Chapter 10 - Regenerative technologies for oral structures

Abstract

The oral cavity is the gateway to the digestive/gastrointestinal system of the human body. The major components of this important area of the body include teeth, bone, soft tissues, neurovascular structures, the joint structure (i.e., the temporomandibular joint or TMJ) and the salivary glands. The major salivary glands are not directly a part of the oral cavity, albeit it is intimately associated with it. The main goal of regenerative medicine as it pertains to this chapter includes a discussion about important cutting-edge technologies and their associated science. We as a human species are a product of millions of years of evolution. Replicating that which nature has designed for us is an enormous challenge that is yet to be fully realized. The input of billions of dollars of scientific funding as well as the efforts of thousands of scientists, researchers, biomedical engineers and clinicians worldwide have resulted in significant strides in this important area of biomedicine. As the area of regenerative medicine and technologies progresses there are bound to be several challenges that can only be addressed with further scientific inquiry and research/development. Some of these can include purely scientific challenges, for instance, the viability and long-term survival of regenerated oral tissues whereas other challenges can be in the areas of federal regulatory and ethical issues. The regeneration of the structures of the oral cavity requires a different recipe and varying skill sets of researchers and clinicians to arrive at a successful outcome. In order to reach the level of sophistication that evolution has provided, the newer generation of scientific thinkers need to focus on a paradigm shift in the way that these problems are addressed. A good analogy to explain here will be that researchers, scientists and biomedical engineers can be considered as the sous chefs and gourmet chefs of the scientific process (i.e., in helping develop the products) whereas the clinicians would be the ones to prepare the entrée (i.e., implanting the developed products in vivo) and the patients would be the customers in the restaurants (i.e., the end users of the finished products). The vital structures in the human oral cavity include the teeth, gingival tissues, bone (alveolar, basal and membranous), joint structure (the temporomandibular joint/TMJ), the neurovascular structures and minor salivary glands. In order to accomplish the regeneration of these previously mentioned structures several approaches have been employed. These include but are not limited to gene therapies, cell therapies and tissue engineering. One of the main challenges of currently available technologies is the inability to fully translate the results of in vitro scientific research into predictable in vivo performance. These can include but may not be necessarily limited to the duration of implanted/regenerated tissues but also to the quality of the regenerated tissue(s) as well as their long-term behavior. Increasingly current scientific efforts are not sufficient to replace damaged/missing tissues but the next level of regenerative efforts should be the ability for the regenerated structures to provide biofeedback (i.e., the ability of the implanted structures to adapt to physiologic responses over time) and biostimulation (i.e., the ability of implanted structures to signal the surrounding in vivo milieu). Owing to the advances being made in the areas of cell and molecular biology, genetics, biomedical engineering, medicine, dentistry and biotechnology, one or more of these areas of science will only be able to advance through collaborative interdisciplinary research efforts. Some of the key areas of such research efforts will invariably include multivariate statistical approaches to analyze the resulting scientific data, short-term and long-term study of the mechanical and microstructural properties of the regenerated tissues, developing technologies to manufacture hybrid materials, biocompatibility, clinical trial designs of hybrid regenerative technologies, policy developments, ethics, socio-economic implications and regulatory challenges.