Effects of Mandibular Extractions with Clear Aligners:A Finite Element Analysis  

作　　者：FENG Qiping CHU Fengting CHEN Rongjing PAN Xiaogang 冯齐平;储沨婷;陈荣敬;潘晓岗(Department of Orthodontics,Shanghai Ninth Peoples’Hospital,College of Stomatology,Shanghai Jiao Tong University School of Medicine,National Clinical Research Center for Oral Diseases,Shanghai Key Laboratory of Stomatology&Shanghai Research Institute of Stomatology,Shanghai,200011,China)

机构地区：[1]Department of Orthodontics,Shanghai Ninth Peoples’Hospital,College of Stomatology,Shanghai Jiao Tong University School of Medicine,National Clinical Research Center for Oral Diseases,Shanghai Key Laboratory of Stomatology&Shanghai Research Institute of Stomatology,Shanghai,200011,China

出　　处：《Journal of Shanghai Jiaotong university(Science)》2021年第3期377-382,共6页上海交通大学学报（英文版）

基　　金：the Clinical Research Program of Ninth People’s Hospital affiliated to Shanghai Jiao Tong University School of Medicine(No.JYLJ-10)。

摘　　要：This study was aimed at analysing the mechanical characteristics of different mandibular extraction modes using a clear aligner.Three experimental schemes of different extraction patterns were designed to treat mandibular crowding,including extraction of one mandibular central incisor,bilateral first premolars,and bilateral second premolars.The stress distribution during the space closing was analysed using the finite element method.When a central incisor was extracted,a significant retraction force was found in the anterior region,in line with the design expectation.The posterior teeth,which were designed to move mesially,acted as anchorage for anterior retraction,and were subjected to a mesial force.The anterior teeth were retracted when the bilateral first premolars were extracted.The lateral incisors and canines were subjected to a significant distal force and moment,while the central incisors and canines were subjected to lingual forces and moments.Additionally,the canines were subjected to a non-designated intruding force.The molars were designed to move mesially when the bilateral second premolars were extracted.All molars were subjected to a significant mesial force,while the lingual force on the front teeth was slight.The bilateral second molars were subjected to non-design mesial moment and extrusive force.The bilateral first molars were subjected to a non-designated mesial moment,and the bilateral first premolars on both sides were subjected to non-designated intrusive force and distal moment.When one incisor was extracted,attachments on the anterior teeth had a controlling effect on the tooth axis,but the anterior teeth still tended to tilt.When the bilateral first premolars were extracted,the anterior teeth showed a tendency for lingual inclination.The risk of distal inclination of the canines and lingual inclination of the central incisor increased.When the bilateral second premolars were extracted and the posterior teeth were designed to move mesially,the teeth on both sides of the extraction sites

关 键 词：clear aligner mandibular incisor extraction finite element analysis 

分 类 号：R783.5[医药卫生—口腔医学] R318.01[医药卫生—临床医学]