Effect of artifact area on cone beam computed tomography scans when integrated with intraoral scans

The aim of this study was to examine whether integration accuracy increases upon removing artifacts from the registration area when integrating maxillofacial cone beam computed tomography (CBCT) scans and intraoral scans.

Three methods were implemented according to the region of interest (ROI): R0, all teeth included as the registration area (artifacts included); R1, anterior teeth included as the registration area (artifacts in premolars and molars not included); and R2, anterior teeth and second molars included as the registration area (artifacts in premolars and first molars not included). Discrepancies between the 2 images were evaluated by using color-mapping methods. The average surface distance was calculated by measuring the shell/shell deviations for overall discrepancies and 3-dimensional distances between the surface points on the 2 images for registration discrepancies.

The R1 method showed more discrepancies between the CBCT and intraoral scans compared with the other 2 methods. The R2 method showed smaller overall discrepancy values compared with the R1 method. Most CBCT artifacts were located in the posterior area. Registration discrepancies were greatest in the x-dimension.

The results suggest that intraoral and CBCT scans might be integrated by using a registration method that involves exclusion of artifacts and inclusion of the second molar on both sides.