使用MBT托槽关闭拔牙间隙的Pancherz头影测量分析

Pancherz analysis for space closure with the use of MBT brackets

目的 本文研究目的为采用3MunitekMBT托槽,对需采用最大强支抗进行矫治的双颌前突或前牙深覆盖患者,通过一步滑动法和两步滑动法关闭上颌拔牙间隙,研究两组之间上颌磨牙及切牙移动量的差异。方法 一步滑动法组包括1 5例患者(男5例,女1 0例,平均年龄1 2 .4±1 .1岁) ,上颌采用强支抗(头帽+TPA) ,上颌牙弓排齐后,滑动法使六个前牙一起后移,关闭上颌拔牙间隙。两步滑动法组包括1 5例患者(男5例,女1 0例,平均年龄1 2 .6±1 .1岁) ,上颌采用强支抗(头帽+TPA) ,上颌牙弓排齐后,向远中牵引尖牙到位,滑动法使四个前牙一起后移,关闭上颌拔牙间隙。在治疗开始和治疗结束后拍摄头颅侧位片,使用Pancherz头影测量方法分析。结果 一步滑动法组和两步滑动法组上颌切牙切缘舌向移动量分别为4 .2±1 .8mm和4 .5±2 .6mm ;上颌磨牙近中移动量分别为4 .6±1 .7mm和4 .7±3.1mm ,两组之间无显著差异。一步滑动法组覆盖减少为3.0±2 .6mm ,两步滑动法组覆盖减少为3.6±2 .6mm ,两组之间无显著差异。结论 本研究的初步结果表明,MBT直丝弓矫治器以其独特的托槽设计,使一步滑动法组和两步滑动法组上颌磨牙近中移动量及上颌切牙切缘舌向量移动量无统计学差异。

Objective To compare the amount of mesial movement of upper first molar and lingual movement of upper incisor between one-step and two-step sliding groups with the use of Pancherz analysis.Methods One-step sliding group consisted of fifteen subjects (5 males and 10 females, average age of 12.4± 1.1 years) with increased overjet. When use of headgear with/without TPA, upper six anterior teeth slid distally to close space after alignment. Two-step sliding group consisted of fifteen subjects (5 males and 10 females, average age of 12.6± 1.1 years) with increased overjet. When use of headgear with/without TPA, upper four anterior teeth slid distally to close space after alignment and retraction of canine into proper position. Cephalgrams were taken at the beginning of the treatment and at the end of the treatment and were analyzed with Pancherz analysis.Results The amount of lingual movement of the tip of the upper incisor was 4.2mm and 4.5mm and the amount of mesial movement of upper first molars was 4.6mm and 4.7mm in one-step sliding group and two-step sliding group, respectively. There was no significant difference between the two groups. The reduction of the overjet was 3.0mm and 3.6mm in one-step sliding group and two-step sliding group, respectively. There was no significant difference between the two groups.Conclusion Due to the characteristics of MBT brackets, the preliminary results of the current study suggested that there was no significant difference in the amount of lingual movement of the tip of the upper incisor and mesial movement of upper first molars between the two groups.