下顎右側第一大臼歯欠損を伴う成人前歯部叢生症例

A 22-year and 10-month-old female exhibited severe anterior crowding with missing of the lower right first molar. She was diagnosed as anterior crowding with high mandibular plane angle due to constricted dental arches and mesial inclination of the upper right and lower left molars. Following extraction of the both carious upper second molars, we laterally expanded the constricted dental arches and uprighted the upper right and lower left molars to correct the discrepancy. The total treatment time was 36 months. After treatment, anterior crowding was corrected and an acceptable occlusion with harmonious profile was obtained. In spite of the small amount of reduction, the acceptable occlusion was maintained without recurrence of anterior crowding after 26-month retention period.