Effectiveness of Titratable Oral Appliance in Management of Moderate to Severe Obstructive Sleep Apnea-A Prospective Clinical Study with Acoustic Pharyngometry.

To assess effectiveness of titratable Oral Appliance (OA) in management of moderate to severe cases of Obstructive Sleep Apnea (OSA). Thirty Polysomnography (PSG) diagnosed cases of moderate to severe OSA were subjected to a thorough cranio-facial-dental evaluation, a detailed sleep history and three dimensional assessment of upper airway geometry utilising Acoustic Pharyngometry (AP) (Eccovision, sleep group solutions). A titratable OA was delivered to all patients for mandibular advancement. Apnea Hypopnea Index (AHI), Oxygen Saturation (SPO2), Epworth's Sleepiness Scale (ESS), Mean area and volume of upper airway were recorded at Baseline (T0) and after 08 weeks of appliance delivery (T1). The mean AHI & ESS scores were significantly lower and SPO2 was significantly higher at T1 compared to T0 (P-value < 0.05 for all). The mean area and volume of upper airway at T1 were significantly higher compared to values at T0 (P-value < 0.05 for both). The mean area showed 19.51% increase at T1 whereas mean volume increased by 18.55%. OA therapy is highly efficacious in cases with moderate to severe OSA, especially, in those with retrognathic mandible. This modality should be considered as an effective alternate to Continuous Positive Airway Pressure (CPAP) therapy in non-compliant patients rather than no treatment. AP is an effective modality to predict airway changes after advancement with OA, to ascertain follow up changes and is highly recommended in routine clinical practice. Large scale, multicenter studies are recommended to elaborate the findings of the present study and to add better quality evidence in this regard.

Combined application of pharyngeal volume and minimal cross-sectional area may be helpful in screening persons suspected of obstructive sleep apnea (OSA).

BACKGROUND: Obstructive sleep apnea (OSA) is a common disease that seriously affects human health and daily life. However, the gold standard for its diagnosis, polysomnography (PSG), is expensive resulting in inadequate diagnosis of this disease in primary clinics. Therefore, a simple and rapid method for initial screening for OSA is needed. Acoustic pharyngometry (APh) is an FDA-approved noninvasive method that is gradually being applied to screening for OSA. MATERIALS AND METHODS: In this study, we applied analysis with receiver operating characteristic (ROC) curves to explore how APh may play a greater role in the screening of subjects with suspected OSA. Patients admitted into the departments of otolaryngology at our hospital from March 2017 to May 2019 were recruited into the study. All subjects underwent PSG monitor and were separated into two groups according to the apnea-hypopnea index (AHI) from the PSG results: OSA group (AHI ≥ 5) and control group (AHI < 5). APh measurements and other indicators of the subjects, including age, height, and weight; Epworth Sleepiness Scale (ESS) score; and the pharynx examination, including the degree of tonsil enlargement and tongue hypertrophy, were also be recorded. RESULTS: The t-test results showed that almost all indicators except age and height have significant differences between the OSA group and control group. Subjects with OSA had greater weight, BMI, ESS, higher degree of tonsil enlargement, and tongue hypertrophy, while they had smaller minimal cross-sectional area (mCSA) and pharyngeal volume than the subjects in control group. The correlation analysis revealed that pharyngeal volume and mCSA were two helpful indicators to screen for OSA. Furthermore, we established the ROC curve and calculated the combining predictors (combining predictors = pharyngeal volume + mCSA * (- 2.347)/(- 0.225)). The area under the ROC curve (AUC) of combining predictors was 0.917 (95% CI 0.842-0.991, P < 0.001), which was higher than combinations of other two independent indicators. The cutoff point of combining predictors was found to be 59.84 (AUC = 0.917, sensitivity = 0.80, 1-specificity = 0.06, P < 0.001). CONCLUSIONS: These findings suggest that APh is a simple, rapid, and economical detection method which may be useful in screening for OSA, especially in communities and primary clinics where PSG cannot be performed.

[Study on the structural changes of pharyngeal cavity after bariatric surgery in obese patients with obstructive sleep apnea].

