[The regulation of re-selection form in the aesthetic factor of upper anterior artificial teeth]

Sixty one cases of selection error due to the esthetic factors of artificial tooth forms were investigated out of the 72 cases of selection error which were committed at the department of Prodosthontics in Nihon University school of dentistry at Matsudo for 17 years from 1971 to 1988. The following were the results of investigation, 1. The cases of S-type were changed to those of ST-type, which emphasized the Tapering type factors. 2. The those of ST-type were changed to those of SO-type and S-type which emphasized the Ovoid type factors and got rid of the Tapering type factors. 3. The those of SO-type were changed to those of STO-type which emphasized the Tapering type factors. 4. The those of T-type were changed to those of TO-type which emphasized the Ovoid type factors. 5. The those of O-type were changed to those of TO-type and STO-type which emphasized the Tapering and Square type factors. The regulations of re-selection showed the tendency of changing from single form to complex form, emphasizing the Tapering type factors.