Reliability of upper airway assessment using CBCT.

Area of Science:

• Dentistry
• Radiology
• Orthodontics

Background:

• Cone-beam computed tomography (CBCT) is frequently used by orthodontists for upper airway analysis.
• However, the established reliability of airway measurements derived from CBCT imaging requires further investigation.

Purpose of the Study:

• To assess the intra-examiner and inter-examiner reliability of comprehensive upper airway volumetric and cross-sectional area assessments using CBCT.
• This includes evaluating the entire process from image orientation to final measurements.

Main Methods:

• Six examiners with varied experience performed manual orientation, slice, and threshold selection on 10 patients' CBCT scans.
• Measurements included nasopharyngeal, oropharyngeal, hypopharyngeal, and total upper pharyngeal airway volumes, plus minimum cross-sectional area.
• All measurements were repeated after 4 weeks, with reliability assessed using the Intraclass Correlation Coefficient (ICC) and 95% Confidence Intervals (CI).

Main Results:

• Threshold selection demonstrated poor intra- and inter-examiner reliability.
• Minimum cross-sectional area analysis yielded moderate intra-examiner and poor inter-examiner reliability.
• Intra-examiner reliability for volumetric measurements ranged from 0.747 (hypopharynx) to 0.976 (oropharynx).
• Inter-examiner reliability for volumetric measurements ranged from 0.175 (nasopharynx) to 0.945 (oropharynx), generally lower than intra-examiner reliability.

Conclusions:

• This study is the first to evaluate the complete CBCT upper airway analysis process.
• Reliability generally improved with examiner experience but remained low for hypopharynx and nasopharynx volumes and minimum cross-sectional area.
• Oropharyngeal volume was the sole parameter exhibiting excellent intra- and inter-examiner reliability.