Volume Of Upper Airway Research Articles

Effects of Craniofacial Morphology on Nasal Respiratory Function and Upper Airway Morphology.

Craniofacial skeletal patterns change after orthognathic surgery. The present study aimed to investigate the effects of different craniofacial patterns on nasal respiratory function and the upper airway. Forty-seven healthy subjects were selected and divided into 3 groups according to their mandibular position. Sixteen were in the skeletal Class I group, 15 were in the skeletal Class II group, and 16 were in the skeletal Class III group. Cone beam computed tomography was performed, and nasal airflow and nasal resistance were measured. Differences in nasal respiratory functions and upper airway were compared among the groups. A correlation analysis was conducted for nasal respiratory function, upper airway, and skeletal patterns. There were significant differences among the 3 groups regarding dominant-side nasal inspiratory capacity (P = 0.001), bilateral nasal inspiratory capacity (P = 0.005), nasal partitioning ratio-inspiration (P = 0.007), and velopharyngeal minimum cross-sectional area (P = 0.029). The values were significantly higher for the skeletal Class III group than the skeletal Class I and II groups. A correlation analysis showed that the nasal partitioning ratio and nasal airway resistance were mostly negatively correlated with SNA, but the upper airway volume and cross-sectional area were positively correlated with SNB and negatively correlated with ANB. The dominant-side nasal expiratory capacity was mainly negatively correlated with the mean velopharyngeal cross-sectional area (r = -0.324, P = 0.026), mean glossopharyngeal cross-sectional area (Glosso-A mean) (r = -0.293, P = 0.046), and mean total airway cross-sectional area (Total-A mean) (r = -0.307, P = 0.036). Craniofacial skeletal morphology may affect nasal respiratory function and the upper airway.

Three-dimensional evaluation of changes in upper airway volume in growing skeletal Class II patients following mandibular advancement treatment with functional orthopedic appliances.

The aim of this study was to assess three-dimensionally the upper airway changes following functional appliance treatment in growing Class II patients. Pre-and post-treatment Cone beam computed tomography scans of 20 patients (age range: 9 to 12; mean: 11.4 ± 1.0 years) were retrieved from the list of patients previously treated with functional appliances in the Postgraduate Clinic at the Section of Orthodontics, Aarhus University, Denmark. Total and partial volumes of the upper airway (ie, lower nasopharynx, velopharynx, and oropharynx) were calculated. To rule out the effect of growth, the changes in the functional appliance group were compared to an age-matched Class I group of 18 patients (age range: 8 to 14; mean: 11.8 ± 1.4 years). In the functional appliance group, all the partial and total volumes were significantly larger at the end of treatment when compared to the start of treatment ( P < .003). On the other hand, when comparing the changes for the total and partial volumes of the upper airway in the functional appliance group with the Class I group, a statistical difference was seen only for the oropharynx ( P = .022) and total volume ( P = .025), with the functional appliance group showing a larger volume increment. An increase in the upper airway volume was found after treatment with functional appliances. This difference was mainly related to the changes at the oropharynx level, which differed significantly from what was observed in the Class I group.

0553 Non-Surgical Osseous Remodeling and Myofunctional Therapy for Skeletal class III Malocclusion with Severe OSA

Obstructive Sleep Apnea (OSA), is a common sleep-disorder; causes of OSA vary, including decreased pharyngeal muscle tone, craniofacial obesity, and craniofacial deficiencies amongst others. Current treatments are continuous positive airway pressure therapy (CPAP), as well as MRA and MMA surgery. This study tests that if a non-surgical biomimetic oral appliance therapy (BOAT) DNA® System is used in combination with a sagittal expander and Myofunctional therapy for soft tissue remodeling and brain remapping; then AHI can be reduced in addition to oxygen desaturation. This study includes two class III adults: male A (45 years) with 65% oxygen desaturation and male B (45 years) with 78% oxygen desaturation. The cases were treated with FDA-cleared DNA Appliance© for osseous remodeling, and Myofunctional therapy for 6 months, followed by sagittal expansion. Before treatment the craniofacial region was imaged using 3D cone-beam CT scans. After 9 months of treatment, the apnea hypopnea index (AHI) was reassessed, without any appliance, by home sleep study (HST). The upper airway volume was reassessed with another 3D cone-beam CT scan and upper airway analysis. This process was repeated after the sagittal expander. For both cases, the mean AHI decreased from severe to mild, while the upper airway volume (from the posterior nasal spine to the epiglottis) increased by 15% and oxygen desaturation decreased. This preliminary study suggests that a decrease in AHI and oxygen desaturation may be associated with combined non-surgical osseous upper airway remodeling, a sagittal expander; and Myofunctional therapy, for soft tissue remodeling and brain pattern remapping, for skeletal class III with severe OSA in adults with craniofacial deficiencies. N/A.

