Department of Orthodontics, The University of Florence, Italy.
Eur J Orthod. 2011 Dec;33(6):601-7. doi: 10.1093/ejo/cjq139. Epub 2010 Nov 8.
To investigate the effect of rapid maxillary expansion (RME) and/or transpalatal arch (TPA) therapy in combination with deciduous canine extraction on the eruption of palatally displaced canines (PDCs).
Hundred and twenty subjects were enrolled in an RCT based on PDCs diagnosed on panoramic radiographs and they were randomly assigned to one of four study groups. Three treatment groups (TGs) (RME followed by TPA therapy plus extraction of deciduous canines, RME/TPA/EC group, 40 subjects; TPA therapy plus extraction of deciduous canines, TPA/EC group, 25 subjects; extraction of deciduous canines, EC group, 25 subjects) were analyzed. A control group (CG, 30 subjects) received no orthodontic treatment. Prevalence rates of eruption of PDCs in the three TGs were compared with the CG at T2. Predictive features at T1 for successful canine eruption were tested in the three TGs.
The prevalence of canine eruption was 80 per cent for the RME/TPA/EC group, 79 per cent for the TPA/EC group, 62.5 per cent for the EC group, versus 28 per cent in the CG, with statistically significant differences between all the groups, with the exception of the comparison between RME/TPA/EC and TPA/EC. Predictive pretreatment variables for the success of treatment were less severe sectors of canine displacement, prepubertal stages of skeletal maturity, and an open root apex of PDCs.
The use of a TPA in absence of RME can be equally effective than the RME/TPA combination in PDC cases not requiring maxillary expansion, thus reducing the burden of treatment for the patient.
研究快速上颌扩展(RME)和/或经腭弓(TPA)治疗联合乳尖牙拔除对腭侧移位恒尖牙(PDC)萌出的影响。
根据全景片诊断的 PDC 纳入 120 名 RCT 受试者,并随机分为四组研究。三个治疗组(TGs)(RME 后行 TPA 治疗联合乳尖牙拔除、RME/TPA/EC 组,40 例;TPA 治疗联合乳尖牙拔除、TPA/EC 组,25 例;乳尖牙拔除、EC 组,25 例)进行分析。一个对照组(CG,30 例)未接受正畸治疗。在 T2 时比较三个 TGs 中 PDC 萌出的发生率与 CG。在三个 TGs 中测试 T1 时预测恒尖牙成功萌出的特征。
RME/TPA/EC 组恒尖牙萌出率为 80%,TPA/EC 组为 79%,EC 组为 62.5%,CG 组为 28%,所有组之间均有统计学差异,除 RME/TPA/EC 组与 TPA/EC 组之间的比较外。治疗成功的预测性预处理变量为恒尖牙移位程度较轻、骨骼成熟的青春期前阶段以及 PDC 根尖开放。
在不需要上颌扩展的 PDC 病例中,使用 TPA 而不使用 RME 可以与 RME/TPA 联合治疗同样有效,从而减轻患者治疗负担。