Department of Oral Diagnosis, Division of Oral Radiology, Piracicaba Dental School, University of Campinas, Piracicaba, Brazil.
Department of Morphology, Division of Anatomy, Piracicaba Dental School, University of Campinas, Piracicaba, Brazil.
Clin Oral Investig. 2018 Dec;22(9):3195-3203. doi: 10.1007/s00784-018-2403-4. Epub 2018 Mar 10.
Previous studies have suggested a relationship between resorption in second molars and pressure from the eruptive force of the third molar. The aim of this study was to simulate functional forces in a mandible model by means of finite element analysis and then assess the biomechanical response produced by impacted third molars on the roots of the second molar.
A cone beam computed tomography scan presenting an impacted mandibular third molar was segmented (Mimics V17 software). The modeling process was performed using the reverse engineering technique provided by the Rhinoceros 3D 5.0 software. The third molar position was changed in order to produce different inclinations of the impacted tooth. Bite forces were simulated to evaluate total deformation, the equivalent von Mises stress, minimum principal stress on hard tissue, and equivalent elastic strain on soft tissue.
Areas of high energy dissipation and compression stress were detected in the second molar root, independently of the inclination of the impacted third molar. In general, the horizontal position was the situation in which major stress and the amount of deformation occurred in the second and third molar regions.
Impacted third molars in close proximity with the adjacent tooth can generate areas of compression concentrated at the site of contact, which suggests an involvement of mechanical factors in the triggering of resorption lesions.
The results of these computational experiments contribute to the understanding of the triggering and progression of resorptive lesions in the adjacent second molar.
之前的研究表明，第二磨牙的吸收与第三磨牙的萌出力之间存在关系。本研究的目的是通过有限元分析模拟下颌骨模型中的功能力，然后评估阻生第三磨牙对第二磨牙根部产生的生物力学反应。
对呈现下颌阻生第三磨牙的锥形束 CT 扫描进行分割（Mimics V17 软件）。使用 Rhinoceros 3D 5.0 软件提供的逆向工程技术进行建模过程。改变第三磨牙的位置以产生不同倾斜度的阻生牙。模拟咬合力以评估总变形、等效 von Mises 应力、硬组织的最小主应力和软组织的等效弹性应变。
在第二磨牙根部检测到高能量耗散和压缩应力区域，与阻生第三磨牙的倾斜度无关。一般来说，水平位置是第二和第三磨牙区域发生主要应力和变形的情况。
与邻牙紧密相邻的阻生第三磨牙会在接触部位产生集中的压缩区域，这表明机械因素参与了吸收性病变的触发。
这些计算实验的结果有助于理解相邻第二磨牙吸收性病变的触发和进展。
