An Evaluation of Inter- and Intraobserver Reliability of Conebeam Computed Tomography- and Two Dimensional-based Interpretations of Maxillary Canine Impactions using a Panel of Orthodontically Trained Observers

OBJECTIVES: To assess intra- and interobserver agreement when evaluating maxillary impacted canines using cone beam computed tomography (CBCT) and two-dimensional (2D) images through a panel of orthodontically trained observers. MATERIALS AND METHODS: An adult skull with permanent dentition was employed to perform 15 simulated maxillary canine impactions. Two sets of 2D and three-dimensional (3D) radiographic images were acquired. A panel of assessors including 11 PhD and MSc postgraduate orthodontic students evaluated maxillary impacted canines using a standard questionnaire with 11 categorical variables. Kappa (K) statistics as well as Krippendorff's alpha (α) coefficients were used for the analysis of reliability. RESULTS: A high level of intraobserver agreement was found for both the CBCT- and 2D-based interpretations. The 11 observers demonstrated a higher interobserver agreement for the CBCT-based interpretations than that of the 2D-based interpretations (α = 0.68 and 0.38 respectively). The employed 3D classifications canines was found to be reliable among observers on CBCT images for the labiopalatal position (K = 0.87), mesiodistal position, vertical position, labiopalatal inclination and mesiodistal inclination (α = 0.95, 0.83, 0.84 and 0.92 respectively). The 2D-based interpretations were not in agreement among the 11 observers, except for the mesiodistal position (α = 0.88) and mesiodistal inclination (α = 0.88). CONCLUSION: The intraobserver agreement was high for both the 2D- and the CBCT-based interpretations. The interobserver agreement for the CBCT-based interpretations was remarkably higher than that of the 2D-based interpretations. The utilized CBCT-based 3D classifications for the location and inclination of maxillary impacted canines were found reliable among observers.