Department of Periodontics and Oral Medicine, University of Michigan School of Dentistry, Ann Arbor, MI.
Department of Reconstructive Dentistry, University Center for Dental Medicine Basel, University of Basel, Basel, Switzerland.
J Prosthodont. 2022 Jan;31(1):22-29. doi: 10.1111/jopr.13366. Epub 2021 May 4.
To investigate the trueness and precision of virtual facebow records using a smartphone as a three-dimensional (3D) face scanner.
Twenty repeated virtual facebow records were performed on two subjects using a smartphone as a 3D face scanner. For each subject, a virtual facebow was attached to his/her maxillary arch, and face scans were performed using a smartphone with a 3D scan application. The subject's maxillary arch intraoral scan was aligned to the face scan by the virtual facebow fork. This procedure was repeated 10 times for each subject. To investigate if the maxillary scan is located at the right position to the face, these virtual facebow records were superimposed to a cone-beam computed tomography (CBCT) head scan from the same subject by matching the face scan to the 3D face reconstruction from CBCT images. The location of maxillary arch in virtual facebow records was compared with its position in CBCT. The "trueness" of the proposed procedure is defined as the deviation between maxilla arch position in virtual facebow records and the CBCT images. The "precision" is defined as the deviation between each virtual facebow record. The linear deviation at left central incisor (#9), left first molar (#14), and right first molar (#3), as well as angular deviation of occlusal plane were analyzed with descriptive statistics. Differences between two objects were also explored with Mann Whitney U test.
The 20 virtual facebow records using the smartphone 3D scanner deviated from the CBCT measurements (trueness) by 1.14 ± 0.40 mm at #9, 1.20 ± 0.50 mm at #14, 1.12 ± 0.51 mm at the #3, and 1.48 ± 0.56° in the occlusal plane. The VFTs deviated from each other by 1.06 ± 0.50 mm at #9, 1.09 ± 0.49 mm at #14, 1.11 ± 0.58 mm at #3, and 0.81 ± 0.58° in the occlusal plane. When all sites combined, the trueness was 1.14 ± 0.40 mm, and the precision was 1.08 ± 0.52 mm. Out of eight measurements, three measurements were significantly different between subjects. Nevertheless, the mean difference was small.
Virtual facebow records made using smartphone-based face scan can capture the maxilla position with high trueness and precision. The deviation can be anticipated as around 1 mm in linear distance and 1° in angulation.
使用智能手机作为三维（3D）面部扫描仪，研究虚拟面弓记录的真实性和精度。
使用智能手机作为 3D 面部扫描仪，对两名受试者进行了 20 次重复的虚拟面弓记录。对于每个受试者，将虚拟面弓附接到上颌弓上，并使用具有 3D 扫描应用程序的智能手机进行面部扫描。通过将虚拟面弓叉对准上颌弓内扫描，将受试者的上颌弓内扫描与面部扫描对齐。对于每个受试者，此过程重复了 10 次。为了研究上颌扫描是否位于正确的面部位置，通过将面部扫描与来自 CBCT 图像的 3D 面部重建相匹配，将这些虚拟面弓记录叠加到来自同一受试者的锥形束 CT（CBCT）头部扫描上。将上颌弓在虚拟面弓记录中的位置与 CBCT 图像中的位置进行比较。所提出的方法的“真实性”定义为虚拟面弓记录中上颌弓位置与 CBCT 图像之间的偏差。“精度”定义为每个虚拟面弓记录之间的偏差。分析了左侧中切牙（#9）、左侧第一磨牙（#14）和右侧第一磨牙（#3）的线性偏差以及牙合平面的角度偏差，并进行了描述性统计。还使用曼-惠特尼 U 检验探索了两个对象之间的差异。
使用智能手机 3D 扫描仪的 20 个虚拟面弓记录在#9 处偏离 CBCT 测量值（真实性）1.14 ± 0.40mm，在#14 处偏离 1.20 ± 0.50mm，在#3 处偏离 1.12 ± 0.51mm，在牙合平面处偏离 1.48 ± 0.56°。VFTs 在#9 处彼此偏离 1.06 ± 0.50mm，在#14 处偏离 1.09 ± 0.49mm，在#3 处偏离 1.11 ± 0.58mm，在牙合平面处偏离 0.81 ± 0.58°。当所有位点合并时，真实性为 1.14 ± 0.40mm，精度为 1.08 ± 0.52mm。在这八项测量中，有三项测量在受试者之间存在显著差异。尽管如此，平均差异很小。
使用基于智能手机的面部扫描制作的虚拟面弓记录可以以高精度和高真实性捕获上颌位置。可以预期偏差约为 1mm 的线性距离和 1°的角度。
