Retropalatal Area Research Articles

Association Between Soft Tissue Measures From Computed Tomography and Upper Airway Collapsibility on Drug-Induced Sleep Endoscopy.

Positive airway pressure (PAP) titration during drug-induced sleep endoscopy (DISE) provides objective measures of upper airway collapsibility. While skeletal measurements relate to collapsibility measures on DISE, the influence of soft tissue dimensions on upper airway collapsibility is not known. We analyzed the relationship of measures of upper airway soft tissue volumes, specifically soft palate, pharyngeal lateral walls, and tongue, with metrics of collapsibility. Cross-sectional analysis from a prospective cohort. Academic medical center. Patients seeking PAP alternative therapies for obstructive sleep apnea (OSA) underwent standardized supine computed tomography (CT) acquisition and DISE protocols. The CT analysis primarily focused on soft tissue volumes and, secondarily, on airway and skeletal volumetric measures. DISE with PAP administration (DISE-PAP) enabled the determination of the pressure at which inspiratory airflow first commenced (pharyngeal critical pressure, PcritA) and the pressure at which inspiratory flow limitation was abolished (pharyngeal opening pressure, PhOP). Both unadjusted and adjusted correlation analyses were performed to understand the relationship between upper airway anatomy and either PcritA or PhOP. One hundred thirty-nine subjects completed both CT and DISE-PAP. On average, patients were male (70.5%), white (84.2%), middle-aged (56.6 ± 13.5 years), and overweight (29.6 ± 4.7 kg/m2), with moderate-severe apnea-hypopnea index (29.7 ± 21.3 events/h). Adjusted for age, sex, body mass index, and skeletal volumes, soft palate, and lateral pharyngeal wall volumes were not associated with PhOP or PcritA, but a larger tongue was associated with more positive PhOP (⍴ = 0.20, P = .02), and more positive PcritA (⍴ = 0.16, P = .07). Exploratory analyses revealed smaller minimum cross-sectional retropalatal area and intramandibular volume were also associated with increased collapsibility measures. After controlling for clinical factors and skeletal volume, greater tongue volume was associated with more severe collapsibility during DISE. These results, in concert with previous work, suggest that greater tongue volume in a smaller skeletal dimensions contribute to the severity of airway collapsibility, a key driver of OSA pathogenesis.

P068 Computational fluid dynamic study in Obstructive Sleep Apnea patients

Abstract Introduction Obstructive sleep apnea (OSA) is a common disorder which may need surgery to widen the airway. However, the success rate of surgery is variable. Thus, it is necessary to predict the outcome of the surgery preoperatively. The purpose of this study is to evaluate the mechanical parameter of upper airway airflow in OSA patients using computational fluid dynamics (CFD) method. Method We conducted a study on the patients with snoring, underwent the full night polysomnograpny (PSG) and paranasal sinus computed tomography(CT). The patients with past history of previous trauma or surgery were excluded. Three-demensional reconstructions of the upper airway were created in the medical imaging software Mimics 16.0 using paranasal CT. The reconstructions extended from nasopharynx to hypopharynx. Steady-state, turbulent, inspiratory airflow simulations were conducted in Fluent 17.0 with following boundary conditions The mechanical parameters (wall shear stress, pressure, plane velocity) were calculated in the three levels of nasopharynx, retropalatal, retrolingual area. Results The maximum wall shear stress values were shown at the retropalatal plane in all patients. There is a tendency for the wall shear stress value of the retropalatal area to increase as the AHI increases. The maximum velocity values were shown at the retropalatal plane in all patients. The maximum pressure values were shown at the nasopharynx plane in all patients. Conclusion the maximum wall shear stress values were shown at the retropalatal plane and the wall shear stress value of the retropalatal area increased as the AHI increased. Thus, the palatal surgery might help the OSA patients.

