Finite Element Analysis Of Invisalignment Of Maxillary Central Incisor Movement Under Different Attachments

Objectives A three-dimensional finite element model of maxillary alveolar bone,maxillary central incisor,periodontal ligament,and invisible braces without brackets was established.Different appendages(horizontal rectangular attachments,horizontal oval attachments,upper half attachments,and upper half tetrahedron attachments)are attached to the center of the crown of the maxillary central incisor.Three-dimensional finite element analysis is used to investigate the attachment of different attachments to the upper jaw The displacement trend of the maxillary central incisor and the stress analysis of the periodontal ligament during the incisive treatment of the middle incisor provide a theoretical basis for the establishment of the clinically invisible orthodontic treatment plan.Methods 1 The patient’s maxillary dentition and alveolar bone were scanned by CBCT to obtain a DICOM data file.2 The model was reconstructed by MIMICS software to obtain the finite element model of maxillary alveolar bone,periodontal ligament and maxillary dentition.3 Use Solidworks software to simulate the construction of different attachments and place them on the buccal side of the maxillary central incisor.4 Use the Geomagic Studio software to thicken the crown and attachment models previously obtained to obtain a transparent appliance model.5 The model was applied to Abaqus software and the maxillary central incisor was moved to the lingual position to a predesigned position.Stress analysis of the periodontal membrane and movement of the maxillary central incisor were obtained.6 When the attachment is the same,the maxillary central incisor is moved to the joint to obtain the displacement trend of the maxillary central incisor and the force of the periodontal ligament.Results 1 Three-dimensional finite element model of maxillary alveolar boneperiodontal membrane-maxillary central incisor-invisible appliance was established.2 When the maxillary central incisor teeth moved lingually,the periodontal membranes of the central incisor without attachments were subjected to greater forces than those of the attachments group,and the adhesive attachment body was optimized(the upper half oval attachment and the upper half tetrahedron attachment).The force of the periodontal ligament is smaller than that of the normal attachment body(horizontal rectangular attachment,horizontal elliptical attachment);in the case of attachment,the movement margin of the maxillary central incisor is smaller than that of the attachment without attachment.3 When the mandibular central incisor moved to the(occlusal)direction,the maxillary central incisors with traditional attachments had a greater distance to move than those with optimized attachments;the addition of conventional attachments to the maxillary central incisor periodontal membranes was stressier than when the optimized attachments were added.Conclusions 1 The established three-dimensional finite element model of maxillary alveolar bone-periodontal membrane-maxillary central incisor-invisible appliance has a good reduction of the actual tissue.2 The movement direction of the tongue inward movement of the maxillary central incisor is the rotational movement when the attachment is not added;the maxillary central incisor tends to move as a whole when adding the attachment;adding the optimized attachment is more biased towards the overall movement than adding the traditional attachment.3 Invisible treatment of maxillary central incisor(occlusal)movement Adding traditional attachments is more suitable than adding optimal attachments.