Japanese Scientists Trial Groundbreaking Medication to Regenerate Teeth

Unlike reptiles and fish, which routinely replace their teeth, it’s long been believed that humans and most mammals only develop two sets over a lifetime.

However, Katsu Takahashi, head of oral surgery at the Medical Research Institute Kitano Hospital in Osaka, explains that a third set of tooth buds lies dormant beneath the gums.

Takahashi’s team began clinical trials at Kyoto University Hospital in October, giving an experimental drug to adult volunteers in hopes of activating the growth of these hidden teeth.

“This is a completely new technology,” Takahashi told AFP.

Natural Tooth Regeneration Could Offer a Less Invasive, More Affordable Alternative to Prosthetics

Traditional prosthetic solutions for tooth loss due to decay, injury, or disease are often expensive and invasive. “Restoring natural teeth clearly offers significant benefits,” he added.

Animal studies on mice and ferrets showed that inhibiting a protein called USAG-1 could trigger the growth of a third set of teeth. The researchers even published lab images showing regenerated teeth in these animals.

In a study released last year, the team reported that their antibody-based treatment successfully promoted tooth regrowth in mice, marking what could be a major breakthrough in addressing human dental abnormalities.

For now, the research team is focusing on patients with the most urgent needs—specifically those born missing six or more permanent teeth, a condition known as congenital tooth agenesis.

A Rare Condition Causes Tooth Gaps and Social Struggles for Affected Youth in Japan

This rare genetic disorder affects about 0.1% of the population and can cause significant difficulties with eating. In Japan, many young people with the condition wear face masks throughout adolescence to conceal the large gaps in their teeth, explained Takahashi.

“This drug could be life-changing for them,” he said.

The treatment is primarily intended for children, and the researchers aim to make it available by 2030.

Angray Kang, a professor of dentistry at Queen Mary University of London, noted that only one other group is working on a similar approach—using antibodies to regenerate or repair teeth.

“In my view, Takahashi’s team is leading the field,” said Kang, who specializes in immunotechnology and is not involved in the study.

Kang described the research as “promising and worth further exploration,” especially since a drug targeting a protein closely related to USAG-1 is already being used to treat osteoporosis.

He compared the long path ahead to “a series of ultra-marathons,” emphasizing that this is just the beginning of the journey toward human tooth regeneration.

Chengfei Zhang, a clinical professor in endodontics at the University of Hong Kong, also praised the approach as “innovative with significant promise.”

Experts Caution That Human Tooth Regrowth Remains Unproven Despite Promising Animal Studies

Still, Zhang called the idea that humans have hidden tooth buds capable of generating a third set “both groundbreaking and controversial.” He warned that positive results in animal models don’t always guarantee success in humans.

He added that while the animal experiments are encouraging, key questions remain—particularly whether the regenerated teeth would be functional and visually suitable as replacements for missing teeth.

Takahashi remains optimistic, stating that the position of a newly grown tooth can be influenced—if not precisely controlled—by the location of the drug injection.

If a tooth grows in an unintended spot, he explained, it can be realigned through orthodontic treatment or even relocated via transplantation.

The initial clinical trial does not include young patients with congenital tooth loss, as the main goal at this stage is to assess the drug’s safety rather than its effectiveness.

For now, the participants are healthy adults who have lost at least one natural tooth.

Tooth Regrowth in Trial Participants Could Offer Early Evidence of the Drug’s Potential

Although tooth regeneration isn’t the primary aim of this trial, Takahashi noted there’s a small chance it could occur—an outcome that would provide early proof the drug works for people who have lost teeth over time.

“If that happens, I’d be absolutely thrilled,” he said.

Such a breakthrough would be especially meaningful in Japan, where the population is rapidly aging. The country has the world’s second-highest proportion of elderly citizens.

According to Japan’s health ministry, over 90% of people aged 75 and older are missing at least one tooth.

“There’s strong hope that our technology can directly help extend healthy life expectancy,” Takahashi added.

Read the original article on: France

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