Department of Orthodontics, Wuxi Stomatological Hospital, Wuxi, Jiangsu, China.
Hospital of Stomatology Xuzhou Medical University, Xuzhou, Jiangsu, China.
Clin Exp Dent Res. 2024 Oct;10(5):e70005. doi: 10.1002/cre2.70005.
This study aims to compare and analyze the biomechanical effect and the displacement trend of RME and MSE on the maxillofacial complex under different palatal shapes by using finite element analysis.
The three-dimensional model of maxillofacial complex was obtained from a computed tomography image of a person with a normal palate. Then, we modified the shape of the palate to obtain the model with a high palate. Additionally, two expander devices were considered. MSE and RME were created and four models were made: Model 1: Normal-palate craniomaxillofacial complex with RME expander; Model 2: Normal-palate craniomaxillofacial complex with MSE expander; Model 3: High-palate craniomaxillofacial complex with RME expander; Model 4: High-palate craniomaxillofacial complex with MSE expander. Then, lateral forced displacement was applied and the analysis results were obtained.
The lateral displacement of the palatal suture of Model 3 is greater than that of Model 1, and the maxilla has more rotation. The crown/root ratio of Model 1 is significantly greater than that of the other three groups. Compared with Model 1, Model 3 has greater stress concentration in the superstructure of the craniomaxillofacial complex. Both of them have greater stress in the anchorage area than Model 2 and Model 4.
Different shapes of the palate interfere with the effects of RME and MSE, and its influence on the stress distribution and displacement of the craniomaxillary complex when using RME is greater than MSE. The lateral displacement of the palatal suture of MSE is significantly larger than that of RME. It is more prone to tipping movement of the anchor teeth using RME under normal palate, and MSE may manage the vertical control better due to the smaller crown/root ratio than RME and intrusive movement of molars.
本研究旨在通过有限元分析比较和分析在不同腭型下，RME 和 MSE 对上颌面部复合体的生物力学效应和位移趋势。
从具有正常腭的人的计算机断层扫描图像中获得上颌面部复合体的三维模型。然后，我们修改了腭的形状以获得高腭模型。此外，还考虑了两种扩展器装置。创建了 MSE 和 RME，并制作了四个模型：模型 1：具有 RME 扩展器的正常腭颅颌面复合体；模型 2：具有 MSE 扩展器的正常腭颅颌面复合体；模型 3：具有 RME 扩展器的高腭颅颌面复合体；模型 4：具有 MSE 扩展器的高腭颅颌面复合体。然后，施加侧向强制位移并获得分析结果。
模型 3 的腭缝侧向位移大于模型 1，上颌骨旋转更多。模型 1 的冠根比明显大于其他三组。与模型 1 相比，模型 3 在上颌面部复合体的上部结构中具有更大的应力集中。与模型 1 相比，模型 3 在上颌面部复合体的上部结构中具有更大的应力集中。与模型 1 相比，模型 3 在锚定区域的应力大于模型 2 和模型 4。
不同形状的腭会干扰 RME 和 MSE 的效果，其对上颌面部复合体使用 RME 时的应力分布和位移的影响大于 MSE。MSE 的腭缝侧向位移明显大于 RME。在正常腭的情况下，使用 RME 更容易发生锚牙的倾斜移动，而 MSE 由于冠根比小于 RME 且磨牙的内倾运动，可能更好地管理垂直控制。
