Comparison of pharyngeal airway volume among different vertical skeletal patterns: a cone-beam computed tomography study.

OBJECTIVE: To test the null hypothesis that there are no significant differences in pharyngeal airway volumes among adult patients with different vertical skeletal patterns and a clinically normal sagittal skeletal pattern using cone-beam computed tomography (CBCT).

MATERIAL AND METHODS: The study sample consisted of 100 adult patients (45 men and 55 women; mean age  =  24.0 ± 5.3 years) with a normal sagittal skeletal pattern divided into three groups according to the vertical skeletal patterns: high angle (32 patients: 15 women and 17 men), low angle (34 patients: 14 women and 20 men), and normal angle (34 patients: 16 women and 18 men) groups. Nasopharyngeal, oropharyngeal, and total airway volumes of patients in all vertical groups were calculated. Group differences were analyzed using one-way analysis of variance and post hoc Tukey tests.

RESULTS: Nasopharyngeal airway volume in the high-angle group (mean  =  6067.9 ± 1693.9 mm(3)) was significantly lower than that of the low- and normal-angle groups (P < .01). Oropharyngeal airway volume was highest in the low-angle group (mean  =  15,957.6 ± 6817.2 mm(3)) and significantly decreased in the control (mean  =  11,826.1 ± 4831.9 mm(3); P  =  .008) and high angle (mean  =  10,869.1 ± 4084.1 mm(3); P  =  .001) groups. Total airway volume was highest in the low-angle group (mean  =  24,261.6 ± 8470.1 mm(3)) and lowest in the high-angle group (mean  =  16,937.0 ± 5027.4 mm(3); P < .001).

CONCLUSION: The null hypothesis was rejected. Significant differences were found in pharyngeal airway volumes among different skeletal vertical patterns.