Pharyngeal cross-sectional area in normal men and women

1986 ◽  
Vol 61 (3) ◽  
pp. 890-895 ◽  
Author(s):  
I. G. Brown ◽  
N. Zamel ◽  
V. Hoffstein
Keyword(s):  
Measurement Techniques ◽  
Upper Airway ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Cross Sectional ◽  
Lung Volumes ◽  
Acoustic Reflection ◽  
Obstructive Sleep ◽  
Males And Females ◽  
Pharyngeal Area

Pharyngeal size and the dynamic behavior of the upper airway may be important factors in modulating respiratory airflow. Patients with obstructive sleep apnea are known to have reduced pharyngeal cross-sectional area. However, no systematic measurements of pharyngeal area in healthy asymptomatic subjects are available, in part due to the lack of simple, rapid, and noninvasive measurement techniques. We utilized the acoustic reflection technique to measure pharyngeal cross-sectional area in 24 healthy volunteers (14 males, 10 females). Pharyngeal area was measured during a continuous slow expiration from total lung capacity (TLC) to residual volume (RV). We compared pharyngeal cross-sectional areas in males and females at three lung volumes: TLC, 50% of vital capacity (VC), and RV. In males, pharyngeal areas (means +/- SD) were 6.4 +/- 1.3 cm2 at TLC, 5.4 +/- 0.9 cm2 at 50% VC, and 4.1 +/- 0.8 cm2 at RV. In females, pharyngeal areas were 4.8 +/- 0.6 cm2 at TLC, 4.2 +/- 0.5 cm2 at 50% VC, and 3.7 +/- 0.6 cm2 at RV. The difference in area between males and females was statistically significant at TLC and 50% VC but not at RV. However, when the pharyngeal cross-sectional area was normalized for body surface area, this difference was not significant. In males there was a negative correlation of pharyngeal area with age. We conclude that sex differences in pharyngeal area are related to body size, pharyngeal area shows a similar variation with lung volumes in males and females, and in males pharyngeal area reduces with age.

A three-microphone acoustic reflection technique using transmitted acoustic waves in the airway

2013 ◽  
Vol 115 (8) ◽  
pp. 1119-1125 ◽  
Author(s):  
Yuki Fujimoto ◽  
Jyongsu Huang ◽  
Toshiharu Fukunaga ◽  
Ryo Kato ◽  
Mari Higashino ◽  
...  
Keyword(s):  
Acoustic Waves ◽  
Cross Sectional Area ◽  
Distance Functions ◽  
Sectional Area ◽  
Wave Tube ◽  
Cross Sectional ◽  
Reflected Waves ◽  
Acoustic Reflection ◽  
Obstructive Sleep ◽  
And Function

The acoustic reflection technique noninvasively measures airway cross-sectional area vs. distance functions and uses a wave tube with a constant cross-sectional area to separate incidental and reflected waves introduced into the mouth or nostril. The accuracy of estimated cross-sectional areas gets worse in the deeper distances due to the nature of marching algorithms, i.e., errors of the estimated areas in the closer distances accumulate to those in the further distances. Here we present a new technique of acoustic reflection from measuring transmitted acoustic waves in the airway with three microphones and without employing a wave tube. Using miniaturized microphones mounted on a catheter, we estimated reflection coefficients among the microphones and separated incidental and reflected waves. A model study showed that the estimated cross-sectional area vs. distance function was coincident with the conventional two-microphone method, and it did not change with altered cross-sectional areas at the microphone position, although the estimated cross-sectional areas are relative values to that at the microphone position. The pharyngeal cross-sectional areas including retropalatal and retroglossal regions and the closing site during sleep was visualized in patients with obstructive sleep apnea. The method can be applicable to larger or smaller bronchi to evaluate the airspace and function in these localized airways.

Upper Airway Effective Compliance during Wakefulness and Sleep in Obese Adolescents Studied via 2-Dimensional Dynamic MRI and Semi-automated Image Segmentation

2021 ◽  
Author(s):  
Kok Ren Choy ◽  
Sanghun Sin ◽  
Yubing Tong ◽  
Jayaram K. Udupa ◽  
Dirk M. Luchtenburg ◽  
...  
Keyword(s):  
Upper Airway ◽  
Dynamic Mri ◽  
Cross Sectional Area ◽  
Apnea Hypopnea Index ◽  
Morphological Operations ◽  
Sectional Area ◽  
Cross Sectional ◽  
Automated Method ◽  
Obstructive Sleep ◽  
Effective Compliance

