Diagnostic Concordance of Panoramic Radiographs and Cone-Beam Computed Tomography and their Influence on Treatment Decision-Making for Impacted Canines

Objective: To evaluate the diagnostic concordance between panoramic radiographs and cone-beam computed tomography (CBCT) and to determine their comparative diagnostic performance in relation to the treatment decision of impacted maxillary canines. Methods: Radiographic records of 51 impacted maxillary canines in 44 patients (37 unilateral and 7 bilateral cases) were analyzed. Panoramic radiographic evaluations included sector classification, the α angle, and the d distance. The KPG index was used in CBCT assessments to determine impaction severity. Results: All imaging parameters showed high intra- and interrater reliability (intraclass correlation coefficients ≥0.927; κ≥0.658; p<0.001). Significant associations were found between the panoramic radiographic parameters (sector, α angle, and d distance) and the CBCT-based KPG index, and between sector classification and buccopalatal position (p<0.05). Regarding treatment decisions, higher parameter values were significantly associated with the choice of surgical extraction (p<0.05). Receiver operating characteristic analysis demonstrated acceptable to excellent discriminatory ability for panoramic radiograph-based and CBCT-based parameters [area under the curve (AUC): 0.715 to 0.843], with no differences among the AUC values (p>0.05). A d distance ≥12.3 mm and an α angle ≥46.1° were identified as thresholds associated with the decision for surgical extraction. Conclusion: Panoramic radiographic parameters demonstrated diagnostic concordance with CBCT, and their performance was comparable to CBCT-based assessment for treatment decisions. The identified 2D thresholds may serve as an effective first-line screening tool for identifying complex cases likely to require surgical extraction, signaling a level of severity at which the superior anatomical detail of CBCT is warranted for precise surgical planning.