Goh Shaun, Dreyer Craig, Weir Tony
Department of Orthodontics, School of Dentistry, the University of Adelaide, Adelaide, South Australia, Australia.
Department of Orthodontics, School of Dentistry, the University of Adelaide, Adelaide, South Australia, Australia.
Am J Orthod Dentofacial Orthop. 2023 Jan;163(1):109-116. doi: 10.1016/j.ajodo.2021.09.020. Epub 2022 Oct 5.
This study aimed to provide an initial investigation into the mandibular curve of Wilson (COW) handling using the Invisalign appliance (Align Technology, Santa Clara, Calif). Individual buccolingual crown inclinations and transverse expansions were also investigated to detect any regions of ineffectiveness in the dental arch.
A retrospective sample of patients treated by an experienced Invisalign provider in private practice was used. All adult patients with Class I or II Angle malocclusions and mild to moderate crowding treated using a minimum of 14 Invisalign aligners without intermaxillary elastics, bite ramps, or auxiliaries and a nonextraction mandibular arch from 2013-2019 were selected. Dental models at the initial scan, the ClinCheck prediction, and the outcome after the initial series of aligners were analyzed with Geomagic Control X software (version 2017.0.3; 3D systems, Rock Hill, SC). The COW, buccolingual crown inclination relative to the occlusal plane and cusp tip expansion were compared between ClinCheck changes and achieved changes.
Forty-two subjects met the selection criteria. 74% of subjects experienced a flatter COW than ClinCheck predictions, and the mean difference was 0.76 mm (P = 0.0149). The first molars encountered 0.52 mm (P <0.001) more buccal crown inclination than ClinCheck predictions. No other teeth experienced statistically significant buccolingual inclination differences to ClinCheck. The second molars were the only teeth to experience significantly more arch expansion than ClinCheck at 0.68 mm (P = 0.0046).
The Invisalign appliance tended to over-flatten the mandibular COW compared with ClinCheck because of the lack of buccal root torque in the mandibular first molars during expansion. The mandibular second molars were the only teeth to experience more expansion than ClinCheck.
本研究旨在初步调查使用隐适美矫治器（爱齐科技公司，加利福尼亚州圣克拉拉）处理威尔逊下颌曲线（COW）的情况。还对个体颊舌向牙冠倾斜度和横向扩展进行了研究，以检测牙弓中任何无效的区域。
采用了由一位经验丰富的私人执业隐适美提供者治疗的患者的回顾性样本。选取了2013年至2019年期间所有患有安氏I类或II类错牙合畸形且有轻度至中度拥挤、使用至少14副隐适美矫治器且未使用颌间弹力牵引、咬合斜面或辅助装置以及不拔牙下颌牙弓的成年患者。使用Geomagic Control X软件（版本2017.0.3；3D系统公司，南卡罗来纳州罗克希尔）分析初始扫描时的牙模、ClinCheck预测以及初始系列矫治器治疗后的结果。比较了ClinCheck变化与实际实现的变化之间的COW、相对于牙合平面的颊舌向牙冠倾斜度和牙尖扩展情况。
42名受试者符合选择标准。74%的受试者的COW比ClinCheck预测的更平坦，平均差异为0.76毫米（P = 0.0149）。第一磨牙的颊侧牙冠倾斜度比ClinCheck预测的多0.52毫米（P <0.001）。没有其他牙齿与ClinCheck相比在颊舌向倾斜度上有统计学上的显著差异。第二磨牙是唯一比ClinCheck有显著更多牙弓扩展的牙齿，为0.68毫米（P = 0.0046）。
由于下颌第一磨牙在扩展过程中缺乏颊侧牙根转矩，与ClinCheck相比，隐适美矫治器倾向于过度平坦化下颌COW。下颌第二磨牙是唯一比ClinCheck有更多扩展的牙齿。
