Cone-beam CT analysis of patients with obstructive sleep apnea compared to normal controls

Multidimensional characterization of craniofacial skeletal phenotype of obstructive sleep apnea in adults

OBJECTIVES

We aimed to characterize a craniofacial skeletal phenotype (CSP) of adult obstructive sleep apnea (OSA) patients from a multidimensional perspective, exploring the impact of transverse skeletal discrepancy (TSD) on multivariable polysomnographic profiles.

MATERIALS AND METHODS

This retrospective, cross-sectional study included 102 adult OSA patients. Sagittal, vertical, and transverse skeletal patterns were categorized on the cone beam computed tomography images. The CSP of OSA patients, characterized by a Class II hyperdivergent pattern, was divided into CSP2D and CSP3D subgroups according to the presence of TSD, and compared with the non-CSP of OSA patients. Both nasal and pharyngeal airway variables were involved for assessment, and 12 polysomnographic variables with a sleepiness symptom variable were used for phenotype-based inter-group comparisons.

RESULTS

The CSP patients revealed greater disease severity than the non-CSP patients (indicated by eight polysomnographic variables), despite being younger (P < .05) and less obese (P < .01). The CSP3D patients with TSD exhibited more severe OSA than the age- and BMI-matched CSP2D patients without TSD, as indicated by nine polysomnographic variables, in relation to smaller nasal airway volume, smaller pharyngeal minimum cross-sectional area, and longer pharyngeal airway length (all P < .05). The probability of multiperspective characteristics among three phenotypes was significantly contrasted in 19 variables.

CONCLUSIONS

From a multidimensional perspective, the CSP patients showed greater OSA severity with more vulnerable nasal and pharyngeal airways than non-CSP patients, despite being younger and less obese. Specifically, the CSP3D patients revealed far more severe OSA than the CSP2D patients, indicating the significance of TSD on the polysomnographic profiles.

Three-dimensional evaluation of the airway morphology after miniscrew-supported en masse retraction in adult bimaxillary protrusion patients by using cone beam computed tomography: A single-arm clinical trial

OBJECTIVE

This study aimed to assess the changes in the pharyngeal airway morphology after premolar extraction and maximum anchorage retraction of the anterior segments in adult bimaxillary protrusion patients by using CBCT.

MATERIAL AND METHODS

Twenty-one subjects (mean age 23.8±4.6 years) requiring extraction of four first premolars and en masse retraction of the anterior segments using maximum anchorage participated in the study from July 2022 to May 2024 with an average treatment duration of 19.9 months. CBCT scans were taken before treatment (pre) and after en masse retraction (post). Airway volume was measured by using Relu software. The pre- and post-CBCT scans were superimposed by using Romexis 1 software. The cross-sectional area (CSA) was measured at the level of the hard palate, soft palate, and epiglottis. The most constricted area (MCA) was recorded. The hyoid bone position was evaluated by using 5 linear measurements. The upper and lower incisor angulations to the Frankfort horizontal plane (FH) were measured before and after retraction. Paired t-test was used to analyse the measurements and correlation analyses were made using Spearman's rank-order correlation coefficient (rs). The significance level was set at P<0.05 within all tests.

RESULTS

Twenty-one participants (16 females, 5 males) followed the inclusion criteria and enrolled in the analysis. There were no significant differences in airway volume, cross-sectional areas, or hyoid bone position between before treatment and after en masse retraction (P>0.05). There was a significant retraction of the incisors after treatment (P<0.001). The change in the most constricted area had a large positive correlation with the change in the airway volume (rs=0.509*) and the area of the soft palate (rs=0.653*).

CONCLUSION

Maximum anchorage retraction had no significant effect on airway volume, cross-sectional area, or hyoid bone position.

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

BACKGROUND

Obstructive sleep apnea (OSA) is the most common sleep-related breathing disorder characterized by repetitive collapse of the upper airway during sleep. However, little evidence is available on the differences between the sub-regions of the upper airway morphology and OSA severity. Since orthodontists frequently perform cone beam computed tomography (CBCT) in the neck area, we aimed to investigate the relationship and the differences between upper airway morphology and OSA severity using CBCT.

MATERIALS AND METHODS

The medical records, CBCT imaging of 21 OSA patients diagnosed by polysomnography, and the apnea-hypopnea index (AHI) results were included to classify OSA severity as mild, moderate, or severe. The minimum cross-sectional areas (MCA) and volumes of the upper pharyngeal airway boundaries in four sub-regions: nasopharynx, retropalatal, retroglossal, and hypopharynx were measured. Dolphin Imaging software was used for upper airway segmentation. The correlation coefficient (r), one-way ANOVA, and the least significant difference post hoc multiple comparison test were applied to fulfill the objectives.

