Airway Evaluation Using 3D CBCT Scans and Reconstructed 2D Cephalograms in an Orthodontic Population

Hypothesis: We hypothesize that there is no statistical significant mean difference nor association of the vertical location and sagittal dimension between the minimum cross sectional area (MCSA) of airway in CBCT scans and the minimum sagittal linear dimension (MSLD) of airway in 2D reconstructed lateral cephalograms (RLC) in an orthodontic population. Objective: To investigate the mean difference and association of the vertical location and sagittal dimension between MCSA of airway in CBCT scans and MSLD of airway in 2D RLC. Methods: CBCT-scans of 91 patients, grouped into three age groups (≤20, 21-40 and >40 years), were utilized to perform a 3D assessment of the upper airway and to reconstruct lateral and postero- anterior cephalograms (PAC). Airway volume, MCSA, vertical level and sagittal dimension of MCSA in CBCT and MSLD of airway in 2D RLC as well as linear transverse measurements in 2D reconstructed PAC were computed and analyzed. Results: In all age groups, there was no significant mean difference between the vertical location of MSCA in CBCT and MSLD in 2D RLC. However, there was a significant mean difference between the sagittal dimension of MCSA in CBCT and MSLD in 2D RLC (p< 0.05). In all age groups, correlation tests showed moderate-strong significant correlation between the vertical location of MSCA in CBCT and MSLD in 2D RLC (0.611 ≥ r ≤ 0.727). Pearson correlation test showed strong significant correlation between the sagittal dimension of MSCA in CBCT and MSLD in 2D RLC (r = 0.873) in the youngest age group. Conclusion: Two dimensional reconstructed lateral cephalograms may be used as screening tool to identify the vertical location of minimum sagittal measurement of oropharyngeal airway. However, comprehensive assessment of airway characteristics is better achieved with CBCT-based 3D evaluation. Funding: UIC College of Dentistry, Department of Orthodontics. IRB/ACC protocol: 2015-0483