Objectives. The aim of this study was (1) to assess intra- and interobserver reliability of the localization of anatomic landmarks
of the upper airway on cone beam computed tomography (CBCT) images; and (2) to assess intra- and interobserver reliability
of the three-dimensional measurements of the upper airway based on these landmarks.
5G (QR systems, Verona, Italy) CBCT data sets were randomly selected from the archives of the Department of Oral Radiology,
Academic Centre for Dentistry (ACTA) at University of Amsterdam and VU University, Amsterdam, The Netherlands. Three observers
localized six anatomic landmarks that are relevant for upper airway analysis twice, with a 10-day interval, using 3Diagnosys
software (v5.3.1, 3diemme, Cantu, Italy). Subsequently, the observers performed upper airway volume measurement based on those
landmarks twice as well, again with a 10-day interval, using Amira software (v4.1, Visage Imaging Inc., Carlsbad, CA). The
upper airway measurements also included the minimum cross-sectional area (CSAmin), location of the CSAmin, and anteroposterior
and lateral dimensions of the CSAmin.
Both intraobserver reliability and interobserver reliability were
excellent for the localization of the anatomic landmarks of the upper airway (intraclass correlation coefficients = 0.97-1.00)
as well as for the three-dimensional upper airway measurements (intraclass correlation coefficients = 0.78-1.00).
The methodology of landmark localization and upper airway measurements, as used in this study, showed an excellent reliability
and can thus be recommended for upper airway analysis on CBCT images.