Alessandri Bonetti Giulio, Incerti Parenti Serena, Zanarini Matteo, Marini Ida
Department of Orthodontics, Alma Mater Studiorum, University of Bologna, Bologna, Italy.
Pediatr Dent. 2010 Sep-Oct;32(5):407-12.
To compare the effects of extraction of primary maxillary canines and first molars (double extraction approach) vs primary maxillary canines extraction (single extraction approach) in cases of ectopic permanent maxillary canines (PMCs).
Palatally or centrally displaced PMCs were randomly assigned as follows: single extraction (Group 1=29 patients, 52 canines); double extraction (Group 2=30 patients, 56 canines). PMCs inclination to the midline and to the long axis of the lateral incisor, mesiodistal position of the PMCs crown, and first premolars angulation to the midline were measured on panoramic radiographs at T0 and after 18 months (T1), on average. Between-group statistical comparison was carried out on T0-T1 changes for all the radiographic variables. Eruption/noneruption of the PMCs was also assessed.
Group 2 exhibited improvements in PMCs intrabony position among all the examined variables (P<.001), obtaining a greater parallelism between the roots of the PMCs and the adjacent lateral incisors (P<.001). An improved position of the first premolars due to a reduced angulation (P<.001) was also observed. Clinical success rates showed no statistically significant difference.
The double extraction approach proved to be a more effective procedure vs the single extraction approach in improving permanent maxillary canines' intraosseous position.
比较在异位上颌尖牙（PMCs）病例中，拔除上颌乳尖牙和第一磨牙（双拔牙法）与拔除上颌乳尖牙（单拔牙法）的效果。
将腭侧或中央移位的PMCs随机分组如下：单拔牙组（第1组 = 29例患者，52颗尖牙）；双拔牙组（第2组 = 30例患者，56颗尖牙）。平均在T0和18个月后（T1），在全景X线片上测量PMCs相对于中线和侧切牙长轴的倾斜度、PMCs牙冠的近远中位置以及第一前磨牙相对于中线的角度。对所有影像学变量的T0 - T1变化进行组间统计学比较。还评估了PMCs的萌出/未萌出情况。
在所有检查变量中，第2组的PMCs骨内位置均有改善（P <.001），PMCs牙根与相邻侧切牙之间的平行度更高（P <.001）。还观察到由于角度减小，第一前磨牙的位置得到改善（P <.001）。临床成功率无统计学显著差异。
在改善上颌恒牙尖牙的骨内位置方面，双拔牙法被证明比单拔牙法更有效。
