Abstract
Explore craniofacial landmarks reliability to superimpose cone beam computed tomography (CBCT) images and assess impact of plane reorientation on airway parameters.
10 CBCTs were marked 3 times at baseline, 3 T1, to test landmark reliability. Measurement errors of new coordinate system were tested using 3 T1, and other 10 paired CBCT images, at T1 and T2. Effect on upper airway was assessed using volume, surface area, and point-based analysis.
Tips of nasal bone and clivus and foramina spinosa defined the new coordinate system. Plane reorientation didn't affect landmark identification reliability and significantly reduced interlandmark distances from T1-T2. Airway volume changed by 25.76 ± 24.9%, surface area by 13.85 ± 10.8%, and mean part analysis was 0.43 ± 0.3 mm. Strong correlation (R(2) > 65%) was found between airway analysis and large distances in second and third cervical vertebrae.
Coordinate transformation significantly reduced measurement errors in longitudinal CBCT data; however, it is not designed to correct for large neck flexion.