High lung deposition of 99mTc-labeled ciclesonide administered via HFA-MDI to patients with asthma

OBJECTIVE

To examine the deposition and pharmacokinetics of ciclesonide administered via hydrofluoroalkane-metered dose inhaler (HFA-MDI) in patients with asthma.

METHODS

Twelve patients with mild asthma (FEV1, 95% predicted) inhaled a single dose of 99mtechnetium (Tc)-ciclesonide 320 microg ex-actuator (400 microg ex-valve). Deposition of ciclesonide in the lung and oropharynx was quantified using two-dimensional (2D)-gamma scintigraphy. Three-dimensional single photon emission computed tomography (3D SPECT) was used to assess the regional distribution of ciclesonide in the lung. The pharmacokinetics of ciclesonide and its active metabolite, desisobutyryl-ciclesonide (des-CIC), were determined by liquid chromatography-tandem mass spectrometry. Ciclesonide and des-CIC concentrations were determined in mouth-rinsing solutions.

RESULTS

2D-gamma scintigraphy indicated that ciclesonide deposition was higher in the whole lung (52%) than in the oropharynx (32.9%). Furthermore, 3D SPECT revealed that ciclesonide deposition within the lungs was highest in the peripheral regions that contain the small airways and alveoli. The pharmacokinetic profile of Tc-labeled ciclesonide and des-CIC was similar to that obtained after inhalation of non-labeled formulations in previous studies. Des-CIC accounted for 14.9% of the total molar concentration of ciclesonide/des-CIC in mouth-rinsing solutions obtained between 7 and 12min after inhalation.

CONCLUSION

Inhalation of ciclesonide via HFA-MDI results in high pulmonary deposition, especially in the peripheral regions of the lung. High pulmonary deposition contributes to ciclesonide's ability to maintain lung function and control symptoms in patients with asthma. Deposition and activation of ciclesonide in the oropharynx is low, consistent with previous reports of low oropharyngeal deposition and a reduced incidence of local side effects in patients receiving ciclesonide therapy.

Evaluation of the upper airway cross-sectional area changes in different degrees of severity of obstructive sleep apnea syndrome: cephalometric and dynamic CT study

BACKGROUND AND PURPOSE

The upper airway lumen is narrower in patients with obstructive sleep apnea syndrome (OSAS) than normal subjects. In this study, we examined changes of the upper airway cross-sectional area in each phase of respiration in different degrees of severity of OSAS with dynamic CT and investigated whether these changes have any correlation with sleep apnea severity parameters, including polysomnography (PSG) and cephalometry.

MATERIALS AND METHODS

Between May and November 2004, 47 patients who had at least 2 of 3 major symptoms of snoring, daytime somnolence, and apnea with witness were included in this prospective study. As control group, 24 habitual snorers were studied. All patients underwent PSG and upper airway CT. The average number of episodes of apnea and hypopnea per hour of sleep (the apnea-hypopnea index, AHI) was calculated. An AHI of 5 -29 represented mild/moderate OSAS and an AHI > or = 30 represented severe OSAS. Cross-sectional area of the airway at the level of oropharynx and hypopharynx were obtained in each phase of quiet tidal breathing and at the end of both the forced inspiration and expiration. Six standard cephalometric measurements were made on the lateral scout view. All parameters were compared between controls and mild/moderate and severe OSAS groups.

RESULTS

Twenty-seven patients had mild/moderate OSAS, and 20 patients had severe OSAS. Patients with severe OSAS had significantly narrower cross-sectional area at the level of uvula in expiration, more inferiorly positioned hyoid bone, and thicker soft palate compared with patients with mild/moderate OSAS (P < .05) and the control group (P < .05). In addition, severe OSAS patients had bigger neck circumference than those in the control group (P < .05).

CONCLUSION

Patients with severe OSAS had significant differences in the parameters. Measurement of the cross-sectional area of oropharynx in expiration can especially be useful for diagnosis of severe OSAS as a new key point.

Pediatric oropharyngeal trauma: what is the role of CT scan?

OBJECTIVES/HYPOTHESIS

Pediatric oropharyngeal trauma (OPT) is a common injury in children with rare, but at times severe complications including carotid injury and dissection of air/micro-organisms into the deep tissues of the neck or chest. Cervical CT scan with contrast (CT angiography (CTA)) is nearly universally available and may enhance the evaluation of OPT patients by screening for these potentially devastating complications.

