A Customized Head Immobilizing System for Setup and Positioning Accuracy on Cone Beam Computed Tomography

摘要

Recent studies indicate that cone beam computed tomography (CBCT) provides better information on interproximal bone loss of the implant patients. However, in order to detect the bone loss, the patient needs to get CBCT scanned more than once at the same time interval. It is important to find the same position that the patient was in on the first scan, every time. Doing this, we are able to measure bone loss accurately. A sensitivity analysis done with Plenmeca Promax 3D CBCT, to investigate the measurement sensitivity during the image acquisition, showed that getting the same position is not possible with the current CBCT process tasks. Based on this sensitivity analysis, a new proposed head immobilizer was designed, and a face tracking software using tracking algorithms was developed. The results showed that using the proposed head immobilizer and the face tracking software as a system reduced the patient positioning variations on X (horizontal) axis by 44.54%, on Y (vertical) axis by 65.42%, and on Z (depth) axis by 59.12%. The study shows that it is possible to reduce the patient positioning error during the CBCT scan, and this study will allow more successful results in the future.