Finite Element Analysis of Mandibular Advancement Comparing Hunsuck/Epker and a Novel Modification of the Low Z Plasty Technique of BSSO

Abstract

This study analyzed the biomechanical behavior under simulated conditions between a novel modification of the Low Z plasty (NM-Low Z) technique and the conventional Hunsuck–Epker (HE) technique on mandibular advancement surgery. The NM-Low Z technique was developed with the purpose of reducing post-operative complications by facilitating the operative method of lower jaw surgery. The models were investigated under physiological muscular and occlusal loads at 1, 2, 4, 6, and 8 weeks post-operation. Finite element analysis was used to analyze stress distribution, elastic strain, and model displacement. Maximum equivalent von Mises stresses were observed on the fixation system and bone. The elastic strain at the fracture site represented the optimal bone-healing capacity. The NM-Low Z model showed lower stress than the HE model at the 2-week post-operation stage and onwards. The elastic strains observed in both models were situated within the normal range for bone healing. The ranges of displacement for the NM-Low Z model were less than those in the HE model. Based on the data sets studied, the biomechanical study of the NM-Low Z technique can be favorably compared to the conventional HE technique. The NM-Low Z technique promotes post-operation skeletal stability by lowering stress on fixation and bone, with less displacement of the segment during bone-healing periods.

Keywords

• bilateral sagittal split osteotomy
• BSSO
• Hunsuck/Epker
• NM-Low Z plasty
• finite element analysis
• orthognathic surgery