Upper Airway Length Research Articles

Effects of twin-block appliance on upper airway parameters in OSA children with class II malocclusion and mandibular retrognathia: a CBCT study.

Correction of class II mandibular retrognathic skeletal malocclusion with twin-block appliance resulted in a significant increase in upper airway volume, MCA, anteroposterior and lateral distances of the MCA at the level of the oropharynx, MCA at the level of the hypopharynx and upper airway length, and a significant decrease in AHI, but it had no effect on nasopharynx parameters. • CBCT imaging has been shown to be an effective and precise diagnostic tool for analyzing the upper airways and craniofacial structures. • Twin block appliance may be an effective treatment modality in children with OSA. • Minimal cross-sectional area of upper ways may be the most relevant potential parameter when explaining how the upper airway anatomy plays role of in the pathogenesis of pediatric OSA. • Twin block appliance induced favorable changes in upper airway morphology (oropharynx area mainly) and respiratory parameters in OSA children with class II malocclusion.

Three-dimensional analysis of upper airways in Class II malocclusion children with obstructive sleep apnea

Morphometric evaluation of upper airways helps in identifying potential craniofacial anatomy that may predispose to pediatric obstructive sleep apnea (OSA). This study evaluated upper airway parameters three-dimensionally in children with OSA, with Class II malocclusion and a retrognathic mandible, to identify cutoff values for cone-beam computed tomography measurements that may predict the presence and severity of pediatric OSA. The study comprised 47 growing children with OSA with Class II malocclusion and 47 low-risk OSA-matched controls. Upper airway was segmented into nasopharynx, oropharynx, and hypopharynx using cone-beam computed tomography and MIMICS16.0 software. Parameters included volume, minimum cross-sectional area (CSAmin), anterioposterior and lateral distances of CSAmin, and upper airway length. The volume, cross-sectional area (CSAmin), and anteroposterior and lateral distances of CSAmin were significantly decreased at the level of the oropharynx in patients with OSA. At the level of the hypopharynx, CSAmin was significantly narrower and upper airway length was significantly increased in patients with OSA. OSA predictive cutoff values were proposed as 41.36 mm2 CSAmin at the level of oropharynx, 52.45 mm2 CSAmin at the level of hypopharynx, and 55.47 mm upper airway length. Only CSAmin at the level of the oropharynx had an independent association with OSA severity (P=0.021). Significant differences were found in the upper airway parameters of children with OSA compared with corresponding controls. CSAmin may represent part of the issues that play a role in the pathogenesis of OSA and may serve as a predictive of disease severity.

Two-dimensional upper airway normative values in children aged 7 to 17 years

ABSTRACT Objective To develop two-dimensional (2D) upper airway normative values in pediatric patients and correlate upper airway measurements with age. Methods Cone beam computed tomography scans of 3738 patients were examined, and a sample of 61 patients, divided into two age groups (7–11 and 12–17 years), was used to reconstruct lateral cephalograms. Results The mean adenoid–nasopharynx (A/N) ratio was 0.45 and 0.44 for age groups 1 and 2, respectively. The mean PNS-ad1 and PNS-ad2 were 24 and 18.7 mm, respectively, for age group 1, and 26.7 and 21.2 mm, respectively, for age group 2. Additional normative values for the hyoid bone, airway space, uvula, and tongue are presented. The highest correlation with age was the upper airway length (r = 0.557, p < 0.001). Conclusion Although cephalometric radiographs remain 2D reconstructions of three-dimensional structures, they have significant value and can aid clinicians in the screening process for pediatric sleep apnea.

