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.

Background: There is lack of reliable and accurate methods to predict treatment out- comes of oral appliance (OA) treatment. Acoustic pharyngometry (AP) is a non-inva- sive 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 pa- tients 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 treat- ment is necessary in order to clarify its possible beneficial contribution to improving OA therapy.

 

Objective: To determine whether combining acoustic pharyngometric parameters with cephalo- metric 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.