Effect of septal extension graft on nasal tip support: A finite element analysis.

[BACKGROUND] Septal extension graft (SEG) is an effective method to control the projection, rotation, and shape of the nasal tip. However, the structural mechanics of SEG have not yet been adequately determined.

[OBJECTIVES] The purpose of this study was to examine the effect of SEG parameters on nasal tip support using finite element analysis.

[METHODS] A multicomponent nasal model was constructed from a computed tomographic scan. A control model without graft and a total of 15 models with different SEGs were created, regarding the direction, length, width, and piece of SEG. The nasal tip compression was simulated to analyze the von Mises stress, reaction force, and strain energy of the tip structure.

[RESULTS] The SEG increased the max stress, reaction force, and strain energy of the nasal tip compared to the normal control. The SEG perpendicular to the nasal dorsum resulted in the highest maximum stress, reaction force, and strain energy for the same size of SEG. With the length increasing from 15 × 8 × 1 mm to 25 × 8 × 1 mm, the reaction force remained relatively stable, but the stress on the graft reduced significantly. Adding the width and pieces of the SEG increased the reaction force and strain energy of the tip.

[CONCLUSION] The placement of SEG can strengthen the nasal tip support. The direction, length, width, and piece of SEG have an impact on the mechanics.

[LEVEL OF EVIDENCE] Diagnostic, III.