Airway Measurements Research Articles

Evaluation of the airway space changes after extraction of four second premolars and orthodontic space closure in adult female patients with bimaxillary protrusion – A retrospective study

Background & objectivesPrevious studies have found that first premolar extractions during orthodontic treatment may alter the upper airway dimensions. The objective of this study is to investigate the effects of second premolar extraction during orthodontic treatment on the dimensions of the upper airway in a sample of female adults. MethodsTwenty-nine female adult patients with ages between 18 and 30 years old and incisor bimaxillary protrusion were included in this study. They were treated with comprehensive orthodontic treatment which included the extraction of four second premolars. Pre and post cephalometric radiographs were analyzed using Dolphin imaging software for changes in tongue length and height, soft palate thickness and length, the superior, middle, and inferior airway space, and vertical airway length. Descriptive statistics were used to characterize measurements. Student’s paired t-test was preformed to compare the pre- and post-test mean values of the dimensions. ResultsA significant increase in the vertical airway length was observed after the extraction of the second premolars (p = 0.02). The soft palate length showed a tendency towards an increase that did not reach statistical significance (p = 0.053). No other significant changes in the airway soft tissue measurements were observed. The proclination and protrusion of the upper and lower incisors were significantly decreased compared to pre-treatment measurements.Interpretation & conclusions.Orthodontic treatment involving the extraction of all four second premolars in females with bimaxillary protrusion increases the vertical airway length, which is the amount of distance between base of the tongue and posterior nasal spine. No other significant alterations in the upper airway measurements were observed.

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.

Chronic Obstructive Pulmonary Disease: Thoracic CT Texture Analysis and Machine Learning to Predict Pulmonary Ventilation.

Background Fixed airflow limitation and ventilation heterogeneity are common in chronic obstructive pulmonary disease (COPD). Conventional noncontrast CT provides airway and parenchymal measurements but cannot be used to directly determine lung function. Purpose To develop, train, and test a CT texture analysis and machine-learning algorithm to predict lung ventilation heterogeneity in participants with COPD. Materials and Methods In this prospective study (ClinicalTrials.gov: NCT02723474; conducted from January 2010 to February 2017), participants were randomized to optimization (n = 1), training (n = 67), and testing (n = 27) data sets. Hyperpolarized (HP) helium 3 (3He) MRI ventilation maps were co-registered with thoracic CT to provide ground truth labels, and 87 quantitative imaging features were extracted and normalized to lung averages to generate 174 features. The volume-of-interest dimension and the training data sampling method were optimized to maximize the area under the receiver operating characteristic curve (AUC). Forward feature selection was performed to reduce the number of features; logistic regression, linear support vector machine, and quadratic support vector machine classifiers were trained through fivefold cross validation. The highest-performing classification model was applied to the test data set. Pearson coefficients were used to determine the relationships between the model, MRI, and pulmonary function measurements. Results The quadratic support vector machine performed best in training and was applied to the test data set. Model-predicted ventilation maps had an accuracy of 88% (95% confidence interval [CI]: 88%, 88%) and an AUC of 0.82 (95% CI: 0.82, 0.83) when the HP 3He MRI ventilation maps were used as the reference standard. Model-predicted ventilation defect percentage (VDP) was correlated with VDP at HP 3He MRI (r = 0.90, P < .001). Both model-predicted and HP 3He MRI VDP were correlated with forced expiratory volume in 1 second (FEV1) (model: r = -0.65, P < .001; MRI: r = -0.70, P < .001), ratio of FEV1 to forced vital capacity (model: r = -0.73, P < .001; MRI: r = -0.75, P < .001), diffusing capacity (model: r = -0.69, P < .001; MRI: r = -0.65, P < .001), and quality-of-life score (model: r = 0.59, P = .001; MRI: r = 0.65, P < .001). Conclusion Model-predicted ventilation maps generated by using CT textures and machine learning were correlated with MRI ventilation maps (r = 0.90, P < .001). © RSNA, 2019 Online supplemental material is available for this article. See also the editorial by Fain in this issue.

