  In order to study the local interactions between facial soft-tissues and a
Silhouette Soft suspension suture, a CE marked medical device designed for the
repositioning of soft tissues in the face and the neck, Finite element
simulations were run, in which a model of the suture was embedded in a
three-layer Finite Element structure that accounts for the local mechanical
organization of human facial soft tissues. A 2D axisymmetric model of the local
interactions was designed in ANSYS, in which the geometry of the tissue, the
boundary conditions and the applied loadings were considered to locally mimic
those of human face soft tissue constrained by the suture in facial tissue
repositioning. The Silhouette Soft suture is composed of a knotted thread and
sliding cones that are anchored in the tissue. Hence, simulating these
interactions requires special attention for an accurate modelling of contact
mechanics. As tissue is modelled as a hyper-elastic material, the displacement
of the facial soft tissue changes in a nonlinear way with the intensity of
stress induced by the suture and the number of the cones. Our simulations show
that for a 4-cone suture a displacement of 4.35mm for a 2.0N external loading
and of 7.6mm for 4.0N. Increasing the number of cones led to the decrease in
the equivalent local strain (around 20%) and stress (around 60%) applied to the
tissue. The simulated displacements are in general agreement with experimental
observations.