Analysis of upper airway structure development in children with different characteristics

Objective: To analyze the development of upper airway in children with different characteristics. Methods: From June 2018 to June 2020, a total of 425 children younger than 16 years old who underwent head MRI examination and did not have sleep-disordered breathing were included in the study. The length of soft palate, tongue, upper airway, mental spine clivus, adenoid thickness and nasopharyngeal width were measured in the midsagittal plane of MRI image. Single factor variance analysis was used to compare the gender differences of upper airway parameters within certain age groups. Pearson correlation analysis was used to analyze the correlation between upper airway parameters and age. Results: The numbers of subjects in infant, young child, preschool, school age and adolescent group were 80, 86, 90, 90 and 79, respectively. There were 219 males, accounting for 51.5% of the study population. The adenoid thickness in the preschooler group was (1.26±0.26) cm, higher than that in the female group (1.15±0.20) cm (P=0.025). The upper airway length (5.89±0.60) cm and the ratio of upper airway length/mental spine-slope length (0.73±0.08) in males were higher than those in females [(5.31±0.45) cm and 0.67±0.07, respectively, P<0.05]. There was no gender difference in other upper airway parameters among different age groups (all P values>0.05). The length of upper airway, mental spine-slope, tongue, soft palate, the width of nasopharyngeal cavity and the thickness of adenoids were positively correlated with age (r=0.932, 0.912, 0.898, 0.705, 0.734 and 0.168, respectively), all P values<0.05. Adenoid thickness was positively correlated with age from birth to age 5 years (r=0.603, P<0.001), and negatively correlated with age after age 6 years (r=-0.259, P=0.001). Conclusion: There are gender differences in the development of upper airway structure in children of different ages.

Association of Craniofacial and Upper Airway Morphology with Cardiovascular Risk in Adults with OSA.

Background and ObjectiveClinical and population-based studies have demonstrated a strong association between obstructive sleep apnea (OSA) and cardiovascular disease (CVD). Anatomical abnormalities of the craniofacial region and upper airway are important risk factors for OSA. The objective of this study was to investigate the association of craniofacial and upper airway morphology with CVD risk biomarkers.MethodsOne hundred and sixty-nine male patients with OSA underwent in-laboratory polysomnography (PSG) and upper airway computed tomography (CT) scanning. Ten-year Framingham CVD risk score (FRS) was calculated and categorized into low- and moderate-to-high-risk groups. N-terminal pro B-type natriuretic peptide (NT-proBNP) was measured as a biomarker of increased myocardial wall stress.ResultsCompared to the low-risk group, total sleep time (TST), the proportion of N3 (N3%) and mean oxygen saturation (SpO2mean) were lower, while the arousal index of non-rapid eye movement (NREM) sleep, apnea index (AI) of NREM sleep, apnea hypopnea index (AHI) of NREM sleep, oxygen desaturation index (ODI) and percentage of total sleep time spent with oxyhemoglobin saturation below 90% (TST90) were higher in the moderate-to-high risk group. The corrected upper airway length (UAL), ANB angle and gonion-gnathion-hyoid angle were larger for subjects in the moderate-to-high risk group than those in the low-risk group. In multiple regression analysis, TST, AINREM and adjusted UAL were independently associated with moderate-to-high CVD risk. Plasma NT-proBNP levels were higher in patients in the moderate- to high-risk group, and among the PSG and CT scan parameters, only SPO2mean was marginally associated with NT-proBNP (r=0.183, P=0.054).ConclusionCraniofacial and upper airway features may contain valid cues about CVD risk, and sleep duration, obstructive event type and occurrence phase may be closely related to CVD risk for patients with OSA.

Are there sex-related differences in therapeutic CPAP levels in adults undergoing in-laboratory titration?

