A Finite Element Analysis of the forced moving secondmandibular premolar

• 1、.Department of Oral and Maxillofacial surgery, Shengjing hospital of China medical University, Shenyang 110004, China

Abstract：BACKROUND：Currently involved in the process of orthodontic treatment of premolars, the three-dimensional finite element stress analysis of the relevant reports, the analysis results of this experiment, add the teeth in the orthodontic finite element in the blank, which can guide the clinical practice to a certain extent. OBJECTIVE：When we force same amplitude but different included angle on the second mandibular premolar .We research the regular between displacement and vector force. Under certain research, result can direct our real cure action. METHODS：Softwares of MIMICS 16.0 and CATIA V5 have been used to build three-dimensional model which is as same as the real tooth, then we used ANSYS12.1 to build the the vector force and boundary environment and simulate displacement and stress of the molar. RESULTS AND CONCLUSION：Under the same couple force(200g), the second mandibular premolar was moving near the middle.As angle(angle between the long axis of the tooth and jaw plane) increasing as far in the root portion of the inclination decreasing. At the same time, there is another rule about the stress: in an angle of 30 (every 15 as an experimental section) can be regarded as a relatively ideal value, while pulling second mandibular premolar, displacement and absorbing value of root achieve a ideal balance value.In the clinical treatment, second mandibular premolar have been forced a reasonable angle (30 degree),making the molar moving forward middle meanwhile decreasing root absorbing value.

Keywords： Mandibular second premolar Three dimensional finite element Mesial movement Stress distribution Inclination Traction angle