1992 Volume 4 Issue 3 Pages 389-402
For the diagnosis of TMJ internal derangement, it is important both to clarify the shapes and the relation of condyle and articular disk, and also to undertake functional analysis of TMJ movement.
Recently the effectiveness of TMJ fluoroscopy has been recognized.
However, it is sometimes difficult to interpretate its because the surrounding bones overlap the TMJ components.
In the present study we tried to apply a digital subtraction system, which is already widely used in clinical medicine for TMJ fluoroscopy and compared its image with the traditional fluoroscopic one. The digital subtraction system can remove the overlapping of surrounding bones and make it easy to observe TMJ components. By using this system in MASK mode we observed a flow of contrast medium indicating the shape, location and existence of perforation of articular disk more clearly than the traditional method.
Using Time Interval Difference (TID) mode we observed TMJ movement (from opening to closing of mouth) more accurately than before. This mode is effective for the classification and analysis of TMJ internal derangement which shows various disturbances of movement. Furthemore, it might be possible to compare the data by this method with those obtained by using other TMJ movement, analysis equipment.
