Hakim Mohamed Ahmed Abdel, Khatab Nagwa Mohamed Ali, Mohamed Kareem Maher Gaber, Elheeny Ahmad Abdel Hamid
Ministry of Health and Population, El Minia, Egypt.
Department of Paediatric and Community Dentistry, Faculty of Dentistry, Minia University, Minya, El Minia, Egypt.
Eur J Dent. 2020 Feb;14(1):107-114. doi: 10.1055/s-0040-1702254. Epub 2020 Mar 13.
This study aims to compare the stress distribution and displacement that resulted from the use of a Gerber space regainer and sagittal distalizer using three-dimensional finite element analysis.
Three-dimensional simulated models of the appliances were developed using a software. The forces applied by the two appliances were 3N (tipping) and 15N (bodily), respectively. Displacement and von Mises stress on the compact and cancellous bone, periodontal ligament (PDL), crowns of the mandibular first, second permanent molars, and deciduous canines were calculated. Stress distribution and displacement values were measured via linear static analysis.
Gerber space regainer showed greater displacement than that produced by the sagittal distalizer at the first permanent molar. However, such displacement was less at the other tested points when compared with that delivered by sagittal distalizer. The stresses created by Gerber appliance were higher in the crown and PDL of the deciduous canine than the crown of the first permanent molar crown.
Gerber appliance generates more distal force and less stress concentration on the crown of the mandibular first permanent molar than that created by the sagittal distalizer. On the other hand, stress concentrations produced by Gerber space regainer are found to be more on the crown and PDL of the deciduous canine. Therefore, it can be concluded that the use of Gerber appliance needs more anchorage.
本研究旨在通过三维有限元分析比较使用格伯间隙保持器和矢状远移器所产生的应力分布和位移。
使用软件建立矫治器的三维模拟模型。两种矫治器施加的力分别为3N（倾斜）和15N（整体移动）。计算密质骨、松质骨、牙周膜（PDL）、下颌第一、二恒磨牙及乳尖牙牙冠上的位移和冯·米塞斯应力。通过线性静态分析测量应力分布和位移值。
在第一恒磨牙处，格伯间隙保持器产生的位移大于矢状远移器产生的位移。然而，与矢状远移器相比，在其他测试点处这种位移较小。格伯矫治器在乳尖牙牙冠和牙周膜上产生的应力高于第一恒磨牙牙冠上的应力。
与矢状远移器相比，格伯矫治器在下颌第一恒磨牙牙冠上产生的远中向力更大，应力集中更小。另一方面，发现格伯间隙保持器在乳尖牙牙冠和牙周膜上产生的应力集中更大。因此，可以得出结论，使用格伯矫治器需要更多的支抗。
