An object of the present invention is to provide a method for quickly acquiring three-dimensional shape data of upper and lower tooth rows. The present invention provides a method for calculating a distance between the upper and lower tooth rows at a high speed, from the three-dimensional shape data of the upper and lower tooth rows thus acquired. Based on technology behind the above methods, the present invention provides a method and an apparatus for performing simulation display of the three-dimensional shapes and an occlusal contact region of the upper and lower tooth rows at a high speed. A jaw movement sensor 30 is fitted to an examinee, and jaw movement data 35 on jaw movement of the examinee is acquired. An impression plate 20 including a rigid flat plate having a top surface and a bottom surface each coated with an impression material is inserted between upper and lower tooth rows of the examinee to which the jaw movement sensor 30 is fitted, and the examinee is guided to perform a temporary occlusion. Impressions left on the impression material 20 and a gauge mark provided on the rigid flat plate are measured by using a three-dimensional shape measuring instrument 25, whereby the three-dimensional shape data of the upper and lower tooth rows and gauge mark data are acquired. Simulation display of movement of the upper and lower tooth rows and occlusal contact regions of the examinee is performed based on the three-dimensional shape data of the upper and lower tooth rows and the gauge mark data, and jaw position data at a time of temporary occlusion and the jaw movement data.
