The application of cone beam CT in the diagnosis of vertical root fracture with different depth of periodontal pocket

Objective To evaluate the role of cone beam computed tomography(CBCT) in clinical diagnosis of vertical root fracture(VRF). Methods A total of 99 suspected VRF teeth were included from 95 patients who visited the Department of Stomatology, Affiliated Hospital of Hangzhou Normal University from August 2016 to August 2019. Both digital periapical radiographs and CBCT were performed respectively. Two experienced periodontists independently analyzed each tooth and reached a consensus diagnose. The gold standard for the diagnosis of VRF is the crack observed directly in the treatment of teeth. The positive rate, specificity, accuracy and sensitivity of CBCT and X-ray apical radiography were statistically analyzed, and the influence of deep periodontal pocket(probing depth ≥ 5 mm) on the diagnosis result of CBCT was analyzed. Results In the 99 suspected VRF teeth, 84 teeth were eventually diagnosed with VRF. The positive rate, sensitivity and accuracy of CBCT in diagnosing VRF were 75.8%, 89.3% and 90.9% respectively, which were significantly different from digital periapical radiographs(41.4%, 48.8% and 54.5%, respectively, all P<0.001). In the deep periodontal pocket group(probing depth ≥ 5 mm), the positive rate and sensitivity of using CBCT for diagnosis of VRF were 81.7% and 93.5%, which were different from the non-deep periodontal pocket group(probing depth ≤ 4 mm, all P<0.05), but there was no statistical difference in accuracy and specificity. Conclusion CBCT is superior to digital periapical radiographs in the diagnosis of VRF, and the presence or absence of deep periodontal pocket will affect the positive rate and sensitivity. In future, CBCT is firstly recommended in the diagnosis of suspected VRF, especially combining the clinical sign of deep periodontal pocket.