Accuracy (trueness and precision) of 3-dimensional virtual patients: An in vitro investigation of different facial scanners and digital integration techniques

Objectives: To investigate the influence of different facial scanners and integration approaches on the accuracy of virtual dental patients (VDPs). Methods: Forty VDPs were generated using a head mannequin and two facial scanners: 1) an industrial scanner and 2) a smartphone scanner. For each scanner, two integration methods were applied: 1) integration by virtual facebow scan and 2) integration by nose-teeth scan. This resulted in four VDP groups, with ten repetitions for each group (n = 10). A cone beam computed tomography (CBCT) scan of the mannequin served as the reference. The linear deviations of the maxillary arches at teeth #16, #21, and #26, as well as the angular deviations of the occlusal planes, were measured to assess accuracy. Results: No significant trueness differences were found between the scanners (p = 0.78 for tooth #16, p = 0.84 for tooth #21, p = 0.35 for tooth #26, p = 0.18 for angular deviations) or between the integration techniques (p = 0.42 for tooth #16, p = 0.29 for tooth #21, p = 0.76 for tooth #26, p = 0.61 for angular deviations). In terms of precision, the industrial facial scanner demonstrated superior outcomes (p < 0.001 for teeth #16, #21, #26, and angular deviations). No significant precision differences were found between the two integration techniques for teeth #16 (p = 0.17) and #26 (p = 0.25), or for angular deviations (p = 0.27); however, the nose-based integration technique showed higher precision for tooth #21 (p = 0.01). Conclusions: The smartphone-based facial scanner exhibited trueness comparable to that of the industrial facial scanner, though with reduced precision. The nose-based integration technique demonstrated better accuracy compared to the virtual facebow-based technique. Clinical Significance: The smartphone-based facial scanner achieves trueness comparable to the industrial facial scanner for VDP integration. Additionally, the nose-based integration technique offers a viable alternative to the virtual facebow-based approach, with a simplified scanning and integration process.