The first-choice therapy for adults with moderate/severe obstructive sleep apnea is continuous positive airway pressure (CPAP). However, studies evaluating whether the therapeutic CPAP level obtained from a titration is affected by sex are surprisingly scarce. Our main objective was to verify if sex influenced the optimal CPAP measurement obtained during a titration. This cross-sectional study was conducted in adults diagnosed with moderate/severe obstructive sleep apnea [baseline apnea-hypopnea index (AHI) ≥ 15.0 events/h] who underwent auto-adjusting CPAP titration (S9 or S10 AutoSet ResMed) in a sleep laboratory setting. All participants used a nasal mask during the titration. The optimal pressure, leak, and residual AHI values were registered. Multiple linear regression was used to evaluate if clinical and polysomnographic data influenced the therapeutic CPAP level setting (95th percentile pressure). A total of 1,006 adults were enrolled: 354 women and 652 men. There were no statistically significant sex-related differences in the CPAP requirements and leak values delineated during the titration; all P-values > .005. However, the median residual AHI was significantly higher in males vs females: 2.7 events/h vs 2.2 events/h (P = .008). Body mass index (β: 0.292, P < .001), baseline AHI (β: 0.167, P < .001), and age (β: 0.065, P = .035) were independent predictors of the therapeutic CPAP level settings. Sex does not significantly influence the therapeutic CPAP settings. However, age, BMI, and baseline AHI emerge as independent predictors of the 95thpercentile CPAP requirement during an auto-adjusting CPAP titration. Duarte RLM, Magalhães-da-Silveira FJ, Gozal D. Are there sex-related differences in therapeutic CPAP levels in adults undergoing in-laboratory titration? JClin Sleep Med. 2021;17(9):1815-1820.

Impact of upper airway configuration on CPAP titration assessed by CT during Müller's maneuver in OSA patients

PurposeContinuous positive airway pressure (CPAP) is the current gold-standard treatment for moderate to severe obstructive sleep apnea (OSA), and upper airway anatomy plays an increasingly important role in evaluating the efficacy of CPAP therapy. The aim of this observational study was to investigate the influence of upper airway anatomy on CPAP titration in OSA patients assessed by computed tomography (CT) during Müller's maneuver. MethodsConsecutive patients under investigation for OSA by undergoing polysomnography and CT scan of the upper airway while awake were enrolled. Successful full-night manual titration was performed to determine the optimal CPAP pressure level for OSA patients in supine position using a nasal mask. ResultsA total of 157 subjects (134 males and 23 females) were included. Both apnea–hypopnea index (AHI) and LaSO2 significantly correlated with CPAP titration level, upper airway length (UAL), distance from mandibular plane to hyoid bone (MPH), and neck circumference (all p < 0.05). There were significant positive correlations between CPAP titration level and UAL (r = 0.348, p = 0.000) and MPH (r = 0.313, p = 0.002). Stepwise multiple linear regression analyses were performed to evaluate the independent predictors of AHI, LaSO2, and CPAP titration level. CPAP titration level was identified as an independent explanatory variable for AHI and LaSO2 after adjustment for confounders. Multiple linear regression analyses also indicated that body mass index (BMI) and UAL were independently associated with CPAP titration level (all p < 0.05). ConclusionsUpper airway abnormalities combined with anthropometric parameters play important roles in CPAP titration for OSA patients, providing additional insight into the factors influencing OSA treatment strategies. UAL and BMI should be taken into consideration when choosing CPAP titration level to improve CPAP compliance.

Upper airway lengthening caused by weight increase in obstructive sleep apnea patients

BackgroundThe longer upper airway is more collapsible during sleep. This study aims to reveal relationships among upper airway length, weight, and obstructive sleep apnea (OSA), particularly to answer why the upper airway of OSA patients is longer than that of healthy people and why some obese people suffer from OSA while others do not.MethodsWe perform head and neck MRI on male patients and controls, and measure > 20 morphological parameters, including several never before investigated, to quantify the effect of weight change on upper airway length.ResultsThe upper airway length is longer in patients and correlates strongly to body weight. Weight increase leads to significant fat infiltration in the tongue, causing the hyoid to move downward and lengthen the airway in patients. The apnea-hypopnea index (AHI) strongly correlates to airway length and tongue size. Surprisingly, a distance parameter h and angle β near the occipital bone both show significant differences between healthy males and patients due to their different head backward tilt angle, and strongly correlates with AHI. The contributions of downward hyoid movement and head tilt on airway lengthening are 67.4–80.5% and19.5–32.6%, respectively, in patients. The parapharyngeal fat pad also correlates strongly with AHI.ConclusionsThe findings in this study reveal that the amount of body weight and distribution of deposited fat both affect airway length, and therefore OSA. Fat distribution plays a larger impact than the amount of weight, and is a better predictor of who among obese people are more prone to OSA.

