Intra- and inter-observer agreement during the assessment of the different stages of root development using four radiographic classifications.

Abstract Introduction This study analyzed intra- and inter-observer agreements during radiographic assessment of the different stages of root development using dichotomous, Moorrees’, Demirjian’s, and Cvek’s classifications, as well as the effect of the observer's level of experience on the result. Methods Two hundred and eighty-five digital periapical radiographs were examined via visual inspection by 3 experienced and 3 non-experienced observers (n= 6) under strict technological and viewing conditions. Following observer calibration, determination of the presence or absence of an open apex and the assignment of a root development stage according to the different sub-divisions of the four indexes was performed. This procedure was carried out by each observer in duplicate in the first round (n= 8) and repeated in the second round (n= 8). The 16 examinations performed by each observer (n= 96) were analyzed to determine the percentage of concordance, followed by intra-, inter- and global observer agreement using the Kappa coefficient (κ) and a weighted κ. Additionally, to determine the level of concordance between the visual determination of an open or closed apex and the apical foramen width measured in millimeters, a dichotomized κ coefficient was applied. Results A good level of global observer agreement was found for the dichotomous, Demirjian and Cvek classifications . However, a significantly low percentage of total concordance and global observer agreement (6.66% and 0.498, respectively) was obtained for Moorrees’ classification, which was more pronounced in non-experienced observers (0.247). Apical foramen width measurements indicated the presence of 143 roots with an open apex (50.2%) and 142 with a closed apex (49.8%), and the dichotomized κ coefficient test revealed a good level of agreement during the visual determination of an open or closed apex (range 0.611 - 0.636). Conclusions The classifications of Cvek and Demirjian provided reliable results when determining the different stages of root development. In contrast, Moorrees´ classification provided the lowest agreement values, with a significant negative effect on non-experienced observers. Finally, the visual estimation of the presence (or absence) of a root with an open apex provided a good level of concordance with the radiographic apical foramen width.