Biomaterials-based approaches to mandibular tissue engineering: where we were, where we are, where we are going.

The mandible is the largest craniofacial bone and plays a crucial role in speech, mastication, swallowing, and facial aesthetics. The form or function of the mandible can be altered by defects as a result of tumors, trauma, infection, and congenital conditions. This paper covers the evolution of biomaterials-based approaches to the reconstruction of critical size mandibular defects. Historically the gold standard for critical size mandibular defect repair has been autologous fibula grafts. The emergence of the field of tissue engineering has led to the current research on biomaterial scaffolds, cells, and biological factors to design highly tunable, bio-inspired, tissue regenerative implants. Scaffold materials can be synthetic or natural and can be fabricated using a variety of additive manufacturing techniques. Mesenchymal stem cells, bone morphogenetic proteins, and transforming growth factor-β are frequently added to scaffolds. While great progress has been made, there are still barriers to translating this research to patients, ranging from insufficient bone regeneration in animal studies to the feasibility of establishing a good manufacturing practice. To address these challenges, the future of mandibular tissue engineering will look toward improving implant vascularization and innervation, personalizing implant shape and biology, and enhancing spatiotemporal control of drug release. With these goals in mind, researchers will ultimately develop biomaterials that can regenerate bone that is structurally and biologically identical to native mandibular tissue, improving both function and quality of life for patients.