| Summary: | 碩士 === 國立成功大學 === 醫學工程研究所碩博士班 === 92 === In the orthodontics, dentists can analyze the functions of teeth and palate from different materials. In these materials, dentists obtain the three dimensional information about bite information and distance between teeth from gypsum dental cast. Besides, dentists also can simulate the orthodontics on the casts. Hence, the dental cast plays an important role on the orthodontics. Because the fragile property of gypsum dental cast and disadvantages of occupying space, these reasons persecute with dentists. Although these problems can be solved by digitizing dental cast, it costs a lot by using laser scanner or computed tomography. Hence, the Shape from Shading method that is developed in our lab past is applied to reconstruct shape of dental cast. Besides, the dental cast is reconstructed partiality every time for obtaining more accuracy virtual result. Then the Thin Plate Splines method is applied to register every part of dental cast to a whole model. The advantage of this method is that permits the matching object to do elastic deformation and retrieve the error of reconstructed. A suitable capturing images system is developed for Shape from shading. And rotated decoders are applied to measure distance between object and CCD camera in this system. We hope that can reduce the error of measurement. Finally, the study result is compared with result that is obtained from laser scanner to estimate the effect of our system. The reconstructed error of partial virtual dental cast is spread from 0.5 mm to -0.5 mm. The reconstructed error of integrated virtual dental cast is spread from 1.09 mm to -1.09 mm.
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