Biomechanical aspects of mandibular fracture fragment fixation research

Abstract

Introduction. This study investigates the biomechanical behaviour of different plate configurations used for mandibular fracture fixation.

Aim. The aim of the study was to evaluate the biomechanical behaviour, stiffness, and stability of different plate configurations used for mandibular fracture fixation under axial loading.

Materials and Methods. Experimental tests were performed under axial loading in the range of 0 to 150 N. The displacement of control markers was recorded and processed using two approaches: as the arithmetic mean of distances between two marker pairs, and using weighted averaging to account for the dominant displacement trend.

Results. Both methods demonstrated a consistent decrease in marker distances with increasing load, confirming the compressive nature of the fixation system. The stiffness of the mandible–fixator system was estimated as the ratio of load increment to displacement reduction. The “2–3” configuration showed the highest stiffness values (≈1575 N/mm) but reduced stability and potential stress concentration near the screw–bone interface. The “3–2” configuration exhibited lower stiffness (≈964 N/mm) and greater micromovements, particularly in the mental region. The “butterfly” plate (“3–3”) provided an optimal balance of stiffness (≈1070 N/mm) and uniform load distribution, reducing torsional deformation and improving spatial stability.

Conclusions. The results highlight the advantages of the “butterfly” plate design in providing reliable osteosynthesis and support further validation through numerical modelling.