Three dimensional evaluation of pharyngeal airway changes associated with maxillary incisors proclination in class II division 2 using cone-beam computed tomography

Objective: To evaluate whether the correction of the axial inclination of retroclined maxillary incisors in Class II division 2 cases might affect the pharyngeal airway size and volume using Cone-Beam Computed Tomography (CBCT) and the Invivo Dental software (Anatomage). Materials and Methods: Eighteen adult male Class II division 2 subjects were enrolled in this study (mean age 23.83 ± 3.67 years). Two CBCT scans were obtained for each subject; pretreatment and after completion of the maxillary arch leveling only. The pretreatment and post-leveling pharyngeal air way mean values (size and volume) were compared using the paired sample t-test. Results: The results showed statistically significant increase (P90.05) in all oropharyngeal airway measurements following maxillary dental arch leveling. There has been 9.53% ±1.45% raise in the oropharygeal airway volume. In addition the analyses of the pretreatment and post-leveling mandibular measurements revealed high statistically significant changes (P9 0.001) as follows: SNB angle increased, and FH-Mn Pl and Y axis-FH angles decreased, following the leveling of upper anteriors. Conclusion: The correction of the maxillary incisors inclination in Class II division 2 subjects improved the pharyngeal airway size and volume. This might be attributed to the anterior mandibular repositioning following the correction of upper incisors retroclination. These findings are of valuable clinical importance, especially in cases of Class II division 2 with breathing problems due to pharyngeal constrictions.