This study aims to specify post-treatment changes occurring in the dentofacial complex displaced by orthodontic treatment. Eighteen patients selected for this study had overjet of 5mm or more before treatment, were then treated by the edgewise technique, had the upper and lower second molars erupted completely after the treatment, had a time-elapse of at least a year between post-treatment and post-retention, and were with maxillary protrusion and 15 years old or older at post-retention. With the use of gnathostatic models and roentgenographic cephalograms, angles and distances were measured and compared before and after treatment. The results were as follows : 1. Decrease by treatment was found in ∠ANB and significant changes were indicated from pre-treatment to post-retention, whereas almost no changes were indicated from post-treatment to post-retention. 2. Overbite had greater percentages of relapse than overjet, showing a tendency toward likelihood to relapse. 3. Althought the upper incisors were comparatively stable after treatment, the lower incisors tended to relapse to pre-treatment positions.