Palatal hybrid surgery for obstructive sleep apnea-state-of-the-art annotation of uvulopalatopharyngoplasty

BackgroundSurgery for obstructive sleep apnea (OSA) has changed in concept and technique that transformed from radical excision to functional reconstruction. The aim of this study was to investigate the safety and effectiveness of palatal hybrid surgery in OSA patients. MethodsPalatal hybrid surgery is a tissue-specific technique (mucosa-preservation, tonsil-excision, fat-ablation, muscle-relocation/suspension) used in treating OSA patients with velopharyngeal obstruction. The study included 46 consecutive adults OSA patients. The palatal hybrid surgery annotates uvulopalatopharyngoplasty in stereoscopic reconstruction of tonsillar fossa (pharyngoplasty), omni-suspension of the soft palate (palatoplasty) and advancement of uvula (uvuloplasty). ResultsNo patient experienced airway compromise, voice change or persistent nasal regurgitation following palatal hybrid surgery. One patient existed postoperative tonsillar fossa bleeding received conservative treatment. Postoperative pain in visual analogue scale (VAS) showed average score of 3, 3, 2, 0 at the 1st, 3rd, 7th, 14th day, respectively. Perioperative snoring severity (VAS) (8.7 vs 2.6) and daytime sleepiness (Epworth Sleepiness Scale) (11.3 vs 5.5) all improved significantly (p < 0.001). Posterior air space in retropalatal area increased from 8.4 to 11.1 mm (p < 0.001). Home sleep test showed that apnea–hypopnea index significantly reduced from 41.8 to 18.2 event/h and minimal oxygen saturation increased from 72.4 to 81.5% (p < 0.001). The success rate in individual Friedman stage was 100% (stage I), 63% (stage II) and 58% (stage III) with a total success rate of 63%. ConclusionPalatal hybrid surgery using tissue-specific maneuver annotates UPPP in concept and technique. The results show that palatal hybrid surgery is mini-invasive with low morbid and is effective in improving subjective clinic symptoms, objective sleep parameters and success rate of OSA.

Effects of Mandibular Distraction Osteogenesis on Three-Dimensional Upper Airway Anatomy in Newborns Affected by Isolated Pierre Robin Sequence.

Effective airway management is critical to Pierre Robin Sequence treatment. The goal of this study is to assess the three-dimensional changes in airway size and shape in 117 newborns with isolated Pierre Robin sequence who underwent mandibular distraction osteogenesis. During the study period (11/29/2016 to 11/26/2019), 117 newborns affected by isolated Pierre Robin sequence met the inclusion criteria for the present study. All 117 included patients underwent linear distraction. Demographic variables were recorded and analyzed. Cone-beam computed tomography were performed before and after mandibular distraction osteogenesis. A systemic quantitative three-dimensional analysis of size and shape of upper airway was performed. The mean age was 71 day (range 12 to 213). The mean weight was 3.9 kg (range 2.3-6.8). A total of 53 patients are female and 64 are male. When the distraction device was removed, the upper and lower jaws were symmetrically aligned. Pre- and post-distraction comparison clearly showed osteogenesis. For the size of the upper airway, airway volume, anteroposterior dimension of the retroglossal airway, lateral dimension of retroglossal airway, minimum retropalatal area, minimum retroglossal area, average cross-sectional area and minimum cross-sectional area increased significantly after mandibular distraction osteogenesis (P < 0.001). However, the airway length did not change significantly (P > 0.05). For the shape of the upper airway, the lateral/anteroposterior ratio in the retroglossal region and the ratio of the retropalatal airway diameter to the retroglossal airway diameter significantly decreased after mandibular distraction osteogenesis (P < 0.001). The airway uniformity significantly increased after mandibular distraction osteogenesis (P < 0.001). Mandibular distraction osteogenesis for isolated Pierre Robin sequence improved size and shape of the upper airway, further confirming mandibular osteogenesis distraction as an effective surgical modality to address the airway obstruction in newborns affected by isolated Pierre Robin sequence. Cone-beam computed tomography scanning and analysis can serve as a safe and effective examination modality for upper airway applications of PRS newborns.

