Scientists at Kyoto University Hospital in Japan are launching the first human trial for a new drug aimed at regrowing lost teeth. The treatment, known as TRG035, targets a protein that inhibits tooth formation, with the potential to help individuals born with missing teeth and those who have lost teeth due to decay, gum disease, or injury.
Tooth agenesis, a condition where some adult teeth fail to develop, affects up to one in 20 people. In cases of severe tooth agenesis, such as oligodontia where six or more teeth are missing, current solutions like dentures can be problematic for children whose jaws are still growing. Dental implants typically cannot be placed until the late teens, leaving younger patients with gaps that can affect chewing and speech.
The development of TRG035 was inspired by the study of supernumerary teeth, or extra teeth, which occur when some individuals naturally grow more than the standard 32 adult teeth. Researchers identified a protein, USAG-1, that acts as a brake on the growth of spare tooth buds. TRG035, administered via injection, is a monoclonal antibody that binds to USAG-1, thereby releasing the brake and allowing tooth growth to proceed.
Animal studies have shown that a single dose of the drug was sufficient to grow a new tooth. The initial human trial will involve 24 children diagnosed with oligodontia. If successful, experts believe this could represent a significant advancement for treating rare dental disorders.
While the immediate focus is on patients with congenital tooth agenesis, the researchers also hope the drug could eventually benefit adults who have lost teeth. However, this presents a greater challenge, as the tooth bud that originally formed a lost tooth has typically disappeared in adulthood, leaving nothing for the drug to act upon.
Experts caution that the full development and availability of such a therapy may still be decades away. For instance, Paul Hatton, a professor of biomaterials science at the University of Sheffield, suggests that it could be many years before this treatment is widely available, although the researchers are reportedly aiming for availability by 2030. Mary MacDougall, an expert in genetic tooth disorders at the University of British Columbia, noted that forming a human tooth from its initial bud stage through eruption is a lengthy process. The current trial is expected to provide crucial data on the efficacy and safety of TRG035 in humans.