STUDY DESIGN

Retrospective record review, systematic review of the literature.

METHODS

Twenty-three patients diagnosed with OPT from 1997 to 2003 at Boston Children's Hospital were identified by database review. Records were reviewed for site and mechanism of injury, use of diagnostic studies, management, and outcomes. Results were compared to previously published reports. The current literature was reviewed to assess the level of evidence pertaining to the evaluation of OPT patients with CT scan. An extrapolation was made to the general trauma literature to further evaluate the ability of CT angiography to detect carotid injury.

RESULTS

Demographics and mechanism of injury in the current series were unchanged from previous reports. CT demonstrated superior detection and localization of free air. Systematic review of OPT literature revealed data on the use of CT scan as evaluation tool were lacking. Extrapolations to the trauma literature strongly indicate helical CTA has high sensitivity and specificity in detecting carotid injury.

CONCLUSIONS

Pediatric oropharyngeal trauma is a common injury with rare, but severe complications. The routine use of CT scan with contrast may assist in the evaluation of these patients to detect injuries that could lead to severe complications. Collection of prospective data on the ability of CT scan to detect carotid injuries is needed but may not be feasible.

Dynamic upper airway soft-tissue and caliber changes in healthy subjects and snoring patients

BACKGROUND AND PURPOSE

The oropharyngeal airways are smaller in those who snore than in those who do not. We sought to determine which soft-tissue component surrounding the airways contributes to upper airway narrowing in those who snore.

METHODS

Ten control subjects and 19 snoring patients underwent CT, with 2-mm-thick axial sections obtained every 0.6 seconds during the respiration cycle at the same oropharyngeal level. We selected two sections with the widest and narrowest parts of the oropharyngeal airway to measure the anteroposterior and lateral dimensions of the airway and the thickness of the bilateral parapharyngeal fat pads, pterygoid muscles, and parapharyngeal walls. Mean values were calculated for each phase. For each subject, differences were calculated by subtracting the values in narrowest phase from those in the widest phase.

RESULTS

Changes in airway dimension (P < .05) and lateral parapharyngeal wall thickness (P < .01) were significantly different between snorers and control subjects. Changes in parapharyngeal wall thickness and transverse oropharyngeal airway diameter changes were significantly related (P < .01) in those who snored but not in control subjects.

CONCLUSION

Airway narrowing predominantly occurs in the lateral dimension in people who snore. Changes in the lateral pharyngeal wall are more important than the parapharyngeal fat pads in airway calibration. Narrowing of the upper airway area at the end of the expirium and the beginning of the inspirium is thought to be the cause of snoring and due to augmented muscle mass and prolonged laxity rather than inadequate activation of the pharyngeal dilating muscles.

Computerized tomographic evaluation of effects of mandibular anterior repositioning on the upper airway: a pilot study

STATEMENT OF PROBLEM

Snoring is related to narrowing of the upper airway. Treatment options for snoring may have potential side effects or discomfort which may not be tolerated by some patients. Mandibular advancement devices may cause fewer negative side effects than other treatment modalities and have been advocated as a treatment for snoring.

PURPOSE

The aim of the pilot study was to evaluate effects of the anterior mandibular positioner (AMP) on upper airway structures in patients with a snoring problem.

MATERIAL AND METHODS

Fifteen subjects with snoring problems as identified by spouses or close relatives were selected to complete a questionnaire related to snoring, respiratory symptoms, body mass index (BMI), and smoking habits. Computerized tomography (CT) scans were obtained with and without AMP device fabricated as a monoblock of acrylic resin. Measurements of the oropharynx including length (mm), cross-sectional area (mm2), and plane angle (degrees) were made using anatomic landmarks on standardized CT images and lateral scanograms. The data were statistically evaluated using Wilcoxon signed rank test (alpha=.05).

RESULTS

When the AMP was inserted, the cross-sectional area of the oropharynx increased by 60 mm2 on average (P<.05). A mean increase of 2.4 mm (range 1-7 mm) was observed in the posterior airway space on lateral scanograms (P<.005). The range for mandibular advancement was between 4 and 8 mm (mean 5.73 mm).

CONCLUSION

The primary effect of the AMP was enlargement of the oropharyngeal airway. Within the limitations of this pilot study, the results suggest that CT evaluation of the upper airway structures may be helpful in determining treatment modality and monitoring the effectiveness of the positioner.