Can MDCT Measures of Upper Airway Dimensions and Central Obesity Indices Predict the Severity of Obstructive Sleep Apnea (OSA)?

Abstract Background: Comparative evaluation of the CT measures of upper air way, tongue adiposity and central obesity in a group of obstructive sleep apnea (OSA) patients and in a control group, and their potential role in grading of OSA severity. Aim of Study: The objective of the present study was to comparatively evaluate the different the upper air way, tongue adiposity and central obesity measures by CT scan in patients with obstructive sleep apnea syndrome (OSA) and in a control group, and their potential role in grading of OSA severity. Material and Methods: This prospective case control study was carried out on 17 OSA patients diagnosed by PSG and 16 control subjects. Non contrast MDCT scan of the upper airway and mid abdomen was performed on Philips 128 detector scanner, 1mm slice collimation during quite breathing. Axial and Sagittal reformatted images were assessed. Man-dibular plane hyoid distance (MPH), upper airway length (UAL), minimum cross-sectional area (MCA), transverse and antero-posterior diameters of the airway (TDA, APD), length and thickness of uvula and soft palate (LUV,TUV), tongue area and tongue base density (TA, TD) were measured. Image J program was used for quantification of neck and visceral adipose tissue (NAT, VAT). Results: Statistically significant difference was found in most CT measures between the OSA and control groups, the highest significant values were found with MCA, TDA, TUV and TA (p < 0.005). MCA and TA had the best diagnostic performance for OSA diagnosis. Statistically significant difference was found in MPH, UAL, MCA, TDA, TA, TD and NAT between the severe OSA and mild/moderate grades, The highest significant values was found with UAL and MCA (p=0.001, 0.002). For identifying severe OSA MCA, TDA and TA offered high diagnostic performances. Binary logistic regression found that TA and MPH were the significant predictors for severe OSA with overall % predicted=88.2%. Conclusion: Our results indicate that CT offers added value in OSA diagnosis and prediction of severity, multiple CT measures varied significantly between OSA and control group as well as between different OSA grades.

Position of the hyoid bone and its correlation with airway dimensions in different classes of skeletal malocclusion using cone-beam computed tomography.

PurposeThis study investigated the position of the hyoid bone and its relationship with airway dimensions in different skeletal malocclusion classes using cone-beam computed tomography (CBCT).Materials and MethodsCBCT scans of 180 participants were categorized based on the A point-nasion-B point angle into class I, class II, and class III malocclusions. Eight linear and 2 angular hyoid parameters (H-C3, H-EB, H-PNS, H-Me, H-X, H-Y, H-[C3-Me], C3-Me, H-S-Ba, and H-N-S) were measured. A 3-dimensional airway model was designed to measure the minimum cross-sectional area, volume, and total and upper airway length. The mean cross-sectional area, morphology, and location of the airway were also evaluated. Data were analyzed using analysis of variance and the Pearson correlation test, with P values <0.05 indicating statistical significance.ResultsThe mean airway volume differed significantly among the malocclusion classes (P<0.05). The smallest and largest volumes were noted in class II (2107.8±844.7 mm3) and class III (2826.6±2505.3 mm3), respectively. The means of most hyoid parameters (C3-Me, C3-H, H-Eb, H-Me, H-S-Ba, H-N-S, and H-PNS) differed significantly among the malocclusion classes. In all classes, H-Eb was correlated with the minimum cross-sectional area and airway morphology, and H-PNS was correlated with total airway length. A significant correlation was also noted between H-Y and total airway length in class II and III malocclusions and between H-Y and upper airway length in class I malocclusions.ConclusionThe position of the hyoid bone was associated with airway dimensions and should be considered during orthognathic surgery due to the risk of airway obstruction.

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

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. 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. 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). A minRPCSA ≤55.3 mm2 is predictive of the presence of OSA in patients with SCS.

Assessment of Upper-Airway Configuration in Obstructive Sleep Apnea Syndrome With Computed Tomography Imaging During Müller Maneuver.

