不同加载方式压低上前牙时初始应力在牙体、牙周膜及牙槽骨分布的三维有限元分析（英文）

背景：探索最佳的既能有效地压低前牙,又不造成牙齿损伤的加载力值尤为重要。目的：模拟在上颌侧切牙和尖牙间使用种植支抗对上颌前牙施加压入力时的受力状况,探讨临床上最佳的加载力值及施力方向。方法：建立上颌前牙段牙齿-牙周膜-矫治系统的三维有限元模型,分析上前牙在不同压低力值及施力方向时牙体、牙周膜及牙槽骨初始应力的分布情况。结果与结论：同时压低6个上前牙的最佳力值范围在0.5～1.0 N。应力峰值集中区域位于侧切牙的远中颈缘;当施力方向为腭向20°时,牙周膜应力分布相对均匀。即在侧切牙和尖牙间唇侧使用种植钉时,加载0.5～1.0 N力的同时配合适当的远中方向牵引力,可对均角型患者达到将上颌前牙整体真性压入的效果,是一种最佳的矫治力系统。

Initial stress distribution of the maxillary anterior teeth,periodontal ligament and alveolar bone by different intruding loadings A three-dimensional finite element analysis

BACKGROUND：It is very important to explore an optimal loading force that can both allow effective intrusion and cause no damage to the teeth.OBJECTIVE：To investigate the optimal loading conditions,including loading force values and directions,in the intruding mechanics of maxillary anterior teeth.METHODS：A three-dimensional finite element model（3D FEM） of the maxillary anterior teeth was constructed to include the periodontal ligament（PDL）,alveolar bone,and appliance（brackets and wire）.The initial stress distribution and force of the maxillary anterior teeth were analyzed when the 3D FEM was loaded with different intruding force values and directions.RESULTS AND CONCLUSION：The optimal value of the intruding force for 6 anterior teeth fell within the range from 0.5 N to 1.0 N.The maximum stress was detected at the distal cervical level of the lateral incisor,and a relatively even distribution of initial stress was observed at 20° palatal deviation to the Y axis.The results suggest that using mini-screw implants at the labial region between the canine and lateral incisor and a combined 0.5-1.0 N intruding force with a distal force could be an optimal intrusion force system by which patients with normal occlusion could obtain a pure intrusion of anterior teeth.