1 found a mean overall variation of 0.25 mm within the face at rest with the largest variations occurring in the mouth and eye regions. Irrespective of the type of scanner applied, the obtained point clouds are mathematically fused to polygonal 3D-meshes.Īlthough the accuracy of the above mentioned 3D-systems have been validated 2, 8, 9, 11, 12, 13, 14, scanning the periorbital region in a reproducible way remains challenging. Trigonometric triangulation is used to calculate the reflection angle of the structured light, and the three-dimensional coordinates are used to digitally reconstruct the object.
#ARTEC STUDIO MIRROR SERIES#
Range-based scanners, such as structured light scanners, project a series of linear patterns of light onto the object to scan and capture its reflection with a sensor. For this reason, stereophotogrammetry has been used to evaluate postoperative changes in the soft tissues of the face following orthognathic surgery and cranio-maxillofacial surgery 7, 10. Stereophotogrammetry is an accurate user friendly image-based scanner method for comparing 3D-photographs of the same individual at different time points 5, 6, 7, 8, 9. Image-based scanners (stereophotogrammetry) reconstruct the surface geometry with the use of two or more photographic images taken from different positions and this creates a point cloud of 3D coordinates. image-based scanners and range-based scanners 2, 3, 4. Two main optical 3D-scanning technologies are commonly applied to evaluate human subjects, i.e. If the variation within the face in a resting position is large, the evaluation of the effect of surgery based on a pre- and postoperative 3D-photograph will be inaccurate, especially when only minor improvements are anticipated. Since 3D-imaging is affected by changes in facial expression, muscle tone and head posture, it is of key importance to minimize such variability to obtain a reproducible 3D-scan. To assess treatment outcomes accurately following facial surgery, pre- and post-treatment 3D-photographs must be captured with the same facial expression 1. Three-dimensional (3D) scanning is a practical method for objective visual comparisons of surgical results.
Scanning with a hand-held 3D-scanning device (Artec Space Spider) is a promising tool to assess changes in the periorbital region following surgical treatment since the median deviations are well below the clinically accepted 1 mm measuring error, for both the natural head and fixated positions. The repeated scanning deviations (baseline versus one year data) were well within the accepted clinical threshold of 1 mm. The reproducibility of the 3D processing was excellent (intraclass correlation coefficient > 0.9). The systematic differences when scanning in a natural head position and fixated position were comparable. On assessing the area between the eyelashes and eyebrows, the medians of the average deviations between the various cross-sections of the one minute interval 3D-scans ranged from 0.17 to 0.21 mm at baseline, and from 0.10 to 0.11 mm when the minute-interval scanning was repeated one year later. Two scans were made with a one minute interval and repeated after 1 year for both a natural head position and with the head in a fixation-device. Facial 3D-scans of 15 volunteers were captured at different time points with a handheld Artec Space Spider structured light scanner. The reproducibility of scanning in the periorbital region with 3D technology to enable objective evaluations of surgical treatment in the periorbital region was assessed.
0 kommentar(er)
