Donohue V E, Marshman L A G, Winchester L J
Queen Victoria Hospital, East Grinstead, West Sussex, UK.
Eur J Orthod. 2004 Aug;26(4):411-20. doi: 10.1093/ejo/26.4.411.
Maxillary expansion using either a quadhelix appliance (Qx) or a nickel titanium palatal expander (Nt) was prospectively compared in 28 consecutive new patients (19 female, nine male) presenting with posterior buccal segment crossbites. Study models taken at each activation were measured to determine the mean maxillary expansion efficacy (Emax) and the mean expansion rate (m(max)) across the first molars and first premolars. Patient discomfort was assessed using visual analogue scores, and cost-effectiveness was also considered. Neither Emax nor m(max) differed significantly between Qx and Nt across either the first molars or the first premolars. However, both Emax and m(max) were significantly greater across the first molars than across the first premolars only with Qx (Emax: 8.4 +/- 0.7 mm versus 5.1 +/- 0.6 mm, P = 0.001; m(max): 0.09 +/- 0.005 mm/day versus 0.05 +/- 0.006 mm/day, P = 0.0001). In addition, greater variance was apparent in m(max) with Nt than with Qx across both the first molars and the first premolars. Overall, Qx and Nt elicited similar discomfort. However, significantly less was reported with Nt on days 6 (P = 0.04) and 7 (P= 0.03) following the second 'activation'. These preliminary results suggest that Qx and Nt are equally efficacious maxillary expanders. However, Qx expansion appeared significantly more controlled, as well as more individually predictable in expansion rate. Overall, Qx and Nt probably elicit similar discomfort, but significantly less discomfort may be seen with Nt following the second activation. Finally, because more than one appliance is invariably required with Nt, Qx expansion is potentially less costly.
对28例连续就诊的患有后牙颊侧段反牙合的新患者（19名女性，9名男性）进行前瞻性比较，分别使用四螺旋矫治器（Qx）或镍钛腭中缝扩展器（Nt）进行上颌扩弓。测量每次加力时制取的研究模型，以确定第一磨牙和第一前磨牙处的平均上颌扩弓效果（Emax）和平均扩弓速率（m(max)）。使用视觉模拟评分评估患者的不适程度，并考虑成本效益。在第一磨牙或第一前磨牙处，Qx和Nt的Emax和m(max)均无显著差异。然而，仅在使用Qx时，第一磨牙处的Emax和m(max)均显著大于第一前磨牙处（Emax：8.4±0.7mm对5.1±0.6mm，P = 0.001；m(max)：0.09±0.005mm/天对0.05±0.006mm/天，P = 0.0001）。此外，在第一磨牙和第一前磨牙处，Nt的m(max)方差均明显大于Qx。总体而言，Qx和Nt引起的不适程度相似。然而，在第二次“加力”后的第6天（P = 0.04）和第7天（P = 0.03），Nt引起的不适报告明显较少。这些初步结果表明，Qx和Nt是同样有效的上颌扩弓器。然而，Qx的扩弓似乎更可控，扩弓速率的个体可预测性也更高。总体而言，Qx和Nt可能引起相似的不适，但在第二次加力后，Nt引起的不适可能明显较少。最后，由于使用Nt通常需要不止一种矫治器，Qx扩弓的成本可能更低。
