Naturally Occurring Periradicular Lesions Confined to Cancellous Bone Can be Detected Radiographically

Objectives: It has been generally perceived that cortical involvement is necessary for the periradicular lesion to be detectable on a conventional radiograph, and lesions confined to cancellous bone may not be visible radiographically. In the previous studies, the lesions were simulated and studied on cadaver jaws, and there is no in vivo study that evaluated the naturally occurring lesions. In this study, using cone beam computed tomography (CBCT) naturally occurring lesions were identified and their radiographic detectability were compared. The objective of this study was to compare the radiographic detectability of the lesions confined to cancellous bone to those that extended to cortical plate.
Methods: Using existing CBCT scans, 25 lesions confined to cancellous bone and 24 lesions that extended to cortical plate were selected. Control cases with absence of an evident periradicular lesion were also selected. Two calibrated observers blindly evaluated the corresponding digital periapical radiographs of the selected cases and scored them as presence or absence of lesion. The data were compared using Chi-Squared test.
Results: Observers were able to radiographically detect 92% of the lesions confined to cancellous bone and 91.6% of the lesions extended to cortical plate. There was no statistically significant difference between the two groups (p=0.966).
Conclusions: Cortical plate involvement is not necessary for detectability of periradicular lesions.