Department of Endodontics, The University of Texas Health Science Center at Houston School of Dentistry, Houston, Texas.
Department of Orthodontics, The University of Texas Health Science Center at Houston School of Dentistry, Houston, Texas.
J Endod. 2022 Nov;48(11):1361-1366. doi: 10.1016/j.joen.2022.08.002. Epub 2022 Aug 11.
Orthodontically induced external root resorption has been labeled an unavoidable consequence of orthodontic tooth movement (OTM). The objective of this study was to investigate the change in surface area (mm) and volume (mm) of endodontically treated teeth (ETT) compared with contralateral teeth with a vital pulp (VPT) after OTM.
Seventy-six teeth were included in this retrospective analysis: ETT (n = 38) and VPT (n = 38). All teeth were evaluated using cone-beam computed tomographic imaging at 2 time periods: before OTM (T1) and after OTM (T2). Study teeth were segmented to include all areas contained within the lamina dura and then were converted into a mesh model for data calculation. The surface area (mm) and volume (mm) of each tooth were calculated at T1 and T2 based on the number of cubic voxels present within the mesh model. Statistical analysis was performed using a linear mixed-effects model.
The average change in surface area after OTM in ETT was 13.01 mm and 19.95 mm in VPT (P < .05). The average percent change in surface area after OTM in ETT was 2.09% and 3.38% in VPT (P < .05). The average change in volume after OTM in ETT was 22.48 mm and 32.44 mm in VPT (P < .05). The average percent change in volume after OTM in ETT was 2.62% and 4.10% in VPT (P < .05).
The results from this study suggest that ETT are less susceptible to root resorption after OTM than their vital counterparts.
正畸性牙根外吸收已被标记为正畸牙齿移动（OTM）的不可避免后果。本研究的目的是研究 OTM 后牙髓治疗牙（ETT）与活髓牙（VPT）相比，其表面积（mm）和体积（mm）的变化。
本回顾性分析共纳入 76 颗牙齿：ETT（n=38）和 VPT（n=38）。所有牙齿均在 2 个时间点使用锥形束 CT 成像进行评估：OTM 前（T1）和 OTM 后（T2）。研究牙齿被分割以包含在硬骨板内的所有区域，然后转换为网格模型进行数据计算。根据网格模型中存在的立方体素数量，在 T1 和 T2 计算每个牙齿的表面积（mm）和体积（mm）。使用线性混合效应模型进行统计分析。
ETT 中 OTM 后表面积的平均变化为 13.01mm，VPT 为 19.95mm（P<0.05）。ETT 中 OTM 后表面积的平均百分比变化为 2.09%，VPT 为 3.38%（P<0.05）。ETT 中 OTM 后体积的平均变化为 22.48mm，VPT 为 32.44mm（P<0.05）。ETT 中 OTM 后体积的平均百分比变化为 2.62%，VPT 为 4.10%（P<0.05）。
本研究结果表明，ETT 在 OTM 后比其活髓对应物更不易发生牙根吸收。
