根尖唇腭向移动对牙根吸收的影响研究

Evaluation of association of cortical plate proximity and apical root resorption during orthodontic treatment

目的探讨正畸矫治过程中根尖唇腭向移动对牙根吸收的影响,以期为正畸医生临床矫治提供参考。方法收集采用MBT传统直丝弓固定矫治的患者30例,并调取患者的锥形束CT(cone-beam computed tomography,CBCT)影像资料,分析上颌切牙矫治前后根尖与唇腭侧骨皮质的位置关系,根据牙位及根尖移动方向,分为中切牙唇向移动(LM)组,腭向移动组(PM);侧切牙唇向移动组(LM),腭向移动组(PM),分别测量分析矫治前后对应上颌切牙牙根长度变化,以测根尖吸收量,研究根尖移动方向、测量移动量,比较根尖吸收量与唇腭向移动量的关系。采用SPSS 21.0软件包对数据进行统计学相关分析。结果中切牙LM组中根尖移动(1.19±0.40)mm,根尖吸收(0.54±0.31)mm,PM组中根尖移动(1.50±0.66)mm,根尖吸收(0.60±0.46)mm;侧切牙LM组中根尖移动(1.04±0.32)mm,根尖吸收(0.84±0.32)mm,PM组中根尖移动(1.69±0.67)mm,根尖吸收(0.89±0.46)mm,根尖吸收量与唇腭向移动量均成正相关,P<0.05具有统计学意义。结论正畸矫治过程中,根尖移动量越多,越接近唇腭侧骨皮质,根尖吸收可能会越多,正畸医生在临床矫治时,特别在牙冠移动过程中,要注意观察根尖的位置及移动范围,尽量减少根尖长距离以及在接触骨皮质范围内的移动。

Objective To provide some reference for orthodontists in clinical orthodontic treatment, we investigated the effects of proximity of the root apex to the maxillary labial cortical plate, palatal cortical plate on apical root resorption after orthodontic treatment.Methods Totally 30 patients who were treated with traditional MBT fixed appliances were collected.Relevant CBCT image data were collected to analyze the positional relationship between the root apex of the incisors and the maxillary labial cortical plate, palatal cortical plate before and after the orthodontic treatment,.The teeth were classified into two groups by the movement directions:the LM group of the central and lateral incisors,which moved labially;the PM group of the central and lateral incisors,which moved palatally.and the changes in the length of the roots before and after the orthodontic treatment were measured and analyzed respectively to get the amount of the resorption.The movement direction and measured movement amount of the root apex were studied, and the relationship between the resorption and the movement amount and direction of the root apex was compared.All analyses were performed by using SPSS 21.0 software package.Results In the LM group of the central incisors, root apex movement was(1.19±0.40) mm and apical root resorption was(0.54±0.31) mm. In the PM group, root apex movement was(1.50±0.66) mm and apical root resorption was(0.60±0.46) mm;In the LM group of the lateral incisors, root apex movement was(1.04±0.32) mm and apical root resorption was(0.84±0.32) mm. In the PM group, root apex movement was(1.69±0.67) mm and apical root resorption was(0.89±0.46) mm.It was statistically significant when P<0.05, and the amount of root apex resorption was positively correlated with the amount of root movement.Conclusion The longer of the movement distance and the closer the root apex was to the labial or palatal cortex during orthodontic treatment, the more the resorption was. Orthodontists should pay attention to the position and range of the apexduring the movement of the crown,try to avoid the longer movement distance of the root and reduce root apex proximity to the cortical plate in clinical orthodontics.