Department of Developmental Sciences/Orthodontics, Marquette University School of Dentistry, Milwaukee, Wis.
Division of Orthodontics, University of Connecticut Health, Farmington, Conn.
Am J Orthod Dentofacial Orthop. 2022 Mar;161(3):e235-e249. doi: 10.1016/j.ajodo.2021.10.010. Epub 2021 Dec 4.
The purpose of this study was to use cone-beam computed tomography to compare immediate and long-term effects of conventional and miniscrew-assisted rapid palatal expansion (MARPE) appliances on root resorption in 2 treatment groups and a control group.
One hundred eighty cone-beam computed tomography images of 60 patients at 3 time points were assessed: initial, postexpansion, and debond. The patients were divided into 3 groups: control (n = 19), rapid palatal expansion (RPE) appliance (n = 21), and MARPE (n = 20). The period of initial to debond varied for the 3 groups: 2 years, 7 months for controls; 2 years, 9 months for RPE; and 2 years, 8 months for MARPE. The length of mesiobuccal, distobuccal, and palatal root of the maxillary first molar (1M); the buccal root of maxillary first premolar; and second premolar were measured. The inclination of the 1M, intercuspal width (ICW), interroot width (IRW), ICW/IRW ratio, maxillary skeletal width were measured in all 3 groups at different time points.
Immediately after expansion, RPE and MARPE groups showed a significant increase in the molar inclination, ICW, ICW/IRW ratio, and maxillary skeletal width compared with controls at postexpansion. However, the long-term comparison did not show any significant difference for root resorption and expansion parameters between the 3 groups, except the ICW/IRW ratio, which was higher in MARPE than controls at debond. A significant negative association was observed between the length of the mesiobuccal root of 1M and molar inclination (β = -0.025; 95% confidence interval, -0.050 to 0.0008; P <0.05). The expansion of ICW and IRW did not show a significant association with root resorption.
The long-term outcomes showed no difference in the amount of root resorption between the RPE, MARPE, and control groups. Molar inclination showed a significant negative association with the length of the mesiobuccal root of the 1M.
本研究旨在使用锥形束 CT 比较传统和微螺钉辅助快速腭扩张（MARPE）器具对 2 个治疗组和对照组的根吸收的即时和长期影响。
对 60 名患者的 180 个锥形束 CT 图像在 3 个时间点进行评估：初始、扩张后和拆带。患者分为 3 组：对照组（n=19）、快速腭扩张（RPE）器具组（n=21）和 MARPE 组（n=20）。3 组的初始到拆带时间不同：对照组为 2 年 7 个月，RPE 组为 2 年 9 个月，MARPE 组为 2 年 8 个月。测量上颌第一磨牙（1M）的近中颊、远中颊和腭根长度；上颌第一前磨牙和第二前磨牙的颊根长度。在所有 3 组的不同时间点测量 1M 的倾斜度、牙尖间宽度（ICW）、根间宽度（IRW）、ICW/IRW 比值、上颌骨宽度。
扩张后即刻，与对照组相比，RPE 和 MARPE 组的磨牙倾斜度、ICW、ICW/IRW 比值和上颌骨宽度显著增加。然而，长期比较显示 3 组之间的根吸收和扩张参数没有显著差异，除了 MARPE 组的 ICW/IRW 比值在拆带时高于对照组。1M 的近中颊根长度与磨牙倾斜度呈显著负相关（β=-0.025；95%置信区间，-0.050 至 0.0008；P<0.05）。ICW 和 IRW 的扩张与根吸收无显著相关性。
长期结果显示 RPE、MARPE 和对照组之间的根吸收量无差异。磨牙倾斜度与 1M 的近中颊根长度呈显著负相关。
