Three-dimensional airway evaluation in 387 subjects from one university orthodontic clinic using cone beam computed tomography

Objective: To determine the linear, volumetric, and cross-sectional area measurements in a large sample of subjects seeking treatment in a university clinic of orthodontics. Materials and Methods: Cone-beam computed tomography (CBCT) scans from 387 patients were analyzed retrospectively. All scans were loaded into the 3dMDvultus program (Atlanta, Ga) for airway analysis using automated segmentation. Gender, age, height, weight, airway length, volume, and area of maximum constriction were collected. Results: The rostrocaudal length of the airway increased with age until the age of 15 years in female subjects but continued to increase in male subjects and ranged from 44 to 88 mm over the period of 8 to 18 years of age with the gender data combined. The volume of the airway increased through the entire 11-year age range from 2000 mm(3) to 27,000 mm(3). The rate of airway volume increased at a slower rate in female than in male subjects. The smallest cross-sectional area increased with age ranging from 20 to 250 mm(2) but at a slower rate with female subjects, while male subjects demonstrated a more exponential increase after the age of 13 years. Conclusions: The human airway increases in length and volume during a rapid period of craniofacial growth in patients between the ages of 8 and 18 years, and the site of maximum cross-sectional area constriction can vary. (Angle Orthod. 2012;82:985-992.)