A pilot study on the biomechanical assessment of obstructive sleep apnea pre and post bariatric surgery

Obesity is a major risk factor for obstructive sleep apnea patients. In obese patients the severity of this risk can be reduced by bariatric surgery. This pilot study investigates the perioperative effects of bariatric surgery on obstructive sleep apnea and on the physical and biomechanical characteristics of the upper airway. Polysomnography and computer tomography data for 10 morbid obese patients promoted for bariatric surgery were conducted before surgery and at 6 and 12 months postoperatively for assessment of the oropharyngeal anatomy, and subsequent three-dimensional modelling of the airway. Mean values for the apnea/hypopnea index and body mass index significantly reduced after surgery. To combine the effect of changes in the upper airway volume and body mass index, a new volume body mass index is introduced. This index increases with a successful bariatric surgery. Although bariatric surgery leads to an effective weight reduction for all age groups, for obstructive sleep apnea patients it may be effective for middle age, less effective for 50–60 years, and further less effective for patients over the age of 60 years.

Effect of Orthodontic Treatment on the Upper Airway Volume in Adults

Effect of Orthodontic Treatment on the Upper Airway Volume in Adults

0636 NON-SURGICAL, UPPER AIRWAY REMODELING FOR UARS

Upper airway resistance syndrome has become a prevalent form of sleep-disordered breathing. The causes for UARS include decreased pharyngeal muscle tone, and craniofacial deficiencies amongst others. Current methods used to manage UARS - include no standard medical treatment; continuous positive airway pressure (CPAP) therapy and/or mandibular advancement appliances have been used without any results. Therefore, this study is to test the hypothesis that a biomimetic oral appliance therapy (BOAT) can be used followed by a DNA appliance, with a forward facial head-gear mask. This pilot study included two adults: 2 females, 29 years and 32 years, (mean age 31yrs.) diagnosed with UARS to mild OSA who were treated with FDA-cleared BOAT (MRNA appliance®) followed with a forward facial mask for osseous remodeling. Prior to treatment the craniofacial region was imaged using 3D cone-beam CT scans. After 9 to 15 months of treatment, the upper airway volume was reassessd with 3D cone-beam CT scans and upper airway analysis. For case 1, the upper airway volume (from the posterior nasal spine to the epiglottis) prior to treatment was 9.28cm 3 and increased to 16cm 3, representing a 29% increase in upper airway volume. For case 2, upper airway volume increased from 16.7cm 3 prior to treatment to 20.5cm 3 post-treatment, showing a 12.5% increase in upper airway volume. By subjective questionnaires of before and after, the patients have improved immensely. This preliminary study indisputably suggests that increases in 3D airway may be associated with non-surgical upper airway remodeling for UARS in adults with craniofacial deficiencies. None

Effect of orthodontic treatment on the upper airway volume in adults

Effect of orthodontic treatment on the upper airway volume in adults

Effect of orthodontic treatment on the upper airway volume in adults.

The aim of this study was to examine the effects of orthodontic treatment with and without extractions on the anatomic characteristics of the upper airway in adults. For this retrospective study, the pretreatment and posttreatment cone-beam computed tomography scans of 74 adult patients meeting defined eligibility criteria were analyzed. Imaging software was used to segment and measure upper airway regions including the nasopharynx, the retropalatal, and retroglossal areas of the oropharynx, as well as the total airway. The Wilcoxon signed rank test was used to compare volumetric and minimal cross-sectional area changes from pretreatment to posttreatment. The reliability values were high for all measurements, with intraclass correlation coefficients of 0.82 or greater. The volumetric treatment changes for the extraction and nonextraction groups were as follows: total airway, 1039.6±3674.3mm3 vs 1719.2±4979.2mm3; nasopharynx, 136.1±1379.3mm3 vs -36.5±1139.8mm3; retropalatal, 412.7±3042.5mm3 vs 399.3±3294.6mm3; and retroglossal, 412.5±1503.2mm3 vs 1109.3±2328.6mm3. The treatment changes in volume or minimal cross-sectional area for all airway regions examined were not significantly (P>0.05) different between the extraction and nonextraction groups. Orthodontic treatment in adults does not cause clinically significant changes to the volume or the minimally constricted area of the upper airway. These results suggest that dental extractions in conjunction with orthodontic treatment have a negligible effect on the upper airway in adults.

