上顎前突の治療における機能的矯正装置と咬合斜面板との効果の比較

抄録

With a view to studying the differences between the effects of using the activator and the jumping plate for treatment of maxillary protrusion accompanied by mandibular distocclusion and deep overbite, a series of examinations was conducted with 60 patients of eight to twelve years old, comprising 40 patients applied the activator and 20 patients applied the jumping plate. The changes in angles as well as in distances were measured by an X-ray cephalometer before and after the treatment, and the data thus obtained were statistically compared. The results were as follows : 1. In correction of overjet, maxillary incisors markedly tipped lingually in both cases of using the activator and the jumping plate, and no significant differences were observed between the uses of the two appliances in the changes before and after the treatment. On the other hand, for mandibular incisors, there were little changes by the use of the activator, while mandibular incisors tipped labially to a significant extent by the use of the jumping plate. 2. The mandibular plane angle and the ramus angle against the S-N plane showed little changes by the use of the activator, while by the use of the jumping plate, those angles showed significantly great increases accompanied by back- and downward rotations of the mandible. Thus it can be induced that the use of the activator would cause parallel downward shift of the mandible, and the use of the jumping plate would cause changes accompanied by clockwise rotations of the mandible.