Advanced personalized mandibular implants

Our goal is to develop and test clinically relevant, patient-specific metamaterial implants that reduce stress shielding and improve the health and quality of life of head-and-neck cancer patients.

Personalized mandibular implants

We propose a workflow to develop personalized mandibular metamaterial implants with a topology-optimized microstructure that improves mechanical performance and reduces stress shielding. Such implants aree ready to used in clinical trials, and the workflow can be appliced to other implantable devices.

Can metamaterial parts in mandibular implants reduce stress shielding in the presence of screws?

Our answer is Yes! We set up photoelasticity experiments to show that metamaterial designs transmit more stresses into adjacent bones than their solid counterparts, under the same geometric and fixation conditions. More details can be found in this work: Heins, J. I., Merema, B. B., Kraeima, J., Witjes, M. J., & Krushynska, A. O. (2025). Mandibular Implants: A Metamaterial‐Based Approach to Reducing Stress Shielding. Advanced Healthcare Materials, 14(13), 2500405 (link).

Why photoelasticity tests for metamaterial implant and how does it work?

The answers to these questions can be found here: Heins, J. I., Merema, B. J., Kraeima, J., Witjes, M. J. H., & Krushynska, A. O. (2025). Stress shielding mitigation by metamaterial implants: Photoelasticity test of clinically relevant designs. Biophysics Reviews, 6(3) (link).

How to estimate the mechanical response of bones for each patient?

Interesting question! We believe that the bone mechanics is correlated with patient's bite force. The bite force depends on multiple parameters, and this study provides the model to estimate this force: Heins, J. I., Gareb, B., Ten Brink, R., Vosselman, N., Halmos, G. B., Krushynska, A. O., ... & Witjes, M. J. (2025). Predictive bite force modelling of head and neck oncology patients for clinical mandibular reconstruction applications. Clinical Oral Investigations, 29(11), 1-9 (link).

Can the metamaterial microstructure be modified to have more uniform stress distribution?

This is definitely possible. We applied a density-based topology optimization to redistribute material between gyroid unit cells, thus, tailoring stiffness to loading conditions and reducing stress shielding by increasing stresses in the mandible parts connected to the implant. The optimized geometry is readily 3D-printable and shows enhanced performance in terms of a more uniformly distributed von Mises stresses within the implant, reducing the risk of failure, decreased stress concentrations in critically loaded parts, and increased stresses in the adjacent bones: Heins, J. I., Veluvali, H. C. V. M. S., van der Laan, A., Witjes, M. J. H., Krushynska, A. O. (2026). Patient-specific mandibular metamaterial implants with topology-optimized microstructure. NPJ Metamaterials, 2, 24 (link).