Can Panoramic Radiography Reliably Detect Root Resorption From Impacted Maxillary Canines?

Background and objective Panoramic radiography (PR) remains widely used for the initial assessment of impacted maxillary canines; however, its diagnostic accuracy for detecting associated root resorption has not been well quantified across different observer categories. This study aimed to evaluate the diagnostic accuracy of PR for detecting root resorption associated with impacted maxillary canines, using cone beam CT (CBCT) as the reference standard. Materials and methods A total of 51 patients (71 impacted canine sites) with paired panoramic radiographs and CBCT images were retrospectively evaluated. Six observers - two oral and maxillofacial radiology residents, two orthodontic residents, and two general dentists - independently assessed panoramic radiographs for the presence, severity, and location of root resorption using a 5-point confidence scale. Two board-certified oral and maxillofacial radiologists established the reference standard findings through consensus evaluation of CBCT images. Diagnostic accuracy was assessed using receiver operating characteristic (ROC) curve analysis. Results Root resorption was present in 39.4% of sites (28/71) based on CBCT evaluation. The overall area under the ROC curve (AUC) for PR was 0.659 (95% confidence interval (CI): 0.615-0.703). At the ≥4 threshold, overall sensitivity was 63.1%, and specificity was 59.3%. Severity classification demonstrated fair agreement for apical resorption (κ = 0.22) and slight agreement for lateral resorption (κ = 0.05). Central incisors were affected in 37.1% of resorption cases. Conclusions Based on our findings, PR demonstrates limited yet clinically useful diagnostic accuracy for detecting root resorption associated with impacted maxillary canines. It retains its value as an initial screening tool.