Does the oropharyngeal fat tissue influence the oropharyngeal airway in snorers? Dynamic CT study

Objective

The aim of this study was to determine if snorers have a narrower oropharyngeal airway area because of fat infiltration, and an elevated body mass index.

Materials and Methods

Ten control subjects and 19 patients that snored were evaluated. We obtained 2-mm-thick axial CT scan images every 0.6 seconds during expiration and inspiration at the same level of the oropharynx. We selected the largest and the smallest oropharyngeal airway areas and found the differences. From the slice that had the smallest oropharyngeal airway area, the thickness of the parapharyngeal and subcutaneous fat was measured. The measurements from the left and right side were added together and single values for parapharyngeal and subcutaneous fat tissue thickness were then found.

Results

The conventional measure of body mass index was significantly higher in the snorers (p < 0.05). The difference in the smallest oropharyngeal airway area between snorers and the controls was statistically significant (p < 0.01). The average difference between the largest and the smallest oropharyngeal area in the control group and the snorer group was statistically significant (p < 0.05). There was no significant difference in the largest oropharyngeal airway area, the total subcutaneous fat width and the total parapharyngeal fat width between snorers and control subjects (p > 0.05).

Conclusion

We concluded that the oropharyngeal fat deposition in snorers is not an important factor, and it does not predispose a person to the upper airway narrowing.

Congenital cervical teratomas

Congenital cervical teratomas are rare, representing 3% of teratomas in childhood. Although mostly benign, they are associated with a high mortality rate due to respiratory distress and require immediate surgical excision. The diagnosis is usually suggested on the physical examination. The imaging investigation is essential for the proper diagnosis and preoperative planning. We present the imaging characteristics of cervical teratomas identified in five neonates over a 10-year-period. The masses were surgically resected. Histopathology revealed the presence of congenital teratomas (three immature, two mature). Two neonates died soon after surgery, while the remaining were discharged from the hospital without symptoms.

Oropharyngeal Dysphagia: Surveying Practice Patterns of the Speech?Language Pathologist

The present study was designed to obtain a comprehensive view of the dysphagia assessment practice patterns of speech-language pathologists and their opinion on the importance of these practices using survey methods and taking into consideration clinician, patient, and practice-setting variables. A self-administered mail questionnaire was developed following established methodology to maximize response rates. Eight dysphagia experts independently rated the new survey for content validity. Test-retest reliability was assessed with a random sample of 23 participants. The survey was sent to 50 speech-language pathologists randomly selected from the Canadian professional association database of members who practice in dysphagia. Surveys were mailed according to the Dillman Total Design Method and included an incentive offer. High survey (64%) and item response (95%) rates were achieved and clinicians were reliable reporters of their practice behaviors (ICC>0.60). Of all the clinical assessment items, 36% were reported with high (>80%) utilization and 24% with low (<20%) utilization, the former pertaining to tongue motion and vocal quality after food/fluid intake and the latter to testing of oral sensation without food. One-third (33%) of instrumental assessment items were highly utilized and included assessment of bolus movement and laryngeal response to bolus misdirection. Overall, clinician experience and teaching institutions influenced greater utilization. Opinions of importance were similar to utilization behaviors (r = 0.947, p = 0.01). Of all patients referred for dysphagia assessment, full clinical assessments were administered to 71% of patients but instrumental assessments to only 36%. A hierarchical model of practice behavior is proposed to explain this pattern of progressively decreasing item utilization.

Infection of the facial area, oral cavity, oropharynx, and retropharynx

Radiologists play an important role in the evaluation of upper neck infections. Although most oral cavity infections arise from diseased teeth, several other sources of infection need to be considered. The distinction between abscess and phlegmon is of particular importance. Cross-sectional imaging is frequently used to identify complications of the initial infection.

[A case branchogenic cyst of oro- and hypoharynx]

In this work was described one case branchiogenic cyst of the oro- et hypopharynx. Provisional diagnosis was tumor of the neck, because of similar symptoms. In the case of brianchiogenic cysts a full diagnostics should be formed. The procedures, which enable us to estimate character and extent of a lesion and determine the proper surgical treatment, should include ultrasonography or CT.

