Objective: To propose the utilization of virtual tooth models (VTMs) created by combining tooth root data from CBCT and crown data captured through intraoral scanning for assessing inter-root distance and angulation during orthodontic treatment when repeated radiographic monitoring is necessary.
Materials and Methods: Patients planning dental implant placement in edentulous areas during or after their orthodontic treatment and who have intraoral scans and CBCT scans at the pretreatment and posttreatment stages were selected. TMs were fabricated by merging intraoral-scanned crowns with corresponding CBCT-scanned roots from pretreatment. Tooth positions posttreatment were estimated by integrating models into posttreatment intraoral scans, and actual positions were obtained from posttreatment CBCTs. Discrepancies in estimated vs. actual tooth positions, including inter-radicular distances and inter-root angulations, were compared.
Results: Minimum inter-radicular distance between two adjacent teeth showed no significant difference between the estimated and actual tooth positions. For inter-root angulation, the difference did not reach statistical significance. Most inter-radicular distances measured at each landmark showed no significant differences between the estimated and actual tooth positions, except for the measurement at the buccolingual midpoint of the cementoenamel junction, which showed a tendency toward difference.
Conclusion: Tooth position of VTMs demonstrated clinically acceptable accuracy compared to CBCT scans. Virtual tooth models can benefit both clinicians and patients by enabling accurate assessment of inter-radicular space for dental implant placement without repeated CBCT scans.

Keywords: Tooth model, intraoral scans, CBCT, inter-radicular space