Three-Dimensional Computed Tomographic Analysis of Airway Anatomy

Purpose: To test the reliability of a 3-dimensional computed tomographic (3D-CT) analysis of airway size and shape and to correlate the 3D-CT findings with lateral cephalometric measurements. Materials and Methods: Fifteen pairs of preoperative maxillofacial 3D-CT scans and digital lateral cephalograms of patients treated for obstructive sleep apnea were used in the present study. Digital 3D-CT reconstructions were created and 12 measurements of airway size and 4 of shape were analyzed. The posterior airway space (PAS), middle airway space, and hyoid to mandibular plane distances were measured on the cephalograms. We then randomly selected 5 CT scans and 5 cephalograms which were analyzed blindly on 5 separate occasions by 2 investigators (Z.A., J.T.) to establish the intraclass correlation coefficients for inter- and intraexaminer reliability. All 15 pairs of images were used to compute the Pearson correlation coefficients to establish the relationship between the CT and cephalometric measurements. Results: The intra- and interexaminer reliabilities were high for all CT (0.86 to 1.0 and 0.89 to 1.0, respectively; P<.001) and cephalometric measurements (0.84 to 1.0 and 0.91 to 0.99, respectively; P<.001). The CT measurements retroglossal anteroposterior dimension and distance between the genial tubercle and hyoid exhibited a positive correlation with the PAS (r = .60, P = 02 and r = .54, P = .04, respectively), and the lateral/anteroposterior dimension demonstrated an inverse correlation (r = -.68, P = .01) with the PAS. Conclusion: The results of the present study indicate that the 3D-CT and lateral cephalometric measurements we selected are reliable and reproducible. The only cephalometric measurement that exhibited any correlation with the CT parameters was PAS. (C) 2010 American Association of Oral and Maxillofacial Surgeons J Oral Maxillofac Surg 68:363-371, 2010