Biomechanical evaluation of various rigid internal fixation modalities for condylar-base-associated multiple mandibular fractures: A finite element analysis.

Condylar-base-associated multiple mandibular fractures are more prevalent than single ones. Direct trauma to mandibular symphysis, body or angle are prone to induce indirect condylar fracture. However, little is known about the effects of various rigid internal fixation modalities in condylar base for relevant multiple mandibular fractures, especially when we are confused in the selection of operative approach. Within the finite element analysis, straight-titanium-plate implanting positions in condylar base contained posterolateral zone (I), anterolateral zone (II), and intermediate zone (III). Von Mises stress (SS) in devices and bone and mandibular displacement (DT) were solved, while maximum values (SS and DT) were documented. For rigid internal fixation in condylar-base-and-symphysis fractures, I + II modality exhibited least SS in screws and cortical bone and least DT, I + III modality exhibited least SS in plates. For rigid internal fixation in condylar-base-and-contralateral-body fractures, I + III modality exhibited least SS in screws and cortical bone, I + II modality exhibited least SS in plates and least DT. For rigid internal fixation in condylar-base-and-contralateral-angle fractures, I + III modality exhibited least DT. The findings suggest that either I + II or I + III modality is a valid guaranty for rigid internal fixation of condylar base fractures concomitant with symphysis, contralateral body or angle fractures.