Angle Orthod. 2017 Jul;87(4):505-512. doi: 10.2319/120616-875.1. Epub 2017 Apr 12.
To evaluate the skeletal, dentoalveolar, and soft tissue effects of skeletally anchored Class II elastics and compare them with a matched control group treated by a monobloc appliance for the correction of skeletal Class II malocclusion due to mandibular retrusion.
Twelve patients (6 girls, 6 boys) were randomly divided into two groups. In the elastics group, six patients (12.9 ± 1.5 years of age; 3 boys, 3 girls) were treated with skeletally anchored Class II elastics. Two miniplates were placed bilaterally at the ramus of the mandible and the other two miniplates were placed at the aperture piriformis area of the maxilla. In the monobloc group (3 boys and 3 girls; mean age, 12.3 ± 1.6 years), patients used the monobloc appliance. The changes observed in each phase of treatment were evaluated using the Wilcoxon matched-pair sign test. Intergroup comparisons at the initial phase of treatment were analyzed by the Mann-Whitney U test.
There were statistically significant group differences in Co-Gn, B-VRL, U1-PP, U1-VRL, Ls-VRL, with significant increases in these parameters in the elastics group (P < .05). The mandibular incisors were protruded in the monobloc group (5.45 ± 1.23°), whereas they were retruded in the elastics group (-3.01 ± 1.66°; P < .01).
The undesirable dentoalveolar effects of the monobloc appliance were eliminated by using miniplate anchorage. Favorable skeletal outcomes can be achieved by skeletal anchorage therapies which could be an alternative to treat skeletal Class II patients with mandibular deficiency.
评估骨锚定 II 类弹性体的骨骼、牙颌和软组织效果,并将其与使用单块矫治器治疗因下颌后缩导致的骨骼 II 类错畸形的匹配对照组进行比较。
将 12 名患者(6 名女孩,6 名男孩)随机分为两组。在弹性体组中,6 名患者(12.9 ± 1.5 岁;3 名男孩,3 名女孩)接受骨锚定 II 类弹性体治疗。在下颌支和上颌梨状孔区两侧各放置 2 个迷你板,另外 2 个迷你板放置在上颌。在单块组(3 名男孩和 3 名女孩;平均年龄 12.3 ± 1.6 岁)中,患者使用单块矫治器。使用 Wilcoxon 配对符号检验评估治疗各阶段观察到的变化。通过 Mann-Whitney U 检验分析治疗初始阶段的组间差异。
Co-Gn、B-VRL、U1-PP、U1-VRL 和 Ls-VRL 两组间存在统计学显著差异,弹性体组这些参数显著增加(P <.05)。单块组下颌切牙突出(5.45 ± 1.23°),而弹性体组则后退(-3.01 ± 1.66°;P <.01)。
使用迷你板锚固消除了单块矫治器的不良牙颌效果。通过骨锚固治疗可以获得有利的骨骼结果,这可能是治疗下颌骨不足的骨骼 II 类患者的替代方法。