Comparison of bisecting and parallel intraoral radiography and cone-beam computed tomography for detecting various horizontal angle root fractures

Objectives The aim of this study was to compare cone-beam computed tomography (CBCT) with intraoral radiography (parallel and bisecting techniques) for their detection capabilities of various horizontal angle root fractures in human teeth. Methods Eighty-one extracted human upper central incisors were divided into three groups: (1) right-angle group ( n = 27), in which a groove was formed perpendicular to the long axis of the root at the middle of the root; (2) 75-degree group ( n = 27), which was grooved at 75° in the cervical third of the root; and (3) 55-degree group ( n = 27), which was grooved at 55° in the middle third of the root. In an additional control group ( n = 9), the teeth remained without grooves. The specimens were examined by the above-mentioned three imaging techniques by seven oral radiologists, and the grooves were visualized as radiolucent lines traversing the roots. Results The detection sensitivities for the parallel technique and CBCT were significantly greater than those for the bisecting technique for the right-angle and 75-degree groups, whereas the bisecting technique and CBCT showed significantly greater detection sensitivities than the parallel technique for the 55-degree group. There were no significant differences in specificity among the three imaging techniques. Conclusions CBCT demonstrated high diagnostic accuracy for teeth with root fractures at any angle. When fracture lines are not located clearly by intraoral radiography at only one projection angle, additional intraoral radiography with different angles can improve detection.