Three-dimensional analysis of pharyngeal airway in preadolescent children with different anteroposterior skeletal patterns.

INTRODUCTION In growing patients with skeletal discrepancies, early diagnosis, evidence-based explanations of etiology, and assessment of functional factors can be vital for the restoration of normal craniofacial growth and the stability of the treatment results. The aims of our study were to compare the 3-dimensional pharyngeal airway volumes in healthy children with a retrognathic mandible and those with normal craniofacial growth, and to investigate possible significant relationships and correlations among the studied cephalometric variables and the airway morphology in these children. METHODS Three-dimensional airway volume and cross-sectional areas of 27 healthy children (12 boys, 15 girls; mean age, 11 years) were measured by using cone-beam computed tomography volume scans, and 2-dimensional lateral cephalograms were created and analyzed. The subjects were divided into 2 groups based on their ANB angles (group I: 2 degrees < or = ANB < or = 5 degrees ; group II: ANB >5 degrees ), and cephalometric variables, airway volumes, and cross-sectional measurements were compared. RESULTS There were statistically significant differences in the following parameters: height of the posterior nasal plane (P <0.05), pogonion to nasion perpendicular distance (P <0.01), ANB angle (P <0.01), mandibular body length (P <0.01), facial convexity (P <0.01), and total airway volume (P <0.05). No statistically significant differences between the 2 groups were found in the cross-sectional area and the volumetric measurements of the various sections of the airway except for total airway volume, which had larger values in group I (P <0.05). CONCLUSIONS The mean total airway volume, extending from the anterior nasal cavity and the nasopharynx to the epiglottis, in retrognathic patients was significantly smaller than that of patients with a normal anteroposterior skeletal relationship. On the other hand, differences in volume measurements of the 4 subregions of the airway were not statistically significant between the 2 groups.