RESULTS

A statistically significant relationship was found between the MCA of the nasopharynx and the AHI (r = -0.473, P < 0.05). Furthermore, a difference was found between mild and moderate and moderate and severe OSA severity in the MCA results of the retroglossal region (P < 0.05). However, no relationship was found between the upper airway volume and OSA severity.

CONCLUSIONS

MCA was moderately negatively correlated to AHI only in the nasopharynx subregion. Moderate OSA presented significantly less MCA than mild and severe OSA only in the oropharynx and retroglossal subregions.

Analysis of the aerodynamic characteristics of the upper airway in obstructive sleep apnea patients

Background/purpose

This study was designed to explore upper airway aerodynamic characteristics in individuals diagnosed with obstructive sleep apnea (OSA) and to evaluate correlations between these characteristics and other anatomical upper airway findings in these patients.

Materials and methods

This was a retrospective study of 40 OSA patients (22 male, 18 female) who were stratified into groups with mild, moderate, and severe disease based upon overnight polysomnographic (PSG) recording results. Newtom5G cone-beam CT scans (CBCT) were conducted for all patients, and the resultant images were used to reconstruct three-dimensional images of the upper airways which were used to calculate aerodynamic characteristics. Differences in these characteristics between groups were evaluated with one-way ANOVAs, while relationships between anatomical and aerodynamic characteristics were assessed through Pearson correlation analyses.

Results

The aerodynamic of the upper airway has typical characteristic in severe group. There was a significant negative correlation in severe group between resistance during inspiration (Rin) and volume (V) (r = -0.693, P = 0.013), minimum axial area (MMA) (r = -0.685, P = 0.014), and lateral dimension (LAT) (r = -0.724, P = 0.008), resistance during expiration (Rex) and LAT (r = -0.923, P < 0.001).

Conclusion

This study showed that airway resistance during inspiration and expiration are most closely associated with upper airway collapse in OSA patients, with repetitive collapse occurring during both of these breathing processes. LAT may be an important anatomical factor associated with OSA pathogenesis and treatment.

Correlation analysis of upper airway morphology in patients with obstructive sleep apnea and anatomically small retruded mandibles

OBJECTIVE

To investigate the relationship between upper airway morphology and the severity of obstructive sleep apnea (OSA) in patients with anatomically small retruded mandibles.

METHODS

Fifty-two patients with small retruded mandibles underwent polysomnography and airway computed tomography. The airway morphology parameters and sleep assessment were compared between the patients with or without OSA.

RESULTS

Twenty-eight patients diagnosed with OSA, according to polysomnography, had a higher distance between the hyoid bone and mandibular plane (HMP), lateral dimension (LAT)/anteroposterior dimension (AP), but lower minimum cross-sectional area (mCSA), AP, surface area, volume, avgCSA, and airway uniformity (U). The apnea-hypopnea index had negative correlations with mCSA, AP, surface area, volume, avgCSA, and U, and had a positive correlation with HMP and LAT/AP.

CONCLUSION

OSA is common among patients with small retruded mandibles and is associated with a more compressed upper airway shape and longer HMP.

An Update on Obstructive Sleep Apnea Syndrome-A Literature Review

Obstructive sleep apnea syndrome (OSAS) is the most common breathing-related sleep disorder. It is characterized by recurrent episodes of partial or complete airway obstruction during sleep, resulting in a reduction in or the total cessation of airflow, despite ongoing respiratory efforts, leading to oxygen desaturation and arousal. The purpose of this literature review is to evaluate the most common characteristics of this pathology, as well as to investigate the most effective treatment options, providing an update on the management of OSA patients.

Methodological parameters for upper airway assessment by cone-beam computed tomography in adults with obstructive sleep apnea: a systematic review of the literature and meta-analysis

BACKGROUND

A reliable method for analyzing the upper airway (UA) remains a challenge. This study aimed to report the methods for UA assessment using cone-beam computed tomography (CBCT) in adults with obstructive sleep apnea (OSA).

METHODS

We performed a systematic review (PROSPERO #CRD42021237490 and PRISMA checklist) that applied a search strategy to seven databases and grey literature.

RESULTS

In 29 studies with moderate-to-high risk of bias, investigators mostly reported the body position during CBCT (upright or supine) and hard tissue references, diverging in UA delimitation and terminologies. The meta-analysis showed two subgroups (upright and supine), and no statistical differences were identified (p = 0.18) considering the UA area. The volume in the OSA group was smaller than that in the control group (p < 0.003 and Cohen's d =  - 0.81) in the upright position. Patients with OSA showed smaller anteroposterior dimensions than the control group and were not affected by the position during image acquisition (p = 0.02; Cohen's d =  - 0.52). The lateral measurements were also lower in the OSA group (supine) (p = 0.002; Cohen's d =  - 0.6).

