A diagnostic accuracy study on an innovative auto-edge detection technique for identifying simulated implant fractures on radiographic images

Abstract

Implant fracture is a rare but devastating complication of treatment in partially or fully edentulous patients which requires prompt diagnosis. Nevertheless, studies on defining the most accurate technique for the detection of implant fractures are lacking. In the present study, the Canny edge detection algorithm was applied on multiple radiographic modalities including parallel periapical (PPA), oblique periapical (OPA), and cone beam CT (CBCT) with and without metal artifact reduction (MAR) to examine its accuracy for diagnosis of simulated implant fractures. Radiographs were taken from 24 intact implants and 24 implants with artificially created fractures. Images were evaluated in their original and Canny formats. The accuracy of each radiograph was assessed by comparison with a reference standard of direct observation of the implant. The greatest area under the receiver operating characteristic curve belonged to Canny CBCT with MAR (0.958), followed by original CBCT with MAR (0.917), original CBCT without MAR = Canny CBCT without MAR = Canny OPA (0.875), Canny PPA (0.833), original PPA = original OPA (0.792), respectively. The Canny edge detection algorithm is suggested as an innovative method for accurate diagnosis of clinically suspected implant fractures on CBCT and periapical radiographies.

Introducing a new auto edge detection technique capable of revealing cervical root resorption in CBCT scans with pronounced metallic artifacts

“…Three parameters of the Canny algorithm including standard deviation of the Gaussian filter, high and low sensitivity thresholds can be set manually by the operator. Previous studies have suggested certain values for these three parameters to achieve the best image quality 15 , 17 . In this study, two experienced oral and maxillofacial radiologists who were not among the observers viewed the images to confirm that the suggested values for the aforementioned parameters provided the finest image details.…”

“…According to the previous studies, CBCT scans using a 0.3 mm voxel size would demonstrate root resorption with high accuracy 14 . Nevertheless, streaking artifacts generated from high-density materials such as intracanal posts and metallic restorations could corrupt the CBCT data by disfiguring the anatomical structures 15 – 23 . Such artifacts could jeopardize the diagnosis of lesions such as ECR especially when they are small and therefore postpone their treatment.…”

“…It has the capability of detecting the outer borders of an object precisely, without being affected by exposure parameters or external conditions 17 . This algorithm has been applied for quantification of metal artifacts in CBCT, diagnosis of osteoporosis, and detection of dental implant fractures 15 , 17 , 26 . Nevertheless, no studies so far have used the Canny algorithm to determine whether it facilitates the diagnosis of cervical resorption in the presence of metallic artifacts.…”