How Science Might Help People Regrow Their Teeth

For as long as people have been people, tooth loss has been an inevitability. Stone Age skeletons show signs of worn enamel and missing molars and ancient remedies (powders, oils, and charms) were powerless against decay.

Dentures carved from bone, ivory, and wood became desperate stand-ins, while modern dentistry armed us with implants, crowns, and bridges. I mean, think about all the rumors about George Washington I’ve heard since I was a little kid.

Yet no matter how far we advanced, there was always a finality to tooth loss. Once a tooth was gone from our mouths, it was gone forever…until now.

We get our baby teeth and lose them, trade with the tooth fairy for some shiny new coins and that’s that. Our permanent teeth arrive and after those guys show up our biology seems to shut down and close shop. A dental implant can be excellent and a crown can save a damaged tooth, but none of them can change the fact that the tooth is our forever teeth.

Now scientists in Japan are trying to change that. This story has moved considerably further than it had when I first wrote about it over a year ago.

Toregem BioPharma, a biotechnology company that grew out of research at Kyoto University, is developing an experimental antibody drug called TRG035. Instead of manufacturing a replacement tooth, the drug targets a protein involved in suppressing tooth development. The idea is almost absurdly simple when you first hear it: remove one of the biological brakes, then see whether a tooth that never developed properly can begin growing.

Unfortunately for us, this isn’t a currently a treatment you can ask your dentist for, and scientists yet to demonstrate that an eighty-year-old can lose a molar and casually grow another one, but this is also no longer just a mouse experiment sitting in a laboratory.

Phase I human testing in Japan has been completed, and in August 2026 Japan’s Pharmaceuticals and Medical Devices Agency completed its required review of the clinical trial notification for a Phase IIa study of TRG035 in people with congenital tooth agenesis.

That is where things get very interesting.

The Science of Tooth Regeneration

At the center of this entire story is a protein called USAG-1. You can think of USAG-1 as one part of the complicated system controlling tooth development. It interacts with important signaling pathways, particularly BMP signaling, that help determine when and how teeth form.

Researchers wondered what would happen if they interfered with it and in animal experiments, the answer was remarkable.

Scientists developed antibodies that blocked USAG-1. In mice, a single administration of one antibody was enough to stimulate the development of an entire tooth. Researchers later saw tooth-generating effects in ferrets, which are particularly interesting because, like us, they normally develop only two generations of teeth.

I’m not saying that scientists just “turned stem cells back on.” The biology is more complicated than that and the current theory is that blocking USAG-1 can release inhibition on developmental pathways and potentially allow tooth germs that failed to progress normally to continue developing. Less Frankenstein lightning bolt and more taking your foot off a biological brake.

Toregem’s drug, TRG035, is a “humanized monoclonal antibody” (that’s what Google told me) designed to neutralize USAG-1. The company says its goal is to promote the eruption of teeth by activating tooth-development potential that already exists within the patient. Its first target is congenital tooth agenesis, a condition in which someone is born missing one or more permanent teeth.

So, researchers are not currently giving the drug to someone who had a normal adult tooth extracted last Tuesday and watching a new one appear. First they’re trying to see if this approach help people whose permanent teeth never developed properly in the first place.

The End of Implants and Dentures?

Ehhh, I doubt it in all honesty. You see a headline saying “Scientists Develop Drug That Regrows Teeth” and suddenly we’re imagining dental implants gathering dust beside fax machines.

Dental implants are enormously useful as it is, so are bridges, crowns and dentures. Tooth regeneration would have to prove that it’s safe, predictable, controllable, durable and actually capable of producing teeth that erupt in useful positions and function properly.

Those are not small details either. A tooth needs to fit into a jaw and have the right shape to do so. It also needs to meet the opposing teeth properly when you bite, which in turn needs appropriate support from bone and surrounding tissues. Growing a tooth and growing the correct tooth in the correct place are two different achievements.

Still, if biological tooth regeneration eventually becomes reliable, it could create an entirely new branch of dentistry.

In folklore, to lose a tooth was to lose power; to dream of tooth loss was to dream of mortality. I’m not sure about you, but I often dream about losing my teeth. It’s such a strange dream.

Sharks, who endlessly regenerate their rows of teeth, became symbols of relentless survival.

Congenital tooth agenesis can range from one missing tooth to severe conditions where many permanent teeth simply never develop. For someone living with severe oligodontia, growing even some of those missing teeth biologically could be life-changing.