Objective:To study whether and how bariatric surgery changes the structure of the pharyngeal cavity in obese patients with obstructive sleep apnea（OSA）. Methods:Forty-two patients who underwent laparoscopic sleeve gastrectomy were recruited. Morphological indicators（BMI, neck and waist circumference）, PSG and acoustic pharyngometry indicators were evaluated pre-operatively and 3, 6, and 12 months post-operatively. Results:All indicators including morphology, pharyngeal cavity structure and OSA severity changed significantly after surgery. Among them, BMI, neck circumference, waist circumference and AHI value were significantly reduced（P<0.001）, while pharyngeal cavity volume, pharynx volume, oropharyngeal junction area, glottis area and LSaO2 increased significantly（P<0.001）. The results of multiple comparisons showed that BMI, neck and waist circumference decreased significantly in the first 6 months, and no further decline occurred during 6 to 12 months postoperatively. The decrease in AHI and LSaO2 mainly occurred within the first 3 months postoperatively, while there was no statistically significant difference in these two indicatiors between 3 months vs. 6 months, 6 months vs. 12 months postoperatively. The area of the oropharyngeal junction increased significantly within 0 to 3 months after surgery, while the volume of the pharyngeal cavity and the area of the glottis increased at 6 months and 12 months after surgery. Conclusion:Bariatric surgery can significantly reduce body weight and reduce fat accumulation in the neck. It can also enlarge the volume and cross-sectional area of the pharyngeal cavity, and improve upper airway obstruction, therefore reduce the symptoms of sleep apnea in obese patients with OSA to a certain extent.

Evaluation and quantification of airway changes in Class II division 1 patients undergoing myofunctional therapy using twin block appliance.

BACKGROUND: The purpose of the present study was to determine the airway changes in skeletal class II division 1 malocclusion patients with mandibular retrognathism, treated with Twin-Block (TB) appliance. METHODS: Airway assessment was carried for twelve patients (mean age 11.7 ± 1.1 years) who underwent myofunctional therapy using TB appliance for correction of skeletal class II division 1 malocclusion with mandibular retrognathism. Acoustic pharyngometry (AP) was used to assess and quantify the comparative changes in the upper airway, pretreatment and posttreatment. RESULTS: Data acquired was subjected to appropriate statistical analysis. The paired 't' test was used to compare pre-treatment (T0) and after the positive pterygoid response (T1). TB appliance increased mean minimum airway area by 0.28 ± 0.25 cm2 and mean airway by 0.47 ± 0.44 cm2 with 95% CI. Posttreatment minimum airway and mean area changes were found to be statistically significant (P-value<0.01). CONCLUSION: TB appliance therapy has a positive effect on upper airway and is beneficial for the treatment of sleep-related disorders associated with Class II division 1 malocclusion for achieving positive functional changes, esthetics, and healthier quality of life.

Acoustic pharyngometry - A new method to facilitate oral appliance therapy.

BACKGROUND: There is lack of reliable and accurate methods to predict treatment outcomes of oral appliance (OA) treatment. Acoustic pharyngometry (AP) is a non-invasive technique to evaluate the volume and minimal cross-sectional area of the upper airway, which may prove useful to locate the optimal position of OAs. OBJECTIVE: This retrospective study aimed to evaluate the effect of applying AP to OA treatment of patients with obstructive sleep apnoea (OSA). METHODS: All patients (n = 244) treated with OAs following an AP protocol at two dental clinics between 2013 and 2018 were invited to participate. A total of 129 patients accepted the invitation, and 120 patients (75 men, 45 women) were included in the analyses. Mean baseline age, BMI and apnoea hypopnea index (AHI) were 59.1 ± 0.9 years, 27.8 ± 0.4 and 21.9 ± 1.1, respectively. Mean follow-up time was 318 ± 24 days. RESULTS: AHI at follow-up was 6.4 ± 0.7, resulting in a treatment success rate of 86.7% (≥50% reduction of baseline AHI). The number of failures (<50% reduction of baseline AHI) did not differ significantly among patients with mild, moderate and severe OSA. 87.6% of the patients reported OA usage every night, and 95.5% reported > 5 hours usage per night, when worn. CONCLUSION: The AP protocol applied seems to contribute to the excellent effect of OA treatment in this study. Further research on the application of AP in OA treatment is necessary in order to clarify its possible beneficial contribution to improving OA therapy.

Does Presurgical Nasoalveolar Molding Have a Long-Term Effect on Nasal and Upper Airway Dimensions?

