1992 Volume 34 Issue 1 Pages 20-32
The purpose of this study was to examine occlusal traumatism and to evaluate the effect of occlusal adjustment in the retruded contact position RCP). An RCP mandibular position-f i (xing device, which enabled the mandible to be guided and fixed in the RCP, was newly developed. With this device, occlusal contact area (OCA) and luminosity grade 1 (LG 1) with the mandible in the RCP were measured by use of an image analyzer system.
The subjects were 10 patients diagnosed as having premature contact in the RCP, i. e., occlusal traumatism. The findings in this normal group (indi viduals without occlusal traumatism of the premature contact teeth in the RCP).
The results obtained were as follows:
1) On examination of the ratio of the LG 1 in the RCP to that in the intercuspal occlusal position, the value in the patient group was found to be relatively high.
2) On examining the ratio of LG 1 to OCA, which reflects the degree of occlusal contact force, we found that the value in the RCP was significantly higher in the patient group than in the normal group p<0.05).
(3) In the RCP, EMG surface bursts were observed in the anterior portion of the temporal muscle on the side displaying premature contact in all of the subjects.