CONCLUSIONS

Patients with OSA showed smaller UA measurements in the upright (volume) and supine (lateral dimension) positions. The anteroposterior dimension was also reduced in patients with OSA compared to the control group, regardless of the position during CBCT acquisition.

Machine Learning Analysis of the Anatomical Parameters of the Upper Airway Morphology: A Retrospective Study from Cone-Beam CT Examinations in a French Population

The objective of this study is to assess, using cone-beam CT (CBCT) examinations, the correlation between hard and soft anatomical parameters and their impact on the characteristics of the upper airway using symbolic regression as a machine learning strategy. Methods: On each CBCT, the upper airway was segmented, and 24 anatomical landmarks were positioned to obtain six angles and 19 distances. Some anatomical landmarks were related to soft tissues and others were related to hard tissues. To explore which variables were the most influential to explain the morphology of the upper airway, principal component and symbolic regression analyses were conducted. Results: In total, 60 CBCT were analyzed from subjects with a mean age of 39.5 ± 13.5 years. The intra-observer reproducibility for each variable was between good and excellent. The horizontal soft palate measure mostly contributed to the reduction of the airway volume and minimal section area with a variable importance of around 50%. The tongue and the position of the hyoid bone were also linked to the upper airway morphology. For hard anatomical structures, the anteroposterior position of the mandible and the maxilla had some influence. Conclusions: Although the volume of the airway is not accessible on all CBCT scans performed by dental practitioners, this study demonstrates that a small number of anatomical elements may be markers of the reduction of the upper airway with, potentially, an increased risk of obstructive sleep apnea. This could help the dentist refer the patient to a suitable physician.

Insight in to the Awareness of CBCT as an Imaging Modality in the Diagnosis and Management of ENT Disorders: A Cross Sectional Study

The advent of Cone-beam computed tomography (CBCT), has revolutionized 3D imaging in dentistry. CBCT has enormous potential to be used as an alternative imaging modality by Otolaryngologists. But their knowledge regarding CBCT is limited. The study aims to evaluate the awareness of CBCT as an imaging modality among Ear, nose and Throat (ENT) practitioners. The validated questionnaire was sent by email and the participants were asked to fill the google form through the link provided to record the responses. The participants were asked to answer 25 multiple choice questions regarding the general information and practice related to CBCT imaging. Data was evaluated according to the descriptive statistics and the Chi-square test was used to determine the test of significance. The response rate for this study was 84.4%. The mean age of the participants was 44.9 ± 11.3. 69% of the respondents were academicians,14.2% had exclusive clinical practice, and 16.8% had both clinical and academic exposure. Among the study population, 76.8% had never advised CBCT in their practice. Only 10.3% of the study participants were aware of the potential of CBCT in ENT disorders. The mean knowledge, attitude and practice scores were very low regarding the applications of CBCT. Most of the study participants advised CBCT for maxillofacial fractures (78.1%) and was statistically significant p < 0.05. The knowledge about various advantages and clinical applications of CBCT among Otolaryngologists is limited. However, continuing medical education and inclusion in the medical curriculum will increase the scope and awareness about CBCT among ENT fraternity.

Comparison of airway changes after maxillomandibular advancement with or without genial tubercle advancement in obstructive sleep apnea using cone-beam computed tomography

INTRODUCTION

This study compared the airway changes of patients with obstructive sleep apnea (OSA) after maxillomandibular advancement (MMA) with or without genial tubercle advancement (GTA) using cone-beam computed tomography.

METHODS

The authors retrospectively studied 26 patients with moderate to severe OSA who underwent MMA with or without GTA. Airway changes were determined from preoperative and postoperative 3-dimensional reconstructed cone-beam computed tomography images. The Wilcoxon signed rank test, Mann-Whitney U tests, and Spearman correlation coefficients were used in data analysis.

RESULTS

Airway was changed in all dimensions significantly after MMA with or without GTA. There was no significant difference in horizontal surgical changes between MMA and MMA with the GTA group. The mean increase in total airway volume was 66.8% for MMA alone and 74.7% for MMA with GTA (P = 0.39). Patients who underwent MMA had a larger percentage change of segmented upper airway volume than patients with MMA and GTA (106.6% vs 85.3%; P = 0.65). The group with MMA and GTA had a greater percentage change of segmented lower airway volume than the MMA alone group (80.1% vs 56.3%; P = 0.42).

