Comparison of two cone beam computed tomographic systems versus panoramic imaging for localization of impacted maxillary canines and detection of root resorption.

The diagnostic accuracy for the localization of impacted canines and the detection of canine-induced root resorption of maxillary incisors were compared between conventional radiographic procedures using one two-dimensional (2D) panoramic radiograph with that of two three-dimensional (3D) cone beam computed tomography (CBCT) scans. The clinical records of 60 consecutive patients who had impacted or ectopically erupting maxillary canines were identified from those seeking orthodontic treatment. For each case, two sets of radiographic information were obtained. The study sample was divided into two groups: group A (n = 30) included those for whom a dental pantomograph (DPT) and CBCT obtained with a 3D Accuitomo-XYZ Slice View Tomograph were available and group B (n = 30) who had a DPT and CBCT obtained with a Scanora. The DPT and CBCT images were subsequently analysed by 11 examiners. Statistical analysis included an evaluation of the agreement between observers based on the standard error of the measurement, kappa statistics and coefficient of concordance, as well as an assessment of the differences between 2D and 3D imaging employing Wilcoxon signed rank and McNemar tests. There was a highly significant difference between the 2D and 3D images in the width of the canine crown (P < 0.001) and in canine angulation to the occlusal plane. Moreover, there was a highly significant difference between the DPT and Scanora CBCT images in canine angulation to the midline (P < 0.001). There was also a significant difference between 2D and 3D images with respect to canine location (P = 0.0074 for group A and P = 0.0008 for group B). The presence or absence of root resorption of the lateral incisor was also significantly different in both groups (P = 0.0201 and P < 0.001 for groups A and B, respectively). Detection of central incisor root resorption was significantly different between the Accuitomo and DPT images (P = 0.045). There was also a significant difference in the severity of lateral incisor root resorption between the DPT and CBCT in both groups (P = 0.02). The results of this study suggest that CBCT is more sensitive than conventional radiography for both canine localization and identification of root resorption of adjacent teeth.