THE CONNECTION BETWEEN POLYSOMNOGRAPHY RESULTS, EPWORTH SCORES AND DRUG-INDUCED SLEEP ENDOSCOPY FINDINGS IN PATIENTS WITH OSAS

Objective: To determine the usefulness of drug-induced sleep endoscopy (DISE) and evaluate correlations between DISE findings, polysomnography and Epworth sleepiness scale values. Material and Method: Included in this study are patients with major OSAS symptoms and apnea-hypopnea index (AHI) values between 5 and 30 who were scheduled for soft palate surgery. The patients were sedated with propofol (0.25 cc/kg) in the operating room for examination of obstructive regions. Anatomical structures affected by obstruction were observed with flexible endoscopy. The images from this examination were analyzed with Ulead video study. Patients with soft palate pathologies were operated and the endoscopic examination repeated postoperatively. Changes in pre- and post-operative obstruction areas were compared with changes in pre- and post-op PSG and Epworth sleepiness scale values. Results: Changes in retropalatal area values were correlated with changes in AHI values. The most important factor affecting this correlation was the formation of base of tongue pathology, despite being absent preoperatively. We also determined the correlation between patients’ Epworth scores, AHI and retropalatal area. Changes in the retropalatal area following OSAS surgery were correlated with changes in AHI and Epworth scores. Conclusion: DISE is an effective diagnostic technique in OSAS with advantages such as a low radiation risk, cost effectiveness and precise findings.

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

ABSTRACTObjective: 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.

Description of the relationship between NOHL classification in drug-induced sleep endoscopy and initial AHI in patients with moderate to severe OSAS, and evaluation of the results obtained with oral appliance therapy.

SUMMARYNowadays, drug-induced sleep endoscopy is widely recognised as a valid tool for diagnosis and treatment planning of obstructive sleep apnoea syndrome (OSAS), as it allows a direct visualisation of sites and patterns of collapse of the upper airways (UA). Various classifications have been proposed in the literature to describe the events observed during DISE, including the NOHL (Nasopharynx cavity and walls, Oropharynx, Hypopharynx, Larynx) classification. This study was aimed at assessing which anatomical structures, according to the NOHL Classification, were most frequently involved in UA collapse in patients with moderate to severe OSAS, and evaluating treatment results with oral appliances (OA), in terms of AHI reduction. The study group consisted of 35 patients (29 M, 6 F, mean age 50.6, average BMI 26) with polysomnographic diagnosis of moderate to severe OSAS, subjected to DISE and classified according to the NOHL classification to identify the anatomical sites and patterns of UA collapse most frequently reported. Patients were subsequently addressed to mandibular advancing device (MAD) therapy and treatment results in terms of AHI reduction were evaluated. In the sample examined, the anatomical structures most frequently involved in the collapse of the UA were the nasopharynx cavity and walls and tongue base, with a correlation index of 0.35 (p < 0.04), while no significance was found for the retro-palatal area or larynx. Descriptive analysis revealed multilevel collapse in all patients, involving multiple anatomical structures in obstructive mechanics. In all patients, AHI reduction was observed after treatment with MAD (p < 0.00).

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.

What Are the Characteristics of the Upper Airway in Patients With Craniofacial Microsomia?

Obstructive sleep apnea (OSA) is a common problem in patients with craniofacial microsomia (CFM); however, the exact pathophysiology in patients with CFM remains unclear. The first aim of this study was to evaluate upper airway volume and morphology in patients with CFM. The second aim was to identify risk factors for the presence of OSA. A cross-sectional study was set up and 3 study groups were identified: 1) CFM with OSA, 2) CFM without OSA, and 3) control. Computed tomographic (CT) scans of the head and neck were included and used to create 3-dimensional models. The age-matched control group consisted of patients evaluated for traumatic head injury or epilepsy. Volumetric and morphologic parameters were measured. The results of patients with CFM were compared among the 3 study groups. Descriptive statistics were computed using the Pearson χ2 test for categorical variables and nonparametric tests for continuous variables. A multiple variable regression model was used to identify risk factors for OSA. In total, 79 patients with CFM were included, of which 25 patients were diagnosed with OSA. A total of 145 CT scans could be analyzed. In addition, a control population of 88 patients was identified. Oropharynx volume, mean cross-sectional area (CSA), minimal CSA, and minimal retropalatal area were found to be markedly smaller in patients with CFM compared with the control population. In contrast, in patients with CFM and OSA, minimal retroglossal area, sphericity, and uniformity markedly differed from those in patients without OSA. Sphericity was identified as the main predicting variable of OSA in patients with CFM. The upper airway of patients with CFM is markedly smaller and puts them at risk for developing OSA. Patients with CFM diagnosed with OSA have a markedly smaller CSA behind the base of the tongue and a difference in sphericity.

