Hemanth M, Deoli Shilpi, Raghuveer H P, Rani M S, Hegde Chatura, Vedavathi B
Professor and Head, Department of Orthodontics and Dentofacial Orthopaedics, Dayananda Sagar College of Dental Sciences, Bengaluru, Karnataka, India.
Consulting Orthodontist at Vasan Dental Care, Bengaluru, Karnataka, India.
J Int Oral Health. 2015 Sep;7(9):114-8.
Simulation of periodontal ligament (PDL) using non-linear finite element method (FEM) analysis gives better insight into understanding of the biology of tooth movement. The stresses in the PDL were evaluated for intrusion and lingual root torque using non-linear properties.
A three-dimensional (3D) FEM model of the maxillary incisors was generated using Solidworks modeling software. Stresses in the PDL were evaluated for intrusive and lingual root torque movements by 3D FEM using ANSYS software. These stresses were compared with linear and non-linear analyses.
For intrusive and lingual root torque movements, distribution of stress over the PDL was within the range of optimal stress value as proposed by Lee, but was exceeding the force system given by Proffit as optimum forces for orthodontic tooth movement with linear properties. When same force load was applied in non-linear analysis, stresses were more compared to linear analysis and were beyond the optimal stress range as proposed by Lee for both intrusive and lingual root torque. To get the same stress as linear analysis, iterations were done using non-linear properties and the force level was reduced.
This shows that the force level required for non-linear analysis is lesser than that of linear analysis.
使用非线性有限元方法（FEM）分析模拟牙周膜（PDL），能更好地洞察牙齿移动生物学机制。利用非线性特性评估了PDL在牙齿垂直向压入移动和舌向根转矩移动时的应力。
使用Solidworks建模软件构建上颌切牙的三维（3D）有限元模型。利用ANSYS软件通过3D有限元分析评估PDL在垂直向压入移动和舌向根转矩移动时的应力。将这些应力与线性和非线性分析结果进行比较。
对于垂直向压入移动和舌向根转矩移动，PDL上的应力分布在Lee提出的最佳应力值范围内，但超过了Proffit给出的具有线性特性的正畸牙齿移动最佳力值。当在非线性分析中施加相同的力载荷时，与线性分析相比应力更大，且超出了Lee针对垂直向压入移动和舌向根转矩提出的最佳应力范围。为了获得与线性分析相同的应力，利用非线性特性进行迭代并降低了力的水平。
这表明非线性分析所需的力水平低于线性分析。
