Validity of Superimposition Range at 3-Dimensional Facial Images

ABSTRACT

PURPOSE: This study was to evaluate the validity of superimposition range at facial images constructed with 3-dimensional (3D) surface laser scanning system.MATERIALS AND METHODS: For the present study, thirty adults, who had no severe skeletal discrepancy, were selected and scanned twice by a 3D laser scanner (VIVID 910, Minolta, Tokyo, Japan) with 12 markers placed on the face. Then, two 3D facial images (T1-baseline, T2-30 minutes later) were reconstructed respectably and superimposed in several manners with RapidForm(TM) 2006 (Inus, Seoul, Korea) software program. The distances between markers at the same place of face were measured in superimposed 3D facial images and measurement were done all the 12 makers respectably.RESULTS: The average linear distances between the markers at the same place in the superimposed image constructed by upper 2/3 of the face was 0.92 +/- 0.23 mm, in the superimposed image constructed by upper 1/2 of the face was 0.98 +/- 0.26 mm, in the superimposed image constructed by upper 1/3 of the face and nose area was 0.99 +/- 0.24 mm, in the superimposed image constructed by upper 1/3 of the face was 1.41 +/- 0.48 mm, and in the superimposed image constructed by whole face was 0.83 +/- 0.13 mm. There were no statistically significant differences in the liner distances of the makers placed on the area included in superimposition range used for partial registration methods but there were significant differences in the linear distances of the markers placed on the areas not included in superimposition range between whole registration method and partial registration methods used in this study.CONCLUSION: The results of the present study suggest that the validity of superimposition is decreased as superimposition range is reduced in the uperimposition of 3D images constructed with 3D laser scanner for the same subject.