Surface Registration Accuracy of Clinically Obtained Intraoral Optical Scans with Manually Threshold Segmented CBCT Data

Abstract

Combining CBCT imaging and intraoral scans with an intention to prepare comprehensive treatment plans is common in clinical practice. Segmentation and superimposition of models is indispensable when planning complicated prosthetic reconstructions. The authors of this publication evaluated registration discrepancies of virtual dental arch models obtained by means of CBCT imaging at different segmentation thresholds with intraoral dental scans. For comparisons, intraoral digital scans and volumetric CBCT scans of the upper and lower jaw were used in randomly selected patients. The mean distance, Gaussian mean and standard deviation from the Gaussian mean as registration inconsistencies between the combined models were measured and subjected to a statistical analysis. The results showed that the registration of superimposed models may be affected by errors of up to 300 microns in the case of full dental arches. The statistical analysis proved that there was no correlation between the segmentation threshold and the quantitative variables studied (e.g. mean distance, Gaussian mean and standard deviation from the Gaussian mean). The results of this study indicate that CBCT data and full arch optical scans can be superimposed and successfully applied under clinical conditions within the accepted error.