Unlike bones, which can heal and regrow after a break, teeth lack this crucial ability. This biological difference contributes to millions worldwide experiencing some form of tooth loss, or edentulism. However, a promising new medicine from Japanese researchers, designed to regrow teeth, is now moving into human trials. If successful, the team hopes the drug could be widely available for all forms of tooth loss by around 2030.
Comprising 206 structures in the average adult, bones are remarkable composites of calcium, minerals, and collagen, forming our body’s resilient internal framework. Should they fracture, bones possess an inherent capacity to heal and regenerate. Teeth, despite being the hardest material in the human body (owing to their protective enamel layer) and sharing some compositional similarities with bone, are fundamentally different. Crucially, they lack the ability to self-repair or regrow. However, this may soon change.
Dr. Katsu Takahashi, head of dentistry at the medical research institute at Kitano Hospital in Osaka, expressed the team’s motivation: “We want to do something to help those who are suffering from tooth loss or absence. While there has been no treatment to date providing a permanent cure, we feel that people’s expectations for tooth growth are high.”
The drug’s development stems from years of research focusing on a specific protein called Uterine sensitization–associated gene-1 (USAG-1). This protein has been identified as an inhibitor of tooth growth in animal studies, specifically in mice and ferrets. In 2021, scientists at Kyoto University—who are also participating in the current human trials—made a significant breakthrough. They discovered a monoclonal antibody (a technique often employed in cancer therapies) capable of disrupting the interaction between USAG-1 and crucial growth-promoting molecules called bone morphogenetic proteins (BMPs).
This discovery paved the way for the current drug. As explained by Dr. Takahashi, a co-author of the earlier study, in a press statement at the time: “We knew that suppressing USAG-1 benefits tooth growth. What we did not know was whether it would be enough.” He further noted the relevance of their animal models, stating, “Ferrets are diphyodont animals with similar dental patterns to humans,” making them excellent models for human tooth development.
