摘要
目的探讨不同拔牙正畸模式下，成人牙弓形态变化的规律。方法选40例拔牙正畸病例，分为G1组20例：拔除四颗第一前磨牙，其中男13例，女7例，平均22岁；G2组20例：拔除四颗第二前磨牙，其中男8例，女12例，平均24岁。用模型测量观察矫治前后牙弓长度及尖牙区、前磨牙区和磨牙区宽度；用X线头影测量观察矫治前后切牙内收及磨牙前移的距离。对模型及头影测量结果进行统计学处理。结果矢状向上，拔牙正畸后，G1组切牙内收幅度较G2组大[（3．70±2．41）mm和（2．85±0．32）mm，P=0．0433]，G2组磨牙前移距离较G1组大[（2．45±0．53）mm和（3．96±0．40）mm，P=0．0124]；两组间矫治前后牙弓长度改变的差异无统计学意义。横向上，拔牙正畸后，G1组尖牙区宽度增加，前磨牙及磨牙区宽度减小；G2组，尖牙及前磨牙区宽度增加，磨牙区宽度减小。其中，两组间矫治前后尖牙区宽度增加的差异无统计学意义；G2组磨牙间宽度减少量较G1组大。结论不同拔牙正畸模式可影响牙齿矢状向的位移并造成牙弓宽度改变的差异。
Objective To investigate dental arch changes after the extractions of four first or second premolar extractions in adults. Methods Forty patients were randomly selected from completed extraction cases and divided into two groups （G1 and G2）. G1 comprised 20 patients （13 males, 7 females, mean age 22 years） treated with 4 first premolar extractions. G2 included 20 patients （8 males, 12 females, mean age 24 years） with 4 second premolar extractions. Positions of incisors and first molars, dental arch length as well as dental width were measured on cephalograms and dental casts before and after treatment. SAS 8. 02 software package was used for statistical analysis. Results Sagittaliy, significantly greater mean incisor retraction was found in G1 than in G2 [（3.70±2. 41）mm and （2. 85±0. 32）mm, P=0. 0433] and significantly greater mean molar forward movement was found in G2 than in G1 E（2.45±0. 53）mm and （3. 96±0. 40） mm, P=0. 0124]. Transversely, the interpremolar and intermolar widths decreased in G1, and intercanine width increased after treatment. The intercanine and interpremolar widths in G2 increased, and intermolar width decreased after treatment. There was significantly greater mean intermolar-width reduction in G2 than in G1 and significantly greater mean interpremolar-width reduction in G1 than in G2 （P〈0. 01）. Conclusions Different premolar extraction sequences could have different impact on dental arch both sagittally and transversely in adults.
出处
《中华口腔正畸学杂志》
2011年第2期97-101,共5页
Chinese Journal of Orthodontics
基金
上海高校创新团队发展计划资助
上海市科学技术委员会资助（项目编号：08411961600）
国家自然科学基金资助（项目编号：10972142）
关键词
成人
拔牙正畸
牙弓宽度
牙弓长度
错[牙合]畸形
Adult
Premolar extractions
Dental arch width
Dental arch length
Malocclusion
