Biomechanical Effects of Different Miniplate Thicknesses and Fixation Methods Applied in BSSO Surgery Under Two Occlusal Conditions

Abstract

Purpose Finite element analysis (FEA) was used to evaluate the effects of different thicknesses, numbers, and positions of the miniplate applied in bilateral sagittal split osteotomy (BSSO) under two occlusal conditions. Methods An FEA model of the mandibles was constructed and combined with different thicknesses (0.6 or 1 mm), number (one or two), positions (upper or lower) of a miniplate and was divided into six models. In addition, external forces were applied to the muscles to simulate the intercuspal position (ICP) and right unilateral molar clench. This study used the reaction force of the temporomandibular joints and the stress of the mandible as observation indexes. Results The results of this study show that, under ICP, the 0.6 mm lower model generated greater TMJ force reaction compared to the 0.6 mm upper model. The same trend was seen in the 1 mm lower model compared to the 1 mm upper model. Regarding the stress of the bone on the screw-implanted sites, under ICP, screw 10 showed greater stress than screw 2, and screw 11 showed greater stress than screw 3. The stress values of the miniplates showed, under ICP, point 1-c was greater than point 3-c, and point 1-b was greater than point 3-b. Conclusion In the case of BSSO mandibular advancement surgery, implanting the miniplate at the upper position can reduce the force on the TMJ and the stress on the distal segment of the mandible. The miniplate can also resist the tensile stress more effectively. In addition, implanting two miniplates with thinner sizes may be an alternative in clinical practice.

Optimizing Spinal Fusion Cage Design to Improve Bone Substitute Filling on Varying Disc Heights: A 3D Printing Study

“…Furthermore, by employing 3D printing, we can quickly and customarily optimize implant design. Furthermore, in addition to simulating and evaluating medical devices through 3D printing [27][28][29][30][31][32], future investigations may incorporate finite element analysis for mechanical simulations [33][34][35]. In addition, future research can use commonly used clinical materials (titanium or PEEK) to make cage models, and then conduct cadaver study, sawbones study, clinical study, or biomechanical evaluation of other implant designs.…”