Biprogressive Therapy 에 依한 Angle Ⅱ級1類 不正咬合의 矯正治驗例

Case Reports of Angle´s Class Ⅱ, Division 1 malocclusions treated by Bioprogressive Therapy

Widths between the first permanent molars and the mesio-distal widths of the four anterior teeth were measured on 32 lower and 33 upper dental casts of young adults aged 18-25 yerars. The casts were, grouped in five categories-two where no anterior crowding existed, and three in which varying degrees of crowding were present. Subjects with a difference between arch width and anterior tooth widths greater than 4mm in the upper arch, or 10mm in the lower arch, rarely had crowding. As arch width changes very little from age 7 onwards, measurements at this age maybe used as a screening mechansim for future arch crowding.