Young T M, Smith R J
Department of Orthodontics, Washington University School of Dental Medicine.
Am J Orthod Dentofacial Orthop. 1993 May;103(5):452-8. doi: 10.1016/S0889-5406(05)81796-2.
Cephalometric radiographs were used to examine soft tissue profiles of 198 orthodontic patients treated with full fixed appliances without extraction of any permanent teeth. Records were selected at random from five sources: cases treated by a Tweed Foundation instructor using the Tweed technique, patients treated with the Begg appliance, patients treated in one of two different practices with pretorqued, preangulated edgewise appliances, and patients treated in two stages with a functional appliance followed by full fixed edgewise appliances. The criteria for selection of cases and the methods of data collection were designed to allow comparisons with data collected by Drobocky and Smith on patients treated with extraction of four first premolars. Although the mean value of soft tissue changes were smaller in the nonextraction patients, the variability of these changes were generally as great as in the four premolar extraction cases. In addition, the percentage of undesirable facial changes was similar in the extraction and nonextraction samples. The results provide additional evidence that it is simplistic and incorrect to blame undesirable facial esthetics after orthodontic treatment on the extraction of premolars.
头影测量X线片用于检查198例接受全固定矫治器治疗且未拔除任何恒牙的正畸患者的软组织侧貌。记录从五个来源随机选取:由Tweed Foundation教员采用Tweed技术治疗的病例、采用Begg矫治器治疗的患者、在两种不同诊所使用预转矩、预成角方丝弓矫治器治疗的患者,以及分两阶段使用功能矫治器随后使用全固定方丝弓矫治器治疗的患者。病例选择标准和数据收集方法旨在便于与Drobocky和Smith收集的拔除四颗第一前磨牙患者的数据进行比较。尽管非拔牙患者软组织变化的平均值较小,但这些变化的变异性通常与四颗前磨牙拔除病例一样大。此外,拔牙和非拔牙样本中不良面部变化的百分比相似。结果提供了更多证据,表明将正畸治疗后不良的面部美学归咎于前磨牙拔除是简单化且错误的。