The purpose of this observational study was to investigate the relationship between upper-airway configuration assessed by CT imaging during the Müller maneuver state and the severity of obstructive sleep apnea syndrome (OSAS). A total of 358 snoring subjects who underwent standard polysomnography and upper-airway configuration by using CT imaging were enrolled. According to the apnea-hypopnea index (AHI), subjects were classified into 4 groups: snoring group (simple snoring), AHI < 5; mild OSAS, 5 ≤ AHI < 15; moderate OSAS, 15 ≤ AHI < 30; and severe OSAS, AHI ≥ 30. We also divided the upper airway into 3 parts, named the nasopharynx, oropharynx, and hypopharynx, from the CT scan and evaluated the minimal cross-sectional area (mCSA) and the shape of each airway level and calculated upper-airway length and distance from mandibular plane to hyoid bone (MPH). Multivariate logistic stepwise regression analysis identified body mass index (BMI), mCSA of nasopharynx, upper-airway length, and MPH as risk factors for the severity of OSAS. When subdivided for BMI and sex, upper-airway length was a risk factor for OSAS in non-obese (BMI < 27 kg/m2) and male subjects, and MPH was a risk factor only in obese (BMI ≥ 27 kg/m2) subjects. Meanwhile, mCSA of nasopharynx was significantly associated with the severity of OSAS independent of BMI. Subjects with severe OSAS have more significant abnormalities of the upper airway. Obesity, mCSA of nasopharynx, upper-airway length, and MPH may contribute to the severity of OSAS. Obesity and sex should be taken into account when evaluating the abnormalities of upper-airway anatomy in snorers and patients with OSAS.

Static craniofacial measurements and dynamic airway collapse patterns associated with severe obstructive sleep apnoea: a sleep MRI study.

Using sleep MRI, we aimed to identify static craniofacial measurements and dynamic upper airway collapse patterns associated with severe obstructive sleep apnoea (OSA) during natural sleep in age and BMI-matched patients. Nested case-control study. Sleep MRI images (3.0 Tesla scanner) and synchronised acoustic recording were used to observe patterns of dynamic airway collapse in subjects with mild and severe OSA. Midsagittal images were also used for static craniofacial measurements. Fifteen male subjects with severe OSA (mean AHI 70.3±23 events/h) were matched by age and BMI to 15 subjects with mild OSA (mean AHI 7.8±1.4 events/h). Subjects were selected from a consecutive sleep MRI study cohort. Static craniofacial measurements selected a priori included measurements that represent maxillomandibular relationships and airway morphology. Axial, sagittal and coronal views of the airway were rated for dynamic collapse at retropalatal, retroglossal and lateral pharyngeal wall regions by blinded reviewers. Bivariate analysis was used to correlate measures associated with severity of OSA using AHI. Statistical significance was set at P<0.01. Lateral pharyngeal wall collapse from dynamic sleep MRI (β=51.8, P<0.001) and upper airway length from static MRI images (β=27.2, P<0.001) positively correlated with severity of OSA. Lateral pharyngeal wall collapse and upper airway length are significantly associated with severe OSA based on sleep MRI. Assessment of these markers can be readily translated to routine clinical practice, and their identification may direct targeted surgical treatment.

Characterization of Upper Air Way Tract in Snoring and Non-Snoring Patients: A CT Based Study

Snoring is part of the spectrum of sleep disordered breathing. The patients with snoring should be evaluated for nasal airway obstruction. In this study, the upper air way tract was characterized in snoring patients and compared with none snoring using a quantify method for the corresponding anatomic upper air way (UA) parameters examined by Computerized Tomography (CT). Two hundred Asian patients undergoing CT scanning for head and neck were included and were divided into two groups (snoring group [n = 127] and non-snoring group [n = 73]) (mean age: 44.8 ± 15.9 years and 26.2 ± 7.0). Total 8 parameters were measured on sagital reconstructed CT images for each subject. The differences in neck circumference (NC), linear distance between mandibular plane and hyoid bone (Mp-H), upper airway length (UAL), the maximum thickness of the soft palate (SP max), soft palate length (PNS-U), linear distance between anterior and posterior nasal spine (ANS-PNS), retroglosal width (RS), retroplatal width (RP) between the snoring and non-snoring groups were compared statistically using independent sample t-test. Results showed that the NC, UAL, and SP max were significantly higher in snoring group; however RP was found to be significantly lower. Inferior positioning of hyoid bone gives longer measurement for MP-H. In snoring group UAL was found to be significantly different at p ≤ 0.000 between the two genders. All the measured variables showed no significant differences in respect to age. UA CT quantitative features play an important role in the characterization of the anatomy and are compared between snoring patients and non-snoring subjects.

