Efficacy of Constructing Digital Hybrid Skull-Dentition Images Using an Intraoral Scanner and Cone-Beam Computed Tomography

Abstract

Cone-beam computed tomography (CBCT) can distort dentition, and additional imaging is often required. A plaster model to help digitize dental images has been widely used in clinical practice, but there are some inconveniences such as complexity of the process and the risk of damage. The aim of this study was to evaluate the potential for improving dentition imaging with CBCT scans using an intraoral scanner instead of a plaster model. The study used laser model-scanned images of plaster models, imaging from two intraoral scanners, and CBCT images from 20 patients aged 12-18 years. CS 3600 (Carestream Dental, Atlanta, USA) and i700 (Medit, Seoul, Korea) were used as intraoral scanners. The full arch was scanned at once or in three sections using intraoral scanners. The segmented scans were merged to obtain full-arch images. With i700, full-arch images were additionally acquired using its “smart stich” function. The virtual skull-dentition hybrid images obtained from intraoral scanners were superimposed with images obtained using a plaster cast. The difference and distance of coordinate values at each reference point were measured. The average distances from the images obtained with the plaster cast were smaller than 0.39 mm, which is the voxel size of CBCT. Scanning the complete or partial arch using CS 3600 or i700 satisfactorily complemented the CBCT when compared to the plaster model. The virtual skull-dentition hybrid image obtained from intraoral scanners will be clinically useful, especially for patients and surgeons who have difficulty in scanning the complete arch at once.

Diagnostic Applications of Intraoral Scanners: A Systematic Review

“…In addition to metrology and 3D model comparison software, point cloud processing software was also used, such as VRMesh (VRMesh studio VirtualGrid), used in [32] to evaluate scarring and asymmetry of the upper lip in surgically managed cases of unilateral cleft lip and cleft palate (UCLP). In [25], a segmented scan was conducted using Geomagic Freeform Plus (3Dsystems, Darmstadt, Germany), a 3D Design and Sculpting Software, to join the models of the arch pieces together. RStudio, with the "molarR" package [63], was also used to produce topographic parameters on which the occlusal tooth wear assessment was based in [37].…”

“…Intraoral scanners have also proven to be excellent tools for making assessments of structural problems in the oral cavity, such as quantifying changes in the width of the dental arches after treatment, e.g., with removable braces in children with malocclusion (orthodontic diagnostics) [22]; in the external regions, such as the evaluation of scarring and asymmetry of the upper lip in surgically managed cases of unilateral cleft lip and cleft palate (UCLP) [32]; and overall in the cranial region, creating hybrid images resulting from the crossing of several diagnostic sources, such as Cone Beam Computed Tomography (CBCT) of the skull with a 3D model of dentition derived from a scanner [25]. In the context of diagnosing functional and structural problems, there is the interesting study by Eom et al [42], who designed and evaluated the performance response of a three-dimensional (3D) intraoral scanning probe based on optical coherence tomography (OCT), showing the ability to reconstruct both the structure and function of human teeth.…”

“…In this case, the use of in vitro Other articles included cover the evaluation of functional and structural problems, the evaluation of periodontal defects, soft tissue analysis, orthodontic diagnosis, and analysis of the nasolabial region. Finally, one paper [25] discusses the improvement of the Cone Beam Computed Tomography (CBCT) technique using intraoral scanners.…”