Biomechanical Analysis of Maxillary Molar Intrusion by Clear Aligners
10.16156/j.1004-7220.2025.04.003
- VernacularTitle:无托槽隐形矫治器压低上颌磨牙的生物力学分析
- Author:
Houwen PAN
1
;
Bokai ZHU
1
;
Yanfei ZHU
1
;
Wenyi ZHANG
1
;
Lingyong JIANG
1
Author Information
1. 上海交通大学医学院附属第九人民医院口腔颅颌面科·正颌正畸中心;上海交通大学口腔医学院;国家口腔医学中心;国家口腔疾病临床医学研究中心;上海市口腔医学重点实验室;上海市口腔医学研究所,上海 200011
- Publication Type:Journal Article
- Keywords:
clear aligners;
maxillary molar;
molar intrusion;
biomechanical analysis
- From:
Journal of Medical Biomechanics
2025;40(4):814-820
- CountryChina
- Language:Chinese
-
Abstract:
Objective This study investigates the force distributions and movement patterns of the maxillary dentition during molar intrusion with clear aligners,aiming to provide a theoretical basis for optimizing clinical orthodontic treatment strategies.Methods A three-dimensional(3D)finite element model of the periodontal ligament-teeth-clear aligners complex was established to simulate different intrusion modes,including bilateral first molar intrusion,bilateral second molar intrusion,and simultaneous intrusion of bilateral first and second molars.The von Mises stress distribution characteristics and displacement patterns of each tooth under different intrusion conditions were systematically analyzed.Results Compared with simultaneous molar intrusion,the individual intrusion design resulted in greater intrusive movement(4.260-10.500 μm)accompanied by distal-lingual crown inclination(distal displacement:-7.690--5.100 μm;buccal displacement:-20.500--6.750 μm).Anchorage teeth displayed a displacement trend opposite to that of the intruded molars.The anterior teeth demonstrated minimal displacement and low stress levels.During maxillary molar intrusion with clear aligners,the maximum equivalent stress in the periodontal ligaments occurred at the anchorage teeth mesial to the intruded molars,primarily concentrated in the apical region and the mesial aspect of the buccal cervical area.Conclusions A sequential intrusion strategy enhances vertical control efficiency compared to simultaneous intrusion.Unanticipated mesiodistal and buccolingual displacements in the posterior region necessitate the implementation of counteracting mechanisms in aligner design.In clinical practice,priority should be given to monitoring the risks of root resorption and bone remodeling effects in stress-concentrated zones(apical and buccal cervical regions)of anchorage teeth.