CONCLUSIONS

Differences in airway changes between MMA alone and MMA with GTA were not statistically significant. Performing the GTA concomitantly with MMA may not cause greater improvement in the pharyngeal airway in patients with OSA compared with MMA alone.

Linear Cephalometric Analysis of Pharynx at the Level of Epiglottis among Snorers and Nonsnorers: A Cross-Sectional Study

Aim  Snoring, which falls within the spectrum of sleep-related breathing disorders, is considered to be one of the common symptoms of airway obstruction. Lateral cephalometric analysis is an effective way of diagnosing airway obstruction by evaluating skeletal and soft tissue abnormalities in patients with sleep-disordered breathing (SDB). The present study was planned to analyze the pharyngeal space among snorers and nonsnorers in the retroglossal region and in the region of hypopharynx at the level of epiglottis.

Materials and Methods  The present cross-sectional study included a total of 60 individuals who were grouped into snorers and nonsnorers based on their answers for the study questionnaire related to snoring. Digital lateral cephalograms were taken for all maintaining the exposure parameters while Digora software was used for measurements related to the soft tissue parameters. The two significant soft tissue parameters analyzed were the distance of epiglottis from the tip of the soft palate, the retroglossal length, and the distance of posterior pharynx from the tip of the epiglottis, the pharyngeal space.

Statistical Analysis  The statistical analysis was done using Statistical Package for Social Sciences (SPSS) version 17.0 (SPSS Inc., Chicago, Illinois, United States) while paired t -test was used for intergroup analysis. A p -value of < 0.05 was considered statistically significant.

Results  The mean retroglossal length was found to be 25.52 mm among the snorers and 23.70 mm among the nonsnorers. In case of pharyngeal space, a mean of 8.54 mm was recorded among the snorers whereas among the nonsnorers, the respective mean value of 10.16 mm was observed.

Conclusion  In the present study, pharyngeal space was found to be less at the level of the tip of epiglottis among the snorers compared with nonsnorers which can be attributed to be one of the significant reasons behind snoring and obstructive sleep apnea syndrome.

Comparison of superior airway dimensions and cephalometric anatomic landmarks between 8–12-year-old children with obstructive sleep apnea and healthy children using CBCT images

Background. The etiology of obstructive sleep apnea (OSA) syndrome in children significantly differs from adults. In previous studies, only some of the indices have been investigated using CBCT. This study compares all the measurable indices of airway dimensions and anatomical cephalometric landmarks between children with OSA and healthy ones using cone-beam computed tomography (CBCT).

Methods. Dimensions of the airway and cephalometric values were measured on CBCT scans of 50 children aged 8–12 (25 patients with OSA and 25 healthy subjects) and then compared between the two groups. The results of this study were analyzed with independent t test using SPSS 17 at a significance level of P<0.05.

Results. Area, length, volume, anteroposterior length, and size of the upper airway in subjects with OSA were lower than those in healthy children, while the average values of SNA, SNB, and ANB in the OSA group were higher than those in the healthy group (P=0.366, P=0.012, and P=0.114, respectively). Also, BaSN, PNS/AD1, and PNS/AD2 measurements in subjects with OSA were lower than healthy subjects (P=0.041, P=0.913, and P=0.015, respectively). In addition, the width and anteroposterior length of the upper airway, SNB, BaSN, PNS/AD1, and PNS/AD2 indices were significantly different between the healthy group and those with OSA (P<0.05).

Conclusion. Reduced upper airway dimensions, adenoid tissue enlargement, and cranial base flexion might play an important role in OSA development in children. However, most skeletal variables, such as the anteroposterior relationship of jaws and jaw rotation, were not significantly different between the two groups.

Correlation of Medical Comorbidities and Upper Airway Measurements among Dental Patients at Risk of Developing Obstructive Sleep Apnea