Static hyoid position and dynamic lateral pharyngeal wall collapse predict OSA severity: Observations based on sleep MRI

Introduction: Numerous cephalometric studies have been conducted to find predictors of OSA severity – all with the common handicap of relying solely on static radiographic measures. Using sleep MRI, we combined both static and dynamic measures to characterize OSA severity more accurately. Materials andmethods: This is a case-control studywith 15 severe OSA patients (AHI > 40) who are age, gender, and BMI matched with 15 controls (AHI 4% in oxygen saturation. Static midsagittal MRI slice was used to measure a priori predictors of OSA severity, including palatal plane, upper airway length, hyoid position (angle from Pogonion to hyoid to the posterior airway), and posterior airway space. Axial and coronal views of the oropharynx were then rated by blinded, independent reviewers, focusing on lateral pharyngeal walls only. The degree of collapse was rated as none (0), partial (1), or complete (2). Univariate analyses withwere conductedwith Pearson and Spearman tests with the a priori predictors as described. Multivariate analysis was then performed to identify independent predictors Results: The mean age, BMI, and AHI of the control group were 42.6, 29.7, and 5.28 . The mean age, BMI, and AHI of the severe OSA group were 42.4, 30.4, and 70.29. There were no statistically significant differences between the two groups. When compared with age, BMI, and gender-matched controls, palatal plane (r2 = 0.46, p = 0.01), hyoid position based on pogonionhyoid-airway angle (r2 = −0.72, p < 0.001), and lateral pharyngeal wall collapse from dynamic sleepMRI (r2 = 0.65, p < 0.001) correlated significantly with severity of obstructive sleep apnea. Upper airway length and posterior airway space did not reach statistical significance. In a multivariate analysis, both hyoid position and lateral pharyngeal wall collapse independently correlate with severity of OSA. Conclusion: While impractical to use sleep MRI for OSA patients to identify sites of airway collapse, this study has important clinical implications. Few static and dynamic predictors are needed to identify severe OSA. Characterizing hyoid position and identifying lateral pharyngeal wall collapse, even from routine nasopharyngoscopy, can be sensitive and cost-effective. Acknowledgements: The senior author of this study would like to thank the team led by Dr. Wang PC from Cathay General Hospital, Prof. LoMT from Central University, and Dr. Shih TT fromNational Taiwan University.

Does the Pharyngeal Airway Recover After Sagittal Split Ramus Osteotomy for Mandibular Prognathism?

Mandibular setback surgery can adversely affect the pharyngeal airway. The aim of this study was to investigate changes of the pharyngeal airway at specific intervals during a 12-month period after bilateral sagittal split ramus osteotomy (BSSO) for correction of mandibular prognathism. This retrospective cohort study included patients with mandibular prognathism who underwent BSSO. The pharyngeal airway was measured at 3 different levels on lateral cephalograms: the uvula tip, the most inferior-anterior point on the body of the second cervical vertebra (low-C II), and a midanterior point on the body of the third cervical vertebra (mid-C III). The pharyngeal airway was measured preoperatively, immediately postoperatively, and 1, 3, 6, and 12months postoperatively. The measurements at each level were compared. Multivariable analysis of variance was used to measure the changes in pharyngeal airway space over time. The study sample was composed of 30 patients (14 men and 16 women) who were diagnosed with mandibular prognathism. The pharyngeal airway at the uvular tip level was significantly reduced by 39% (P < .001) after surgery and was significantly improved by 26% (P < .01) from baseline at 1month postoperatively. The pharyngeal airway at the low-C II level was significantly reduced by 27% (P < .001) after surgery and was significantly improved by 24% (P < .01) from baseline at 1month postoperatively. The pharyngeal airway at the mid-C III level was significantly reduced by 23% (P<.001) after surgery and was improved by only 13% from baseline at 1month postoperatively. Additional statistical changes were not noted on 3 and 6months postoperative radiographs at all levels. The pharyngeal airway was decreased by 16, 19, and 8% from baseline at 12months postoperatively, respectively. The upper airway length was significantly increased immediately after surgery (P < .001), but was incompletely recovered at 12months postoperatively. The outcomes of this study indicate that the pharyngeal airway gradually recovers over time. An immediate postoperative reduction in pharyngeal airway space can induce or exacerbate obstructive sleep apnea symptoms; thus, any pre-existing symptoms should be screened and considered for surgical treatment planning.