Practices that Can Impact Proper Assessment of the Upper Airway Volume

Practices that Can Impact Proper Assessment of the Upper Airway Volume

Correlation between the Friedman staging system and the upper airway volume in patients with obstructive sleep apnea

Correlation between the Friedman staging system and the upper airway volume in patients with obstructive sleep apnea

Changes in Upper Airway Volume in Edentulous Obstructive Sleep Apnea Patients Treated with Modified Mandibular Advancement Device.

This study was an attempt to verify the utility of complete dentures modified as a mandibular advancement device (MAD) in effecting expansion in pharyngeal volume to treat obstructive sleep apnea (OSA) in edentulous patients. The sample consisted of 17 patients (12 male, 5 female, average age 61 ± 4 years; BMI, 22 ± 5; apnea hypopnea index [AHI] 15 to 30). All patients had worn complete dentures for at least 1 year; all patients had the dentures modified to a MAD. Five variables were assessed preoperatively and 6 months after wearing the modified MADs. These variables were: sleep efficiency, AHI, oxygen desaturation events/hr., mean oxygen saturation, snoring index, and airway volume. This assessment was done by subjecting the patients to all-night polysomnography. Without any prosthesis or device in the edentulous patients, the mean velopharyngeal volume was 8.05 ± 0.58 cm(3) , oropharyngeal volume was 2.14 ± 0.38 cm(3) , and hypopharyngeal volume was 3.26 ± 0.78 cm(3) . With complete dentures (unaltered) in the edentulous patients, the mean velopharyngeal, oropharyngeal, and hypopharyngeal volumes were 10.73 ± 0.98 cm(3) , 2.60 ± 0.48 cm(3) , and 4.31 ± 0.89 cm(3) , respectively. There was a statistically significant change in the airway volume following insertion of the complete dentures modified as MADs with velopharyngeal, oropharyngeal, and hypopharyngeal volume recorded as 11.76 ± 1.07 cm(3) , 3.33 ± 0.51 cm(3) , and 4.94 ± 0.83 cm(3) , respectively. From the results obtained in this limited small sample study, it was inferred that the pharyngeal expansion induced by complete dentures modified as MADs effectively reduced symptoms of OSA. Increased volume was most pronounced in the velopharynx region followed by hypopharynx and oropharynx.

Do Mandibular Advancement Devices Influence Patients' Snoring and Obstructive Sleep Apnea? A Cone-Beam Computed Tomography Analysis of the Upper Airway Volume

The upper airway volume is central to the development and treatment of snoring and obstructive sleep apnea, and mandibular advancement devices (MADs) have increasingly been used as an effective alternative to continuous positive airway pressure for these 2 conditions. We investigated the changes in breathing patterns and upper airway volume parameters measured on cone-beam computed tomography (CBCT) scans of patients with and without the use of custom-made MADs. We performed a prospective study at the Department of Oral and Maxillofacial Surgery, Odense University Hospital, on consecutively treated patients. CBCT scans were performed with and without the MAD to measure the changes in the upper airway volume. The patients underwent diagnostic cardiorespiratory monitoring before and after 3 months of MAD therapy. Measurements with and without MAD were compared using Student's t test and the Wilcoxon signed rank test, and mixed-model analyses were performed adjusting for sleep apnea severity, type 2 diabetes, body mass index, gender, and age. A total of 44 patients (31 men and 13 women, age 50 ± 13 years, body mass index 31 ± 5.6 kg/m(2)) completed the trial. MAD therapy was associated with an increase in the total upper airway volume from 22.9 ± 8.7 cm(3) before treatment to 26.7 ± 10.7 cm(3) after treatment (P < .001). MAD therapy reduced the apnea-hypopnea index (AHI) from 15.8 ± 17.4 events/hour before treatment to 6.2 ± 9.8 events/hour after treatment (P < .001). The results of the present study indicate that MAD therapy appears to produce significant changes in the upper airway volume that correlate with a decrease in the AHI.

The effect of teeth extraction for orthodontic treatment on the upper airway: a systematic review.