Association Between Peripheral Eosinophil Counts and Infant Lung Function

&#x0D; Background and Hypothesis: Some children with allergic asthma have peripheral eosinophilia early in life, suggesting that physiological changes in the lung begin during infancy. While this association has been established, studies have not examined if a link exists between eosinophilia and physiological airway measurements during the first year of life. It is hypothesized that systemic eosinophilia during the first year of life is associated with lower infant pulmonary function measurements.&#x0D; Experimental Design or Project Methods: A birth cohort study investigating the development of the upper airway microbiota over the first year of life was utilized for this study. Systemic absolute eosinophil counts were examined to determine if eosinophilia is associated with decreased infant pulmonary function test (iPFT)values. Blood and iPFT data were collected at 3 and 12 months.&#x0D; Results: 28 participants had blood samples collected. 15 samples were taken at 3 months and 13 at one year. 16 subjects were male, with a majority identifying as African American (14). The average height and weight were 68.0 cm and 8.6 kg. The median absolute eosinophil count was 0.2010^3/uL. Infant iPFT data included tidal volume, respiratory rate, expiration time, tPTEF/tE, resistance, and compliance. No significant correlations were identified between eosinophil counts and iPFT data. This held true when all time points were combined and when examining each visit separately. The strongest correlation coefficient was -0.36 between absolute eosinophil count and FEV0.5. The estimated number of samples needed to power a study examining the association between FEV0.5 and eosinophil counts is 80 samples.&#x0D; Conclusion and Potential Impact: Based on preliminary results, there are not enough samples to achieve significant correlations supporting the original hypothesis. The next step is to analyze more blood from current study participants. It is also planned to examine the association between the airway microbiome and eosinophilia to determine if early allergic markers in the blood may results from airway dysbiosis.

Changes in Pharyngeal Airway After Mandibular Setback Surgery: A Retrospective Cephalometric Study

Aim: To cephalometrically evaluate the alterations taking place in the pharyngeal airway space, hyoid bone, soft palate, and head posture after mandibular setback surgery (bilateral sagittal split osteotomy) for correction of mandibular prognathism, as well as to evaluate the immediate postsurgical and more than 6 months postsurgical adaptations of these structures. Setting and Design: A retrospective cephalometric study. Materials and Method: The study group consisted of 40 nongrowing patients (20 females and 20 males) with mandibular prognathism and ANB less than or equal to –2 degree for which mandibular setback surgery by bilateral sagittal split ramus osteotomy was performed along with fixed appliance therapy. There presurgical (T1), immediate postsurgical (T2), and more than 6 months postsurgical (T3) lateral cephalograms were analyzed. Statistical Analysis Used: Intragroup comparison was done by paired t-test. Results: Skeletal measurements after orthognathic surgery remained stable in the long term. It was evident that mandibular setback surgery narrowed the pharyngeal airway; however, these changes were not significant except at the base of the tongue. During the follow-up airway measurements at the base of the tongue, the intersection of tongue at the inferior border of mandible and the vallecula increased but they did not reach the presurgical values. Soft palate length increased significantly after surgery. Angulation of soft palate to nasal line also increased significantly following surgery but decreased during follow-up. Extension of the head occurred after surgery which was maintained even at long term. Conclusion: Careful analysis of airway should be performed, particularly in connection with large anteroposterior discrepancies and in those who have risk factors for development of obstructive sleep apnea. Such cases should be corrected by combined maxillary and mandibular osteotomies.

TRACHEOBRONCHOPLASTY PROVIDES LONG-TERM ANATOMIC, FUNCTIONAL, AND SUBJECTIVE BENEFIT FOR PATIENTS WITH SEVERE, DIFFUSE TRACHEOBRONCHOMALACIA