The morphology and resilience change of upper airway in patients with OSAHS: A MSCT study

Objective:To analyse the morphology and resilience of upper airway in patients with OSAHS using 128-slice MSCT. Method:CT imaging of the upper airway in 49 patients with OSAHS was acquired in two respiratory status (quiet respiration and Müller maneuver). The two-dimensional measurements of retropalatal and retroglossal regions, airway volume, and airway resilience were measured in patients with severe OSAHS and non-severe OSAHS. And the results were compared between those two groups. Result:① The following measurements during Müller maneuver were smaller than those during quiet respiration: the smallest cross section area of retropalatal and retroglossal region, the anteroposterior diameters(AP) and lateral diameters(L) of retropalatal region, L of retroglossal region, volume and average volume of upper airway and retropalatal area（P<0.01）.②The pharyngeal wall resilience of retropalata region was larger than those of retroglossal region in patients with severe OSAHS. The total resilience of retropalatal was larger than that of retroglossal region in patients with non-severe OSAHS. The pharyngeal wall resilience between severe and non-severe OSAHS had no significant difference. ③ L of retropalatal and retroglossal region, and average area of retropalatal region, were smaller in patients with severe OSAHS than those with non-severe OSAHS during Müller maneuver（P<0.05）.④ The cross-section of upper airway tend to be horizontal oval in retropalatal regions, and vertical oval in retroglossal regions. Conclusion:128-slice MSCT scan can achieve both positioning and quantitative analysis of the morphology and resilience changes of the upper airway in patients with OSAHS.

Dynamic Upper Airway Imaging during Wakefulness in Obese Subjects with and without Sleep Apnea.

Obesity is a major risk factor for obstructive sleep apnea. Although greater dimensional changes in the upper airway during wake respiration have been noted in patients with apnea compared with control subjects, whether these differences remain in the presence of obesity is unknown. To evaluate upper airway anatomic characteristics and airway compliance (distensibility) in obese subjects with obstructive sleep apnea compared with obese control subjects. Dynamic magnetic resonance imaging was performed in 157 obese subjects with apnea and 46 obese control subjects during wakefulness in the midsagittal and three axial upper airway regions (retropalatal, retroglossal, epiglottal). Differences in measurements between subjects with apnea and control subjects, and correlations with apnea-hypopnea index among subjects with apnea, were examined. Measurements included airway areas and linear dimensions. Subject-specific coefficients of variation were calculated to examine variability in airway size. Controlling for covariates, the retropalatal area during respiration was significantly smaller in subjects with apnea than control subjects, based on the average (P = 0.003), maximum (P = 0.004), and minimum (P = 0.001) airway area. Airway narrowing was observed in anteroposterior and lateral dimensions (adjusted P < 0.05). Results were similar in an age, sex, and body mass index-matched subsample. There were significant correlations between apnea-hypopnea index and dynamic measures of airway caliber in the retropalatal and retroglossal regions among subjects with apnea. Upper airway caliber during respiration was significantly narrower in obese subjects with apnea than obese control subjects in the retropalatal region. These findings provide further evidence that retropalatal airway narrowing plays an important role in the pathogenesis of obstructive sleep apnea in obese subjects.

Retropalatal and retroglossal airway compliance in patients with obstructive sleep apnea

ObjectivesWe hypothesized that preferential retropalatal as compared to retroglossal collapse in patients with obstructive sleep apnea was due to a narrower retropalatal area and a higher retropalatal compliance. Patients with a greater retropalatal compliance would exhibit a recognizable increase in negative effort dependence (NED). MethodsFourteen patients underwent upper airway endoscopy with simultaneous recordings of airflow and pharyngeal pressure during natural sleep. Airway areas were obtained by manually outlining the lumen. Compliance was calculated by the change of airway area from end-expiration to a pressure swing of −5 cm H2O. NED was quantified for each breath as [peak inspiratory flow minus flow at −5 cm H2O]/[peak flow] × 100. ResultsCompared to the retroglossal airway, the retropalatal airway was smaller at end-expiration (p < 0.001), and had greater absolute and relative compliances (p < 0.001). NED was positively associated with retropalatal relative area change (r = 0.47; p < 0.001). ConclusionsRetropalatal airway is narrower and more collapsible than retroglossal airway. Retropalatal compliance is reflected in the clinically-available NED value.

