Damon-Ⅲ自锁托槽矫治安氏Ⅱ类2分类错畸形患者下颌位置及面部比例的变化

Changes of mandibular position and facial ratio of patients with angle class Ⅱ division 2 malocclusion by Damon-Ⅲ self-locking brackets technique

背景:自锁托槽直丝弓矫治技术是一种低摩擦轻力矫治技术,其无需结扎的自锁托槽与高性能的弹性弓丝的结合使用,带来了临床的高效矫治和固定正畸技术革命性的改变。目的:探讨Damon-Ⅲ自锁托槽矫治技术治疗安氏Ⅱ类2分类错畸形患者治疗前后的硬组织变化。方法:选择采用Damon-Ⅲ自锁托槽矫治技术和Roth直丝弓矫治技术治疗的安氏Ⅱ类2分类错畸形患者各13例,治疗前后拍摄患者头颅侧位X线片并进行测量。结果与结论:Damon-Ⅲ自锁组和Roth直丝组治疗后蝶鞍点-鼻根点-上牙槽座点角增大,下牙槽座点角减小,说明治疗后上下颌矢状向的不调得到了纠正;治疗后与自锁组比较,直丝组下颌有顺时针旋转趋势,下后牙升高量不明显(P<0.05),下前牙唇倾较明显(P<0.05)。提示Damon-Ⅲ自锁托槽配合平面导板+Ⅱ类牵引引起下颌及面部比例的改变比直丝弓托槽配合平面导板+Ⅱ类牵引更明显,在下前牙唇倾度上有良好的控制。

BACKGROUND：Self-locking brackets straight wire appliance is a kind of low fraction and light force correction technique.The combination of self-locking brackets without ligation and high-performance elastic arch wire provide revolutionary change of the efficient correction and fixed orthodontic technique on the clinical treatment.OBJECTIVE：To investigate the changes of mandibular position and facial ratio of patients with angle class Ⅱ division 2 malocclusion by Damon-Ⅲ self-locking brackets technique.METHODS：The sample was consisted of 13 patients with angle class Ⅱ division 2 malocclusion treated by traditional Roth straight wire appliance and 13 patients with angle class Ⅱ division 2 malocclusion treated by Damon-Ⅲ self-locking brackets technique.The pre-and after-treatment cephalometric films were measured to assess the treatment effect.RESULTS AND CONCLUSION：After treatment,the sella-nasion-point A（SNA） angle was increased in Damon-Ⅲ self-locking brackets group and Roth straight wire appliance group,and the sella-nasion-point B（SNB） angle was decreased.It indicated that the mandible in two groups changed significantly in sagittal direction,and had the trend to increase in vertical.Compared with the self-locking brackets group after treatment,the lower mandible had the clockwise trend and the increasing of the mandibular posterior alveolar was not obvious（P 0.05）,the lower incisors inclined was obvious（P 0.05）.The study showed that the changes of the lower mandible and facial proportion caused by the Damon-Ⅲ self-locking brackets combined with occlusal guide plate＋Class Ⅱ traction was more obvious than the changes caused by Roth straight wire appliance combined with occlusal guide plate＋Class Ⅱ traction,and had the favorable regulation on the lower incisors inclination.