Obstructive Sleep Apnea (OSA) is a partial or total upper airway collapse resulting in sleep-breathing disturbances. There are many medical comorbidities associated with OSA; hence, this study is important as the prevalence of patients with medical comorbidities associated with OSA is increasing. The study aimed to correlate medical comorbidities and OSA symptoms of the patients along with their upper airway dimensions using Cone Beam Computed Tomography (CBCT) scans to identify patients at risk of developing OSA. This cross-sectional study included patients who had CBCT imaging taken between 2014 and 2020. A questionnaire was used to gather information on patients’ medical history and OSA symptoms. The upper airway dimensions of the CBCT scans were evaluated before logistic regression and Fisher’s exact test were carried out to determine the relationships between the variables. p ≤ 0.05 was considered statistically significant. Logistic regression revealed an association of longer length (p = 0.016), smaller total volume (p = 0.017) and width (p = 0.010) of upper airways with hypertension. Furthermore, loud snoring was seen in patients with hypertension, heart disease and obesity whereas difficulty concentrating during the day was present in subjects with deviated nasal septum, tonsillitis and depression. For upper airway dimensions, a smaller average volume was associated with loud snoring (p = 0.037), difficulty concentrating during the day (p = 0.002) and mood changes (p = 0.036). A larger anterior-posterior dimension was also associated with excessive daytime sleepiness (p = 0.042), difficulty concentrating during the day (p < 0.001) and mood changes (p = 0.009). Longer airway length was additionally found to be associated with loud snoring (p = 0.021). CBCT taken for dental investigations could be correlated with patients’ medical history and OSA symptoms to screen patients at risk of OSA.

A 3D CBCT Analysis of Airway and Cephalometric Values in Patients Diagnosed with Juvenile Idiopathic Arthritis Compared to a Control Group

Introduction: The temporomandibular joint (TMJ) is affected in 30–45% of juvenile idiopathic arthritis (JIA) patients, with all JIA subtypes at risk for TMJ involvement. JIA patients with TMJ involvement may present with altered craniofacial morphology, including micrognathia, mandibular retrognathia, a hyperdivergent mandibular plane angle, and skeletal anterior open bite. These features are also commonly present and associated with non-JIA pediatric patients with obstructive sleep apnea (OSA). Materials and Methods: The study was comprised of a group of 32 JIA patients and a group of 32 healthy control subjects. CBCT images were taken for all patients and were imported into Dolphin Imaging software. The Dolphin Imaging was used to measure the upper airway volumes and the most constricted cross-sectional areas of each patient. Cephalometric images were rendered from the CBCT data for each patient, and the following cephalometric values were identified: SNA angle, SNB angle, ANB angle, anterior facial height (AFH), posterior facial height (PFH), mandibular plane angle (SN-MP), FMA (FH-MP), overjet (OJ), and overbite (OB). Airway volumes, the most constricted cross-sectional area values, and cephalometric values were compared between the JIA and control groups. Results: For airway values, statistically significant differences were seen in the nasopharynx airway volume (p = 0.004), total upper airway volume (p = 0.013), and the most constricted cross-sectional area (p = 0.026). The oropharynx airway volume was not statistically significant (p = 0.051). For cephalometric values, only the posterior facial height showed a statistically significant difference (p = 0.024). Conclusions: There was a significant difference in airway dimensions in the JIA patients as compared to the control patients. In addition, the posterior facial dimensions seem to be affected in JIA patients. The ODDs ratio analysis further corroborated the findings that were significant.

Usefulness of Hard Palate Measurements in Predicting Airway Dimensions in Patients Referred for Cone Beam CT

Purpose:

The aim of the study was to evaluate the usefulness of hard palate measurements in predicting airway dimensions in patients referred for cone-beam CT (CBCT).

Materials and Methods:

Six hundred forty-three patients (239 males and 404 females) were examined by CBCT. Using dedicated CBCT software (Kodak CS 3D imaging version 3.8.6, Carestream, Rochester, NY, USA); different hard palate (palatal interalveolar length, palatal arch depth, maxillo-palatal arch angle, and alveolar width) and airway measurements (airway volume, minimum cross-sectional area, minimum anteroposterior distance, minimum right to left distance and airway length) were obtained and correlated using Pearson’s correlation coefficients and regression analysis.

Results:

Although the correlation between hard palate and airway measurements was weak (Pearson coefficient (r) < 0.40), there were significant (P < 0.05) additive effects for hard palate measurements in predicting airway dimensions. Maxillo-palatal arch angle was the only hard palate measurement that had no effect in predicting airway dimensions.

Conclusion:

Hard palate measurements are considered useful in predicting airway dimensions in patients referred for CBCT.

The Usefulness of Modified Mallampati Score and CT Upper Airway Volume Measurements in Diagnosing OSA among Patients with Breathing-Related Sleep Disorders