OBJECTIVES: To compare nasal and upper airway dimensions in patients with cleft lip and palate (CLP) who underwent nasoalveolar molding (NAM) with those without NAM during infancy using acoustic pharyngometry and rhinometry. MATERIALS AND METHODS: Eccovision acoustic pharyngometry and rhinometry (Sleep Group Solutions) was used for assessment of mean area and volume of nasal and upper airway in patients with complete unilateral CLP (age range 16-21 years) treated with NAM (group 1, n = 19) versus without NAM (group 2, n = 22). RESULTS: The mean nasal cross-sectional areas and volume were higher in group 1 compared to group 2 on both cleft (P value <.001) and noncleft side (P value >.05). The mean area and volume of upper airway were also significantly higher in group 1 compared to group 2 (P value <.05). CONCLUSIONS: Nasoalveolar molding being one of the first interventions in chronology of treatment of patients with CLP, its long-term outcome on nasal and upper airway patency needs to be ascertained. The results of the present study show that the patients with CLP who have undergone NAM during infancy have better improvement in nasal and upper airway patency compared with those who had not undergone NAM procedure. The basic advantages of being noninvasive, nonionizing and providing dynamic assessment of nasal and upper airway patency make acoustic pharyngometry and rhinometry a diagnostic tool of choice to be used in patients with CLP.

Evaluation of Tonsillotomy Effects on Pharyngeal Volume and Compliance in Children.

Our objective was to assess whether adenotonsillotomy improved pharyngeal compliance, which is a risk factor for sleep-disordered breathing. Otherwise healthy children underwent Obstructive Sleep Apnea (OSA)-18 questionnaire and a pre- and postoperative acoustic pharyngometry in both sitting and supine positions, allowing the measurement of the volume of the palatine tonsil region and pharyngeal compliance. Thirty-five children (median age 5.3 years) were enrolled; they were reevaluated at a median of 18 days (25th-75th percentiles, 15-25) after surgery. Participants were compared according to a normal (n = 18) or an increased (n = 17) preoperative pharyngeal compliance. Surgery was associated with a significant decrease in OSA-18 and Brodsky scores, with a median increase in palatine volume of 0.13 cm3 (25th-75th percentiles, 0.00-0.73). A decrease in pharyngeal compliance was observed in children with increased preoperative compliance. The variation of palatine volume after surgery was positively related to the variation of pharyngeal compliance, suggesting that obstruction relief was associated with muscle relaxation in children with normal preoperative compliance.

Utility of acoustic pharyngometry for screening of obstructive sleep apnea.

OBJECTIVE: To determine whether combining acoustic pharyngometric parameters with cephalometric and clinical parameters could improve the predictive power for significant obstructive sleep apnea (OSA) in a Korean population. METHODS: A total of 229 consecutive adult patients with suspected OSA were enrolled. The predictability for significant OSA using acoustic pharyngometric or cephalometric parameters or combining these parameters and clinical factors was calculated and compared using multivariate logistic regression and receiver operating characteristic (ROC) curves. RESULTS: In multivariate logistic regression, age, sex, minimum upper airway cross-sectional area (UA-CSA), and mandibular plane to hyoid distance (MPH) were all significant independent predictors of significant OSA. The minimum UA-CSA of 0.85 cm2 provided fair discrimination for OSA [area under the curve (AUC): 0.60, 95% confidence interval (CI): 0.52-0.67]. The MPH of 18.75 mm provided fair discrimination for OSA (AUC; 0.65, 95% CI: 0.58-0.72). The discriminative ability of the final model of multivariate ROC curve analyses that included the minimum UA-CSA, age, sex, body mass index (BMI), and MPH was better than the minimum UA-CSA alone (AUCs: 0.77 vs. 0.60). Optimal cut-off values of predictors for discriminating significant OSA were as follows: male for sex, 40 years for age, 25.5 kg/m2 for BMI, 1.06 cm2 for minimum UA-CSA, and 18 mm for MPH. CONCLUSION: Minimum UA-CSA measured using acoustic pharyngometry while sitting might be a useful method to predict OSA. Combining minimum UA-CSA with age, sex, BMI and MPH improved the predictive value for significant OSA.

The utility of acoustic pharyngometry and rhinometry in pediatric obstructive sleep apnea syndrome.

