Rocke R T
Orthodontic Center, Westville, IN 46391.
Am J Orthod Dentofacial Orthop. 1994 Oct;106(4):341-50. doi: 10.1016/S0889-5406(94)70054-0.
The straight-wire appliance was developed in part to reduce wire bending and therefore make treatment results more predictable. Because tip prescription is built into the bracket slots, teeth are held at their final crown angulations throughout treatment. Straight-wire brackets are used in an attempt to produce bodily tooth movement. However, teeth tend to tip when a force is applied. This tipping, especially when canines are retracted, can deflect the arch wire causing supereruption of the incisors with a resultant increase in anterior overbite and an open bite in the canine/premolar area. Placing Tip-Edge brackets (TP Orthodontics, Inc., LaPorte, Ind.) on canines and employing tipping and uprighting mechanics on these teeth can overcome these problems. Two cases are presented to illustrate this approach to treatment.
直丝弓矫治器的研发部分是为了减少弯制弓丝,从而使治疗结果更可预测。由于托槽槽沟中预设了转矩,在整个治疗过程中牙齿都保持在其最终的冠倾斜度。使用直丝弓托槽试图实现牙齿整体移动。然而,施加力时牙齿往往会倾斜。这种倾斜,尤其是在尖牙远移时,会使弓丝发生偏移,导致切牙过度萌出,进而使前牙覆合增加,尖牙/前磨牙区出现开牙合。在尖牙上放置Tip-Edge托槽(TP正畸公司,印第安纳州拉波特)并对这些牙齿采用倾斜和直立机制可以克服这些问题。现介绍两个病例以说明这种治疗方法。