Oropharyngeal Scintigraphy: A Reliable Technique for the Quantitative Evaluation of Oral–Pharyngeal Swallowing

A valid and reliable technique to quantify the efficiency of the oral-pharyngeal phase of swallowing is needed to measure objectively the severity of dysphagia and longitudinal changes in swallowing in response to intervention. The objective of this study was to develop and validate a scintigraphic technique to quantify the efficiency of bolus clearance during the oral-pharyngeal swallow and assess its diagnostic accuracy. To accomplish this, postswallow oral and pharyngeal counts of residual for technetium-labeled 5- and 10-ml water boluses and regional transit times were measured in 3 separate healthy control groups and in a group of patients with proven oral-pharyngeal dysphagia. Repeat measures were obtained in one group of aged (> 55yr) controls to establish test-retest reliability. Scintigraphic transit measures were validated by comparison with radiographic temporal measures. Scintigraphic measures in those with proven dysphagia were compared with radiographic classification of oral vs. pharyngeal dysfunction to establish their diagnostic accuracy. We found that oral ( p = 0.04), but not pharyngeal, isotope clearance is swallowed bolus-dependently. Scintigraphic transit times do not differ from times derived radiographically. All scintigraphic measures have extremely good test-retest reliability. The mean difference between test and retest for oral residual was -1% (95% CI -3%-1%) and for pharyngeal residual it was -2% (95% CI -5%-1%). Scintigraphic transit times have very poor diagnostic accuracy for regional dysfunction. Abnormal oral and pharyngeal residuals have positive predictive values of 100% and 92%, respectively, for regional dysfunction. We conclude that oral-pharyngeal scintigraphic clearance is highly reliable, bolus volume-dependent, and has a high predictive value for regional dysfunction. It may prove useful in assessment of dysphagia severity and longitudinal change.

The Relationship between Wearing Complete Dentures and Swallowing Function in Elderly Individuals: a Videofluorographic Study

The role of complete dentures in masticatory function is well established, but their effect on swallowing has been little examined. This study investigated the effect of complete dentures on swallowing in the elderly. Lateral projection videofluorography (VF) was performed for nine healthy edentulous elderly volunteers (mean age 73.9 +/- 2.9 years) while they swallowed 8 ml of liquid and paste barium with and without complete dentures. A total of 35 VF records were analyzed for temporal and spatial measurements of oropharyngeal motion during swallowing. The tongue tip contacted the inside of the lip between the upper and lower alveolar ridges during swallowing without but not with complete dentures. The hyoid moved further upward (P = 0.002) during swallowing without dentures (liquid: 5.85 +/- 3.99 mm, paste: 6.41 +/- 5.25 mm) than with dentures (liquid: 3.70 +/- 4.57 mm, paste: 3.69 +/- 4.07 mm). The larynx moved further forward (P = 0.044) during swallowing without dentures (liquid: 6.39 +/- 2.58 mm, paste: 6.46 +/- 2.87 mm) than with dentures (liquid: 5.34 +/- 2.04 mm, paste: 5.93 +/- 1.50 mm). The timing of the movements of these structures was not affected by the presence of the dentures or bolus consistency. These results showed that the hyoid and larynx moved more in swallowing without than with complete dentures, perhaps because of tongue tip protrusion when not wearing dentures. These findings suggest that complete dentures have a significant effect on swallowing function as well as masticatory function in elderly individuals.

Surgical management of obstructive sleep apnea

Nasal CPAP is and should be the first-line treatment for OSA. Any physician who uses nasal CPAP undoubtedly recognizes that this treatment modality has limitations, however. The authors believe that surgery offers a viable alternative to nasal CPAP in patients who are intolerant of nasal CPAP. Potential risks and complications must be explained fully to any potential surgical candidate. The selection of surgical procedure(s) should be determined based on a patient's airway anatomy, medical status, severity of sleep apnea, and his or her desire and preference.

Evaluation of Pediatric Lateral Oropharyngeal Trauma

OBJECTIVE: We reviewed the mechanism of injury, presentation, and evaluation of children with trauma to the lateral oropharynx.

STUDY DESIGN AND SETTING: We conducted a retrospective review of patients in an urban pediatric emergency department with trauma to the lateral oropharynx over a 5-year period.