OBJECTIVE: Our objective was to evaluate the usefulness of acoustic pharyngometry and rhinometry in assessing obstructive sleep apnea (OSA) syndrome in children. PATIENTS/METHODS: Patients who were hospitalized for polysomnography underwent acoustic pharyngometry and rhinometry in sitting and supine positions to measure anatomical (pharyngeal and nasopharyngeal) volumes and collapsibility characteristics (reduction of pharyngeal volume, estimated pharyngeal compliance, and reduction of nasopharyngeal volume). RESULTS: In this study, we prospectively enrolled 103 children (median age, 10.4 years; 47 girls). Measures obtained from rhinometry correlated with height and were further height-normalized whereas measures obtained from pharyngometry did not correlate with height. Sleep apnea was ruled out in 51 subjects, while 52 children fulfilled OSA criteria (35 with obstructive apnea-hypopnea index ≥ 2 and < 5.h-1 [mild] and 17 with an index ≥ 5). The three groups differed on the z-score of BMI, the reduction of pharyngeal volume when supine, the estimated pharyngeal compliance and the supine normalized nasopharyngeal volume. These four factors linearly correlated with the apnea index even though children without OSA and mild OSA were found to be similar overall. A multivariate analysis with apnea index as the dependent variable and BMI z-score, neck circumference, mean pharyngeal area in supine position, estimated pharyngeal compliance and normalized nasopharyngeal volume as independent variables, showed that only BMI z-score and estimated compliance remained independent predictors of obstructive apnea (r2 value = 0.25, p < 0.0001). CONCLUSION: An increase in pharyngeal compliance is an independent risk factor of OSA syndrome in children; it can be measured using acoustic pharyngometry while awake.

[The evaluation of severity and treatment for OSAHS by acoustic pharyngometry which in different postures].

Objective: To investigate the optimal position in application of acoustic pharyngometry to detect the pharyngeal condition and to assess its therapeutic effect on obstructive sleep apnea hypopnea syndrome(OSAHS). Method: Eight adult males were assigned to the normal group, and 57 male patients with OSAHS diagnosed by polysomnograhy(PSG) were assigned to the snoring group. Of the snoring group, 11 patients who were diagnosed severe OSAHS underwent low-temperature plasma uvulopaltopharyngoplasty(UPPP) and coblationchanneling of the tongue(CCT), were assigned to the operation subgroup; 8 patients underwent continuous positive airway pressure(CPAP), which was assigned to the CPAP subgroup. And remainders underwent conservative treatment, including weight loss and position change. Acoustic pharyngometry (three positions including sitting position, supine position and lateral position) and PSG exam were performed in all participants. Additionally, acoustic pharyngometry under three positions was conducted again in patients in the operation and CPAP subgroups three months after treatment. Result: The minimum cross-sectional area was negatively associated with both AHI and the percentage of time with oxygen saturation below 90%(SIT90)( P<0.01). The correlation coefficient of the minimum crosssectional area insupine position with AHI and SIT90 were r=-0.569,r=-0.478, respectively. Under supine position, the minimum crosssectional area was negatively correlated with body mass index(BMI)(r=-0.265, P=0.033), and the minimum crosssectional area was negatively associated with neck circumference(r=-0.309, P=0.012). The minimum cross-sectional area was significantly increased after treatment of OSAHS(both operation and CPAP), which was statistically different before and after treatment compared to the control group(P<0.01). Conclusion: ①The minimum cross-sectional area is significantly correlated with AHI and SIT90, respectively. The acoustic pharyngometry can be used to screen OSAHS patients. ②In this study, the minimum cross-sectional area under supine position is significantly smaller than that under sitting position. In addition, the minimum cross-sectional area under supine position harbored a better correlation with AHI and SIT90, which could better reflect the narrowness of pharyngeal cavity during sleep. ③Acoustic pharyngometry could be a simple, rapid and non-invasive technique that can objectively evaluate the efficacy of surgical and CPAP methods, and provided a more favorable basis for future clinical work..

Volumetric Changes to the Pharynx in Healthy Aging: Consequence for Pharyngeal Swallow Mechanics and Function.

Pharyngeal lumen volume is prone to increase as a consequence of pharyngeal muscle atrophy in aging. Yet, the impact of this on swallowing mechanics and function is poorly understood. We examined the relationship between pharyngeal volume and pharyngeal swallowing mechanics and function in a sample of healthy community-dwelling seniors. Data were collected from 44 healthy seniors (21 male, mean age = 76.9, SD = 7.1). Each participant swallowed 9 boluses of barium (3 × 5 ml thin, 3 × 20 ml thin, 3 × 5 ml nectar). Pharyngeal shortening, pharyngeal constriction, pyriform sinus and vallecular residue were quantified from lateral view videofluorosopic swallowing studies. Pharyngeal lumen volume was captured during an oral breathing task with acoustic pharyngometry. In addition, within-participant measures of strength and anthropometrics were collected. Four linear mixed effects regression models were run to study the relationship between pharyngeal volume and pharyngeal constriction, pharyngeal shortening, pyriform sinus residue, and vallecular residue while controlling for bolus condition, age, sex, and posterior tongue strength. Increasing pharyngeal lumen volume was significantly related to worse constriction and vallecular residue. In general, larger and thicker boluses resulted in worse pharyngeal constriction and residue. Pharyngeal shortening was only significantly related to posterior tongue strength. Our work establishes the utility of acoustic pharyngometry to monitor pharyngeal lumen volume. Increasing pharyngeal lumen volume appears to impact both pharyngeal swallowing mechanics and function in a sample of healthy, functional seniors.

