| Purpose:The stress distribution and displacement changes of the maxillary anterior teeth were Observed by means of three-dimensional finite element analysis of the resistance of plant branches to the maxillary anterior teeth at different angles.Method:1.A patient is selected as the experimental data,and the CBCT is used to s-can the data.The obtain data is introduced into the Mimics 17.0 software to extract the outline of the model.Then use the Geomagic Studio 10.0 soft to smooth and optimize the model.Finally,the finiteelement analysis software Ansys 15.0 is used to establish a three-dimensional finite element model of the implants to lower the maxillary front teeth.2.After the model was successfully established,the maxillary front teeth were lowered in different ways,and the way of lowering thepressure was divided into two kinds.Mode one:A single implant anchorage was implanted under the nasal spinous force value of one hundred grams,pointing to the implant anchorage head.Mode two:Two implantanchorages were implanted in the maxillary incisor and lateral incisors respectively,the force value was fifty grams each,and the direction pointed to the implant anchorage head.The stress distribution and displacement of the two methods are analyzed.3.After the model was successfully established,the torque of four incisors at different angles is lowered.The set of the degrees isdivided into five groups,respectively-10°?-5°?0°?5°?10°,Thefive groups were divided into groups of patients themselves,the angle of the teeth and the alveolar bone.The angle of the canine is unchanged.Only the angle of the incisor is changed,because the position of the canine is located in the arch of the arch,and the decisive factor of the canine is that the axis of the canine is mild but not the torque.Comparison of the stress distribution in the above two methods.Result:1.A three-dimensional finite element model,including the maxillary anterior teeth,?the alveolar bone?the periodontal membrane?the brackets?the arch wire and the implant anchorage has been successfully established.The geometric similarity is high,the structure is complete,and the quality of the gird is excellent.It lays a solid foundation for the successes of the follow-up experiment.2.In the two way to lower the maxillary anterior teeth,the maximum stress i-n mode one is located in two central incisors,and the stress on the periodontal ligament is also concentrated in two centralincisors.The maximum stress concentrates on the labial margin of twomiddle incisors.The maximum stress of the in mode two is located in two middle incisors and lateral incisors,and the stress o-f the periodontal ligament is also concentrated on the two medium and lateral incisors.The maximum stress is located in the labial margin of two middle incisor-s and lateral incisors.The two ways can effectively reduce the anterior teeth,the ways one central incisor's pressure is much larger than the lateral incisor,while the way two has a smaller difference between the incisors and the lateral incisors.The displace ment of the canine teeth varies slightly in the two ways.The crown and lip of the teeth will move in the two ways,but the way t-wo is slower than the one.In mode one,the cleft lip of the middle incisor is fa r greater than the lateral incisor,and the difference between the middle incisor a-nd the lateral incisor is smaller in mode two.The displacement of mode one and mode two on showed that the incisors,the lateral incisors and the canines were all inclined to the far middle of the way one.In mode two,the incisors incline to the middle,and the lateral incisors and canines tilt to the far middle.3.The process of pressing lower maxillary anterior teeth at different angles,the two way is the 10° concentrated area on the lip side median edge,the 5° stress concentrates on the lip edge,but it is less than the 10° concentration area,and the 0° is smaller than the 5° concentration area.Conclusion:1.The three-dimensional finite element can well simulate the organization structure,and can realize the clinical data that can not be measured and observed directly.It has a high accuracy for the model,its operation is fast,the operation is relatively simple,the result of the experiment is clear,and it has some guiding significance to the clinic.2.The above two methods can achieve the effective reduction of the anterior teeth,of which 2 of the lower stress distribution is more uniform,and the control of the teeth is better.From the comparison of the displacement diagram,the displacement change of mode 2 isalso smaller than that of the mode one.So mode two is the first to consider the way of depression.3.The above two methods lower anterior teeth,anterior lip inclination increases,the stress concentration at the edge of the lip side more.On the other hand,the greater the anterior tongue inclination,the stress concentration near the partial lingual and apex more. |
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