Creation of a Three-Dimensional Virtual Patient for Acquiring X-ray Tube Positioning Parameters in the Bisecting-Angle Technique for Periapical Radiography: A Preliminary Technical Feasibility Study

The bisecting-angle technique is a commonly used method for periapical radiography. Its successful execution requires the operator to position the X-ray tube so that the central beam is perpendicular to the imaginary bisector of the angle formed by the tooth and the image receptor—a process heavily reliant on operator experience. Detailed tube positioning parameters for different teeth are therefore essential for effective training. However, due to radiation risks, obtaining these parameters through direct measurement on patients is not feasible. This study addresses this challenge by creating a three-dimensional (3D) virtual patient. Using data from an intraoral scanner, cone-beam computed tomography (CBCT), and a facial scanner, the virtual patient was constructed through image segmentation, 3D modeling, and image registration. This model enables simulation of periapical radiographic examinations in a software environment, allowing accurate determination of key parameters for the bisecting-angle technique—including vertical and horizontal tube angulations and the facial entry point of the central beam—for any specific tooth.