  We present a fully automated method of integrating intraoral scan (IOS) and
dental cone-beam computerized tomography (CBCT) images into one image by
complementing each image's weaknesses. Dental CBCT alone may not be able to
delineate precise details of the tooth surface due to limited image resolution
and various CBCT artifacts, including metal-induced artifacts. IOS is very
accurate for the scanning of narrow areas, but it produces cumulative stitching
errors during full-arch scanning. The proposed method is intended not only to
compensate the low-quality of CBCT-derived tooth surfaces with IOS, but also to
correct the cumulative stitching errors of IOS across the entire dental arch.
Moreover, the integration provide both gingival structure of IOS and tooth
roots of CBCT in one image. The proposed fully automated method consists of
four parts; (i) individual tooth segmentation and identification module for IOS
data (TSIM-IOS); (ii) individual tooth segmentation and identification module
for CBCT data (TSIM-CBCT); (iii) global-to-local tooth registration between IOS
and CBCT; and (iv) stitching error correction of full-arch IOS. The
experimental results show that the proposed method achieved landmark and
surface distance errors of 112.4 $\mu$m and 301.7 $\mu$m, respectively.
