Design of a Metal 3D Printing Patient-Specific Repairing Thin Implant for Zygomaticomaxillary Complex Bone Fracture Based on Buttress Theory Using Finite Element Analysis

Abstract

<jats:p>This study developed a zygomaticomaxillary complex (ZMC) patient-specific repairing thin (PSRT) implant based on the buttress theory by integrating topology optimization and finite element (FE) analysis. An intact facial skeletal (IFS) model was constructed to perform topology optimization to obtain a hollow skeleton (HS) model with the structure and volume optimized. The PSRT implant was designed based on the HS contour which represented similar trends as vertical buttress pillars. A biomechanical analysis was performed on a ZMC fracture fixation with the PSRT implant and two traditional mini-plates under uniform axial loads applied on posterior teeth with 250 N. Results indicated that the variation in maximum bone stress and model volume between the IFS and HS models was 15.4% and 75.1%, respectively. Small stress variations between the IFS model and repairing with a PSRT implant (2.75%–26.78%) were found for compressive stress at frontal process and tensile stress at the zygomatic process. Comparatively, large stress variations (30.67%–96.26%) with different distributions between the IFS model and mini-plate models were found at the corresponding areas. This study concluded that the main structure/contour design of the ZMC repair implant according to the buttress position and orientation can obtain a favorable mechanical behavior.</jats:p>

New Innovation: Custom Titanium Zygomaticomaxillary Complex (ZMC) Plate for Facial Reconstruction

“…Reconstructive plating devices, typically made of titanium, have previously been used for more complex facial injuries. However, the large volume of titanium facial implants may cause increased stress and lead to increased bone resorption [ 5 ]. Additionally, polydioxanone (PDS) sheets and 3D-printed titanium mesh using a mirroring technique from the unaffected side have proven useful in the reconstruction of orbital fractures, but these are limited to smaller injuries that only span the orbit [ 6 ].…”

“…Traditional methods of surgical fixation of ZMC fractures comprise one, two, and three-point fixation reduction with a plate and screw [ 3 , 5 ]. Standard plates are limited by their difficulty with bending to fit the contour of the patient, which can result in malreduction [ 6 ].…”

Three-dimensional Measuring of Zygomaticomaxillary Complex Symmetry after Fixation of Unilateral Zygomaticomaxillary Complex Fracture

“…The disadvantages of the conventional miniplates such as screw loosening, plate corrosion, and fracture that occur due to plate over bending can be overcome by the integration of CNC milled patient-specific plates that based on digital files designed by computers have been created. The plate design is based on the individual patient's 3D imaging data which done by using block of titanium cut sheet (14) and therefore the custom made plate can accurately fit the contour without any bending, thus facilitating the intraoperative procedures, reducing the time spent for operation, and improving results accuracy. in this study, the needed for ZMC reduction and fixation in group A was 68±21 minutes which is shorter than group B (109±68 minutes).…”

“…The plates were designed to accurately rely on intact bones of the ZMC structures, to provide adequate stability. The design was done by cutting through block of titanium using 3D data through a CNC milling machines, using CAD/CAM (14) . The custom made plate thickness was 1 mm.…”

Three-Dimensional Finite Element Analysis of Stress Distribution in a Tooth Restored with Full Coverage Machined Polymer Crown

“…Finite element analysis (FEA) is a more intriguing innovation technique to evaluate the stress-strain relationship and has been applied widely in dentistry [14][15][16][17][18][19][20][21][22]. FEA uses computerized data and is a numerical method of analyzing stress distribution.…”