Orthodontic Dentistry, The Nippon Dental University Niigata Hospital, 1-8 Hamaura-cho, Chuo-ku, Niigata, 951-8580, Japan.
Odontology. 2012 Jan;100(1):76-86. doi: 10.1007/s10266-011-0028-z. Epub 2011 Jun 15.
The purpose of this study was to evaluate the effects of the maxillary arch expansion on maxillomandibular arch widths in patients treated with the quad-helix versus untreated controls. The treatment group consisted of 50 consecutive patients treated for maxillary incisor crowding with a quad-helix appliance in the early mixed dentition. Lateral cephalograms and dental casts taken at the start (T0) and end (T1) of the quad-helix treatment were obtained. The control group consisted of 50 untreated patients with the same type of malocclusion. Two consecutive lateral cephalograms and dental casts of each untreated patient were taken at about the same time as T0 and T1. All these study materials were analyzed for comparison between the two groups. The mean ages at T0 and T1 in the two groups were about the same. The maxillary first molars moved and tipped distally in the treatment group and mesially in the control group. The quad-helix treatment actually expanded the mandibular and maxillary arches concurrently. The more the maxillary arch widths were expanded and the less the maxillary first molars were inclined distally, the more the mandibular arch widths were expanded. The quad-helix activation caused lingual tipping and mesiobuccal rotation of the maxillary first molars. The mesiobuccal rotation of the maxillary first molars could turn molar occlusal relationships for the better from Class II to Class I. The quad-helix treatment gives rise to spontaneous expansion of the mandibular arch concurrent with maxillary expansion in the early mixed dentition patients with maxillary incisor crowding.
本研究旨在评估上颌弓扩张对接受四圈簧和未接受治疗的对照组患者的上下颌弓宽度的影响。治疗组由 50 名连续患者组成，他们在混合牙列早期因上颌切牙拥挤而接受四圈簧治疗。在四圈簧治疗的开始（T0）和结束（T1）时，获得了侧颅面片和牙模。对照组由 50 名未经治疗的具有相同错颌类型的患者组成。对每个未经治疗的患者，在大约与 T0 和 T1 相同的时间拍摄了连续的两张侧颅面片和牙模。对所有这些研究材料进行了分析，以比较两组之间的差异。两组患者在 T0 和 T1 的平均年龄大致相同。上颌第一磨牙在治疗组中向远中移动和倾斜，在对照组中向近中移动。四圈簧治疗实际上同时扩展了下颌和上颌弓。上颌弓宽度扩展越多，上颌第一磨牙向远中倾斜越少，下颌弓宽度扩展越多。四圈簧激活导致上颌第一磨牙舌倾和近中颊向旋转。上颌第一磨牙的近中颊向旋转可以使磨牙的咬合关系从 II 类变为 I 类。在混合牙列早期，上颌切牙拥挤的患者中，四圈簧治疗会引起下颌弓的自发扩展，同时上颌弓也会扩展。
