Researchers at Kyoto University Hospital have begun the first human trial of TRG-035, a drug meant to grow new teeth in people who are missing them. Humans keep a set of dormant tooth buds left over after the adult teeth come in, but a protein holds them switched off for life. The drug blocks that protein, which the researchers call "the body's molecular off-switch for tooth development." Thirty adult men, each short a tooth, have enrolled in the study.
The discovery came from a genetic accident. Mice bred without the gene for that protein sprouted teeth they were never supposed to have. One shot of the antibody later produced working teeth in mice and ferrets, with no serious safety problems.
No one in this trial is expected to grow a tooth. The first round, which began in late 2024 and was tracked for 11 months, tests only whether the drug is safe in people. The researchers say "actual tooth regrowth in these adult participants is unlikely."
If the drug clears the safety stage, the next round will treat children aged 2 to 7 who were born without teeth. About one person in a thousand is born missing six or more, which makes chewing hard and, the researchers say, draws enough cruelty that some teenagers wear masks. Dr. Angray Kang of Queen Mary University of London said that similar antibody drugs are already safely used to treat osteoporosis. Dr. Chengfei Zhang of the University of Hong Kong asked whether a regrown tooth would come in straight; the team said braces can reposition it.
People who lost teeth to cavities or an accident would be treated last. Toregem BioPharma, the startup behind the drug, wants it on the market by 2030. The researcher Takahashi said he hopes the technology could "directly extend healthy life expectancy." Among Japanese people over 75, fewer than one in ten still has a full set of teeth.
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