People who have lost teeth may be able to get others naturally, according to Japanese dentists who are testing a pioneering drug that they hope will provide an alternative to dentures or implants.
Unlike reptiles and fish that are usually able to replace their tusks, it is widely known that humans and most other mammals only grow two sets of teeth in their mouths.
But under the gums there are dormant buds of a third group, according to Katsuo Takahashi, head of the Department of Oral Surgery at the Osaka Medical Research College Medical Center.
Last October, his team launched clinical trials at this hospital, providing adults with an experimental drug that the medical team says can stimulate the growth of hidden teeth.
Takahashi told Agence France-Presse that it is a “completely new” technology in the world.
Treatments used for missing teeth due to decay or infections are often seen as expensive and requiring surgical intervention.
“Restoring natural teeth certainly has its advantages,” stresses Takahashi, the project leader.
Tests conducted on mice and rodents indicate that stopping the action of the USAG-1 protein can awaken the third set of teeth, and researchers have published laboratory images of animals’ teeth that have grown again.
In a study published last year, the team said, “The treatment in mice is effective in regenerating teeth and could constitute a breakthrough in treating dental deformities in humans.”
It’s just the beginning
Currently, dentists are prioritizing the “critical” needs of patients who have lost six or more permanent teeth since birth.
Takahashi points out that the genetic aspect affects about 0.1% of people who may have great difficulty chewing, and in Japan they often spend most of their adolescence wearing a mask to hide the wide gaps in their mouths.
He adds, “This medicine may be a turning point for them.” Therefore, the drug primarily targets children, and researchers want to make it available before 2030.
Anggray Kang, a professor of dentistry at Queen Mary University of London, knows of only one other team pursuing a similar goal, using antibodies to make teeth grow back or repair them.
Speaking to Agence France-Presse, an expert in immunotechnology who is not involved in the Japanese research says, “Takahashi’s group is leading the way.”
Kang considers Takahashi’s work “interesting and worth pursuing” because the antibody drug targets a protein almost identical to OSAG-1, which is already used to treat osteoporosis.
He added, “The race to renew human teeth is not short, but rather a series of successive marathon races as an analogy.”
“This is only the beginning,” he continues.
Chenfei Zhang, professor of endodontics at the University of Hong Kong, sees Takahashi’s method as “innovative and has potential.”
“The confirmation that humans possess hidden tooth buds capable of producing a third set of teeth is a revolutionary and controversial issue,” he told Agence France-Presse.
He points out that “the results observed in animals cannot always be translated directly to humans.”
Zhang says the results of animal experiments raise “questions about whether new teeth can functionally and aesthetically replace missing teeth.”
New Sunnah website
Takahashi points out that the location of the new tooth in the mouth can be controlled, if not determined, by the site of the drug injection.
If teeth grow in the wrong place, they can be moved via braces or implants, he said.
No young patient suffering from a congenital dental problem participated in the first clinical trial, as the main goal was to test the safety of the drug, not its effectiveness.
Therefore, participants in the current phase represent healthy adults who have lost at least one tooth.
Although tooth regeneration is not the explicit goal of the experiment this time, there is a small chance of that happening to the participants, according to Takahashi.
If their teeth grow, the researchers will have confirmed that the drug is effective for those suffering from tooth loss, which would constitute a medical success.
“I would be very happy if that happened,” Takahashi says.
This news may be particularly welcomed in Japan, which has the second-highest population in the world.
Ministry of Health data shows that more than 90% of people over the age of 75 have lost at least one tooth.
“There is high expectation that our technology will directly be able to extend healthy life expectancy,” says Takahashi.