SESSION TITLE: Clinical Outcomes in Cardiothoracic Surgery SESSION TYPE: Original Investigations PRESENTED ON: 10/21/2019 1:30 PM - 2:30 PM PURPOSE: Tracheobronchoplasty significantly improves quality of life in patients with tracheobronchomalacia when assessed at 3 months post-operatively. This study examines the mid-term (1-2 years) and long-term (5 years) effect of tracheobronchoplasty on expiratory collapse, six minute walk duration, and quality of life scores in patients with tracheobronchomalacia. METHODS: This was a single institution retrospective review study consisting of sequential patients that underwent tracheobronchoplasty 2002 – 2016. Cross-sectional area of central airways were measured at the proximal and distal trachea, bilateral mainstem bronchi and bronchus intermedius. Expiratory collapse was calculated as the difference between inspiratory and expiratory cross-sectional areas, divided by inspiratory cross-sectional area. Primary outcome was improvement of expiratory collapse at years 1, 2, and 5 following tracheobronchoplasty. Secondary outcomes included mean response profile for dyspnea scale, six minute walk test, and cough quality score. Repeated-measures analysis of variance was used for statistical analyses. RESULTS: The cohort included 50 patients who had repeated airway measures of the central airway throughout duration of the study. Their median age was 58 years (interquartile range [IQR], 51-63 years). Preoperative mean expiratory collapse was 70% ± 19.5 in the upper trachea, 75% ± 21 in the lower trachea, 72.3± 20.2 in the right mainstem bronchus (RMSB) 73% ± 20 in the bronchus intermedius (BI), and 70± 19.5 in the left mainstem bronchus (LMSB). Overall, there is a significant linear decrease in the percentage of mean expiratory collapsibility of the central airways following tracheobronchoplasty over time. This effect is most significant at year 1 in the upper (70% vs. 45%, P<0.001) and lower trachea (75% vs. 38%, P <0.001) as well as the RMSB (73% vs. 31%, P <0.001). Radiographic repair durability was observed at years 2 and 5, though after year 2 the effect is less prominent in the BI and LMSB. Concordant to radiographic findings, we also observed significant improvement in the six minute walk test (1079 vs. 1268 ft, P <0.001), Karnofsky score (65 vs. 82, P <0.001) and cough specific quality of life score (68 vs. 55, P <0.001). Comparable findings were demonstrated in quality of life indices. CONCLUSIONS: Tracheobronchoplasty has durable salutary effects on airway anatomy, functional status, and symptoms in a carefully selected cohort of patients suffering from severe tracheobronchomalacia. Continued follow-up study is warranted, as is analysis of the subset of patients who did not have long-term benefit. CLINICAL IMPLICATIONS: Herein, we have shown the positive mid- and long-term effect of tracheobronchoplasty on expiratory collapsibility in patients with severe diffuse tracheobronchomalacia. These findings may help guide decision making for patients considering this effective, though arduous procedure. DISCLOSURES: No relevant relationships by Abraham Bezuidenhout, source=Web Response No relevant relationships by Daniel Buitrago, source=Web Response Consultant relationship with Boston Scientific Please note: $1001 - $5000 Added 03/15/2019 by Alex Chee, source=Web Response, value=Consulting fee research relationship with On Target Laboratories Please note: >$100000 Added 03/13/2019 by Sidhu Gangadharan, source=Web Response, value=Grant/Research Support No relevant relationships by Diana Litmanovich, source=Web Response Consultant relationship with Boston Scientific Please note: $1001 - $5000 Added 03/16/2019 by Adnan Majid, source=Web Response, value=Consulting fee Consultant relationship with olympus Please note: $5001 - $20000 Added 03/16/2019 by Adnan Majid, source=Web Response, value=Consulting fee Consultant relationship with pinacle biologics Please note: $1001 - $5000 Added 03/16/2019 by Adnan Majid, source=Web Response, value=Consulting fee Consultant relationship with cook medical Please note: $1001 - $5000 Added 03/16/2019 by Adnan Majid, source=Web Response, value=Consulting fee No relevant relationships by Yehuda Malul, source=Web Response No relevant relationships by Mihir Parikh, source=Web Response No relevant relationships by Jennifer Wilson, source=Web Response

A Genetic Risk Score Associated with Chronic Obstructive Pulmonary Disease Susceptibility and Lung Structure on Computed Tomography.