Novel biomarkers of upper airway biomechanics may improve diagnosis of Obstructive Sleep Apnea Syndrome (OSAS). Upper airway effective compliance (EC), the slope of cross-sectional area versus pressure estimated using computational fluid dynamics (CFD), correlates with apnea-hypopnea index (AHI) and critical closing pressure (Pcrit). The study objectives are to develop a fast, simplified method for estimating EC using dynamic MRI and physiological measurements, and to explore the hypothesis that OSAS severity correlates with mechanical compliance during wakefulness and sleep. Five obese children with OSAS and five obese control subjects age 12-17 underwent anterior rhinomanometry, polysomnography and dynamic MRI with synchronized airflow measurement during wakefulness and sleep. Airway cross-section in retropalatal and retroglossal section images was segmented using a novel semi-automated method that uses optimized singular-value decomposition (SVD) image filtering and k-means clustering combined with morphological operations. Pressure was estimated using rhinomanometry Rohrer coefficients and flow rate, and EC calculated from the area-pressure slope during five normal breaths. Correlations between apnea-hypopnea index (AHI), EC, and cross-sectional area (CSA) change were calculated using Spearman rank correlation. The semi-automated method efficiently segmented the airway with average Dice Coefficient above 89% compared to expert manual segmentation. AHI correlated positively with EC at the retroglossal site during sleep (rs=0.74, p=0.014), and with change of EC from wake to sleep at the retroglossal site (rs=0.77, p=0.01). CSA change alone did not correlate significantly with AHI. EC, a mechanical biomarker which includes both CSA change and pressure variation, is a potential diagnostic biomarker for studying and managing OSAS.

Effect of position and lung volume on upper airway geometry

1987 ◽  
Vol 63 (1) ◽  
pp. 375-380 ◽  
Author(s):  
J. M. Fouke ◽  
K. P. Strohl
Keyword(s):  
Lung Volume ◽  
Supine Position ◽  
Upper Airway ◽  
Upright Position ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Position Change ◽  
Cross Sectional ◽  
Acoustic Reflection ◽  
Residual Capacity

The occurrence of upper airway obstruction during sleep and with anesthesia suggests the possibility that upper airway size might be compromised by the gravitational effects of the supine position. We used an acoustic reflection technique to image airway geometry and made 180 estimates of effective cross-sectional area as a function of distance along the airway in 10 healthy volunteers while they were supine and also while they were seated upright. We calculated z-scores along the airway and found that pharyngeal cross-sectional area was smaller in the supine than in the upright position in 9 of the 10 subjects. For all subjects, pharyngeal cross-sectional area was 23 +/- 8% smaller in the supine than in the upright position (P less than or equal to 0.05), whereas glottic and tracheal areas were not significantly altered. Because changing from the upright to the supine position causes a decrease in functional residual capacity (FRC), six of these subjects were placed in an Emerson cuirass, which was evacuated producing a positive transrespiratory pressure so as to restore end-expiratory lung volume to that seen before the position change. In the supine posture an increase in end-expiratory lung volume did not change the cross-sectional area at any point along the airway. We conclude that pharyngeal cross-sectional area decreases as a result of a change from the upright to the supine position and that the mechanism of this change is independent of the change in FRC.

Retropalatal Cross-Sectional Area Is Predictive of Obstructive Sleep Apnea in Patients With Syndromic Craniosynostosis

2019 ◽  
Vol 57 (5) ◽  
pp. 560-565 ◽  
Author(s):  
Cory M. Resnick ◽  
Jason K. Middleton ◽  
Carly E. Calabrese ◽  
Karan Ganjawalla ◽  
Bonnie L. Padwa
Keyword(s):  
Obstructive Sleep Apnea ◽  
Sleep Apnea ◽  
Upper Airway ◽  
Cross Sectional Area ◽  
Secondary Outcome ◽  
Outcome Variable ◽  
Sectional Area ◽  
Cross Sectional ◽  
Syndromic Craniosynostosis ◽  
Obstructive Sleep

Objective: There is a high rate of obstructive sleep apnea (OSA) in patients with syndromic craniosynostosis (SCS). Little is known about the airway anatomy in this population. The purpose of this study is to characterize the 3 dimensional (3D) upper airway in patients with SCS with and without OSA. Design: This is a retrospective study of patients with SCS treated at Boston Children’s Hospital from 2000 to 2015. Patients were divided into OSA and no-OSA groups based on polysomnography. Predictor variables included age, sex, body mass index (BMI), and 3D upper airway measurements. The primary outcome variable was the presence or absence of OSA. Secondary outcome variables were apnea–hypopnea index and oxygen saturation nadir. Descriptive and bivariate statistics were computed, and significance was set as P < .05. Results: There were 24 patients: 16 in the OSA group and 8 in the no-OSA group. The 2 groups did not differ significantly by age, BMI, or syndromic diagnosis. The presence of OSA was associated with a smaller minimum retropalatal cross-sectional area (minRPCSA; P < .001). In a logistic regression model controlling for age, sex, and upper airway length, minRPCSA was the primary predictor of OSA ( P ≤ .002). Receiver operating characteristic analysis determined minRPCSA = 55.3 mm2 to be the optimal diagnostic threshold for OSA, with sensitivity = 100% and specificity = 87.5% ( P < .001). Conclusion: A minRPCSA ≤55.3 mm2 is predictive of the presence of OSA in patients with SCS.