The purpose of this study was to evaluate the effect of teeth extraction for orthodontic treatment on the upper airway. Relevant trials assessing the effect of orthodontic extractions on the upper airway were retrieved electronically through PubMed, Embase, Medline, Web of Knowledge, and the Cochrane Library. The processes of literature search, selection, quality assessment, and data extraction were performed by two authors independently. Seven articles were included in this systematic review. They were categorized into three groups according to their indications for extractions, namely anteroposterior discrepancy (group 1), crowding (group 2), and unspecified indications (group 3). In group 1, enrolled patients were diagnosed with class I bimaxillary protrusion and had four first premolars extracted, with a significant decrease in upper airway dimension. In group 2, increase in the upper airway dimension was reported in patients who were diagnosed with class I crowding and four first premolars extracted. In group 3, all patients were adolescents and no significant change in the upper airway dimension was observed. Currently, it is difficult to draw evidence-based conclusions because of the exceeding heterogeneity among included studies, and more qualified trials are required to provide reliable evidence. Extractions followed by large retraction of the anterior teeth in adult bimaxillary protrusion cases could possibly lead to narrowing of the upper airway. Mesial movement of the molars appeared to increase the posterior space for the tongue and enlarge the upper airway dimensions. Although the effect of teeth extraction on upper airway dimension seems to be related to indications for extraction, accepted scientific evidence is still insufficient owing to the limited number of included studies. The relationship between the upper airway size and the respiratory function has not been demonstrated. While there may be a decrease in the upper airway volume, there is no evidence that this would turn an airway more collapsible. None of the studies assessed in this review had actual functional assessment of breathing. Additional qualified trials are necessary to verify reliability.

Resolution of Sleep Bruxism using Biomimetic Oral Appliance Therapy: A Case Report

Background: Evidence suggests that sleep bruxism is centrally regulated, and that the highest risk factor associated with sleep bruxism is obstructive sleep apnea. Current treatments for sleep bruxism include dental nightguards or occlusal splints, which are often provided without upper airway or sleep assessments. Methods: In this case report, we used biomimetic oral appliance therapy to address sleep bruxism by redeveloping the maxilla and repositioning the mandible in a 17 yr. old, female patient. Results: The upper airway volume increased by 313% (from 7.7 cm3 to 24.1 cm3) and the minimum upper airway cross-sectional area increased by 230% from (120 mm2 to 276.5 mm2), which improved both sleep bruxism and orthodontic relapse. Conclusion: We conclude that dentists and orthodontists can help in the recognition and treatment of both sleep bruxism and malocclusion, thereby preventing systemic co-morbidities associated with obstructive sleep apnea.

Upper airway collapsibility is associated with obesity and hyoid position.

Upper airway anatomy plays a major role in obstructive sleep apnea (OSA) pathogenesis. An inferiorly displaced hyoid as measured by the mandibular plane to hyoid distance (MPH) has been consistently associated with OSA. The hyoid is also a common landmark for pharyngeal length, upper airway volume, and tongue base. Tongue dimensions, pharyngeal length, and obesity are associated with OSA severity, although the link between these anatomical variables and pharyngeal collapsibility is less well known. We hypothesized that obesity as measured by body mass index (BMI), neck and waist circumferences, and variables associated with hyoid position (pharyngeal length, upper airway volume, and tongue dimensions) would be associated with passive pharyngeal critical closing pressure (Pcrit). Cross-sectional. Academic hospital. 34 Japanese-Brazilian males age 21 to 70 y. N/A. We performed computed tomography scans of the upper airway, overnight polysomnography, and Pcrit measurements in all subjects. On average, subjects were overweight (BMI = 28 ± 4 kg/m(2)) and OSA was moderately severe (apnea-hypopnea index = 29 [13-51], range 1-90 events/h). Factor analysis identified two factors among the studied variables: obesity (extracted from BMI, neck and waist circumferences) and hyoid position (MPH, pharyngeal length, tongue length, tongue volume, and upper airway volume). Both obesity and hyoid position correlated with Pcrit (r = 0.470 and 0.630, respectively) (P < 0.01). In addition, tongue volume, tongue length, pharyngeal length, and MPH correlated with waist and neck circumferences (P < 0.05). Pharyngeal critical closing pressure is associated with obesity and hyoid position. Tongue dimensions, pharyngeal length, and the mandibular plane to hyoid distance are associated with obesity variables. These findings provide novel insight into the potential factors mediating upper airway collapse in obstructive sleep apnea.

Correlation between the Friedman Staging System and the Upper Airway Volume in Patients with Obstructive Sleep Apnea

Objectives: This study was designed to evaluate the correlation between computed tomography (CT) findings and data from the physical examination, such as Friedman Staging System (FSS) in patients with obstructive sleep apnea (OSA).

Preliminary Study on the Application of Upper‐Airway Model Construction with 3DMIA in OSAHS of Children

Objectives: Investigate the applicability of 3DMIA software to upper airway modeling in children with obstructive sleep apnea hypopnea syndrome (OSAHS). Methods: A total of 12 children diagnosed with OSAHS by polysomnography were included in this study. Data regarding upper airway structure were collected via spiral computed tomography (CT) while sleeping and awake, from which a 3-dimensional model of the upper respiratory tract from the nasopharynx to the supraglottic region using 3DMIA software was constructed. The upper airway volume and airway minimum cross-sectional area were measured employing software algorithms. Results: The upper airway volume and airway minimum cross-sectional area of the 12 children during sleep were significantly less than while awake ( P &lt; .01). Conclusions: 3DMIA software modeling and software algorithm measurement were more objective than traditional radiology with respect to evaluation of the extent of the upper airway narrowing in OSAHS children, and showed good applicability to studying upper airway morphology and function in children with OSAHS.