Rationale: Chronic obstructive pulmonary disease (COPD) has been associated with numerous genetic variants, yet the extent to which its genetic risk is mediated by variation in lung structure remains unknown.Objectives: To characterize associations between a genetic risk score (GRS) associated with COPD susceptibility and lung structure on computed tomography (CT).Methods: We analyzed data from MESA Lung (Multi-Ethnic Study of Atherosclerosis Lung Study), a U.S. general population-based cohort, and SPIROMICS (Subpopulations and Intermediate Outcome Measures in COPD Study). A weighted GRS was calculated from 83 SNPs that were previously associated with lung function. Lung density, spatially matched airway dimensions, and airway counts were assessed on full-lung CT. Generalized linear models were adjusted for age, age squared, sex, height, principal components of genetic ancestry, smoking status, pack-years, CT model, milliamperes, and total lung volume.Measurements and Main Results: MESA Lung and SPIROMICS contributed 2,517 and 2,339 participants, respectively. Higher GRS was associated with lower lung function and increased COPD risk, as well as lower lung density, smaller airway lumens, and fewer small airways, without effect modification by smoking. Adjustment for CT lung structure, particularly small airway measures, attenuated associations between the GRS and FEV1/FVC by 100% and 60% in MESA and SPIROMICS, respectively. Lung structure (P < 0.0001), but not the GRS (P > 0.10), improved discrimination of moderate-to-severe COPD cases relative to clinical factors alone.Conclusions: A GRS associated with COPD susceptibility was associated with CT lung structure. Lung structure may be an important mediator of heritability and determinant of personalized COPD risk.

Lower Incisor Inclination in Relation to Head Posture, Tongue and Hyoid Positions

Objectives: To investigate the relationship between head posture, hyoid bone, tongue position and lower incisor inclination. Materials and Methods: The study sample consisted of 98 subjects (35 males, 63 females), who had a mean age of 17.7 years in the permanent dentition and with a skeletal Class I relationship. Lower incisor inclination, craniovertical, craniocervical and craniohorizontal postural variables, tongue and hyoid position and airway measurements were evaluated on lateral cephalograms taken in natural head position. The study sample was divided into two groups according to lower incisor inclination (48 had IMPA&amp;lt;90 ⁰ with a mean degree of 88.09 and 50 had IMPA&amp;gt;90 ⁰ with a mean degree of 102.84) and a Student-t test was performed to compare and describe head posture, tongue and hyoid bone positions.Results: The subjects with upright incisors had a more posteriorly positioned hyoid bone relative to the mandibular symphysis compared with the subjects with flared incisors (p&amp;lt;0.05). Tongue length was greater in the flared incisor group than in the upright incisor group (p&amp;lt;0.05). In relation to head posture measurements, the upright incisor group had 3-3.5° larger cranio-cervical angles (NSL-OPT, NSL-CVT, NL-OPT, NL-CVT angles, p&amp;lt;0.05) than the flared incisor group. The airway measurements revealed no statistically significant difference between the groups.Conclusions: The position of the hyoid bone, tongue length and craniocervical head posture showed significant differences between upright and flared lower incisors.

Comparative analysis of the oropharyngeal airway in patients aged over 40 years: A cone beam computed tomography study

Abstract Aim: This study was carried out to compare different measurements of the oropharyngeal airway in patients aged over 40 years on cone beam computed tomography (CBCT) images. Materials and Methods: Seven hundred and five patients aged over 40 years were divided into three groups (40–49, 50–59, and ≥60 years). A comparative analysis of oropharyngeal airway (volume, minimum cross-sectional area, minimum anteroposterior distance, and minimum right to left distance) between the groups was carried out on CBCT images acquired for different dental purposes. Data were analyzed using the one-way ANOVA statistical test. Results: There were statistically significant differences between the groups in mean value of oropharyngeal airway measurements (P &lt; 0.05). In the middle age group of patients aged from 50 to 59 years, the mean value of each measurement was lower than its counterpart in other groups. Conclusions: Patients aged from 50 to 59 years had the smallest oropharyngeal airway measurements; therefore, they might be at high risk of developing sleep-related breathing disorders, and further assessment is recommended.

Morphometric evaluation of the pterygoid hamulus and upper airway in patients with obstructive sleep apnea syndrome.

