Noorollahian Saeed, Alavi Shiva, Shirban Farinaz
Dental Implants Research Center, School of Dentistry, Isfahan University of Medical Sciences, Isfahan, Iran.
Dental Materials Research Center, School of Dentistry, Isfahan University of Medical Sciences, Isfahan, Iran.
Dental Press J Orthod. 2016 Jun;21(3):85-93. doi: 10.1590/2177-6709.21.3.085-093.oar.
The aim of this study was to introduce a new method for bilateral distal movement of the entire maxillary posterior segment.
A 17-year-old girl with Class I skeletal malocclusion (end-to-end molar relationships, deviated midline and space deficiency for left maxillary canine) was referred for orthodontic treatment. She did not accept maxillary first premolars extraction. A modified Hyrax appliance (Dentaurum Ispringen, Germany) was used for bilateral distalization of maxillary posterior teeth simultaneously. Expansion vector was set anteroposteriorly. Posterior legs of Hyrax were welded to first maxillary molar bands. All posterior teeth on each side consolidated with a segment of 0.017 × 0.025-in stainless steel wire from the buccal side. Anterior legs of Hyrax were bent into eyelet form and attached to the anterior palate with two mini-screws (2 × 10 mm) (Jeil Medical Corporation Seoul, South Korea). Hyrax opening rate was 0.8 mm per month. Lateral cephalometric radiographs were used to evaluate the extent of distal movement. 3.5-mm distalization of posterior maxillary teeth was achieved in five months.
A nearly bodily distal movement without anchorage loss was obtained.
The mini-screw-supported modified Hyrax appliance was found to be helpful for achieving en-masse distal movement of maxillary posterior teeth.
本研究旨在介绍一种使整个上颌后段向远中移动的新方法。
一名17岁的I类骨骼错合畸形女孩（磨牙为端对端关系，中线偏斜且左上尖牙间隙不足）前来接受正畸治疗。她不接受拔除上颌第一前磨牙。使用改良的Hyrax矫治器（德国Dentaurum Ispringen公司生产）同时对上颌后牙进行双侧远中移动。扩弓向量设置为前后向。Hyrax矫治器的后臂焊接在上颌第一磨牙带环上。每侧的所有后牙从颊侧用一段0.017×0.025英寸的不锈钢丝固定。Hyrax矫治器的前臂弯成小孔状，并用两颗微型螺钉（2×10毫米）（韩国首尔Jeil Medical Corporation公司生产）固定在前腭部。Hyrax矫治器每月打开0.8毫米。使用头颅侧位片评估远中移动的程度。在五个月内实现了上颌后牙3.5毫米的远中移动。
实现了几乎整体的远中移动且无支抗丧失。
发现微型螺钉支持的改良Hyrax矫治器有助于实现上颌后牙整体远中移动。
