抄録
The stability of the complete denture during mastication and deglutition are known to depend on the occlusion. Presently, bilateral balanced occlusion is believed to be one of the ideal types of occlusion for the complete denture. However, there have been some criticisms against it, based on the discrepancy found between the occlusion on an articulator and actual occlusal contacts during the oral function.
In this study, occlusal contacts during mastication were studied in order to re-clarify which type of occlusion is the best for complete dentures.
Three patients were asked to wear an upper complete denture and a lower bilateral distal exten-sion partial denture, constructed specially to suit for the experimental design. This allowed the occlusal patterns to be exchanged the molar region into bilateral balanced occlusion, lingualized occlusion and disclusion. Occlusal contacts both on the chewing side and on the nonchewing side in the premolar and molar region were studied.
The results are as follows;
1. The initial occlusal contacts occurred approximately at the same time in the bilateral balanced occlusion and in the lingualized occlusion, but occurred earlier than in the disclusion.
2. The occlusal contacts, occurred in the following order : molar region of the nonchewing side, the premolar region of the nonchewing side, the premolar region of the chewing side and the molar region of the chewing side.
3. From these results, we could expect dentures to be depressed on the chewing side and be elevated on the nonchewing side. Also rotational movements of dentures around the masticatory center will be created.
In order to avoid these movements we believe that distal balancing contact is necessary for the occlusion of complete denture.
