Background and objectives: The objective of this study was to develop a 3D pharyngeal airway analysis using cone-beam computed tomography (CBCT) in class III patients and to compare airway parameters to the sagittal position of the upper and lower jaw.
Methods: CBCT scans were obtained from 10 Class III patients. Pharyngeal airway of each patient was isolated and studied at three levels: (1) the posterior nasal spine, (2) the most inferior point of the soft palate, and (3) the top of the epiglottis. Cross-sectional area at each of these levels and volume of all three parts between sections was measured. The level and area of maximum constriction were determined. All measurements were compared with SNA, SNB and ANB angles.
Results: The mean pharynx volume was 23.98 cm 3 (13.0–34.2 cm 3 ) and the mean ANB angle −3.38° (−8.0–0.5°). The only statistically significant positive correlation was found between ANB angle and the volume between the PNS point and the most inferior point of soft palate.
Conclusions: 3D evaluation of the connection between the jaw position and the size of the airway provides an opportunity for the estimation of the effects of orthognathic treatment on pharyngeal airway.
Key words : pharyngeal airway; CBCT; Class III patients.