Effects of orthopedic force magnitude and miniscrew length, diameter and insertion angle on the stability of miniscrews. A three dimensional finite element analysis

Abstract

The aim of the study was to evaluate the effects of orthopedic force magnitudes (200 and 250 gm), miniscrew lengths (9, 11 and 13mm), diameters (1.5 and 2mm) and insertion angles (45o and 90o) on the stability of the miniscrew using three dimensional FEA.

The three dimensional model consisted of the following components: Screw, cortical and spongy bone. The screw solid modeling were created on Autodesk Inventor Version (8)* based on manufacturer dimensions (MONDEAL LOMAS standard system). The cortical and spongy bone were modeled in the finite element package , The bone geometry was simplified and simulated as a parallelogram representing cortical bone (20 mm length x 20 mm width x 2 mm height), the spongy bone (20 mm length x 20 mm width x 13 mm height). Finally these components were assembled in ANSYS† environment and complete osseointegration was assumed.

The resultant deformations and stresses of the applied loading