Pharyngeal Airway: An Analysis Using 2D vs. 3D Images in Different Malocclusions

Introdouction: The aim of this study was to compare information regarding pharyngeal airway sizes in adolescent subjects with different malocclusion classes obtained from lateral cephalograms and 3–dimensional (3D) cone-beam computed tomography (CBCT) scans. In this prospective cross-sectional study, CBCT scans and lateral cephalograms of 35 subjects, taken within one week, were included. Measurements of the pharyngeal airway area from the lateral cephalograms and airway volume from the CBCT scans were analyzed using one-way ANOVA; post-hoc tests were used for comparison of the airway area and volume in different malocclusion classes. A linear regression of the airway area to volume was performed to discern associations and determine correlation coefficients. Descriptive statistics for airway dimensions were determined. No significant differences were detected between the sexes for any measurement; therefore, all data were combined. Regression analysis showed that for every mm2 increase in airway area, there was a corresponding 11.94- mm3 increase in mean airway volume. One-way ANOVA and post-hoc tests demonstrated significant differences in airway area and volume between the three malocclusion classes (p < 0.001). The highest mean airway area and volume was observed in class III malocclusion, followed by classes I and II malocclusion. Pharyngeal airway area, as measured on the lateral cephalogram, concurs with volumetric data. However, accurate determination of airway volume and shape is achieved by 3D imaging, owing to great variability in the shape of the pharyngeal air space.