Design of porous titanium scaffold for complete mandibular reconstruction: The influence of pore architecture parameters

Abstract

Patients having a medical history of oral cancer, infectious diseases or trauma are often advised surgical intervention with customized complete mandibular constructs (CMC) made of Titanium (Ti) scaffolds. A numerical framework based on a homogenization technique was developed to investigate the influence of pore architecture parameters on homogenized orthotropic material properties of the scaffolds. A comparative 3D Finite Element (FE) analysis of six CMC models, having homogenized orthotropic material properties, under a mastication cycle, was undertaken to pre-clinically determine the optimal CMC for a patient. Orthotropic material properties of Ti-scaffolds decreased with an increase in the inter-strut distance. Stress and strain distributions of CMC models during right molar bite were investigated. Despite small differences in stress distributions in the ‘body’ region of CMC models, the overall stress distribution (tensile and compressive) of CMC models (30–32 MPa) were well comparable to that of an intact mandible (34.54 MPa). Higher magnitudes of tensile strains were observed for models with 0.2 mm (9884μɛ) and 0.4 mm strut diameter (SD), both having 0.5 mm inter-strut distance (ID), at articular condyle area, body and symphysis equivalent part of the constructs. The maximum principal tensile strains were higher in the CMC models with 0.5 mm ID as compared to those having 0.3 mm ID. Comparatively, the scaffolds with lesser ID (0.3 mm) resulted in higher stiffness, thereby evoking less principal strains in the CMC models. Moreover, considering the weight of the scaffolds, the CMC models having 0.3 mm ID with 0.2 mm SD and 0.5 mm ID with 0.6 mm SD seemed most appropriate for a patient.