Upper Airway Length Decreases Following Maxillomandibular Advancement in Patients With Obstructive Sleep Apnea

Upper Airway Length Decreases Following Maxillomandibular Advancement in Patients With Obstructive Sleep Apnea

Effect of weight loss on upper airway size and facial fat in men with obstructive sleep apnoea

BackgroundObstructive sleep apnoea (OSA) is commonly associated with obesity and can be improved by weight loss. Changes in upper airway size related to regional fat loss may mediate the improvement...

Class II Division II Malocclusion Does Not Influence Upper Airway Length

We recently received an inquiry from a reader regarding our article entitled “Cephalometric measurement of upper airway length correlates with the presence and severity of obstructive sleep apnea.” 1 Susarla S.M. Abramson Z.R. Dodson T.B. et al. Cephalometric measurement of upper airway length correlates with the presence and severity of obstructive sleep apnea. J Oral Maxillofac Surg. 2010; 68: 2846 Abstract Full Text Full Text PDF PubMed Scopus (58) Google Scholar The reader made the astute observation that, if there were a greater number of subjects without sleep apnea who had Class II Division II or “deep bite” malocclusions, the measurement of upper airway length could be potentially confounded by this factor. The reader's hypothesis was that a deep bite would be associated with a lower gonial angle, a more horizontally positioned mandible, and given the method of measuring upper airway length, an effectively shortened upper airway. Cephalometric Measurement of Upper Airway Length Correlates With the Presence and Severity of Obstructive Sleep ApneaJournal of Oral and Maxillofacial SurgeryVol. 68Issue 11PreviewThe purpose of this study was to measure upper airway length (UAL) on lateral cephalograms and to assess its relationship with the presence and severity of obstructive sleep apnea (OSA). Full-Text PDF

Upper Airway Length Decreases After Maxillomandibular Advancement in Patients With Obstructive Sleep Apnea

Most reports on airway anatomy after maxillomandibular advancement (MMA) for obstructive sleep apnea (OSA) have focused on changes in airway diameter, ie, posterior airway space (PAS), rather than airway length. The purpose of this study was to evaluate changes in cephalometrically measured upper airway length (UAL) after MMA. This was a retrospective cohort study. The sample was composed of subjects who underwent MMA for OSA. The primary outcome measurement was change in UAL measured on lateral cephalograms. Predictor variables included patient demographic and cephalometric characteristics. Secondary outcome measurements were changes in sleep disturbance. Descriptive, bivariate, and regression statistics were computed. For all analyses, P ≤ .05 was considered statistically significant. The sample included 23 adult subjects (mean age, 39.3 ± 12.1 years; 6 women). Subjects had average maxillary and mandibular advancements of 9.8 ± 2.0 and 10.8 ± 2.2 mm, respectively. Mean pre- and postoperative UALs were 75.8 ± 7.0 and 67.0 ± 5.7 mm, respectively (P < .001). Mean pre- and postoperative respiratory disturbance indexes were 53.2 ± 22.4 and 19.0 ± 12.0 events/hour, respectively (P = .003). All patients had improvement in OSA symptoms, but 3 (13%) required continuous positive airway pressure. The results of this study suggest that UAL decreases as a result of MMA. In addition, these results support the observation that MMA is associated with objective and subjective improvements in patients with OSA.