Upper airway morphological changes in obstructive sleep apnoea: effect of age on pharyngeal anatomy

2020 ◽  
Vol 134 (4) ◽  
pp. 354-361
Author(s):  
F Gao ◽  
Y R Li ◽  
W Xu ◽  
Y S An ◽  
H J Wang ◽  
...  
Keyword(s):  
Body Mass Index ◽  
Body Mass ◽  
Obstructive Sleep Apnoea ◽  
Upper Airway ◽  
Sleep Apnoea ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Cross Sectional ◽  
Obstructive Sleep ◽  
Airway Morphology

AbstractObjectiveTo evaluate the upper airway morphology changes associated with ageing in adult Chinese patients with obstructive sleep apnoea.MethodsA total of 124 male patients diagnosed with obstructive sleep apnoea by overnight polysomnography, who underwent upper airway computed tomography, were enrolled. The linear dimensions, cross-sectional area and volume of the upper airway region and the surrounding bony frame were measured. The association between ageing and upper airway morphology was analysed.ResultsSoft palate length, minimum cross-sectional area of the retroglossal region, lateral dimensions at the minimum cross-sectional area of the retropalatal and retroglossal regions, nasopharyngeal volume, and average cross-sectional area of the nasopharyngeal region were found to significantly increase with ageing in all patients, while the upper airway shape flattened with ageing. The volume of the retropalatal region increased with ageing among the patients with a body mass index of less than 24 kg/m2. The volume of parapharyngeal fat pad increased with ageing among patients with a body mass index greater than 28 kg/m2.ConclusionA number of dimensional, cross-sectional and volumetric parameters of the pharynx increased with age, indicating that non-anatomical factors may play a more important role in the pathogenesis of obstructive sleep apnoea in aged patients.

scholarly journals Pharyngeal mucosal wall folds in subjects with obstructive sleep apnea

2015 ◽  
Vol 118 (6) ◽  
pp. 707-715 ◽  
Author(s):  
Kristina Kairaitis ◽  
Sheryl Foster ◽  
Jason Amatoury ◽  
Manisha Verma ◽  
John R. Wheatley ◽  
...  
Keyword(s):  
Surface Tension ◽  
Obstructive Sleep Apnea ◽  
Healthy Subjects ◽  
Liquid Surface ◽  
Upper Airway ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Cross Sectional ◽  
Liquid Surface Tension ◽  
Obstructive Sleep

Mechanical processes underlying pharyngeal closure have not been examined. We hypothesized that the pharyngeal mucosal surface would fold during closure, and lowering the upper airway lining liquid surface tension would unfold areas of mucosal apposition, i.e., folds. We compared baseline pharyngeal fold numbers and response to reduction in upper airway liquid surface tension in healthy and obstructive sleep apnea (OSA) subjects. Awake, gated magnetic resonance pharyngeal airway images of 10 healthy and 11 OSA subjects were acquired before and after exogenous surfactant administration (beractant). Upper airway liquid surface tension was measured at the beginning and end of image acquisition and averaged. Velopharyngeal and oropharyngeal images were segmented and analyzed separately for average cross-sectional area, circumference, and fold number. Compared with healthy subjects, at baseline, velopharynx for OSA subjects had a smaller cross-sectional area (98.3 ± 32.5 mm2 healthy, 52.3 ± 23.6 mm2 OSA) and circumference (46.5 ± 8.1 mm healthy, 30.8 ± 6.1 mm OSA; both P < 0.05, unpaired t-test), and fewer folds (4.9 ± 1.6 healthy, 3.1 ± 1.8 OSA, P < 0.03). There were no differences in oropharynx for cross-sectional area, circumference, or folds. Reduction in upper airway liquid surface tension from 61.3 ± 1.2 to 55.3 ± 1.5 mN/m ( P < 0.0001) did not change cross-sectional area or circumference for velopharynx or oropharynx in either group; however, in OSA subjects, oropharyngeal folds fell from 6.8 ± 3.1 to 4.7 ± 1.2 ( n = 8, P < 0.05), and velopharyngeal folds from 3.3 ± 1.9 to 2.3 ± 1.2 ( P = 0.08), and were unchanged in healthy subjects. Subjects with OSA have fewer velopharyngeal wall folds, which decrease further when surface tension falls. We speculate that reduced pharyngeal wall folds contribute to an increase in pharyngeal collapsibility.

scholarly journals A retrospective study: does upper airway morphology differ between non-positional and positional obstructive sleep apnea?

