Biomechanical comparison of a multidirectional locking plate and conventional plates for the osteosynthesis of mandibular angle fractures-A preliminary study.

PURPOSE: The objective of surgical fracture management is to reduce and fixate fractures accurately and rapidly. Two osteosynthesis plates are usually used in the treatment of mandibular angle fractures to enhance torsional stiffness. We conducted biomechanical tests under static and cyclic loading to assess whether a single locking plate is as efficacious as two conventional plates in the osteosynthesis of mandibular angle fractures.

MATERIALS AND METHODS: Fracture gaps were created in synthetic mandible replicas. After pretests, the stiffness of a single locking plate and different types of non-locking, two-plate systems was assessed and compared under static and cyclic loading. The plates were subjected to a maximum static load of 750 N and underwent cyclic loading at a constant force of 400 N during a maximum of 500,000 cycles.

RESULTS: No plastic deformation occurred in the static tests. Both types of osteosynthesis showed high static stability. The locking plate was significantly stiffer than the non-locking plates (p = 0.0079). Cyclic loading tests did not reveal any significant differences.

CONCLUSION: Within the limitations of this preliminary study, a single locking miniplate appears to be as efficacious in biomechanical tests as non-locking, two-plate systems for the management of mandibular angle fractures.