Pharyngeal airspace of asthmatic individuals and those suffering from obstructive sleep apnea syndrome: Study by CBCT

PurposeThe objective of the present study was to comparatively evaluate the oropharyngeal space of patients with obstructive sleep apnea syndrome (OSA) and asthma by means of Cone Beam Computed Tomography (CBCT) images. Material and methodsThe study included individuals with OSA and asthma (n=10), with OSA and without asthma (n=6), asthmatics without OSA (n=6) and healthy individuals (n=25). All patients were evaluated by a pneumologist and submitted to a nocturnal polysomnogram. Participants underwent CBCT examinations using an I-CAT® device (Imaging Sciences International, Hatfield, PA, U.S.A.) and all images were exported to Dolphin Image 3D® software. Cephalometric measurements were taken, as well as measurements of length (C), volume (VOL), sagittal area (SA) and minimum cross-sectional area (MCA); an evaluation was made of the format and contour of the upper airway in three dimensions, with p<0.05 considered significant. ResultsIn the results of the present study, a statistically significant difference was found between VOL, SA and MCA (p=0.011; p=0.009; p=0.010) with reduced elevated values among the OSA+Asthma, OSA, Asthma and Control groups. Significant differences were seen between the linear (AP), cross-sectional (TR) and mean transverse area (TA) measurements in the group of patients with OSA and asthma as compared to the control group. In the control group, the greatest narrowing of the airway was observed either in the retroglossal or retropalatal area, while more patients in the experimental groups showed narrowing in the retropalatal area. ConclusionThe condition of OSA+asthma was associated with a substantial reduction in upper airway measurements in comparison to controls.

Change in the Upper Airway of Patients With Obstructive Sleep Apnea Syndrome Using Computational Fluid Dynamics Analysis

The aim of the study was to compare the effect of conventional maxillomandibular advancement (MMA) and modified MMA with anterior segmental setback osteotomy (MMA-ASSO) on the airway changes in patients with obstructive sleep apnea syndrome (OSAS) using three-dimensional computational fluid dynamics (3D-CFD) analysis. Two adult male patients with Class I malocclusion, lip protrusion, acute nasolabial angle, and OSAS were treated with conventional MMA (Case 1) and modified MMA-ASSO (Case 2). Individualized 3D airway models were fabricated using computed tomography data obtained 1 month before (T0) and at least 6 months after surgery (T1). A total of 7 cross-sectional areas of the airway were established, starting just above the hard palate (plane 1) with interval of 1 mm caudally. Airflow velocity and negative pressure were investigated using CFD analysis, and polysomnography studies were performed at T0 and T1. There were improvement of apnea-hypoapnea index and the lowest O2 level (T0 versus T1; 43.2 versus 15.2, 79% versus 90% in Case 1; 61.0 versus 6, 89% versus 92% in Case 2). At plane 2 (retropalatal area) in Cases 1 and 2, there were increase in the smallest cross-sectional areas (57.9% versus 28.4%), decrease in the airflow velocity and increase in the negative pressure at the peak of expiration (49.5% versus 31.7%; 88.4% versus 54.3%), end after expiration (53.2% versus 32.2%; 83.2% versus 47.9%), and peak of inspiration (53.1% versus 29.2%; 75.3% versus 48.2%). Modified MMA-ASSO method might be an effective treatment option for OSAS patients with improvement of airway problems and esthetic facial profile.