Many anatomical factors are known to cause obstructive sleep apnea syndrome (OSAS), but only few studies have examined the relationship between the morphology of pterygoid hamulus (PH), upper airway, and OSAS severity. This study aimed to investigate the relationship between the severity of OSAS and PH morphology and other anatomical variations of the upper airway. The data of the patients who underwent polysomnography and diagnosed with OSAS were retrospectively reviewed, and those who underwent paranasal sinus computed tomography were determined. The patients were divided into three groups according to the apnea-hypopnea index (AHI) scores obtained from the polysomnography (mild, moderate, and severe). The relationship between PH thickness, length and interpterygoid distance, and the severity of AHI was investigated. Seventy-four patients were included in the study. In patients with severe OSAS (1.83 ± 0.29mm), the PH bone thickness was significantly thicker compared to those with mild OSAS (1.59 ± 0.36mm) (p = 0.03). When the interpterygoid distance and its ratio to the velopharyngeal length were examined, it was found significantly shorter in patients with severe OSAS than mild cases (p < 0.001; p = 0.045, respectively). Our results showed that OSAS severity was associated with hamulus thickness, interpterygoid distance, and the ratio of interpterygoid distance to VL. Our study provides further insight into the pathophysiology of sleep apnea, suggesting that morphometric evaluation of the pterygoid hamulus and upper airway measurements can assist clinicians in stratifying and determining the best treatment options for patients with OSAS.

Airway and cephalometric changes in adult orthodontic patients after premolar extractions.

To examine changes in the airway and cephalometric measurements associated with orthodontic treatment of adults with and without premolar extractions. The study investigated whether extractions had a direct or indirect effect on the airway and examined selected skeletal and dental features. This retrospective study used pre- (T1) and posttreatment (T2) cone-beam computed tomography scans of 83 adult patients matched for age and sex. A total of 15 airway and 10 skeletal and dental measures were analyzed by means of repeated-measures analysis of variance. There were no results showing that extractions affected airway dimensions that could not be accounted for as reflections of measurement error. There was no evidence that extractions affected the airway indirectly through skeletal and dental changes. There were strong and consistent findings that patients with small airways showed larger ones after treatment and that patients with large airways showed smaller ones later. These effects were independent of whether or not extractions were part of treatment. The measurement phenomena of regression toward the mean and of differential unfolding of natural changes over time could have accounted for the results observed. There was no evidence that extractions in nongrowing patients have negative consequences on the size of various airway measures in the nasopharynx, retropalatal, or retroglossal regions.

S12-17 SESSION 12: FACIOCRANIOSYNOSTOSIS – PART II PAN-FACIAL DISTRACTION FOR SEVERE CRANIO-MAXILLOFACIAL RETRUSION:

Introduction: Monobloc distraction can effectively improve patients with severe cranio-maxillofacial retrusion suffering from increased intra-cranial pressure, orbital proptosis and obstructive sleep apnea. In these patients, their mandibles may look normal or even protrusive. However, at the end of the monobloc distraction advancement, their mandibles commonly become retrusive when compared with the forwarded distracted midface. Their obstructive sleep apnea might not improve as the retro-lingual airway becomes the bottle-neck. The aim of the presentation is to present a new concept of pan-facial distraction for cranio-synostosis children suffering from severe cranio-maxillofacial retrusion. Methods: Children with typical midfacial depression, orbital proptosis and increased intra-cranial pressure having confirmed cranio-synostosis will go through a full upper airway assessment by a combination of CT scan, computerized airway measurement and sleep endoscopic evaluation. The upper airway at different levels (naso-pharyngeal, uvula, base of tongue, larynx) were measured in transverse and antero-posterior planes as well as Volumatic measurement of airway volume. When the upper airway at the nasopharynx, retro-uvula and retro-lingual dimensions were restricted, pan-facial distraction by means of simultaneous mono-bloc and mandibular distraction was performed with a combination of external and internal distractors. Results: Clinical cases will be presented to illustrate the clinical improvement that can be achieved when this concept was implemented in children with syndromal craniosynostosis. Conclusion: Pan-facial distraction is effective in alleviating the obstructive sleep apnea syndrome of children with syndromal craniosynostosis suffering from multiple levels of airway obstruction.

Cone-beam computed tomography airway measurements: Can we trust them?