Toregem’s current development program is specifically focused on this group. In 2025, Japan’s Ministry of Health, Labour and Welfare granted TRG035 orphan-drug designation for severe congenital hypodontia.

That is much more specific than the viral version of this story, but honestly, I think the real version is more interesting, because this is how massive changes in medicine usually begin: with one very specific problem.

A Future of Renewal

Toregem has already completed its Phase I study in Japan, which the company says confirmed the safety needed to continue development. The next stage moves closer to asking whether the treatment actually produces the intended biological effect in patients with congenital tooth agenesis.

So where are we now you might wonder. Well, further than mice but nowhere near replacing your dentist.

As of August 2026, Phase I testing of TRG035 has been completed in Japan. Toregem has also communicated with the U.S. Food and Drug Administration through the pre-IND process about potentially developing the treatment in the United States. The company says the discussions included future clinical-trial design and strategies that could eventually involve children with congenital tooth agenesis.

In May 2026, Toregem raised another approximately 850 million yen, around $5.3 million, to help fund continued Phase II development in Japan and prepare for future development in the United States.

Then on August 17, 2026, Toregem announced that the PMDA had completed its investigation of the clinical trial notification for the Phase IIa study. Those are real milestones, but will it actually regrow useful teeth in humans? Ehh…not sure yet, we’ll have to wait and see is the best answer I have for you.

The Memory of Evolution

There is a temptation to describe this research as humans “remembering” some ancient ability to continuously grow teeth. It’s beautiful to think of like that, but also a little far fetched. Our evolutionary lineage has been working with restricted tooth replacement for a very long time. Most mammals are diphyodont, meaning they normally produce two generations of teeth.

The molecular machinery controlling tooth development however, didn’t disappear in time. Genes still communicate and proteins still regulate growth inside of us. BMP and Wnt signaling still participate in building teeth during development and USAG-1 still helps regulate that process.

What researchers are learning is that some developmental pathways may be more manipulable than we once realized.

The Emotional Landscape of a Smile

Teeth are not only tools for chewing, they’re central to our identity.

A smile is one of the first gestures a baby learns, a language understood across cultures without translation. To lose teeth is to lose part of that universal conversation and many who wear dentures or implants speak quietly of self-consciousness, of covering their mouths when they laugh. Regeneration in this sense is more than biology, it restores dignity, confidence, and the radiant act of smiling without hesitation.

Smile for the Future

I do not think we are entering an era where teeth magically return whenever we lose them…not yet at least. Something genuinely unusual is happening though, because scientists identified a protein that helps suppress tooth development.

When they blocked it, animals grew teeth, so a humanized antibody drug was created. That drug entered human clinical trials and now Phase I was completed. A Phase IIa study targeting congenital tooth agenesis is moving forward in Japan.

Somewhere in the future, a person may sit in a dental chair with a tooth their body was never supposed to produce beaming out at the world, a real biological tooth!

Disclaimer: Research into tooth regeneration is ongoing. The current work is being led by Toregem Biopharma, a Kyoto-based biotech startup in collaboration with Kyoto University. Human clinical trials are expected to begin in 2025. While early results in animal studies are promising, this therapy is not yet available to the public and its long-term safety and effectiveness remain under investigation.

Sources:

Murashima-Suginami, Akiko, et al. “Anti-USAG-1 Therapy for Tooth Regeneration Through Enhanced BMP Signaling.” Science Advances, 2021.

Kyoto University. “New Drug to Regenerate Lost Teeth.” Kyoto University Research News, March 31, 2021.

Toregem BioPharma. “Notification of Receipt of Response Regarding Pre-IND Meeting With the US FDA.” November 27, 2025.

Toregem BioPharma. “TRG035 Designated as an Orphan Drug by Japan’s Ministry of Health, Labour and Welfare for the Treatment of Severe Congenital Oligodontia.” September 2025.

Toregem BioPharma. “Toregem BioPharma Passes AMED Stage Gate Evaluation Under the Strengthening Program for Pharmaceutical Startup Ecosystem.” February 25, 2026.

Toregem BioPharma. “Toregem Raises Approximately USD 5.3 Million in Pre-Series C Financing.” May 19, 2026.

Toregem BioPharma. “Announcement for Completion of the PMDA Investigation of CTN for TRG035 Phase IIa Trial.” August 17, 2026.