Upper airway changes in obstructive sleep apnea suffers after H-uvulopalatopharyngoplasty and H-uvulopalatopharyngoplasty combined with transpalatal advancement pharyngoplasty

To compare the different postoperative changes of the pharynx in obstructive sleep apnea hypopnea syndrome (OSAHS) patients treated with H-uvulopalatopharyngoplasty (H-UPPP) combined with transpalatal advancement pharyngoplasty (PA) surgery or H-UPPP alone. The upper airway in 43 patients with OSAHS were scanned during the end of normal respiration before and after treatment. There were 17 patients undergoing H-UPPP alone, 26 patients undergoing H-UPPP combined with PA, with PSG before and after treatment. To compare the efficacy of H-UPPP with PA surgery or H-UPPP alone, upper airway characteristics were measured following each procedure in 43 patients using a quantitative 3-D CT. The 3-D CT measurement were made in lateral and anterior-posterior diameters, cross-section areas and volumes of retropalatal and retroglossal region. The changes in the structure of OSAHS patients treated with H-UPPP combined with PA surgery and H-UPPP alone were compared preoperatively and postoperatively, and the correction features that were presented in AHI and structural changes were analysed. The difference between H-UPPP combined with PA (n = 26) and H-UPPP (n = 17) in the changes in apnea hypopnea index (AHI) were (67.5 ± 18.9, 38.7 ± 42.0, t = 2.84, P < 0.05), hard palate lengths were (4.50 ± 3.72) mm and (0.06 ± 0.22) mm (t = 5.55, P < 0.01); anteroposterior diameters of the hard palate level were (3.5 ± 4.3) mm and (-1.7 ± 4.4) mm (t = 3.90, P < 0.01); the minimum anteroposterior diameters of retropalatal were (1.2 ± 2.2) mm and (-1.2 ± 2.3) mm (t = -3.49, P < 0.01); the minimum lateral diameters of retroglossal area were (4.9 ± 9.6) mm and (13.1 ± 9.1) mm (t = 2.80, P < 0.01) preoperatively and postoperatively. The changes in the hard palate lengths were positively correlated to the change in AHI (r = 0.407, P < 0.01), also the change in anteroposterior diameter of the hard palate level (r = 0.351, P < 0.05), the minimum anteroposterior diameter of retropalatal area (r = 0.381, P < 0.01), and the minimum cross-section area of retropalatal (r = 0.312, P < 0.05). H-UPPP combined with PA offers benefit over H-UPPP alone in OSAHS patients, which may be achieved by increased retropalatal airway size. Both the anteroposterior dimensions and the cross-area size are related with the efficacy of surgery.

Effect of uvulopalatopharyngoplasty on retropalatal region

Flexible optic laryngoscopy (FOL) allows us to visualize the obstructive sleep apnea (OSA)-related airway passages. Retropalatal region is a part of upper airway contributing to the OSA. We aimed to demonstrate the changes in the retropalatal surface area (RPSA) after submucosal uvulopalatopharyngoplasty (smUPPP) in an attempt to exhibit enlargement as a predictor of surgical treatment. It is a prospective, case-control study and conducted at the Otolaryngology department in a university hospital. Twenty patients with OSA who underwent smUPPP were prospectively evaluated. Pre and postoperative respiratory disturbance index (RDI) and RPSA measurements were studied. Retropalatal region videos were obtained at the base of uvula during FOL. Photographic images were captured at the same level of a virtual horizontal line passing through the base of uvula posteriorly to measure RPSAs using AutoCad2004. RDI levels, RPSA measurements were compared using paired t test. Twenty patients underwent smUPPP. There were 17 (85 %) male and 3 (15 %) female. The mean age was 37 years. The RPSA measurements were between 18.41 and 144.102 (mean 63.39) preoperatively. The RPSA measurements were between 83.784 and 255.463 (mean 143.87) postoperatively. The RPSA measurements were significantly enlarged postoperatively (p < 0.0005). The mean RPSA increased from 63.39 ± 29.3 to 143.82 ± 57.8. The mean RDI decreased from 22.95 ± 19.2 to 9.0 ± 8.2 (p = 0.011). RPSA increases in smUPPP patients postoperatively, evidencing enlarged retropalatal region. Decreased RDI levels indicate amelioration in OSA. RPSA measurements can be used to predict UPPP surgical treatment success.