Background: Obstructive sleep apnea (OSA) is a condition causing restriction of the airflow through the upper airways during sleep, despite preserved inspiratory muscle activity. This may lead to the development of secondary hypertension, ischemic heart disease, myocardial infarction, and arrhythmia. Moreover, the prevalence of OSA is on the rise. Methods: Comparison of scores from the Berlin Questionnaire, modified Mallampati scores (MMP), pulse oximetry readings and Upper Airway Volume (UAV) data obtained from CBCT (Cone Beam Computed Tomography). The study group of 129 patients of both sexes reporting sleep-related breathing problems completed the Berlin Questionnaire, had their oxygen saturation (SpO2) measured with a PO40 pulse oximeter, and oropharyngeal tissues assessed according to MMP. CBCT scans were put into 3D Amira TM 3D computer analysisto obtain UAV values. Results: Snoring was associated with significantly higher BMI compared to non-snoring patients. Furthermore, snoring patients had higher heart rate, modified Mallampati score, and lower UAV than the non-snoring group. The multifactorial analysis showed MMP as a useful indicator of the risk of snoring (OR = 7.468 (3863–14, 507, p < 0.001)). Conclusions: The composition of MMP together with UAV and the Berlin questionnaire might be reliable indicators to assess the risk of snoring.

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

Purpose

The 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.

Methods

A 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.

Results

The 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 \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$0.89\pm 0.03$$\end{document}0.89±0.03, \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$0.87\pm 0.02$$\end{document}0.87±0.02, and \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$0.79\pm 0.08$$\end{document}0.79±0.08 for tongue, pharynx, and soft palate tissues, respectively. The results were similar to other approaches and consistent with expert readings.

Conclusion

Due 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.

Cone-beam computed tomography assessment of upper airway dimensions in patients at risk of obstructive sleep apnea identified using STOP-Bang scores

Purpose

The aim of this study was to identify correlations between the STOP-Bang score and upper airway dimensions using cone-beam computed tomography (CBCT) scans.

Materials and Methods

This study included 101 subjects (46 men, 55 women) from dental patients who received CBCT scans from 2014 to 2020. The patients were divided into those with a low obstructive sleep apnoea (OSA) risk (STOP-Bang score<3) and those with an intermediate to high OSA risk (STOP-Bang score≥3), and their upper airway dimensions were then analysed on CBCT scans. Comparisons between the low-risk and intermediate/high-risk groups were conducted using the t-test and the Mann-Whitney test. Correlations between the total STOP-Bang score and upper airway dimension parameters were established using Spearman correlation coefficients. P values≤0.05 were considered to indicate statistical significance.

Results

Intermediate/high-risk subjects were predominantly male and over 50 years of age, with a higher body mass index. They had significantly longer upper airways, smaller average airway volumes, and smaller widths and antero-posterior dimensions of the narrowest upper airway segment. The total upper airway length was positively correlated with the STOP-Bang score (r_s= 0.278). The average volume (r_s= −0.203) and width of the narrowest upper airway segment (r_s= −0.305) were both negatively correlated with STOP-Bang scores.

Conclusion

Subjects with higher STOP-Bang scores had upper airways that were longer, narrower, and smaller in terms of average volume. CBCT scans taken for dental patients as part of investigative procedures could be correlated with STOP-Bang scores to screen for patients at risk of OSA.

Effect of surgical mandibular setback on the occurrence of obstructive sleep apnea

The aims were to assess the airway morphologic changes, and to evaluate sleep respiratory function and the occurrence of obstructive sleep apnea (OSA) after mandibular setback. Fifteen prognathism patients underwent bilateral sagittal split ramus (BSSRO) with or without maxilla surgery were grouped by distance of mandibular setback as group A (≤6 mm, n = 7) and group B (>6 mm, n = 8). Morphological changes were assessed using lateral cephalometric radiography and cone-beam computed tomography (CBCT) at preoperative (T0) and 6 months after surgery (T1). Sleep respiratory functions were evaluated using polysomonography. On lateral cephalometric radiography, group B showed significant decreased at Vp (p = 0.028) and PAS-p (p = 0.017). It also significant different between groups (p = 0.011 and p = 0.009 respectively). On CBCT, airway volume and AP width of airway, except Np, decreased in both groups but not significant different between groups. Only group A showed significant different between T0 and T1, cross-sectional area of Vp (p = 0.043), AP width of Vp (p = 0.043), Hp (p = 0.042), and PAS-t (p = 0.043). In group B, apnea hypopnea index increased at T1 (p = 0.043) and REM sleep differed between groups (p = 0.04). In conclusion, mandibular setback decreased the pharyngeal airway dimensions although no OSA occurred. It might be predisposing of OSA.

Evaluation of Upper Airway in Children with Obstructive Sleep Apnea Using Cone-Beam Computed Tomography

OBJECTIVE

Cone-beam computed tomography (CBCT) offers three-dimensional structures in assessing upper airway of patients. This study aims to compare the cone-beam computerized tomography scan measurements between children with obstructive sleep apnea (OSA) and primary snoring.

STUDY DESIGN

Case-control study.

