Comparison of standard miniplates and locked miniplates in post-traumatic fracture stabilization

Bicortical screws (lag and positional) or miniplates with monocortical screws are generally used for the rigid fixa-tion of the sagittal split ramus osteotomy (SSRO) in maxillofacial surgery. However, in this osteosynthesis method, the plate must be perfectly adapted to the bone to prevent misalignment of the bone segment and occlusal changes. In addition, it is necessary to prevent the position of the condyle in the mandibular fossa from changing after fixation. In recent years, locked miniplate systems have been used to overcome these complications.

The aim of this study is to compare the commonly used 2.0 mm standard miniplate/screw systems and 2.0 mm locking miniplate/screw systems in fresh sheep jaws with Obwegeser-Dal Pont (OD) and Hunsuck-Epker (HE) modifications, by evaluating standard parameters.

Our study consists of two main groups and two subgroups. 40 sheep hemimandibulae were randomly divided into two main groups. Each group was randomly divided into two subgroups. There are ten hemimandibulae (n=10) in each subgroup. Linear force test was applied using 4-hole standard miniplate and 4-hole locking miniplate systems on sheep jaws with 5 mm advancement by applying OD and HE techniques, which are two frequently preferred modifications in SSRO. For statistical analysis SPSS® 16.0 (Sta-tistical Package for the Social Sciences, SPSS Inc. Chicago, Illinois, USA) package program was used. It was statistically compared with the 95% confidence interval using the Pearson coefficient, and p<0.05 was interpreted as significant. The values of the loading forces applied to the samples in the groups were subjected to analysis of variance (ANOVA) to confirm the normality of the sample. Multiple comparisons were made between groups using the Tukey test. The mean loadings in the groups were analyzed by one-way ANOVA.

In general, as the strength of the force increases, the displacement values increase in all groups, but although it was observed that the locked miniplate/screw system was more stable than the standard miniplate/screw system, no statistically significant difference was found.