Finite Element Analysis Of Mandibular Anterior Dentition Correction With Bracketless Invisible Correction

Orthodontics is a branch of stomatology that studies the etiology,diagnosis,analysis,prevention and treatment of malocclusion.In recent years,with the continuous promotion of oral health knowledge and people’s pursuit of high-quality life,many people have realized the importance of orthodontics.Invisible appliance is a kind of removable appliance which is beautiful,comfortable,hygienic and convenient,which is favored by many patients.At present,many scholars have carried out relevant research on the biomechanical effects of stealth correction technology,and have achieved certain results.Related studies mainly focus on the local,the whole dentition and periodontal tissue of the study is less.In this paper,a biomechanical model of mandibular complete dentition,periodontal tissue and invisible orthodontic device was established from the perspective of the whole.The force system of invisible orthodontic technology as well as the stress distribution and size of the corresponding periodontal tissue were analyzed truly and accurately on the whole by defining the contact method.The main work contents are as follows:(1)Establishment of biomechanical model of invisible correction.Based on spiral CT scan samples of the head,MIMICS 19.0 was used to conduct 3D reconstruction of the overall contour around the alveolar bone and the conglutination of the oral and mandibular dentition,and then imported to3-MATIC for surface smoothing.The tooth crown and root were separated by means of surface separation,and the surface of the invisible orthodontic device was obtained.The conglutinated mandibular teeth were separated to obtain the model of mandibular teeth.The periodontal ligament and alveolar bone model are obtained through Boolean operation.Mesh each part of the model.Comparing the established model with foreign classical in vivo mechanics experiments,it was found that the pressure generated by the appliance when the buccal side of the first premolar was tilted and the data measured in vivo experiments were within an order of magnitude,which verified the effectiveness of the model.(2)Finite element analysis of biomechanical effects of stealth correction technology.Finite element simulation of the method of invisible appliance treatment under different types of tooth movement methods(parallel movement,tilt movement,rotation movement,depression movement).Analyze the biomechanical effect of stealth correction technology under various working conditions.The results show: The position where the maximum amount of deformation occurs in the appliance is the part of the invisible appliance corresponding to the moving tooth,and the deformation amount of the invisible appliance gradually decreases from the tooth to be moved to the supporting molar area;During parallel movement,the overall deformation law of the invisible appliance is similar to that of tilt movement,and for the part of the invisible appliance corresponding to the immovable tooth,parallel movement is easier to deform the lip convexity than tilt movement;The effect of the invisible orthodontic device on the immobilized teeth can be reduced by thickening the lingual surface of the teeth corresponding to the convex deformation of the lip and the concave deformation of the teeth corresponding to the lingual surface of the teeth;When the invisible jaws are used to correct the misaligned jaw deformity,the maximum stress points of teeth,periodontal ligament and alveolar bone all appear near the teeth to be moved.The results of this paper can provide reference for the biomechanics research of stealth correction technology.