Department of Oral and Maxillofacial Surgery, School of Dentistry, Istanbul Medipol University, Istanbul, Turkey.
Eur Rev Med Pharmacol Sci. 2023 Jun;27(4 Suppl):41-57. doi: 10.26355/eurrev_202306_32744.
A strong postoperative occlusal relationship is essential for the long-term stability of the jaw relations post orthognathic surgery. In multi-piece Le Fort I osteotomy, obtaining a satisfactory inter-maxillary fixation (IMF) of the mobilized segments in the correct position and according to the preoperative plan is difficult. Herein, we aimed to evaluate three different IMF techniques (tooth-supported, bone-supported, or hybrid IMF) using finite element analysis (FEA) of the occlusal surfaces of four models: three multi-piece (lateral incisor-canine, central incisor-central incisor, and canine-first premolar) and a single one-piece Le Fort I osteotomy scenario.
Three different IMF techniques were applied separately to three different multi-piece models and a single one-piece Le Fort I model designed using related software. Simulation brought the lower and upper jaw models to the planned occlusion. Each model's occlusal force was applied to determine their distributions under 100 N, 300 N, and 800 N loads. Forces on the maxilla and mandible during fixation, the effect of these forces on the force distribution in the occlusion, and the accumulated stresses in these regions were determined with Algor Fempro and Rhinoceros software to determine the ideal fixation method. Data obtained were interpreted and evaluated according to the advantages and disadvantages of the actual surgical scenario.
In all four models studied, the hybrid IMF technique was found to be the ideal IMF technique, followed by the teeth- and bone-supported IMF techniques.
FEA allows the manipulation of single parameters, which clinical methods cannot obtain, thereby allowing each to be examined separately. Further clinical trials are required to validate these findings.
术后良好的咬合关系对于正颌手术后颌关系的长期稳定至关重要。在多块 Le Fort I 截骨术中，获得移动段在正确位置并符合术前计划的满意的颌间固定（IMF）是困难的。在此，我们旨在使用四个模型的咬合面有限元分析（FEA）评估三种不同的 IMF 技术（牙支持、骨支持或混合 IMF）：三个多块（侧切牙-尖牙、中切牙-中切牙和尖牙-第一前磨牙）和一个单块 Le Fort I 截骨术场景。
分别将三种不同的 IMF 技术应用于三种不同的多块模型和一个使用相关软件设计的单块 Le Fort I 模型。模拟将上下颌模型带到计划的咬合位置。对每个模型的咬合力进行应用，以确定它们在 100 N、300 N 和 800 N 负载下的分布情况。确定固定时上颌和下颌上的力、这些力对咬合力分布的影响以及这些区域的累积应力，使用 Algor Fempro 和 Rhinoceros 软件来确定理想的固定方法。根据实际手术场景的优缺点对获得的数据进行解释和评估。
在所研究的四个模型中，混合 IMF 技术被认为是理想的 IMF 技术，其次是牙支持和骨支持的 IMF 技术。
FEA 允许操纵单个参数，而临床方法无法获得这些参数，从而可以分别检查每个参数。需要进一步的临床试验来验证这些发现。
