Jäger A, el-Kabarity A, Singelmann C
Department of Orthodontics, University of Göttingen.
J Orofac Orthop. 1997 Feb;58(1):30-43.
The outcome of orthodontic treatment involving early extraction of 4 second molars was evaluated in 52 patients (29 girls, 23 boys). Computer-assisted analysis of cephalograms, casts and panoramic X-rays was performed at the start (T1, mean age 11.5 years) and at the end (T2, mean age 14.4 years) of treatment. Following treatment, mesial migration of upper and lower first molars was counteracted; however, treatment only moderately influenced normal development of the position of the incisors and the profile. At the end of treatment, the third molars had erupted in only 3 patients. Nevertheless, on average a significant mesial movement of these teeth was observed. In addition, there was a significant improvement in the axial inclination of the third molars, especially in the upper arch. This improvement was correlated with the original position of the teeth. All patients needed a longer follow-up period and it seems reasonable that some of them might require a second treatment phase to adjust the position of the third molars.
对52例患者（29名女孩，23名男孩）进行了正畸治疗，该治疗包括早期拔除4颗第二磨牙。在治疗开始时（T1，平均年龄11.5岁）和结束时（T2，平均年龄14.4岁），对头颅侧位片、石膏模型和全景X线片进行了计算机辅助分析。治疗后，上下第一磨牙的近中移动得到了抵消；然而，治疗仅适度影响了切牙位置和面部轮廓的正常发育。治疗结束时，只有3例患者的第三磨牙已萌出。尽管如此，平均观察到这些牙齿有明显的近中移动。此外，第三磨牙的轴倾度有显著改善，尤其是在上颌牙弓。这种改善与牙齿的原始位置相关。所有患者都需要更长的随访期，而且他们中的一些人可能需要第二个治疗阶段来调整第三磨牙的位置，这似乎是合理的。
