Force and deformation stresses in customized and non-customized plates during simulation of advancement genioplasty

Abstract

Purpose: The aim of this study was to evaluate the distribution of deformation stresses in customized and non-customized plates during simulated advancement genioplasty, using the finite element method.

Methods: A customized plate (Traumec) was developed with 4.75 mm advancement, in ASTM F67 Grade 2 titanium, with four screws. Non-customized (standard) plates with 6 mm advancement (Stryker with six screws and Osteomed with four screws) were used for comparison. All the screws presented the same length (10 mm) and fixation system (2.0). The Traumec and Osteomed plates were fixed with two screws in the mandible, and another two in the segment, whereas the Stryker plate was fixed with three screws in the mandible, and another three in the segment. Six virtual models were generated in a computer-aided design program (Rhinoceros), in which the advancement and insertion of the plates were evaluated. All the plates were submitted to application of perpendicular and oblique forces of 5 N in the chin region.

Results: The Osteomed plate showed the highest stress value (1506 MPa), and the Traumec, the lowest stress value (560.20 MPa). The Stryker plate showed higher stress values for the segment screws than for the mandibular screws, unlike the other plates.

Conclusions: The customized Traumec plate showed better deformation stress distribution and plate/segment stabilization when submitted to advancement genioplasty.

Keywords: Finite element method; Genioplasty; Plates.