Marquette University School of Dentistry, Department of Developmental Sciences/Orthodontics, WI, Milwaukee, USA.
University of Connecticut Health, Division of Orthodontics, Farmington, CT, USA.
Int Orthod. 2021 Dec;19(4):591-600. doi: 10.1016/j.ortho.2021.10.002. Epub 2021 Oct 27.
The purpose of this study was to determine the effects of alveolar decortications (AD) closer and farther from the tooth on Orthodontic tooth movement (OTM) and root resorption.
Twenty-four Wistar rats (age 17 weeks) were used in the study. Three groups were formed by randomly dividing the rats into: 1) Control Group (N=8): OTM (14 days) without any surgical insult; 2) Near Group (N=8) OTM (14 days)+Alveolar Decortications (AD) adjacent to roots of the maxillary first molar; 3) Far Group (N=8) OTM (14 days)+AD 5mm away from the roots of the maxillary first molar. OTM was performed using a closed coil Nickel-Titanium (NiTi) spring to apply a mesial force on maxillary first molars of 8-10 grams. AD was performed with high-speed quarter round bur on the palatal aspect of alveolar bone. The rats were euthanized after 2 weeks of OTM and microfocus computed tomography and histological analysis were performed.
Near-AD and Far-AD groups exhibited significantly increased OTM and reduction of Bone volume fraction compared to control. The root volume was significantly decreased (increased root resorption) in the Near-AD group. Histological analysis showed no statistically significant difference between the groups.
Alveolar decortications lead to a significant increase in the rate of OTM. Increased root resorption was observed when the alveolar decortications were performed close to the maxillary molar.
本研究旨在确定距离牙齿更近和更远的牙槽骨切开术(AD)对正畸牙齿移动(OTM)和牙根吸收的影响。
本研究使用了 24 只 17 周龄的 Wistar 大鼠。通过随机分组将大鼠分为三组:1)对照组(N=8):OTM(14 天),无任何手术损伤;2)近组(N=8):OTM(14 天)+上颌第一磨牙根附近的 AD;3)远组(N=8):OTM(14 天)+上颌第一磨牙根 5mm 外的 AD。使用闭合线圈镍钛(NiTi)弹簧在上颌第一磨牙上施加 8-10 克的近中力来进行 OTM。AD 采用高速四分之一圆形车针在牙槽骨的腭侧进行。OTM 2 周后处死大鼠,进行微焦点计算机断层扫描和组织学分析。
近 AD 和远 AD 组与对照组相比,OTM 显著增加,骨体积分数减少。近 AD 组的牙根体积明显减少(牙根吸收增加)。组织学分析显示各组之间无统计学差异。
牙槽骨切开术可显著增加 OTM 速率。当 AD 靠近上颌磨牙进行时,观察到牙根吸收增加。