Objective: Establishing a finite-element model of the fracture tooth of first premolar.To evalute the change of the stress distribution of different treatment and compare with normal tooth.

• 目的：应用三维有限元法建立上颌第一前磨牙纵折模型，分别对不同治疗组的牙体各部分的应力改变进行力学分析，并与正常牙体对照，从生物力学角度为纵折牙的治疗提供理论依据。