METHODS

This prospective study was conducted in a tertiary referral center. Thirty-six children with moderate-to-severe OSA (with apnea-hypopnea index [AHI] > 5 events/hour) and 36 age-, gender-, and obesity-matched children with primary snoring (AHI <1) were enrolled. The measurements in CBCT parameters were compared between children with moderate-to-severe OSA and primary snorers by conditional logistic regression model.

RESULTS

A total of 72 children (mean age, 7.9 ± 2.8 years; 64% male) were included. Children with moderate-to-severe OSA had a significantly smaller nasopharyngeal (2900 ± 1400 vs. 3800 ± 1800 mm³ , P = .017) and oropharyngeal airway volume (5600 ± 2700 vs. 7400 ± 4000 mm³ , P = .026) than those with primary snoring. Children with moderate-to-severe OSA, as compared to primary snorers, also had a significantly smaller minimal airway area in nasopharynx (77.4 ± 37.7 vs. 107.7 ± 52.0 mm² , P = .006) and oropharynx (66.6 ± 61.9 vs. 101.6 ± 65.8 mm² , P = .023). Moreover, the airway length was not significantly different between children with moderate-to-severe OSA and primary snoring.

CONCLUSIONS

The three-dimensional CBCT airway analysis could be used as a useful tool to evaluate upper airway in children with OSA.

LEVEL OF EVIDENCE

3 Laryngoscope, 131:680-685, 2021.

Dynamic tongue base thickness measured by drug-induced sleep ultrasonography in patients with obstructive sleep apnea

BACKGROUND/PURPOSE

The aim of this study was to determine the value of drug-induced sleep ultrasonography (DISU) for evaluating tongue base thickness (TBT) from the awake state to drug-induced sleep, to further understand the impact of dynamic changes in TBT in obstructive sleep apnoea (OSA) patients.

METHODS

From May 2017 to May 2018, thirty patients with OSA were prospectively recruited. Sleep was induced with propofol via use of a target-controlled infusion (TCI) system. The depth of sedation was monitored by the bispectral (BIS) index with BIS levels ranging from 50 to 70. The dynamic change in the tongue base from the awake state to drug-induced sleep was recorded. The correlation between TBT in the awake state and in drug-induced sleep with OSA severity was analysed.

RESULTS

The mean TBT in drug-induced sleep was significantly greater than that in the awake state (66.2 ± 4.8 mm vs 61.6 ± 4.6 mm, P < 0.001). TBT in drug-induced sleep was more correlated with AHI compared to TBT in the awake state (r = 0.50 vs r = 0.40). This study showed that TBT in drug-induced sleep had the largest AUC (Area Under the Curve) in the ROC (Receiver Operating Characteristics) analysis (0.875), providing a cut-off point of 63.20 mm with 95% sensitivity for diagnosis of moderate versus severe OSA.

CONCLUSION

Our findings validate the use of DISU in objectively assessing the tongue base collapse in OSA patients. It provides a convenient and non-invasive way to evaluate the upper airway changes in OSA patients in the future.

Use of cone beam computed tomography imaging for airway measurement to predict obstructive sleep apnea

Objective: This retrospective chart review examined whether airway parameters were correlated with scores on the STOP-Bang questionnaireMethods: Minimal upper airway area, upper airway volume, minimal retropalatal area, retropalatal volume, minimal retroglossal area, and retroglossal volume were calculated from cone beam computed tomography (CBCT) images. Patients were grouped based on their STOP-Bang scores (<3 or ≥3) for obstructive sleep apnea (OSA), and airway parameters were compared across the 2 groups.Results: Thirty-one (43%) of 72 patients with a minimal upper airway area of <110 mm² had STOP-Bang scores of ≥3. Most patients (90%) with STOP-Bang scores of ≥3 had minimal retropalatal areas of <110 mm². Differences were found between groups for minimal upper airway area (P=.03), upper airway volume (P=.04), and minimal retropalatal area (P=.001).Discussion: To assess OSA risk, dentists should compare CBCT images with STOP-Bang scores.

The Interaction Between Craniofacial Computed Tomographic Dimensional Parameters and BMI in Obstructive Sleep Apnea

Introduction

The impact of the dimensional parameters of the pharyngeal bony frame by its length, width and the position of the hyoid upon the severity of obstructive sleep apnea syndrome (OSAS) has not been investigated in depth. Interactions of those parameters with body mass index (BMI) and their overall reciprocal effect on OSAS severity have also not been established.

