The Application Of Three-dimensional Scanning In Quantitative Study Of Cleft Lip Patients

The assessment of treatment outcome of cleft lip and palate repair has been the focused topic of cleft lip (and palate) research for such a long time. However, no agreement has been reached on the issue of evaluation method, standard and system. With the development of three-dimensional imaging technology, three-dimensional image and measurement have been considered as the most promising method in cleft lip and palate assessment. This research use the three-dimensional hand-held scanner to analyze the facial morphology of 18 patients with unilateral cleft lip in order to study the validity and reproducibility of three-dimensional scanning measurement and its application in quantitative study of cleft lip patients.18 patients with unilateral cleft lip were scanned by a three-dimensional hand-held scanner in a day before surgery and a month after surgery accordingly. Anthropometric landmarks both in the cleft and noncleft sides were identified and measured on the three-dimensional images. Direct measurement on the same anthropometric landmarks was done before surgery as well. All the collected data was analyzed by SPSS13.0 statistic software. Validity was defined by accuracy and bias. Reproducibility was defined by reliability and precision. The evaluation of cleft lip repair was defined by the difference between measurements before and after surgery and the asymmetry ratio of all measurement.Using the three-dimensional hand-held scanner to do three-dimensional scanning measurement, all the digital values correlated highly with direct measurement, the mean correlation coefficient was 0.92. The difference between digital values and direct measurement had no statistical significance. Both of the reliability and precision of three-dimensional scanning measurement were high. The mean correlation coefficient of test and re-test measurement was 0.95 and the overall precision of all digital measurement was less than 0.1mm. There were significant differences between all measurements before and after surgery except the height of lateral upper lip. The asymmetry ratios of all measurement were within the normal range except the asymmetry ratio of columella length.The following conclusion can be reached from the result of this research. First, compared with direct measurement, the validity and reproducibility of three-dimensional scanning measurement using a three-dimensional hand-held scanner is high and comparable. It can be applied in the study of facial morphology of congenital defects. And it can even be applied to infants with cleft lip (and palate). Second, three-dimensional hand-held scanner can also be applied in quantitative study of cleft lip (and palate) patients to evaluate if the measurement is within normal range and the symmetry of both sides, so that the assessment of treatment outcome can be concluded. Because of the ability of quick imaging and precise measurement, three-dimensional hand-held scanner can even be applied in the data-base establishment of craniofacial characterization and animation of cleft repair surgery in the future.