上颌四眼圈簧扩弓后对上颌牙齿及上颌骨变化影响的CBCT研究

Changes of maxillary teeth and maxilla following quad helix maxillary expansion observed by Cone-Beam CT(CBCT)

目的:使用锥体束CT(CBCT)评估上颌四眼簧慢速扩弓后上颌牙齿及上颌骨宽度的变化。方法:选择13例需要综合性正畸治疗的患者(男5例,女8例),平均年龄(14.4±2.2)岁,使用上颌四眼圈簧扩弓。对患者扩弓前(T1)后(T2)的变化进行CBCT扫描,测量扩弓前后两侧尖牙、第一前磨牙、第二前磨牙和第一磨牙之间的牙冠和根尖之间的宽度,第一磨牙的倾斜度,基骨弓和腭中缝宽度的变化。应用SPSS 17.0软件对测量结果进行配对t检验。结果:四眼圈簧扩弓后牙弓变化明显。4对牙的牙间距分别增加了(2.47±1.05)mm、(2.97±1.90)mm、(2.79±1.21)mm、(3.15±1.15)mm,根尖距分别减小了(1.19±0.40)mm、(2.12±0.68)mm、(2.02±0.65)mm、(1.34±0.63)mm,左侧磨牙倾斜度减小了4.45°±2.86°,右侧磨牙倾斜度减小了4.02°±1.45°,基骨弓宽度增加了(2.37±0.96)mm,腭中缝宽度增加了(1.21±0.50)mm,差异均具有统计学意义(P<0.001)。结论:四眼圈簧扩弓器对上颌牙弓的扩弓主要通过牙齿倾斜移动完成,而非整体移动。

Objective： To evaluate dental and skeletal changes following slow maxillary expansion with quad helix using Cone-Beam computer tomography（ CBCT）. Methods： 13 patients（ 5males and 8 females,mean age 14. 38 ± 2. 22 years） requiring maxillary expansion as a part of their comprehensive orthodontic treatment were included. Each patient had CBCT images taken pre-（ T1） and post-（ T2） maxillary expansion with quad helix. Changes of the distances between bilateral canines,first premolars,second premolars,first molars,the width of basal bone and palatal suture were measured. paired t-test results were analyzed using SPSS 17. 0 software. Results： The distances between the 4 bilateral teeth increased by（ 2. 47 ± 1. 05） mm,（ 2. 97 ± 1. 90） mm,（ 2. 79 ± 1. 21）mm and（ 3. 15 ± 1. 15） mm,the apical distances decreased by（ 1. 19 ± 0. 40） mm,（ 2. 12 ± 0. 68） mm,（ 2. 02 ± 0. 65） mm and（ 1. 34 ± 0. 63） mm,respectively. The inclination of the first molars were decreased by（ 4. 45 ± 2. 86） ° and（ 4. 02 ± 1. 45） ° on the left and right side respectively. The width of basal bone and palatal suture increased by（ 2. 37 ± 0. 96） mm and（ 1. 21 ± 0. 50） mm respectively,the differences between T1 and T2 were all statistically different（ P 〈0. 001）. Conclusion： Quad helix expands maxillary arch by greater dental changes than by skeletal changes.