[The application of acoustic pharyngometry in diagnosis and treatment of OSAHS].

Obstructive sleep apnea-hypopnea syndrome (OSAHS) is a common clinical disease that seriously threatens human health and life. Accurate location of the upper airway obstruction is the key to the diagnosis and treatment of OSAHS. Acoustic pharyngometry uses sound reflection to quickly assess the cross-sectional area and volume of the upper airway. Acoustic pharyngometry represents a simple, quick, non-invasive method for measuring upper airway dimensions which could predict sleep apnea risk. In this article we sought to introduce the application of acoustic pharyngometry in the diagnosis and treatment of OSAHS.

The application of acoustic pharyngometry in diagnosis and treatment of OSAHS / 临床耳鼻咽喉头颈外科杂志

Obstructive sleep apnea-hypopnea syndrome (OSAHS) is a common clinical disease that seriously threatens human health and life. Accurate location of the upper airway obstruction is the key to the diagnosis and treatment of OSAHS. Acoustic pharyngometry uses sound reflection to quickly assess the cross-sectional area and volume of the upper airway. Acoustic pharyngometry represents a simple, quick, non-invasive method for measuring upper airway dimensions which could predict sleep apnea risk. In this article we sought to introduce the application of acoustic pharyngometry in the diagnosis and treatment of OSAHS.

Utility of Acoustic Pharyngometry for the Diagnosis of Obstructive Sleep Apnea.

RATIONALE: Owing to resource limitations, the testing of patients for obstructive sleep apnea (OSA) is often delayed. There is a need to accurately triage and expedite testing in those with a high pretest probability of OSA. Acoustic pharyngometry is a simple, noninvasive technique used to assess the upper airway cross-sectional area (UA-XSA), which is known to be reduced in those with OSA. OBJECTIVES: To determine the discriminative ability and predictive value of UA-XSA measurements by acoustic pharyngometry for OSA. METHODS: We conducted a cross-sectional study with a clinical cohort of consecutive adults with suspected OSA who had undergone both polysomnography and acoustic pharyngometry. OSA was defined as an apnea-hypopnea index greater than or equal to 5. Multivariable logistic regression analyses and receiver operating characteristic curves were used. MEASUREMENTS AND MAIN RESULTS: The cohort included 576 subjects, 87% of whom had OSA and 64% of whom were men. The subjects' median body mass index (BMI) was 30.3 kg/m2, and their median age was 57 years. The median UA-XSA at FRC when sitting was significantly smaller in those with OSA compared with those without OSA (3.3 cm2 [interquartile range, 2.7-3.8] vs. 3.7 cm2 [interquartile range, of 2.9-4.2]). When the analysis was controlled for age, sex, BMI, and comorbidities, the odds of OSA increased for every 1-cm2 decrease in the mean UA-XSA FRC when sitting (odds ratio, 1.62; 95% confidence interval, 1.23-2.13). The mean UA-XSA provided fair discrimination for OSA (area under the curve, 0.60). A cutoff value of 3.75 cm2, the point with the best sum of sensitivity and specificity, had sensitivity of 73% and specificity of 46%. The magnitude of the incremental discriminative value of UA-XSA over clinical variables (age, sex, BMI, and comorbidities) was small and nonsignificant (P = 0.5). CONCLUSIONS: The mean UA-XSA at FRC when sitting or supine provided no further significant advantage over clinical variables for the discernment of OSA.

The Reliability of Oral and Pharyngeal Dimensions Captured with Acoustic Pharyngometry.

