sleep Apnea

2010 ◽  
Vol 113 (4) ◽  
pp. 812-818 ◽  
Author(s):  
Yugo Tagaito ◽  
Shiroh Isono ◽  
Atsuko Tanaka ◽  
Teruhiko Ishikawa ◽  
Takashi Nishino
Keyword(s):  
Obstructive Sleep Apnea ◽  
Sleep Apnea ◽  
Cross Sectional Area ◽  
Anesthesia Induction ◽  
Sectional Area ◽  
Postural Change ◽  
Cross Sectional ◽  
Pharyngeal Airway ◽  
Supine Posture ◽  
Obstructive Sleep

Background Obstructive sleep apnea (OSA) is an independent risk factor for difficult and/or impossible mask ventilation during anesthesia induction. Postural change from supine to sitting improves nocturnal breathing in patients with OSA. The purpose of this study was to evaluate the effect of patient position on collapsibility of the pharyngeal airway in anesthetized and paralyzed patients with OSA. The authors tested the hypothesis that the passive pharynx is structurally less collapsible during sitting than during supine posture. Method Total muscle paralysis was induced with general anesthesia in nine patients with OSA, eliminating neuromuscular factors contributing to pharyngeal patency. The cross-sectional area of the pharynx was measured endoscopically at different static airway pressures. Comparison of static pressure-area plots between the supine and sitting (62° head-up) allowed assessment of the postural differences of the mechanical properties of the pharynx. Results : Maximum cross-sectional area was greater during sitting than during supine posture at both retropalatal (median (10th-90th percentile): 1.91 (1.52-3.40) versus 1.25 (0.65-1.97) cm) and retroglossal (2.42 (1.72-3.84) versus 1.75 (0.47-2.35) cm) airways. Closing pressure of the passive pharynx was significantly lower during sitting than supine posture. Differences of the closing pressures between the postures are 5.89 (3.73-11.6) and 6.74 (4.16-9.87) cm H2O, at retropalatal and retroglossal airways, respectively, and did not differ between the pharyngeal segments. Conclusions Postural change from supine to sitting significantly improves collapsibility of pharyngeal airway in anesthetized and paralyzed patients with OSA.

scholarly journals Long-term effects of mini-screw–assisted rapid palatal expansion on airway:

2020 ◽  
Author(s):  
Shivam Mehta ◽  
Dennis Wang ◽  
Chia-Ling Kuo ◽  
Jinjian Mu ◽  
Manuel Lagravere Vich ◽  
...  
Keyword(s):  
Cross Sectional Area ◽  
Control Group ◽  
Sectional Area ◽  
Long Term Effects ◽  
Cross Sectional ◽  
Palatal Expansion ◽  
Rapid Palatal Expansion ◽  
Pharyngeal Airway ◽  
Significant Difference

ABSTRACT Objectives To evaluate the long-term effects on airway in patients with mini-screw–assisted rapid palatal expansion (MARPE), rapid palatal expansion (RPE), and controls with three-dimensional cone-beam computed tomography (CBCT) analysis. Materials and Methods A total of 180 CBCTs of 60 patients were analyzed at different time points, such as pretreatment, postexpansion, and posttreatment. Patients were divided into three groups: mini-screw assisted rapid palatal expansion (MARPE), rapid palatal expansion (RPE), and controls. The nasal cavity, nasopharyngeal, oropharyngeal, and laryngopharyngeal airway volume and area were measured. Changes in total airway volume, total airway area, minimal cross-sectional area, maxillary intermolar width, external maxillary width, and palatal width were also evaluated. Results Both MARPE and RPE caused a statistically significant increase in the airway after expansion as compared with the control group, but there was no statistically significant difference in the change in airway between MARPE, RPE, and the control group at posttreatment, except for nasopharyngeal volume, which was significantly increased in the MARPE group. There was no correlation between the amount of expansion and increase in total airway volume. Conclusions There was a significant increase in total airway volume, total airway area, and minimal cross-sectional area with MARPE and RPE immediately after expansion, but at posttreatment, the changes in the MARPE and RPE groups were similar to the change in the control group. However, MARPE led to a significant long-term increase in nasopharyngeal volume. The amount of expansion did not correlate with the increase in pharyngeal airway volume.

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