Edentulous mandible with four splinted interforaminal implants exposed to three different situations of trauma: A preliminary three-dimensional finite element analysis.

Abstract

An increasing number of elderly patients with implant-prosthodontic rehabilitation of the edentulous mandible frequently show increased life activity, and consequently, a greater number of aged patients is at risk for maxillofacial trauma. The aim of this 3-dimensional (3D) finite element analysis (FEA) was to evaluate the biomechanical effects of the edentulous mandible (EM) with and without four splinted interforaminal implants exposed to three different trauma applications including assessment of different mandibular fracture risk areas. In a 3D-FEA study design, EM with and without four splinted interforaminal implants were exposed to the application of 1000N at the symphyseal, parasymphyseal, and mandibular angle region. On four pre-defined superficial cortical mandibular areas (symphysis region, mental foramen region, angle of mandible, and mandibular neck) representing regions of interest (ROI), the von Mises stresses were measured for the three trauma applications. For all ROIs, stress values were evaluated and compared for the different force application sites as well as between EM models with and without interforaminal implants. For EM with and without four splinted interformaninal implants, all traumatic loads generated the highest stress levels at the mandibular neck region. However, in the EM with four splinted interforaminal implants, an anterior symphyseal force application generated significantly (P<.01) increased stress values in the parasymphyseal (mental foramen) region than in EM without implants. For force applications at the parasymphaseal region (mental foramen) and at the angle of the mandible elevated, von Mises stress values were noted directly at the application sites without difference between edentulous mandibles with and without four interforaminal implants. In an edentulous mandible model with four splinted interforaminal implants, the condylar neck and the mental foramen represent the predilectional risk areas for mandibular fracture for both anterior symphyseal and lateral parasymphyseal force application.