[Cuspid protection and muscular reaction]

In an epidemiological study we found bilateral cuspid guidance in only 4, and unilateral cuspid guidance in 3 patients out of 247 patients examined. This suggest that cuspid guidance is a rare form of articulation. In the experimental part of this study the electric activity of the masseter and anterior temporal muscles was measured during empty mastication before and after the canines were treated with build-ups in a patient group with muscular and TMJ problems and matched against the results obtained in a control group of 10 healthy probands. Apart from the mean muscle activity also the path of excursion was recorded. Both values were combined in activity/path diagrams providing information on the muscular response to different forms of occlusion. Existing balancing contacts in mediotrusion, for instance, may produce high activities. With cuspid build-ups allowing correct cuspid guidance the patients with muscular and TMJ problems were symptom-free after just three days. After approx. one year the patients and the probands were recalled for a follow-up check. These and other results are discussed.