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The use of computed tomography (CT) for craniofacial measurements is common in medical imaging, but concerns about accuracy and reliability persist, especially with different CT technologies. This study assessed the accuracy of twenty-six common measurements on consecutive CT images from the same patients, using multidetector CT (MDCT) and cone-beam CT (CBCT) with two software programs (Amira and Dolphin). Ten adult subjects with consecutive CBCT scans within one year were randomly selected. Another ten subjects with consecutive MDCT scans were paired with the CBCT group based on age, gender, race, occlusion, and craniofacial pattern. All digital imaging and communications in medicine (DICOM) files were randomly coded and analyzed using the two software programs. Intra-examiner reliability was assessed using the intraclass correlation coefficient. Successive measurement errors from consecutive scans for both imaging modalities and software programs were compared. For most skeletal linear and angular measurements, Dolphin showed greater successive measurement errors compared to Amira. Eight of the 26 common measurements had errors greater than one unit (millimeter or degree). Despite almost perfect intra-examiner reliability for upper airway analysis, average successive measurement errors were notably high, particularly for intraoral and oropharyngeal airway volumes. The successive Dolphin measurement error for oropharyngeal airway volume on CBCT images was over three times that on MDCT images. Given the substantial successive measurement errors observed during consecutive CT scanning for the upper airway, this study does not support the quantitative use of CT for analyzing changes in airway dimensions for research purposes. [ABSTRACT FROM AUTHOR]

Objectives: To compare the intra- and inter-examiner reliability of multidetector computed tomography (MDCT) and cone-beam computed tomography (CBCT) using Amira and Dolphin software analyses for craniofacial/airway measurements by six examiners., Materials and Methods: Five adults and one dry skull with CBCT and MDCT scan files were duplicated and randomly numbered. Six orthodontic residents imported these files into two software programs, oriented the images, set thresholds, and performed 26 measurements. Intra- and inter-examiner reliabilities were determined by using intraclass correlation coefficient (ICC) and presented with scatterplots., Results: Variables including anterior nasal width, posterior nasal width, frontomaxillary suture right-to-left, inner nasal contour point right-to-left, and minimum cross-sectional area in the oropharynx showed "moderate" to "substantial" intra- or inter-examiner agreement. Amira provided relatively reliable airway assessment, while Dolphin showed standard deviations 10 to 30 times larger for volumetric airway measurements. MDCT scans significantly reduced airway volume/area measurements compared to CBCT, except for intraoral airway volume., Conclusions: Unreliable skeletal measurements and low reliability of Dolphin for airway analysis discourage using CT to quantitatively correlate changes in craniofacial structures with airway dimensions., (© 0000 by The EH Angle Education and Research Foundation, Inc.)