Relocation pharyngoplasty

Relocation pharyngoplasty

Sleep magnetic resonance imaging as a new diagnostic method in obstructive sleep apnea syndrome

Although precise localization of obstruction sites in the upper airway during sleep is essential in subjects with obstructive sleep apnea syndrome (OSAS), no gold standard diagnostic method has been established. This study aimed to evaluate the dynamic collapse inside the upper airway by using cine magnetic resonance imaging (MRI), also called sleep MRI. Cross-sectional study with retrospective data. The changes in the transverse and anteroposterior diameters of the retrolingual airway were studied during a respiratory cycle in 35 snoring subjects. The collapsibility of the airway was calculated by using axial images, and the actual obstruction sites were also identified by using sagittal images. Airway collapse occurred in the retropalatal area in 13 (37.1%) of 35 subjects and in both the retropalatal and retrolingual regions in 20 subjects (57.1%). The respiratory disturbance index (RDI) and supine RDI were higher and the minimal oxygen saturation during sleep (MinSaO₂) value was lower in subjects with both retropalatal and retrolingual obstruction than in those with only retropalatal obstruction. Airway collapse analyzed by using axial images was classified into four subgroups: patent group (five of 35, 14.2%), anteroposterior collapse group (one of 35, 2.9%), transverse collapse group (14 of 35, 40%) and circumferential collapse group (15 of 35, 42.9%). Supine RDI, MinSaO₂, and age were significantly different between these four groups. In addition, anteroposterior, transverse, and circumferential collapses correlated well with MinSaO₂. Significant correlation was also found between RDI/supine RDI and transverse collapse. Sleep MRI is a valuable method for evaluating dynamic obstruction during sleep and may be helpful in selecting the appropriate treatment approaches.

Soft palate length and upper airway relationship in OSA and non-OSA subjects

The narrowest area of the airway between the posterior nasal opening and the epiglottis is usually located in the retro palatal area. Many consider this the most likely site of airway obstruction during an obstructive sleep apnea (OSA) event. The aim of this study was to investigate the differences in soft palate and airway length between OSA and non-OSA patients. In this study, we analyzed the ratio of the soft palate and the upper airway length in 45 consecutive patients. Twenty-five had an Apnea-Hypoapnea Index of more than five events per hour and were classified in the OSA group (male, 19; female, 6). These patients were compared with 20 normal controls (male, 12; female, 8). Controls who complained of snoring did have sleep studies (n=5). The other fifteen controls were clinically asymptomatic and did not have sleep studies. Medical computed tomography scans were taken to determine the length of the upper airway and the soft palate length measured in the midsagittal image. Soft palate length was significantly larger in OSA patients compared to controls (p=0.009), and in men compared to women (p=0.002). However, there were no differences in airway length. The soft palate length, as a percent of oropharyngeal airway length, was significantly larger in OSA patients compared to controls (p= <0.0001) and in men compared to women (p=0.02). Soft palate length increases significantly with age by 0.3 mm per year in males (after adjustment for body mass index (BMI) and OSA). Soft palate length as a percent of airway length is larger in OSA patients and increases significantly with BMI in males only after adjusting for age. In this study, OSA patients had a longer soft palate in proportion to their oropharyngeal airway compared to controls as well as men compared to women. This proportion could be used for identifying patients at risk for OSA in combination with age.

Upper Airway Dimensions in Class II Malocclusion

To study the effects of cervical headgear treatment of Class II division 1 malocclusion on upper airway structures in children. Forty children aged 9.1 (7.2-11.5) years with Class II division 1 malocclusion were treated using a cervical headgear as the only treatment appliance. The headgear consisted of a long outer bow bent 15 degrees upward and a large inner bow expanded 10 mm larger than the intermolar distance. Lateral cephalograms were taken before and after the treatment. Upper airway structures were estimated from the cephalograms. The results were compared to cross-sectional data of 80 age-matched controls with a Class I molar relationship. A Class I molar relationship was achieved in all treated children. The mean treatment time was 1.6 (0.3-3.1) years. The Class II malocclusion was accompanied by a similar or wider nasopharyngeal space than in the controls but narrower oro- and hypopharyngeal spaces. The retropalatal area was widened by the treatment (P < .05), whereas the rest of the oropharynx and hypopharynx remained narrower than in the controls. Before the treatment, the mandibular plane was in a more horizontal position than in the controls, but during the treatment, it rotated to a position similar to that of the controls. Class II division 1 malocclusion is associated with a narrower upper airway structure even without retrognathia. Headgear treatment is associated with an increase in the retropalatal airway space.