A novel algorithm for streamlined surgeon-dominated patient-specific implant design in computer-assisted jaw reconstruction.

Background: Computer-assisted surgery has transformed the approach to jaw resection and reconstruction in recent years. However, the extensive time and technical expertise needed for the planning and creation of patient-specific implants and guides have posed significant challenges for many surgeons in the field. This study introduces a novel algorithm designed to streamline the traditionally intricate and time-consuming Computer-Aided Design (CAD) process for developing patient-specific implants (PSIs).

Methods: The algorithm requires a three-dimensional (3D) model of the reconstructed part. A set of points is selected along the planned location of the plate by the surgeon, defining both the geometry and the positions of the screw holes. These points are then connected to create trace lines, followed by smoothing using cubic-spline data interpolation. Subsequently, a rectangle is swept along the trace line to form the skeleton of the PSI's surface model. Screw holes are incorporated into the surface model, which is then converted into 3D printable file format. Finite element analysis is conducted to evaluate the functionality of the designed PSI.

Results: Implant design time exhibits significant reductions with the proposed algorithm, which optimizes the model files for printing. Finite Element Analysis is successfully applied to demonstrate the stress levels in the implant plate, which are within safe limits for titanium 3D-printed implants.

Conclusions: This algorithm offers a faster, more efficient, and accurate alternative to traditional CAD methods, with the potential to revolutionize the field of patient-specific implant design. Furthermore, the study demonstrates the utility of a mechanistic model for correlating patient bite force with muscle forces in the literature.