Novel Design of Interlocking 3-Dimensional Miniplate in Mandibular Angle Fractures: An In Vitro Study

The evolution of osteosynthesis has led to the development of novel miniplate designs, including 3-dimensional (3D) miniplates, which offer improved biomechanical stability. However, mandible fractures resulting from the high impact have a complex fracture configuration. Hence, the authors developed interlocking 3D miniplate to overcome the difficulty in miniplate and screw placement to avoid critical anatomic structures, that is, dental roots and nerve, while still providing stability for the fracture fragments. The interlocking 3D miniplates can be formed according to the specific needs by adjusting the horizontal and vertical cross struts configuration. This study describes a design process of interlocking 3D miniplates and evaluates biomechanical performance compared to standard miniplates. Finite element analysis was performed to evaluate the design's stress state using human and goat mandible models under various loading conditions. After the authors, established that our design was feasible for fabrication, the authors developed the prototype for biomechanical testing. Biomechanical testing was conducted on 10 goat mandibles to compare stability and displacement under various load between the interlocking 3D miniplate and the standard miniplate configuration. Biomechanical testing revealed reduced displacement in all directions with the interlocking 3D miniplate compared to the standard miniplate. Furthermore, there was a significant difference in all loads in the buccal-lingual displacement (P<0.05). The novel interlocking 3D miniplate design shows an adequate ability to provide stability for fixation for mandibular fractures, as evidenced by finite element analysis and biomechanical testing. Further research is necessary to validate these findings and explore the clinical application of interlocking 3D miniplates in mandibular fracture management.