RESULTS: Forty-eight patients were identified with documented injuries of the lateral oropharynx placing the internal carotid artery at risk of injury. The average age was 42 months, with a male-to-female ratio of 1.5:1. Seventy-seven percent of patients had a documented neurologic examination. Examinations were normal in all cases. Computed tomography scans were obtained in 14 patients, identifying 3 patients with carotid abnormalities. Angiography subsequently diagnosed intimal injuries in 2 of the 3 patients. There were no known cases of neurovascular compromise.

CONCLUSION: Contrast-enhanced computed tomography may be an effective screening examination in this patient population, helping to determine which children should be admitted for angiography and observation.

Esophageal contractions and oropharyngeal and esophageal transits in patients with iron deficiency anemia

OBJECTIVE

Patients with iron deficiency may have reduced power of the pharyngeal muscle for bolus propulsion into the esophagus. We hypothesized that esophageal muscle is similarly impaired.

METHODS

We studied the oropharyngeal and esophageal transits and esophageal motility of 12 patients (11 women) aged 31-50 yr (median 36 yr) with iron deficiency anemia (serum iron less than 40 microg/dl) and 17 normal volunteers (16 women) aged 26-52 yr (median 37 yr) with serum iron greater than 60 microg/dl. The esophageal motility was studied by the manometric method, with continuous perfusion and 10 swallows of a 2-ml bolus of water alternated with 10 swallows of a 7-ml bolus; and the oropharyngeal and esophageal transits were studied by scintigraphy, with swallows of a 10-ml bolus for the study of oropharyngeal transit and of a 10-ml bolus for the study of esophageal transit. Motility and transit were studied in the supine position.

RESULTS

The amplitude, duration and area under the curve of contractions were lower in patients than in volunteers. There were no differences in peristaltic contraction velocity, lower esophageal sphincter pressure, and lower esophageal sphincter relaxation duration. There was no difference in oropharyngeal transit. In the esophagus the transit was slower in patients than in volunteers. The time needed by the scintigraphic activity to reach a peak in the proximal esophagus was longer in patients than in volunteers.

CONCLUSIONS

Iron deficiency may decrease esophageal contractions and impair esophageal transit.

Emergence of oropharyngeal, laryngeal and swallowing activity in the developing fetal upper aerodigestive tract: an ultrasound evaluation

The developing fetal upper aerodigestive system provides the structural support for respiratory and ingestive functions necessary to sustain life at birth. This study investigated prenatal development of upper aerodigestive anatomy and the association of emerging functions as predictors of postnatal feeding skills. Biometric measures of oral, lingual, pharyngeal and laryngeal structures were obtained in fetuses 15-38 weeks gestational age using a four-plane sonographic technique. Accompanying ingestive behaviors were tallied across development. The data from 62 healthy controls were compared to seven cases at risk for postnatal feeding and swallowing dysfunction (Type II Arnold Chiari Malformation, trisomy 18, polyhydramnios, intrauterine growth restriction, Brachmann-de Lange Syndrome). Significant (p<0.001) linear regressions occurred in pharyngeal and lingual growth across gestation while ingestive behavior such as suckling emerged in a sequence of basic to complex movement patterns. Jaw and lip movements progressed from simple mouth opening to repetitive open-close movements important for postnatal suckling. Lingual movements increased in complexity from simple forward thrusting and cupping to anterior-posterior motions necessary for successful suckling at term. Laryngeal movements varied from shallow flutter-like movements along the lumen to more complex and complete adduction-abduction patterns. Fetal swallowing primarily occurred in the presence of concomitant oral-facial stimulatory activity. Significant variations (p<0.01) in the form and function of the ingestive system occurred in comparisons of gestational age-matched controls to at-risk cases. We postulate that prenatal developmental indices of emerging aerodigestive skills may guide postnatal decisions for feeding readiness and, ultimately, advance the care of the premature, medically fragile neonate.

[The significance of CT measurement of craniopharyngeal cavity in healthy person]

OBJECTIVE

In order to investigate where is the most part in upper airway of patients with obstructive sleep apnea syndrome (OSAS). The craniopharyngeal cavity in 50 healthy persons was measured by CT.