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e3918 ◽  
Author(s):  
Xiao Jiao ◽  
Jianyin Zou ◽  
Suru Liu ◽  
Jian Guan ◽  
Hongliang Yi ◽  
...  
Keyword(s):  
Obstructive Sleep Apnea ◽  
Retrospective Study ◽  
Sleep Apnea ◽  
Soft Palate ◽  
Upper Airway ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Cross Sectional ◽  
Obstructive Sleep ◽  
Airway Morphology

Objective The objective of this study was to explore the differences in upper airway morphology between positional (POSA) and non-positional (NPOSA) obstructive sleep apnea. Methods This retrospective study enrolled 75 patients (45 NPOSA and 30 POSA) who underwent polysomnography (PSG) and computed tomography (CT). The differences in, and relationships of, the PSG values and CT data between POSA and NPOSA were analyzed. Results Significant (p < 0.05) differences between the two groups were found in the apnea/hypopnea index (AHI), lateral-AHI (L-AHI), soft palate length (SPL), cross-sectional palatopharyngeal area, and the coronal diameter (CD) of the palatopharyngeal area at the narrowest part of the glossopharynx, which were all higher in POSA, except for SPL, AHI, and L-AHI. L-AHI was correlated with the cross-sectional area (r =  − 0.306, p = 0.008) and CD (r =  − 0.398, p < 0.001) of the palatopharyngeal area, the cross-sectional area (r =  − 0.241, p = 0.038) and CD (r =  − 0.297, p = 0.010) of the narrowest level of the glossopharynx, the CD of the glossopharynx (r = 0.284, p = 0.013), body mass index (BMI, r = 0.273, p = 0.018), SPL (r = 0.284, p = 0.014), and vallecula-tip of tongue (r = 0.250, p = 0.030). The SPL and CD at the narrowest part of the glossopharynx were included in the simplified screening model. Conclusions In NPOSA, the CD of the upper airway was smaller, and the soft palate was longer, than in POSA. These differences may play significant roles in explaining the main differences between NPOSA and POSA.

A Simple Endoscopic Technique for Measuring the Cross-Sectional Area of the Upper Airway in a Rabbit Model

2018 ◽  
Vol 127 (4) ◽  
pp. 275-281 ◽  
Author(s):  
Paul R. Wistermayer ◽  
Wesley R. McIlwain ◽  
Nicholas Ieronimakis ◽  
Derek J. Rogers
Keyword(s):  
Rabbit Model ◽  
Upper Airway ◽  
Cross Sectional Area ◽  
Endoscopic Technique ◽  
Sectional Area ◽  
Cross Sectional ◽  
The Cross

Upper Airway 3D Changes of Patients With Cleft Lip and Palate After Orthognathic Surgery

2018 ◽  
Vol 56 (3) ◽  
pp. 314-320 ◽  
Author(s):  
Marilia Sayako Yatabe-Ioshida ◽  
Letícia Dominguez Campos ◽  
Renato Yassukata Yaedu ◽  
Ivy Kiemle Trindade-Suedam
Keyword(s):  
Orthognathic Surgery ◽  
Cleft Lip ◽  
Cleft Lip And Palate ◽  
Upper Airway ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Class Iii ◽  
Linear Measurements ◽  
Cross Sectional ◽  
Skeletal Class

Objectives: The purpose of this study was to 3-dimensionally assess the airway characteristics of patients with unilateral cleft lip and palate (UCLP) and bilateral cleft lip and palate (BCLP) who underwent orthognathic surgery. Design: This was a retrospective study. Setting: The study took place at a national referral center for cleft lip and palate rehabilitation. Patients and Participants: The sample comprised cone-beam computed tomography (CBCT) scans obtained before and after orthognathic surgery of 15 individuals (30 CBCT scans), divided into 2 groups: UCLP group (n = 9 patients/18 CBCT scans) and BCLP group (n = 6/12 CBCT scans). All patients had a nonsyndromic UCLP or BCLP and a skeletal class III malocclusion at the preoperative period. Interventions: Airway volume, pharyngeal minimal cross-sectional area (mCSA), location of mCSA, sella-nasion-A point (SNA) and sella-nasion-B point (SNB) angles, and condylion-A point and condyloid-gnathion linear measurements were assessed in open-source software (ITK-SNAP and SlicerCMF). Main Outcome Measure: Airway dimensions of patients with UCLP and BCLP increase after orthognathic surgery. Results: After orthognathic surgery, UCLP group showed a significant 20% increase in nasopharynx volume. Although not significant, BCLP group also showed an increase of 18% in the same region. Minimal cross-sectional area remained dimensionally stable after surgery and was all located in the oropharynx region, on both groups. Additionally, a positive correlation was observed between volume and mCSA on both groups. Conclusion: Overall, individuals with UCLP and BCLP showed an increase in the upper airway after orthognathic surgery and this might explain the breathing and sleep improvements reported by the patients after the surgery.

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