Studies on the Retruded Positions and Lateral

Abstract

The mandibular position can be interpreted the meaning of occlusal and condylar position. Furthermore, it is the subject to must be made clear as occlusion is studied in the same way of the mandibular movement.Two experiments were conducted in the two groups, 8 men aged from 19 to 24 (adolescence group) and 6 men aged from 48 to 65 (advanced age group). First, occlusal positions and position of the condyle in swallowing position and capsular position as mandibular retruded position were registered by means of pantograph, and these positions were calculated three-dimentionally. Second, swallowing position and capsular position of the condyle, and lateral position of the condyle were surveyed by radiograph. Then the distance from above measured various occlusal positions and centric occlusion, and the distance from above measured various positions of the condyle and the con. dyle position in centric occlusion were calculated.The following conclusions were obtained:1. Swallowing occlusal position and capsular occlusal position were both located more rear-inferior to centric occlusion in advanced age group than in adolescence group. And capsular occlus al position was located rear-inferior to swallowing one in both groups.2. Swallowing position, capsular position and terminal hinge position of the condyle were all located more rear-inferior to stable condylar position in advanced age group than in adolescence group. Swallowing position of the condyle was located far distant in all, and capsular position, terminal hinge position were followed.3. The amount of rear-inferior-outward mov ement of left and right lateral occlusal positions from centric occlusion was greater in advanced age group than in adolesceece.4. In both adolescence and advanced age, lateral position of the condyle on the left and right, was moved in working side rear-sup rioroutwards of and in balancing side pro-inferiorinwards of stable condylar position. The amount of the movement was greater in adolescence than in advanced age.5. Aboved mentioned findings were proved to be correct by means of radiographic survey, too.