Test Tube Teeth
Teeth may be the first bioengineered organs
Tooth loss is clearly an important issue for most individuals.
According to Paul Sharpe, PhD, head of the division of craniofacial
biology and biomaterials at the Dental Institute at King’s College in
London, England and Conan Young, PhD, instructor in oral and
developmental biology at the Harvard School of Dental Medicine, after
age 50, the average person will have lost 12 teeth. As adults have only
32 teeth, the average person thus loses over a quarter of his teeth and
often must turn to a prosthetic replacement.
Soon, however, people may no longer have to put up with prostheses. Dr. Sharpe and Dr. Young have been able to “grow” teeth for pigs and rats by using endogenous cell signaling pathways. By carefully manipulating intercellular communication, they forced cells to rearrange themselves, forming a tooth. Surprisingly, the signaling pathways can be used to assemble teeth from adult stem cells as well as existing dental cells. Best of all, bioengineering teeth from an individual’s own tissues avoids immune rejection and allows for a more realistic replacement, since tooth size, shape, and color are genetically determined. Unfortunately, the challenges of growing roots and identifying ideal raw materials remain. Even so, scientific progress can be fast, and teeth may be the first successfully engineered organs.
This discovery has even larger implications than real replacement teeth for patients; it may bring a new angle to organ transplants as a whole. If it is possible to use the intrinsic cellular signals to induce pre-existing cells or adult stem cells to form teeth on a biodegradable scaffold that replicate their natural 3-D environment, then it is not too far-fetched to think that in the future scientists will be able to grow organs such as kidneys, hearts, or livers from an individual’s own cells.