[The vertical changes of orthodontic area with treatment and retention in extraction cases].

The purpose of this study is to determine the vertical changes of orthodontic area during active orthodontic treatment and retention. 10 subjects with Angle class I malocclusion having mean skeletal age of 14 years 3 months were examined. After extraction of first premolars, orthodontic treatments were performed at a mean period of 17.6 months by using "Modified Edgewise Technique"; the Hawley Retainers were used during the retention period for 16.8 months after the active orthodontic treatment. 10 subjects with normal occlusion having mean age 13 years 11 months and 10 subjects with normal occlusion having mean age 15 years 6 months were separated as control groups.