Acoustic Pharyngometry (APh) is a method for quantifying oropharyngeal tract configuration using sound wave reflection and is commonly used in diagnostics and research of sleep apnea. The standard preset output of APh (minimal cross-sectional area) has been established as reliable. However, by conducting post-processing measures on specific breathing tasks, APh data can also reveal oral length, oral volume, pharyngeal length, and pharyngeal volume. Given that these measures may have utility in dysphagia research, the reliability of these measures is unknown and is the focus of the current study. Ten young healthy female volunteers completed two sessions of APh data collection to obtain measures of oral length, oral volume, pharyngeal length, and pharyngeal volume 1 week apart. Two-way mixed intraclass correlation coefficients were calculated to establish intra-rater reliability, inter-rater reliability, and test-retest reliability. Results revealed excellent levels of agreement within and across raters for all oropharyngeal tract parameters. Levels of test-retest agreement for oral length and oral volume indicated these parameters are appropriate for monitoring change within an individual. All parameters were deemed to have acceptable test-retest values as outcome measures in group-level analysis.

Acoustic pharyngometry measurement of minimal cross-sectional airway area is a significant independent predictor of moderate-to-severe obstructive sleep apnea.

STUDY OBJECTIVES: The current gold-standard method of diagnosing obstructive sleep apnea (OSA) is polysomnography, which can be inefficient. We therefore sought to determine a method to triage patients at risk of OSA, without using subjective data, which are prone to mis-reporting. We hypothesized that acoustic pharyngometry in combination with age, gender, and neck circumference would predict the presence of moderate-to-severe OSA. METHODS: Untreated subjects with suspected OSA were recruited from a local sleep clinic and underwent polysomnography. We also included a control group to verify differences. While seated in an upright position and breathing through the mouth, an acoustic pharyngometer was used to measure the minimal cross-sectional area (MCA) of the upper airway at end-exhalation. RESULTS: Sixty subjects were recruited (35 males, mean age 42 years, range 21-81 years; apnea-hypopnea index (AHI) 33 ± 30 events/h (mean ± standard deviation), Epworth Sleepiness Scale score 11 ± 6, body mass index 34 ± 8 kg/m(2)). In univariate logistic regression, MCA was a significant predictor of mild-no OSA (AHI < 15). A multivariate logistic regression model including MCA, age, gender, and neck circumference significantly predicted AHI < 15, explaining approximately one-third of the total variance (χ(2)(4) = 37, p < 0.01), with only MCA being a significant independent predictor (adjusted odds ratio 54, standard error 130; p < 0.01). CONCLUSIONS: These data suggest that independent of age, gender, and neck size, objective anatomical assessment can significantly differentiate those with mild versus moderate-to-severe OSA in a clinical setting, and may have utility as a component in stratifying risk of OSA.

Predictability of Acoustic Pharyngometry for the Obstructive Sleep Apnea / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Acoustic pharyngometry is a relatively new noninvasive method that quantifies the geometrically complex oropharyngeal dimensions. We aimed this study to investigate the predictability and usefulness of acoustic pharyngometry in the diagnosis of obstructive sleep apnea (OSA). SUBJECTS AND METHOD: We conducted a prospective clinical trial in consecutive 49 patients with snoring or sleep apnea. Polysomnography was used to determine whether the patient had OSA. All subjects were examined by acoustic pharyngometry in sitting, supine, and both lateral recumbent positions while awake with tidal breathing. Morphometric oral cavity measurements were obtained and the Kushida index was calculated for each patient. RESULTS: Upper-airway cross-sectional areas measured by acoustic pharyngometry were significantly smaller in patients with OSA than in subjects without OSA. Especially, the oropharyngeal junction area (OPJ) in supine position was the most prominent parameter to discriminate between them. CONCLUSION: Acoustic pharyngometry can be a clinically useful tool for localizing the upper-airway obstruction and for predicting obstructive sleep apnea.

Predictive Value of Kushida Index and Acoustic Pharyngometry for the Evaluation of Upper Airway in Subjects With or Without Obstructive Sleep Apnea

Acoustic pharyngometry is a relatively new noninvasive method that quantifies geometrically complexed pharyngeal dimensions. Our study aimed to investigate the predictability and usefulness of acoustic pharyngometry in diagnosis of obstructive sleep apnea (OSA), and we developed a prospective clinical trial in 16 subjects without apnea and 54 subjects with apnea. All seventy subjects received polysomnography (PSG) to assess the sleep architecture, including breathing and the degree of apnea hypopnea index. Acoustic pharyngometry was performed in four body positions (sitting, supine, right and left lateral) while awake with tidal breathing in addition to morphometric measurements (Kushida index) of oral cavity. This study shows that the cross-sectional area and volume of the upper airway is smaller in the supine position than any other positions. As well, the oropharyngeal junction area of the supine position is the most predictive parameter to discriminate between subjects with or without OSA. Acoustic pharyngometry can be a clinically useful tool for localizing the narrowed portion of the upper airway and predicting obstructive sleep apnea.