Materials and Methods

This retrospective cross-sectional study was conducted on 108 male OSAS patients followed in OSAS outpatient clinics between November 2014 and October 2015. They all underwent a polysomnography test, and an apnea-hypopnea index (AHI) was calculated. They also underwent an upper airway computerized tomographic scan in which three craniofacial parameters were evaluated: inter-pterygoid distance (IPD), hard palate-to-hyoid (HP-H) distance, and gnathion plane-to-hyoid (GP-H) distance.

Results

A longer pharynx and an inferiorly placed hyoid bone correlated with the AHI (r = 0.33, p = 0.001 and r = 0.226, p = 0.03, respectively). GP-H correlated with body mass index (BMI) (r = 0.3243, p < 0.001), while HP-H and IPD did not. We found an interaction between BMI and HP-H, but none between GP-H and BMI. IPD did not correlate with OSAS severity, but it correlates with the age of the OSAS patients (r = 0.235, p = 0.015).

Conclusion

Pharynx length and hyoid position have significant effects upon OSAS severity, and they interact differently with BMI in terms of those effects. Hard palate width increases with age but has no correlation with OSAS severity.

Evaluation of Three-Dimensional Changes in Pharyngeal Airway Following Isolated Lefort One Osteotomy for the Correction of Vertical Maxillary Excess: A Prospective Study

Background

Orthognathic surgery involves movement of jaws in all three planes, and this being a part of airway complex, displacement of jaws can influence the dimension of airway at all levels. Lefort one osteotomy surgery with superior repositioning is a common procedure done for patients with vertical maxillary excess.

Purpose

The purpose of this study was to evaluate the three-dimensional volumetric changes in airway after lefort one impaction surgery using three-dimensional cone beam computed tomography (3D-CBCT) in patients with vertical maxillary excess (VME).

Methods

A prospective analysis of 15 patients who underwent isolated lefort one impaction surgery was done with pre-operative (T0) and 3-months (T1) post-operative 3D-CBCT scans. Airway was divided into three segments, nasopharyngeal, velopharyngeal and oropharyngeal. Volumetric analysis of all these segments was done before and after surgery. Paired 't test' was used to assess the mean difference in airway volume and area between T0 and T1. One-way ANOVA was used to check the mean percentage difference in airway volume and area among the three segments.

Results

The mean percentage of nasopharyngeal volume difference was - 0.6299 ± 0.9146%, velopharyngeal volume difference was - 0.5205 ± 1.107%, oropharyngeal volume difference was - 1.492 ± 2.745%. Though volume and area of pharyngeal airway were decreased after maxillary impaction surgery in all three segments of airway studied, they were not statistically significant.

Conclusion

Among the three segments of airway studied, oropharyngeal airway volume has shown the highest post-surgical reduction though statistically insignificant. ESS scores were within normal limits. Hence, we are of the opinion that there is lack of evidence to conclude that the patients undergoing lefort one superior repositioning for the treatment of VME might develop significant narrowing of PAS that may predispose the patient to breathing disorders.

Mandibular width as a novel anthropometric measure for assessing obstructive sleep apnea risk

Craniofacial abnormalities are a known obstructive sleep apnea (OSA) risk factor, but still need to be better characterized. This study investigates the relationship between mandibular width and the risk of developing OSA.We retrospectively analyzed 3D reconstructions of head and neck computed tomography (CT) scans at our institution for mandibular width, neck circumference, neck fat volume (NFV), airway volume (AWV), and NFV:AWV ratio. Age, gender, and BMI were also documented. Patients were contacted to complete a STOP-BANG survey to assess OSA risk. Only patients with reconstructable scans and completed STOP-BANG questionnaires were included in the study. Survey results were analyzed to assess the correlation between mandible width and STOP-BANG. Mandible association was also compared to the associations of the other known risk factors.The final analysis included 427 patients with a mean age of 58.98 years (standard deviation = 16.77), 56% of whom were male. Mandibular width was found to positively correlate with STOP-BANG score (r = .416, P < .001). Statistically significant differences between mandible size for each risk group was seen (P < .001). After controlling for age and sex, mandible size was significantly different only for the low risk vs. high risk groups (odds ratio = 1.11; 95% confidence interval = 1.03-1.20; P = .007). Furthermore, when stratified according to mandible size, the small mandible group (<77.50 mm) predominantly consisted of low risk patients; the medium size mandible group (77.50-84.40 mm) was predominated by intermediate risk patients, and large mandible (>84.40 mm) was predominantly seen in high risk patients. Mandible width expressed a stronger association than NFV:AWV ratio, but neck circumference and NFV had stronger associations than did mandible width.In addition to previously documented OSA risk factors, mandibular width is positively correlated with OSA as an independent risk factor. Observation of a wide mandible (jaw) should raise awareness of OSA risk and increase screening methods when appropriate.