METHODS: Patients in the mixed dentition were included with a transverse discrepancy between the two arches of at least 3 mm. A conventional RME screw was compared to a new expansion screw (Leaf expander) designed to produce SME. Both screws were incorporated in a fixed expander. The primary outcome was the difference of the facial tissue changes in the nasal area measured on facial 3D images captured immediately before application of the expander (T0) and after one year of retention, immediately after the expander removal (T1). Secondary outcomes were soft tissue changes of other facial regions (mouth, lips, and chin). Analysis of covariance was used for statistical analysis.
RESULTS: Fourteen patients were allocated to the RME group, and 14 patients were allocated to the SME group. There were no dropouts. Nasal width change showed a difference between the two groups (1.3 mm greater in the RME group, 95% CI from 0.4 to 2.2, P = 0.005). Also, intercanthal width showed a difference between treatments (0.7 mm greater in the RME group, 95% CI from 0.0 to 1.3, P = 0.044). Nasal columella width, mouth width, nasal tip angle, upper lip angle, and lower lip angle did not show any statistically significant differences. The Y-axis (anterior-posterior) components of the nasal landmark showed a statistically significant difference between the two groups (0.5 mm of forward displacement greater in the RME group, 95% CI from 0.0 to 1.2, P = 0.040). Also, Z-axis (superior-inferior) components of the lower lip landmark was statistically significant (0.9 mm of downward displacement in favor of the RME group, 95% CI from 0.1 to 1.7, P = 0.027). All the other comparisons of the three-dimensional assessments were not statistically significant.
CONCLUSIONS: RME produced significant facial soft tissue changes when compared to SME. RME induced greater increases in both nasal and intercanthal widths (1.3 mm and 0.7 mm, respectively). These findings, though statistically significant, probably are not clinically relevant. Trial registration ISRCTN, ISRCTN18263886. Registered 8 November 2016, https://www.isrctn.com/ISRCTN18263886?q=Franchi&filters=&sort=&offset=2&totalResults=2&page=1&pageSize=10.
方法:包含混合牙列的患者,两个牙弓之间的横向差异至少为3mm。将常规RME螺杆与设计用于生产SME的新型膨胀螺杆(叶片膨胀器)进行了比较。两个螺钉都包含在固定的扩张器中。主要结果是在应用扩张器之前(T0)和保留一年后立即捕获的面部3D图像上测得的鼻腔区域面部组织变化的差异。在膨胀机移除后立即(T1)。次要结果是其他面部区域的软组织变化(口腔,嘴唇,和下巴)。采用协方差分析进行统计分析。
结果:14名患者被分配到RME组,14例患者被分配到SME组.没有辍学。鼻腔宽度变化显示两组之间存在差异(RME组大于1.3mm,95%CI从0.4到2.2,P=0.005)。此外,can间宽度显示出治疗之间的差异(RME组大0.7mm,95%CI从0.0到1.3,P=0.044)。鼻小柱宽度,口宽,鼻尖角度,上唇角,和下唇角没有显示任何统计学上的显著差异。鼻标志的Y轴(前后)分量在两组之间显示出统计学上的显着差异(RME组中向前位移更大0.5mm,95%CI从0.0到1.2,P=0.040)。此外,下唇标志的Z轴(上下)分量具有统计学意义(向下位移0.9mm,有利于RME组,95%CI从0.1到1.7,P=0.027)。三维评估的所有其他比较均无统计学意义。
结论:与SME相比,RME产生了明显的面部软组织变化。RME引起更大的增加,在鼻和can间宽度(1.3毫米和0.7毫米,分别)。这些发现,尽管具有统计学意义,可能与临床无关。ISRCTN试用注册,ISRCTN18263886。2016年11月8日注册,https://www.isrctn.com/ISRCTN18263886?q=Franchi&filters=&sort=&offset=2&totalResults=2&page=1&pageSize=10。