Pharyngeal airway space (PAS) assessment has been used in the past for a better understanding of orthodontic and surgical outcomes; however, this analysis could be unreliable. Our objective was to evaluate possible changes in the PAS reading in the same patient from their consecutive cone-beam computed tomography (CBCT) scans. We evaluated a total of 27 patients' CBCT scans obtained at 2 time points with the use of a standardized acquisition protocol. The mean age at T0 was 31years (range 17-62years) and the follow-up records (T1) were taken after 4-6months. Dolphin Imaging software was used to measure the volumes of the nasopharynx, oropharynx, and hypopharynx. We also evaluated the craniocervical position with the use of a lateral cephalogram. The variables exhibited high intraclass correlation coefficients (ICCs) when measuring the same CBCT scan twice (T0 and T0). However, The ICC between the measurements performed on the first and second CBCT scans (T0 and T1) showed that the only variable with high reproducibility between the 2 scans was cranial base, with an ICC>0.97. Average differences of 682.1mm3, 2255.3mm3, and 517.4mm3 were found for the nasopharynx, oropharynx, and hypopharynx, respectively. Regarding the cephalometric angles, average differences between T0 and T1 scans were 0.6°, 2.7°, and 0.4° for OPT.CVT, OPT.SN, and cranial base, respectively. Different CBCT exams with equal scanning and patient positioning protocols can result in different 3D PAS readings. A more careful interpretation of CBCT volumetric data to achieve adequate conclusions of the clinical outcomes is necessary.

Pharyngeal Airway Modifications in Skeletal Class III Patients Undergoing Bimaxillary Advancement Surgery

The purposes were to study the pharyngeal airway in patients with skeletal Class III malocclusion submitted to surgical orthodontic treatment and to correlate the alterations with bone movements. The sample consisted of multislice computed tomography images from 13 patients obtained before and 6months after maxillomandibular advancement surgery. The following measurements were obtained using Dolphin Imaging software (Dolphin Imaging, Chatsworth, CA): volume and area of the oropharynx, nasopharynx, and total airway, as well as the most constricted area, anteroposterior and lateral dimensions of the narrowest axial cross-sectional area, and airway length. The paired ttest was applied at a significance level of 5%. Sagittal displacement of the maxilla and mandible was correlated with airway alterations using the Pearson correlation test. Alterations in airway measurements were observed in all patients after surgery. We noted a significant increase (P<.05) in total airway area, oropharyngeal area, and anteroposterior dimension of the most constricted area, as well as a significant reduction (P<.05) in airway length. A significant correlation (P<.05) was observed between nasopharyngeal area and maxillary movement and between airway length and mandibular movement (P<.05). The results of this study suggest significant alterations in pharyngeal airway measurements when preoperative and postoperative periods of bimaxillary advancement surgery were compared.

Evaluation of the Relationship Between Airway Measurements and Laryngoscopic View in Newborn and Infants

Evaluation of the Relationship Between Airway Measurements and Laryngoscopic View in Newborn and Infants

Evaluation of Airway Measurements in Class II Patients Following Functional Treatment.

This study aimed to evaluate the effect of fixed and removable functional treatment on pharyngeal airway measurements in class II patients. In this study, patients treated with fixed (Forsus Fatigue Resistant Device-FRD) and removable (twin-block-TWB) appliances were included (n=15, eight females, seven males in each group). These groups were compared with untreated individuals as the control group (n=10). The mean age of individuals was 13.22±2.39 years. Initial and post-treatment cephalometric radiographs were digitized, and the sagittal pharyngeal airway changes were evaluated. The pharyngeal airway was divided into the nasopharynx, oropharynx, and hypopharynx. The one-way ANOVA, Kruskal-Wallis test, and paired samples t-test were used for statistical analyses. At the initial values, no statistically significant difference was observed between the groups. Only the ANB values differed between the groups (p<0.05). Although the skeletal effects of removable and fixed treatment were not exactly the same, the changes of the airway dimensions were similar. The TWB and FRD appliances lead to an increase in nasopharynx, oropharynx, and hypopharynx sagittal dimensions. However, in terms of the effect on airway sagittal dimensions, there was no significant difference between treatment groups and the control group.

Correlation between Subjective and Linear Measurements of The Palatal Airway on Lateral Cephalometric Radiography

