Albogha Mhd Hassan, Kitahara Toru, Todo Mitsugu, Hyakutake Hiroto, Takahashi Ichiro
a PhD candidate, Section of Orthodontics and Dentofacial Orthopedics, Faculty of Dental Science, Kyushu University, Fukuoka, Japan.
b Associate Professor, Section of Orthodontics and Dentofacial Orthopedics, Faculty of Dental Science, Kyushu University, Fukuoka, Japan.
Angle Orthod. 2016 Jan;86(1):24-31. doi: 10.2319/120514-875.1. Epub 2015 Apr 1.
To investigate the most reliable stress or strain parameters in subject-specific finite element (FE) models to predict success or failure of orthodontic mini-implants (OMIs).
Subject-specific FE analysis was applied to 28 OMIs used for anchorage. Each model was developed using two computed tomography data sets, the first taken before OMI placement and the second taken immediately after placement. Of the 28 OMIs, 6 failed during the first 5 months, and 22 were successful. The bone compartment was divided into four zones in the FE models, and peak stress and strain parameters were calculated for each. Logistic regression of the failure (vs success) of OMIs on the stress and strain parameters in the models was conducted to verify the ability of these parameters to predict OMI failure.
Failure was significantly dependent on principal strain parameters rather than stress parameters. Peak maximum principal strain in the bone 0.5 to 1 mm from the OMI surface was the best predictor of failure (R(2) = 0.8151).
We propose the use of the maximum principal strain as a criterion for predicting OMI failure in FE models.
研究个体化有限元（FE）模型中预测正畸微种植体（OMI）成败的最可靠应力或应变参数。
对28颗用于支抗的OMI进行个体化有限元分析。每个模型使用两个计算机断层扫描数据集构建，第一个在OMI植入前获取，第二个在植入后立即获取。在这28颗OMI中，6颗在前5个月内失败，22颗成功。在有限元模型中，骨腔被分为四个区域，并计算每个区域的峰值应力和应变参数。对模型中OMI的失败（与成功相对）与应力和应变参数进行逻辑回归分析，以验证这些参数预测OMI失败的能力。
失败显著依赖于主应变参数而非应力参数。距OMI表面0.5至1毫米处骨内的峰值最大主应变是失败的最佳预测指标（R² = 0.8151）。
我们建议将最大主应变作为有限元模型中预测OMI失败的标准。
