Researchers discover method to control tooth root development
LOS ANGELES, U.S./SICHUAN, China: Though genetic research has become increasingly relevant in the fields of medicine and biology, it has remained relatively untouched when it comes to dentistry. In a promising development, researchers have found that epigenetic regulation—the study of changes in organisms caused by modification of gene expression—can control root patterning and development in teeth, potentially leading someday to the regeneration of teeth.
Researchers at the University of Southern California’s Herman Ostrow School of Dentistry and Sichuan University’s West China Hospital of Stomatology jointly conducted the study, which examined a protein called enhancer of zeste homolog 2 (EZH2) that is known to aid in the development of facial bones. What was not known, however, was what happens when EZH2 is not present in developing molars. The study found that EZH2 and a protein called AT-rich interactive domain-containing protein 1A (ARID1A) must both be present and in balance to form the tooth root pattern and allow for the proper integration of roots with jawbones.
“I feel excited about this because, through human evolution, there are changes in our diet and environment that can influence our epigenome—the ways our genes are regulated—and you can clearly see a difference between the root formation of our dentition versus Neanderthals,” said Dr. Yang Chai, Associate Dean of Research at the Herman Ostrow School, in an interview on USC’s website. According to Chai, the root trunks of molars in Neanderthals are longer than those of modern molars, a possible effect of the increased pressure on EZH2 and ARID1A today as a result of changes in exercise and diet.
Chai further explained that the current goal of this research is to be able to regenerate molar roots and to place crowns on top of them. The ultimate goal is to regrow teeth. “It would be the best of both worlds: a natural integration of the root with the jawbone with the periodontal ligament in place, and a reduction in the amount of time we need by using just a crown to restore function,” he added.
The study, titled “Antagonistic interaction between Ezh2 and Arid1a coordinates root patterning and development via Cdkn2a in mouse molars,” was published online on July 1, 2019, in eLife.