Introduction: hypertrophied adenoid tissue is one of the most common health problems that occurs in childhood that results in many symptoms including 1. Nasal obstruction. 2. Mucoid, mucopurulent nasal discharge and postnasal discharge 3. Snoring and obstructive sleep apnea. 4. Recurrent acute otitis media (A.O.M). Objective: to evaluate the correlation between subjective and linear measurements of palatal airway on lateral cephalographs. Patients and Methods: Diagnostic lateral cephalometric imaging study that took place from March 2017, to July 2018. 200 Children with chronic mouth breathing (116 boys and 84 girls), with age range from 2 to 14 years, were enrolled in this study. Patients were grouped into three groups according to age: a- 2 - <6 years were 84 patients (42%). b- 6 - <10 years were 76 patients (38%). c- 10 – 14 years were 40 patients (20 %). Results: The age was inversely correlated with the grade of airway obstruction. The correlations between the palatal airway grading with the shortest adenoid distance (SAD) and the most convex adenoid distance (CAD) were r= -0.826 and r= -0.424, respectively, which is statistically significant. The relation between SAD and CAD was directly proportional to each other accounting for correspondence of evaluation in more than 50% of the population which is statistically significant. Conclusion: subjective grading of palatal airway obstruction correlates with the objective measurements of SAD and CAD. Although both methods are reliable in measurement particularly the more severe obstructions, SAD is a more favorable objective tool.

Correlation between Subjective and Linear Measurements of The Palatal Airway on Lateral Cephalometric Radiography

Correlation between Subjective and Linear Measurements of The Palatal Airway on Lateral Cephalometric Radiography

Pharyngeal airway changes following symohyseal distraction osteogenesis

Introduction: The aim of this study was to analyze the effects of mandibular symphyseal distraction osteogenesis (MSDO) on the pharyngeal airway dimensions in a group of adult patients.Subjects and Methods: The sample consisted of digital lateral cephalograms of 10 patients (7 females and 3 males)with a mean age of 21.0 ± 2.5 years. Radiographs were taken before start of distraction (T1) and following distraction(T2) (12.5 days ± 2.3 days after surgery). Symphyseal distraction was done using a bone-borne distractor. The mean value of mandibular symphyseal distraction was 8.4 ± 1.7 mm. Digital lateral cephalometric tracing was done to evaluate airway changes following symphyseal distraction.Results: Digital lateral cephalometric analysis revealed no statistically significant changes in nasopharyngeal airway(0.3 ± 0.1 mm) (P > 0.05). There were statistically significant changes in oropharyngeal and hypopharyngeal airway widths (1.2 ± 0.3 mm) and (0.7 ± 0.4 mm) respectively (P 0.05) while statistically significant decrease were evident for the vertical measurement H-C3RGN (- 1.2 ± 0.2 mm) (P < 0.01).Conclusion: The results propose that MSDO significantly affects the lower pharyngeal airway dimensions but has no effect on the upper pharyngeal airway measurements. No significant effects on hyoid bone position were observed except mild decrease of its vertical measurement to reference planes. The normal reflex mechanisms that conserve the patency of the airway may have negated any potential changes in the hyoid bone position.

Comparison of upper airway measurement by lateral cephalogram in upright position and CBCT in supine position

Background/PurposeObstructive sleep apnea syndrome (OSAS) is a common form of sleep disorder. Lateral cephalograms and cone-beam computed tomography (CBCT) have been used for evaluation. However, it is lack of position comparison for these two assessments. Therefore, this study was aimed to evaluate the difference of upper airway measurements taken from lateral cephalograms in upright position and CBCT in supine position. Material and methodsThis retrospective study enrolled patients with lateral cephalograms and CBCT images due to diagnostic necessity. The anterior-posterior distance of most constricted area in pharynx (PASmin) and the distance from mandibular plane to hyoid bone (MP-H) were identified and measured from 21 normal subjects without obstructive sleep apnea (9 males and 12 females, mean age 21.2 years). A paired data were measured from lateral cephalograms taken in upright position and lateral cephalometric images derived from CBCT taken in supine position. Both images were taken within two months. All data were analyzed statistically. ResultsNo significant difference was identified in intra-examiner reliability (P > 0.05). PASmin measured from lateral cephalograms in upright position was larger than that taken from CBCT derived cephalometric images, but without statistical significant difference (P = 0.073). Significant difference of MP-H length was identified between two different image taking methods (P = 0.000), and the measurement was significantly larger in cephalograms taken from upright position. No correlations were found among the variables (Body Mass Index (BMI), age, gender) in this study. The only two variables correlated were PASmin and MP-H, and they were negatively correlated (r = −0.535). ConclusionThe anterior-posterior distance of most constricted area in pharynx (PASmin) and distance of mandibular plane to hyoid bone (MP-H) can be influenced due to change of body position.