Although the widespread cone-beam computed tomography (CBCT) is a diagnosing tool for impacted canines, the surgical exposure-based diagnostic accuracy of this 3D imaging modality has not been established yet.  Therefore this study aimed to (1) compare the accuracy of CBCT- and 2D-based interpretations of impacted canine and its relationships with the neighbouring structures with the gold standard (GS) readings, (2) and calculate the diagnostic accuracy, sensitivity, and specificity values of the variables assessed using CBCT and 2D methods.


 To compare 2D- and CBCT-based assessments with the GS values, Cochran's Q tests, Friedman's tests, McNemar's, McNemar-Bowker's, and Wilcoxon tests were applied.


 Significant differences were found between the CBCT-based assessments and the GS only concerning shape and bony coverage of the IMC (P=0.001 and P<0.001, respectively).  CBCT-based assessments had remarkably higher values of diagnostic accuracy, sensitivity, and specificity compared to 2D-based ones.


 The diagnostic accuracy of CBCT outperformed 2D radiography in localizing the IMC (labiopalatal, mesiodistal, and vertical location), detecting root apex development of the IMCs, and the resorption of the adjacent incisors.  Although both 2D and 3D techniques showed the same ability in the diagnosis of IMCs ankylosis, the diagnostic accuracy of CBCT was superior. 
CBCT
The diagnostic accuracy of CBCT outperformed 2D radiography in localizing the IMC (labiopalatal, mesiodistal, and vertical location), detecting root apex development of the IMCs, and the resorption of the adjacent incisors. 
2D radiography
To compare 2D- and CBCT-based assessments with the GS values, Cochran's Q tests, Friedman's tests, McNemar's, McNemar-Bowker's, and Wilcoxon tests were applied.



Cochran's Q tests
To compare 2D- and CBCT-based assessments with the GS values, Cochran's Q tests, Friedman's tests, McNemar's, McNemar-Bowker's, and Wilcoxon tests were applied.



Friedman's tests
To compare 2D- and CBCT-based assessments with the GS values, Cochran's Q tests, Friedman's tests, McNemar's, McNemar-Bowker's, and Wilcoxon tests were applied.



McNemar's
To compare 2D- and CBCT-based assessments with the GS values, Cochran's Q tests, Friedman's tests, McNemar's, McNemar-Bowker's, and Wilcoxon tests were applied.



McNemar-Bowker's
To compare 2D- and CBCT-based assessments with the GS values, Cochran's Q tests, Friedman's tests, McNemar's, McNemar-Bowker's, and Wilcoxon tests were applied.



Wilcoxon tests