Integration of digital maxillary dental casts with 3D facial images in orthodontic patients:

Abstract

Objective To evaluate three-dimensional (3D) accuracy and reliability of nonradiographic dentofacial images integrated with a two-step method. Methods 3D facial images, cone-beam computed tomography (CBCT) images and digital maxillary dental casts were obtained from 20 pre-orthodontic subjects. Digital dental casts were integrated into 3D facial images using a two-step method based on the anterior tooth area. 3D coordinate values of five dental landmarks were identified in both dentofacial images and CBCT images. The accuracy of the integration method was assessed with paired t-tests between dentofacial images and CBCT-based reference standards. Intraclass correlation coefficients (ICCs) were assessed for the reliability of dentofacial images and CBCT-based images. Analysis of variance and Kruskal-Wallis tests evaluated the accuracy of the method in different dimensions. Results There was no statistical difference between dentofacial images and CBCT reference standards in both translational and rotational dimensions (P > .05). Translational mean absolute errors for full dentitions were within 0.42 mm and ICCs were over 0.998 in x, y, and z directions. Rotational mean absolute errors for full dentitions were within 0.92° and ICCs over 0.734 in pitch, yaw, and roll orientations. Integration errors were significantly greater in the first molar, z-translation, and pitch rotation (P < .05). Conclusions Integrating 3D dentofacial images with the two-step method is precise and acceptable for clinical diagnostics and scientific purposes. Errors were greater in the molar region, z-translation, and pitch rotation.

Effects of Artificial Extraoral Markers on Accuracy of Three-Dimensional Dentofacial Image Integration: Smartphone Face Scan versus Stereophotogrammetry

“…To evaluate the accuracy of the dentofacial integration, the 3D deviation of matched maxilla models was measured with regard to general 3D positional discrepancy, occlusal plane, and dental midline ( Figure 7 ). The general 3D positional discrepancy of image matching was calculated as root-mean-square errors ( RMSE ) between 3D surfaces with the following equation [ 31 ]: where is the measuring point on the reference image, is the measuring point on the scanned image, and is the total number of measuring points.…”

The Effect of Perioral Scan and Artificial Skin Markers on the Accuracy of Virtual Dentofacial Integration: Stereophotogrammetry Versus Smartphone Three-Dimensional Face-Scanning

“…According to the image matching areas and the dental scans used for the image registration, the following three experimental groups were defined: teeth image only (TO), perioral area without marker (PN), and perioral area with marker (PM). In the TO group, three anatomic landmarks, including the proximal contact area between teeth 11 and 21, the cusp tip of teeth 13 and 23, were selected as the fiducial points [ 27 ]. In the PN and PM groups, the nasal structure in the perioral image was used for the image matching in addition to the dental landmarks presented in the TO group ( Figure 3 ) [ 22 ].…”

Comparison of the accuracy of different handheld-type scanners in three-dimensional facial image recognition

“…However, this procedure is uncomfortable for patients with claustrophobia. Moreover, there is a risk of facial shape deformation during the impression-taking process owing to the weight of the materials[1,3-5].In recent years, studies have employed facial imaging data obtained using three-dimensional (3D) optical scanners in the field of dental treatment, such as maxillofacial prostheses, oral surgery, orthodontics, and cosmetic dentistry [6][7][8][9][10][11]. The application of a 3D optical scanner reduces patient discomfort during facial impression process.Several types of 3D optical scanners are currently commercially available at various prices, performances, and sizes.…”

“…The scanned data are usually output as a standard triangulated language (stl) or Wavefront obj file formats (obj). These can be integrated with other data such as dentition scanned using another device [9][10][11]. The stl file format comprises only one file of 3D geometrical data, whereas the obj file format comprise three types of files: 3D geometrical data (obj), texture data (such as jpg or png), and…”

“…In recent years, studies have employed facial imaging data obtained using three-dimensional (3D) optical scanners in the field of dental treatment, such as maxillofacial prostheses, oral surgery, orthodontics, and cosmetic dentistry [6][7][8][9][10][11]. The application of a 3D optical scanner reduces patient discomfort during facial impression process.…”