Bai Ding, Xiao Liwei, Chen Yangxi
Department of Orthodontics, West China College of Stomatology, Sichuan University, Chengdu 610041.
Sheng Wu Yi Xue Gong Cheng Xue Za Zhi. 2002 Jun;19(2):287-90.
To evaluate the effects of preadjusted bracket base shape, the morphology of tooth surface where bracket locates, and the suitability relevant to location of bracket on the preadjusted edgewise appliance technique. 1 vertical curve and 3 horizontal curves of the clinical crown surface of anterior teeth and bicuspid teeth were measured with the precise contour instrument on the 60 plaster models of the subjects who have normal occlusion in Sichuan province. It was found that variation of identical curve exists at the different heights between the teeth and between the individuals; the surface of the central zone of tooth-crown gradually protrudes from incisors to bicuspid teeth in the vertical direction, and the mesial contour of cuspid is more prominent than the distal in the horizontal direction.
The 4 mm X 3 mm contour of the vestibular central zone of identical tooth-crown in different individuals is fairly stable; it is suitable for the location of preadjusted brackets. The vertical shifts of brackets could change the preadjusted torque value and the design of cuspid bracket should have the distinction between mesial and distal shape.
为评估预调整托槽基底形状、托槽所在牙面形态以及预调整方丝弓矫治技术中托槽位置的适配性。使用精密轮廓仪在四川省60例正常咬合受试者的石膏模型上测量前牙和双尖牙临床冠面的1条垂直曲线和3条水平曲线。发现同一曲线在牙间不同高度以及个体之间存在变异；牙冠中央区表面在垂直方向上从切牙到双尖牙逐渐突出，在水平方向上尖牙的近中轮廓比远中更突出。
不同个体同一牙冠前庭中央区4mm×3mm的轮廓相当稳定；适合预调整托槽的定位。托槽的垂直移位会改变预调整扭矩值，尖牙托槽的设计应有近远中形态区别。
