Fig 1.
(A) Acquisition of face models (Face_A by 3dMD scanner, Face_B by FaceScan scanner, Face_R by Faro scanner); (B) Registration of reference and test models (green: Faro model, yellow: FaceScan model, purple: 3dMD model); (C) Trimming superimposed models by the same boundary and dividing into upper, middle, and lower parts. (D) 3D comparison between reference and test models in 3D error for partial and global accuracy of the test facial scanners.
Fig 2.
Division of face model for a maxillary defects patient.
Patient’s head in the coordinate system (XYZ) of natural head position (NHP); the “red lines” were the cutting planes parallel to the XOZ system plane to segment the face model into upper, middle, and lower parts. (A) Front view of the face model; (B) Side view of the face model.
Fig 3.
Difference color images of deviation between test and reference scanners for a maxillary defects patient.
Difference color map is set from -5 mm to +5 mm. Yellow to red color indicates positive deviations, blue color shows negative deviation, green color signifies virtually zero error between two superimposed models. The black color shows the deviation out of 5 mm or -5 mm that would not be included in the calculation. (A) Difference color image of deviation between 3dMD (Test) and Faro (Ref) models; (B) Difference color image of deviation between FaceScan (Test) and Faro (Ref) models.
Table 1.
Mean (SD) of 3D error (in mm) for global and partial face models.
Fig 4.
Boxplot of 3D error measurement for upper, middle, and lower face groups.
The yellow boxplot shows data groups for 3dMD scanner, and the red for FaceScan scanner. The circles represent outliers, and asterisks signify P < 0.05.
Table 2.
Paired t-test analysis result of 3D error between 3dMD and FaceScan scanners.