Three-dimensional analysis of pharyngeal airway volume in Class I, II, and III malocclusion

Abstract

Aim: This study aimed to evaluate pharyngeal airway dimensions using cone-beam computed tomography (CBCT) in patients with Class I, II, and III malocclusions and normal growth patterns. Methods: All CBCT images were categorized into three groups: Class I (0° < ANB < 4°, −1 mm < Wits < 0 mm), Class II (ANB > 4°, Wits > 0 mm), and Class III (ANB < 0°, Wits < −1 mm). CBCT images were obtained from individuals with normal growth patterns (32 ± 5° = GN/GO – SN), where GN represents gonion, GN is gnathion, and SN equates to the sella-nasion distance. Measurements were taken for total pharyngeal volume, velopharyngeal volume, glossopharyngeal volume, and oropharyngeal volume, and the narrowest area of the airway was measured. ANOVA and Tukey’s post hoc test were used to compare the airway dimensions among skeletal classes I, II, and III. Results: The CBCT images were captured from 90 patients (45 males and 45 females) aged 17 to 39. The mean volume of the total pharyngeal airway, velopharyngeal, glossopharyngeal, and oropharyngeal and the most constricted area were significantly greater in patients with skeletal Class III malocclusion compared to patients with skeletal Class II malocclusion showing normal growth pattern. Total pharyngeal airway, velopharyngeal, and oropharyngeal volumes were lower in Class II patients compared to Class I and III patients with normal growth patterns. There was a significant difference in the pharyngeal space between males and females with Class II malocclusion. Pharyngeal space in female Class II malocclusion was higher than that in males. There was no difference regarding airway space between female and male patients with Class 1 malocclusion. Pharyngeal space between females and males with Class III malocclusion showed no difference. Conclusion: Class III pharyngeal volumes were generally larger in Class I and II malocclusions. Sex differences in the volumes of various pharyngeal spaces were only present in the case of Class II malocclusions. Relevance for Patients: Class II pharyngeal volumes were generally smaller in Class I and III malocclusions.