Abstract
During clenching at the intercuspal position, the direction and the amount of teeth displacement are different even between occluding upper and lower teeth of one subject. Therefore, there is a possibility of change in the occlusal contact relation depending on the clenching force. In this investigation, teeth displacements were measured with the Displacement Transducer type M-3 and interoccluion at the intercuspal position was recorded.
The conclusions were as follows:
1. Using black silicone, agar and silicone impression materials, real occlusal contacts can be recorded in addition to close occlusal areas.
2. The clenching force is related to the amount rather than the direction of teeth displacements.
3. The more different the direction and the amount of displacements between upper and lower teeth are, the greater the change of the occlusal contact relation becomes.
4. The occlusal contact relation is changed depending on the clenching force, which is the buccal parts of the occlusal surface becomes closer, and real occlusal contacts increase.
5. Since the number of actual contact is few in dental arches in light clenching at the intercuspal position, the mandibular position is unstable. Thus the mandibular position in heavy clenching with more contacts should be a reference.
