无托槽隐形矫治牙根吸收的临床研究

Root resorption during orthodontic treatment with Aligners

目的评价使用无托槽隐形矫治器患者的牙根吸收发病率及严重程度,并对牙根吸收的相关因素进行分析。方法选取150例仅使用无托槽隐形矫治技术治疗的患者,分别使用曲面断层片及头颅侧位片测量其治疗前后的牙根吸收率及牙根移动量,并探讨影响牙根吸收程度的相关因素。结果几乎所有患者都至少有一颗牙发生牙根吸收,平均每例患者有5.85±2.27颗牙发生牙根吸收。在1800颗观测牙中,有869颗牙齿(48.28%)发生牙根吸收。前后牙的牙根吸收率及严重程度没有统计学差异。上下前牙牙根吸收率没有统计学差异(P>0.05),但下前牙牙根吸收率在10%~20%组及>20%组的比例高于上前牙,有统计学差异(P<0.05)。上下第一磨牙牙根吸收率没有统计学差异(P>0.05),但上颌第一磨牙牙根吸收率在10%~20%组及>20%组的比例高于下颌第一磨牙,有统计学差异(P<0.05)。回归模型发现前牙的牙根吸收与疗程以及牙根的垂直向移动量有关。结论接受无托槽隐形矫治技术治疗的正畸患者,在治疗过程中几乎所有牙位均有牙根吸收的发生,且下前牙及上颌磨牙发生严重牙根吸收的几率分别高于上前牙及下颌磨牙。影响前牙的牙根吸收的相关因素包括疗程及前牙牙根的垂直向移动量。

ObjectiveTo investigate the incidence and severity of root resorption in patients treated with aligners. Further on, to explore the possible factors relating to the severity of root resorption.Methods150 patients who treated exclusively with aligners (Invisalign, Align Technologies, Santa Clara, CA, USA) were recruited. To investigate the root resorption, root and crown lengths of 1800 teeth were measured in panoramic radiographs at the beginning (T0) and at the end (T1) of aligner therapy. The relative changes of rRCR, which represent the reduction of the root length during treatment were calculated than. Additionally, tooth movements of the anterior teeth were assessed by lateral cephalograms. The relationship between root resorption severity of the teeth and the variables were analyzed than.ResultsAlmost all patients had a minimum of one teeth affected with a reduction of root length, on average 5.85±2.27 teeth per patient. 48.28% of 1800 measured teeth presented a root reduction of the post-treatment root length. A reduction of 0~10% of the pre-treatment root length was found in 31.89%. A distinct reduction of 10%~20% in 13.56%. 2.83% of the teeth were affected with a considerable reduction of >20%. The incisors and the molars show the same outcome in root resorption severity. In anterior teeth, there were significant differences between the resorption group 10%~20% and >20% (P>0.05). No statistically significant differences show between the reduction of root length in the upper molars and that in the lower molars. However, there were significant differences between the resorption group 10%~20% and >20%. The Logisitc regression analysis shows that duration and the vertical movement of the anterior teeth were associated with root resorption.ConclusionsOrthodontic treatment with aligners could lead to RR. The lower incisors and the upper molars show higher incidence in severity of root resorption than the upper incisors and the lower molars separately. The treatment duration and vertical movement of the anterior teeth were related to the root resorption.