METHOD

The 50 volunteers were instructed on supine position. The Scanning was made taken with SCT-7000 spiral computer (Philips company Holland). Scanning was from cupular part of nasopharyngeal cavity to an apex of epiglottis cartilage on the datum line of lower eye socket, every stratum was 5 mm, every lamella distance was 8 mm. Scanned and took photographs up and down using RIO-MAN key (Region of interesting Management). Some irregular area were selected to measure such as 1. the lamella of nasopharyngeal cavity(the pharynges and opening of auditory tube were showed clearly); 2. the lamella of oropharyngeal cavity(the narrowest place of oropharyngeal cavity); 3. the lamella of laryngolpharyngeal cavity(epiglottis cartilage was just appeared). T test was used to analyze.

RESULT

The areas of oropharyngeal, nasopharyngeal and pharyngolaryngeal cavity were (2.28 +/- 1.17) cm2. (4.39 +/- 1.52) cm2 and (3.83 +/- 1.57) cm2 respectively (P < 0.05).

CONCLUSION

The oropharyngeal cavity is the physiologic narrow place of pharyngeal cavity in normal adults and it is easily obstructed and lead to a chain of pathologic and physiologic manifestations.

Imaging the treated oral cavity and oropharynx

Cross-sectional imaging has become essential in the evaluation of the treated oral cavity and oropharynx. The purpose of this paper is to review the imaging guidelines for the evaluation of this region and to detail the typical changes encountered on imaging following surgical and radiation treatment for cancer.

Postural variation in oropharyngeal dimensions in subjects with sleep disordered breathing: a cephalometric study

This radiographic study analysed the changes that occurred in the airway and surrounding structures when subjects with sleep disordered breathing moved from the upright to the supine position. Radiographs of 100 dentate, Caucasian males were examined. Fifty individuals were non-apnoeic snorers and in 50 a diagnosis of obstructive sleep apnoea (OSA) had been confirmed by polysomnography. Radiographs were traced and digitized and comparisons were made of the behaviour of the oropharynx, soft palate, tongue, and hyoid between the two groups. When moving from the upright to the supine position, both OSA and snoring subjects showed a similar pattern of change. The antero-posterior dimensions of the oropharyngeal airway decreased highly significantly (P < 0.001) at all levels, with a concomitant reduction in cross-sectional area (P < 0.001). The narrowing was most severe behind the soft palate, where the minimum airway reduced by approximately 40 per cent. Behind the tongue, a 20 per cent decrease was seen. The soft palate showed small but significant increases in area, whilst the tongue altered in shape but not in its overall cross-sectional area. In non-apnoeic snorers only, tongue proportion increased (P < 0.05). At the same time, the hyoid dropped and moved anteriorly, maintaining a constant relationship with the lower border of the mandible. There were no differences between the non-apnoeic snorers and the OSA subjects in any of the postural changes recorded.

Airway assessment by volumetric computed tomography in snorers and subjects with obstructive sleep apnea in a Far-East Asian population (Chinese)

OBJECTIVES

To evaluate the airway dimension of simple snorers and subjects with obstructive sleep apnea (OSA) in a Far-East Asian population (Chinese).

STUDY DESIGN

Prospective study of 117 near-consecutive patients evaluated for snoring and possible OSA from January 1998 to December 1998 in a sleep laboratory. Overnight polysomnography (PSG) was performed on all patients and the sleep parameters, including respiratory disturbance index (RDI), snoring index, minimal oxygen saturation (min O2), percentage of slow wave sleep (SWS), and rapid eye movement (REM) were recorded. Three-dimensional computerized tomography (CT) during awake periods was performed. The anteroposterior (AP) and the lateral distance of the retropalatal (RP) region in the oropharynx, the smallest area of RP, and retroglossal (RG) regions, and the total volume of the oropharynx were measured.

RESULT

Ninety-eight patients were diagnosed with OSA (mean RDI, 41.48 +/- 26.45 events per hour; min O2, 72.82 +/- 12.86%), whereas 19 were simple snorers. The AP and the lateral distance of the RP region, as well as the smallest area of the RP region, are significantly smaller in subjects with OSA. However, no differences in the RG region and the total volume of the oropharynx were found between the two groups. Linear regression analysis demonstrated that the lateral dimension and the smallest RP area in overweight subjects inversely correlated with the RDI, but only the AP dimension of the RP area was found to have an inverse correlation with the RDI in the underweight subjects.

CONCLUSION

In Far-East Asians (Chinese), the RP airway was found to be the primary site of narrowing in subjects with OSA, and the narrowest RP area was inversely correlated with RDI. Furthermore, weight may influence the pattern of RP narrowing by contributing to lateral collapse.