Finite element analysis of various fixation patterns in mandible bone fracture

Mandibular fractures are among the most serious injuries to the maxillofacial region, with controversy surrounding their diagnosis, classification, and management Fixation mini-plate systems are commonly used for treatment of mandibular fractures. Previous studies have examined plate configurations with various locking systems. However, the impact of plate thickness on the performance of unlocking screw mechanisms has not been investigated in the literature. Also, there exist conflicting findings concerning the impact of the locking and unlocking screw mechanisms on the concentration of stress within the screws. This study investigates the effect of plate thickness and plate-screw locking mechanisms on the performance of the fixation system using the finite element analysis. The complex relation between jawbone thickness and occurred cracks or fractions made us build a precised model for investigating the fixation patterns. Results showed that the locking screw mechanism reduced the von Miss stress in the buccal and lingual regions of the bone. Increasing the plate thickness also decreased the von Miss stress and maximum pressure in the bone. The unlocking screws application resulted in lower values of stress and displacement in the plate and screws compared to the locking screws. Moreover, while using a plate with a higher thickness resulted in a pronounced decrease in plate von Mises stress, it led to a higher stress on the screws. The study investigated crack propagation by analyzing bone density, which was directly related to age and an individual's lifestyle. This method enables a more precise use of the viscoelastic characteristics of mandibular bones tailored to everyone. The outcomes of this study indicated that the locking screw mechanism demonstrated enhanced features in light of the reduced stress on the bone. Nevertheless, the screws and plate experienced an elevated stress level using this mechanism.