抄録
The hinge axis is the starting point of gnathology. Clinically, the region which can be effectively used as the hinge axis is limited to the very first period of hinge rotation during jaw opening. Opening beyond this is not rotation centered around the condyle, but is rather rotation of the entire mandible around an axis in the body of the mandible. In other words, the condyle moves anterior and the angle of the mandible moves posterior, in the opposite direction.
In the aging society of today, there seems to be an increase in patients having infraocclusion where there is a decease in the vertical maxillomandibular distance. The position of the mandible in these patients brings about a posterior displacement of the mandible together with infraocclusion, and posterior deviation of the condyle is often seen.
Carrying out prosthetic treatment under conditions like this will interfere with normal masticatory function. Therefore, it is desirable to restore the occlusion to a condition where the position of the condyle has been placed back in its correct location.
In cases like this, it becomes possible to take the interocclusal record with the posteriorly deviated condyle in its correct position by clinically utilizing the anterior translation of the Condyle which accompanies the previously mentioned opening of the mouth.
In order to clinically verify the above hypothesis, using temporomandibular joint radiographs, I would like to compare and explain the condylar position prior to treatment, and changes in the position after elevation of the occlusion.
