Angle Orthod. 2018 Sep;88(5):523-529. doi: 10.2319/102717-728.1. Epub 2018 Apr 23.
To evaluate the long-term effects of rapid maxillary expansion (RME) and posterior bite block (BB) in prepubertal subjects with dentoskeletal open bite.
The treatment group (TG) comprised 16 subjects (14 girls, 2 boys) with dentoskeletal open bite with a mean age of 8.1 ± 1.1 years treated with RME and BB. Three consecutive lateral cephalograms were available before treatment (T1), at the end of the active treatment with the RME and BB (T2), and at a follow-up observation at least 4 years after the completion of treatment (T3). The TG was compared with a control group (CG) of 16 subjects (14 girls, 2 boys) matched for sex, age, and vertical skeletal pattern. An independent sample t-test was used to compare the T1 to T3, T1 to T2, and T2 to T3 cephalometric changes between the TG and the CG.
In the long term, the TG showed a significantly greater increase in overbite (+1.8 mm), reduced extrusion of maxillary and mandibular molars (-3.3 mm), and, consequently, a significant decrease in facial divergence (-2.8°) when compared with untreated subjects.
The RME and BB protocol led to successful and stable recovery of positive overbite in 100% of the patients considered. Correction of open bite was associated with reduced extrusion of maxillary and mandibular molars with a significant improvement in vertical skeletal relationships when compared with the CG.
评估快速上颌扩张（RME）和后牙垫（BB）在骨骼-牙列性开骀的青春期前患者中的长期效果。
治疗组（TG）包括 16 名（14 名女孩，2 名男孩）骨骼-牙列性开骀患者，平均年龄 8.1±1.1 岁，接受 RME 和 BB 治疗。在治疗前（T1）、RME 和 BB 主动治疗结束时（T2）和治疗结束后至少 4 年的随访观察时（T3），获得了连续的 3 张头颅侧位片。TG 与性别、年龄和垂直骨骼模式匹配的 16 名（14 名女孩，2 名男孩）对照组（CG）进行比较。采用独立样本 t 检验比较 TG 和 CG 在 T1 至 T3、T1 至 T2 和 T2 至 T3 时的头影测量变化。
在长期随访中，TG 在覆盖增加（+1.8mm）、上颌和下颌磨牙内收减少（-3.3mm）方面表现出显著增加，因此面型发散度显著减少（-2.8°），与未治疗的患者相比。
RME 和 BB 方案使 100%的患者成功稳定地恢复了正覆盖。与 CG 相比，开骀的矫正与上颌和下颌磨牙内收减少相关，垂直骨骼关系显著改善。
