Ultrasound Examination to Visualize and Trace Sinus Tracts of Endodontic Origin

Introduction: The detection of a tooth with a sinus tract (ST) of endodontic origin and its pathway are conventionally assessed with a periapical radiograph and a gutta-percha cone introduced into its stoma. The aim of this study was to evaluate the possibility to detect STs and trace their route using ultrasound real-time examination. Methods: Two calibrated examiners performed echography on 10 patients who had a lesion of apical periodontitis (AP) and ST and 10 patients in the control group with AP without an ST recruited in 2 endodontic practices. They also traced the pattern of the STs with a computer program. The images were then submitted to 2 calibrated and blinded observers who were asked to describe the presence of AP and ST and to trace it with the same program. The data obtained were compared with the clinical and radiographic diagnosis of ST. For sensitivity, specificity, accuracy, and positive and negative predictive values, the receiver operating characteristic curve and Fisher exact test were used (P < .05). Results: Interobserver agreement was high as was the diagnostic accuracy of the ultrasound examination of STs (mean value = 97.5%), and the Fisher exact test showed statistical significance (P < .05). High sensitivity and a negative predictive value and 100% specificity and a positive predictive value were also obtained. The application of the 3-dimensional mode further enabled the reconstructions of the more complex paths, and the implementation with color power Doppler disclosed the vascularity surrounding the STs. Conclusions: The ultrasound examination is a technique feasible to describe and trace the STs of endodontic origin.