Department of Orthodontics, Bauru Dental School, University of São Paulo, Brazil.
Department of Orthodontics, School of Dental Medicine, Case Western Reserve University, Cleveland, OH, USA.
Eur J Orthod. 2021 Jun 8;43(3):265-273. doi: 10.1093/ejo/cjaa050.
To compare posterior crossbite correction frequency and dentoalveolar changes of the expander with differential opening (EDO) and the fan-type expander (FE).
Two-arm parallel randomized controlled trial.
Forty-eight patients from 7 to 11 years of age were allocated into two groups. Twenty-four patients were treated with the EDO and 24 patients were treated with the FE. Block randomization was performed. The study was single blind. Digital dental models were acquired before treatment and 6 months after rapid maxillary expansion. The primary outcomes were crossbite correction rate and maxillary arch width changes. Secondary outcomes were interincisal diastema, arch perimeter, length, size and shape, and mandibular dental arch changes.
The final sample comprised 24 patients (13 female and 11 male; mean initial age of 7.62 years) in the EDO group and 24 patients (14 female and 10 male; mean initial age of 7.83 years) in the FE group. The crossbites were corrected in 100 per cent of subjects from EDO group and in 75 per cent of patients in FE group. EDO showed greater increases in maxillary intermolar region (P < 0.001), while the FE demonstrated greater increases in the intercanine distance (P = 0.008). Increase in mandibular inter-first permanent molar distance was slightly greater in the EDO group (mean difference of 0.8 mm). Changes in arch length and perimeter were similar in both groups. Both expanders changed the maxillary arch shape. The post-treatment arch shape was larger in the anterior region for FE and in the posterior region in the EDO group.
Discomfort during activation was reported by 54 per cent of the participants. A temporary change in the nasal bridge was reported by one patient from FE group.
Maxillary arch width and shape changes were distinct between the EDO and the FE. Greater transversal increases of the anterior and posterior regions were observed for the FE and the EDO, respectively. A slightly greater mandibular spontaneous expansion was observed for the EDO only at the molar region.
NCT03705871.
比较差动扩弓（EDO）与扇型扩弓（FE）矫正后牙反颌的频率和牙牙槽变化。
双臂平行随机对照试验。
将 7-11 岁的 48 名患者分为两组。24 名患者接受 EDO 治疗，24 名患者接受 FE 治疗。采用区组随机化。研究为单盲。在快速上颌扩张治疗前和 6 个月后获取数字牙模。主要结局是反颌矫正率和上颌弓宽度变化。次要结局是切牙间隙、弓周长、长度、大小和形状以及下颌牙弓的变化。
最终样本包括 EDO 组 24 名患者（13 名女性，11 名男性；平均初始年龄为 7.62 岁）和 FE 组 24 名患者（14 名女性，10 名男性；平均初始年龄为 7.83 岁）。EDO 组的反颌完全矫正率为 100%，FE 组为 75%。EDO 组上颌磨牙区增加明显（P < 0.001），而 FE 组尖牙间距离增加明显（P = 0.008）。EDO 组下颌第一恒磨牙间距离略有增加（平均差值为 0.8mm）。两组的弓长和周长变化相似。两种扩弓器都改变了上颌弓的形状。FE 组治疗后的前区弓形状较大，EDO 组后区弓形状较大。
54%的参与者报告在激活过程中有不适。FE 组有一名患者报告出现暂时性鼻桥改变。
EDO 和 FE 之间的上颌弓宽度和形状变化明显。FE 组的前区和后区横向增加较大，EDO 组则分别较大。EDO 组仅在磨牙区观察到下颌自发性扩张略有增加。
NCT03705871。
