Department of Orthodontics, School of Dental Medicine, State University of New York at Buffalo, Buffalo, NY, United States.
Department of Orthodontics, School of Dental Medicine, State University of New York at Buffalo, Buffalo, NY, United States.
Int Orthod. 2023 Dec;21(4):100810. doi: 10.1016/j.ortho.2023.100810. Epub 2023 Sep 27.
A TiNb alloy wire (GUMMETAL® [GM], Toyota Central R&D Labs, Inc., Nagakute, Japan) was recently developed with unique properties for orthodontic applications. This pilot split-mouth randomized controlled trial compared maxillary canine retraction during space closure using sliding mechanics on GM vs. stainless steel (SS) archwires.
Subjects who met the inclusion criteria were treated with fixed appliances and maxillary first-premolar extractions between September 2020 and March 2022. After leveling and aligning, maxillary archwires, fabricated by crimping together segments of 0.016×0.022" GM and SS archwires, were placed and canine retraction initiated using nickel-titanium coil springs. Digital models of the maxillary arch were superimposed at 0, 4, 8 and 12 weeks and the amount of canine movement (mm), rate of movement (mm/month), and 3-dimensional changes (rotational, vertical extrusion, tip) were measured and compared statistically.
Of the 12 subjects recruited, only six completed the study with a median age of 15.8 years (12.0-17.4 years). At 12 weeks, the median canine retraction was 3.41mm (IQR: 2.10, 4.76) with GM versus 3.71mm (IQR: 1.62, 6.45) with SS. The retraction rate was 1.14mm/month (IQR: 0.69, 1.59) with GM, versus 1.24mm/month (IQR: 0.54, 2.15) with SS. The median rotational, vertical and tip changes of the canine were 7.90̊, 0.59mm and 6.15̊ with GM, and 7.25̊, 0.29mm and 2.05̊ with SS. Intergroup differences with all measurements were not statistically significant.
No significant differences were found between GM and SS during maxillary canine retraction. GM demonstrated clinical potential for space closure mechanics, however, future larger studies are needed.
一种 TiNb 合金丝（GUMMETAL® [GM]，丰田中央研发实验室，Nagakute，日本）最近因其在正畸应用中的独特特性而被开发出来。这项试点分口随机对照试验比较了使用滑动机制在 GM 与不锈钢（SS）弓丝上关闭间隙时上颌尖牙的回收情况。
符合纳入标准的受试者于 2020 年 9 月至 2022 年 3 月期间接受固定矫治器和上颌第一前磨牙拔除治疗。在整平排齐后，通过将 0.016×0.022" GM 和 SS 弓丝的片段压接在一起来制作上颌弓丝，并使用镍钛螺旋弹簧开始尖牙回收。在 0、4、8 和 12 周时对上颌弓丝的数字模型进行叠加，并对尖牙的移动量（mm）、移动速度（mm/月）和 3 维变化（旋转、垂直挤压、尖端）进行测量和统计学比较。
在招募的 12 名受试者中，只有 6 名完成了研究，中位年龄为 15.8 岁（12.0-17.4 岁）。在 12 周时，GM 的中位尖牙回收量为 3.41mm（IQR：2.10，4.76），SS 为 3.71mm（IQR：1.62，6.45）。GM 的回收速度为 1.14mm/月（IQR：0.69，1.59），SS 为 1.24mm/月（IQR：0.54，2.15）。GM 的尖牙旋转、垂直和尖端变化的中位数分别为 7.90°、0.59mm 和 6.15°，SS 为 7.25°、0.29mm 和 2.05°。所有测量指标的组间差异均无统计学意义。
在上颌尖牙回收过程中，GM 与 SS 之间未发现显著差异。GM 显示出在关闭间隙力学方面的临床潜力，但需要进一步开展更大规模的研究。