Correlation Between the Friedman Staging System and the Upper Airway Volume in Patients With Obstructive Sleep Apnea

This study was designed to evaluate the correlation between computed tomography findings and data from the physical examination and the Friedman Staging System (FSS) in patients with obstructive sleep apnea (OSA). We performed a retrospective evaluation by reviewing the medical records of 33 patients (19 male and 14 female patients) with a mean body mass index of 30.38 kg/m(2) and mean age of 49.35 years. Among these patients, 14 presented with severe OSA, 7 had moderate OSA, 7 had mild OSA, and 5 were healthy. The patients were divided into 2 groups according to the FSS: Group A comprised patients with FSS stage I or II, and group B comprised patients with FSS stage III. By use of the Fisher exact test, a positive relationship between the FSS stage and apnea-hypopnea index (P = .011) and between the FSS stage and body mass index (P = .012) was found. There was no correlation between age (P = .55) and gender (P = .53) with the FSS stage. The analysis of variance test comparing the upper airway volume between the 2 groups showed P = .018. In this sample the FSS and upper airway volume showed an inverse correlation and were useful in analyzing the mechanisms of airway collapse in patients with OSA.

Mechanical ventilation causes airway distension with proinflammatory sequelae in mice.

The pathogenesis of ventilator-induced lung injury has predominantly been attributed to overdistension or mechanical opening and collapse of alveoli, whereas mechanical strain on the airways is rarely taken into consideration. Here, we hypothesized that mechanical ventilation may cause significant airway distension, which may contribute to the pathological features of ventilator-induced lung injury. C57BL/6J mice were anesthetized and mechanically ventilated at tidal volumes of 6, 10, or 15 ml/kg body wt. Mice were imaged by flat-panel volume computer tomography, and central airways were segmented and rendered in 3D for quantitative assessment of airway distension. Alveolar distension was imaged by intravital microscopy. Functional dead space was analyzed in vivo, and proinflammatory cytokine release was analyzed in isolated, ventilated tracheae. CT scans revealed a reversible, up to 2.5-fold increase in upper airway volume during mechanical ventilation compared with spontaneous breathing. Airway distension was most pronounced in main bronchi, which showed the largest volumes at tidal volumes of 10 ml/kg body wt. Conversely, airway distension in segmental bronchi and functional dead space increased almost linearly, and alveolar distension increased even disproportionately with higher tidal volumes. In isolated tracheae, mechanical ventilation stimulated the release of the early-response cytokines TNF-α and IL-1β. Mechanical ventilation causes a rapid, pronounced, and reversible distension of upper airways in mice that is associated with an increase in functional dead space. Upper airway distension is most pronounced at moderate tidal volumes, whereas higher tidal volumes redistribute preferentially to the alveolar compartment. Airway distension triggers proinflammatory responses and may thus contribute relevantly to ventilator-induced pathologies.

Skeletal, soft tissue, and airway changes following the alternate maxillary expansions and constrictions protocol

To evaluate the skeletal, soft tissue, and airway effects of the alternate maxillary expansions and constrictions (Alt-RAMEC) protocol in prepubertal patients. The appliance containing a double-hinged expansion screw was applied to 20 patients with Class III skeletal malocclusion characterized by maxillary retrognathia. The mean age of the study group was 9 years and 8 months. The patients' parents were instructed to open the screw by 1 mm per day during the first week and to close it by 1 mm per day the week after. This alternate opening and closing was repeated for 9 consecutive weeks. Cone beam computed tomography records and three-dimensional photographs were taken before treatment and after 9 week of the Alt-RAMEC protocol. Point A moved slightly forward (0.89 mm) and downward (0.92 mm) (P < .05). The average amount of expansion achieved at the level of point A was 5.54 mm (P < .05). Besides the maxilla, the expansive forces also affected the nasal bone, the zygomaticomaxillary and zygomaticotemporal sutures (P < .05). The soft tissue nasal width increased significantly. The airway volume of the anterior nasal compartment and the nasal cavity also increased (P < .05). Slight forward movement of point A occurred with the Alt-RAMEC protocol. The expansion affected not only the maxilla but also other structures of the face. Significant cutaneous changes occurred in the paranasal area. Some significant increase in the upper airway volume was obtained.