顆路の立体的運動野に関する研究

Abstract

The purpose of this report is to make clear the three dimensional movement of the condyle. The author investigated lateral movements of the center (point C), frontside edge 5 mm (point F), backside edge 5 mm (point B), inside edge 5 mm (point I), and outside edge 5 mm (point O) of the condyle on the horizontal plane by using Denar Pantograph tracing and roentogenogram. Subject was male in age from 23 to 27 years. The results were as follows. 1) The major diameter of the condyle was 19.9±0.54 mm at the right side, 19.5±0.45 mm at the left side and the average value was 19.7±0.34 mm. 2) The distances from facial surface to outside edge and center of the condyle were about 11.4 mm and 21.3 mm respectively. 3) The working side condyle had a complex movement involved rotation and sliding. The displacement and direction had a considerable variation on a case-by-case basis. 4) At the working side condyle center, the displacement was 1.4 mm on the horizontal plane and 1.9 mm on the frontal plane. 5) On the horizontal working side plane, the displacement decreased in order of point F, O, I, C and B. 6) 48 per cent in point C of 28 subject was moved outward and backward on horizontal working side plane, 32 per cent outward and forward and 20 per cent outward on the same plane. 7) The movement area of the working side condyle was -66.5∿88.5° (total 152°) at the right side and -46.5∿74° (total 120.5°) at the left side on the horizontal plane. On the frontal plane, the movement area was -54∿60° (total 114°). 8) The balancing side condyle was moved downward, forward and midward in all cases. 9) In balancing side, the displacement of the condyle center was 3.8 mm in the average and the Bennett angle was 8.8° at the right side and 12.7° at the left side and the average was 10.8° on the horizontal plane. On the frontal plane, the average of the displacement of the condyle center was 3.2 mm. 10) The Bennett angle and the curvature of the condyle path was closely associated with the displacement of the working side condyle. 11) The displacement and the angle of the condyle path by using clutch differed slightly from those by using schiene on the horizontal plane. On the frontal plane, they had apearent differences.