Campos Marcio José da Silva, Silva Karine Simões, Lupatini Paula Moraes, Fraga Marcelo Reis, Vitral Robert Willer Farinazzo
a Department of Orthodontics , Juiz de Fora Federal University , Juiz de Fora , Brazil.
J Orthod. 2018 Mar;45(1):23-28. doi: 10.1080/14653125.2017.1417780. Epub 2017 Dec 27.
In orthodontic treatment, an increased bone mineral density of the alveolar bone is considered as a risk factor for apical root resorption (ARR), whereas the mineral density of cementum has been associated with root protection against resorption.
This study aimed at evaluating the grey values (GVs) of the apical third of the root and of the alveolar bone adjacent to maxillary incisors with and without ARR in orthodontic patients. Twenty-one patients under treatment who presented one incisor with ARR and its corresponding contralateral without ARR were selected and submitted to cone-beam computed tomography. GVs were evaluated on the images obtained of four areas of the apical third of the root and of four areas of the adjacent alveolar bone.
The radicular tissue of the apical third of the incisors with ARR showed greater root GV (p < .05) than that of the incisors without ARR. Supra-apical alveolar bone exhibited greater GV in the incisors without ARR than incisors with ARR (p < .05). Root GV was not associated with root protection, but rather seemed to have facilitated the process of resorption. The GV of the lingual bone was associated with a higher progression of ARR in the incisors.
在正畸治疗中，牙槽骨骨密度增加被认为是根尖牙根吸收（ARR）的一个风险因素，而牙骨质的矿物质密度与牙根抗吸收有关。
本研究旨在评估正畸患者中存在和不存在ARR的上颌切牙牙根根尖三分之一处以及相邻牙槽骨的灰度值（GVs）。选择21名正在接受治疗的患者，其中一颗切牙出现ARR，其对应的对侧切牙未出现ARR，并对其进行锥形束计算机断层扫描。在从牙根根尖三分之一处的四个区域和相邻牙槽骨的四个区域获得的图像上评估GVs。
出现ARR的切牙根尖三分之一处的牙根组织显示出比未出现ARR的切牙更高的牙根GV（p < 0.05）。根尖上方的牙槽骨在未出现ARR的切牙中比出现ARR的切牙表现出更高的GV（p < 0.05）。牙根GV与牙根保护无关，反而似乎促进了吸收过程。舌侧骨的GV与切牙中ARR的更高进展相关。
