Faculty of Dentistry, University of Sydney, Sydney, Australia.
Edinburgh Dental Institute, University of Edinburgh, Edinburgh, UK.
Prog Orthod. 2019 Sep 18;20(1):37. doi: 10.1186/s40510-019-0290-0.
The aim of this prospective case series study is to assess the three-dimensional (3D) skeletal and soft tissue effects of the alternate rapid maxillary expansion and constriction (Alt-RAMEC) protocol in conjunction with a miniscrew-supported class III elastic wear in class III growing patients.
Fourteen consecutive participants (mean age 12.05 ± 1.09 years), who displayed class III malocclusions with retrognathic maxillae, were recruited. A cone beam computed tomography (CBCT) scan was acquired before commencing treatment (T1). All participants were treated with a tooth-bone-borne rapid maxillary expansion (hybrid MARME) appliance that was activated by the Alt-RAMEC protocol for 9 weeks. This was followed by full-time class III elastics, delivering 400 g/side, to protract the maxilla. When a positive overjet was achieved, protraction was ceased and a post-treatment CBCT scan (T2) was taken. The 3D analysis of pre- and post-treatment CBCT scans was blinded. The scans were registered on the anterior cranial base. The Euclidean distance between the two extracted surface models of the pre- and post-treatment scans was displayed as a color surface map.
All participants completed the intervention successfully. The majority of the participants showed protraction of the anterior maxillary region (71.4%) and in the zygomatic processes (64.2%). The maxilla significantly protracted (SNA 1.87° ± 1.06°; Vert.T-A 3.29 ± 1.54 mm), while the mandibular base significantly redirected posteriorly (SNB - 2.03° ± 0.85°, Vert.T-B - 3.43 ± 4.47 mm) and that was reflected on the ANB and Wits measurements. No adverse effects were observed.
Class III elastics combined with the Alt-RAMEC activation protocol of the hybrid MARME appliance is an effective treatment method for mild/moderate class III malocclusions. A long-term follow-up and comparisons with other treatment modalities are required.
本前瞻性病例系列研究的目的是评估交替快速上颌扩张和收缩（Alt-RAMEC）方案与微型螺钉支持的 III 类弹性矫治器联合使用在伴有上颌后缩的 III 类生长患者中的三维（3D）骨骼和软组织效果。
共招募了 14 名连续参与者（平均年龄 12.05±1.09 岁），他们表现出 III 类错颌畸形伴上颌后缩。在开始治疗前（T1）获得了锥形束计算机断层扫描（CBCT）扫描。所有参与者均接受了牙齿-骨骼快速上颌扩张（混合 MARME）矫治器治疗，该矫治器通过 Alt-RAMEC 方案激活，持续 9 周。随后全天佩戴 400g/侧的 III 类弹性矫治器以牵引上颌。当获得正覆颌时，停止牵引，并进行治疗后 CBCT 扫描（T2）。治疗前和治疗后 CBCT 扫描的 3D 分析是盲法的。扫描在颅前底注册。将前后两次扫描的提取表面模型之间的欧几里得距离显示为彩色表面图。
所有参与者均成功完成干预。大多数参与者表现出上颌前部区域（71.4%）和颧骨突（64.2%）的牵引。上颌明显向前牵引（SNA 1.87°±1.06°；Vert.T-A 3.29±1.54mm），而下颌基骨明显向后移位（SNB -2.03°±0.85°，Vert.T-B -3.43±4.47mm），这反映在 ANB 和 Wits 测量值上。未观察到不良反应。
III 类弹性矫治器与混合 MARME 矫治器的 Alt-RAMEC 激活方案联合使用是治疗轻度/中度 III 类错颌的有效方法。需要长期随访并与其他治疗方式进行比较。
