Can a Drug Regrow Lost Teeth? Where the Research Stands

Not yet. A 2021 study from Kyoto University and the University of Fukui showed that an antibody blocking a protein called USAG-1 could grow new teeth in mice and ferrets born with missing teeth. A first safety study in people began in Japan in late 2024, but no tooth regrowth drug is approved anywhere, and the first intended patients are children born without several teeth, not adults who have lost teeth.

What question did the 2021 study ask?

Tooth development depends on two signaling systems, BMP (bone morphogenetic protein) and Wnt. They also control growth throughout the body, so drugs that act on them directly could have wide side effects. USAG-1 is a protein that dampens both signals. Mice that lack USAG-1 grow extra teeth. The researchers asked whether blocking USAG-1 could restore teeth in animals born without some of them, a condition called congenital tooth agenesis.

What did they find?

• In several mouse models of inherited tooth agenesis, removing the USAG-1 gene or giving an antibody against USAG-1 allowed missing teeth to form.

• Some antibodies blocked USAG-1's effect on both BMP and Wnt. Those harmed the animals' growth and survival.

• One antibody blocked only the interaction between USAG-1 and BMP. It was the useful one. According to the researchers, a single dose was enough to grow a whole tooth.

• The approach also worked in ferrets, which, like people, have baby teeth followed by adult teeth.

The likely mechanism is that the antibody rescues tooth buds that start to form but normally stop developing.

What has happened since?

The research group and a company spun out of the university, Toregem BioPharma, developed a humanized version of the antibody called TRG035. In late 2024, a Phase 1 study began at Kyoto University Hospital. It is a randomized, placebo-controlled study in about 30 healthy adult men, testing a single intravenous dose at increasing strengths. A Phase 1 study looks at safety and how the body handles a drug. It is not designed to show whether new teeth grow.

The developers have said the next step is a study in children with congenital absence of multiple teeth. Whether the approach could ever help adults who lost teeth to decay, gum disease or injury is a separate, longer-term question.

What are the limits?

• The strong results so far are in animals.

• Phase 1 tests safety in a small group. Larger trials are needed to show that a tooth actually forms in people, in the right place, with a normal shape and root.

• Approval, if it comes, would be for a defined group of patients first.

What are the options for a missing tooth today?

Today a missing tooth is replaced with a dental implant, a bridge or a removable denture, and each has trade-offs. Our post on how dental implants work explains the parts and healing process, and our dental implants page describes how we approach implant care. If you are missing a tooth in Jacksonville, contact our office to talk through your options.

Sources

1. Murashima-Suginami A, Kiso H, Tokita Y, et al. Anti-USAG-1 therapy for tooth regeneration through enhanced BMP signaling. Sci Adv. 2021;7(7):eabf1798. doi:10.1126/sciadv.abf1798. Retrieved via PubMed.

2. Takahashi K, Kiso H, Mihara E, et al. Development of a new antibody drug to treat congenital tooth agenesis. J Oral Biosci. 2024;66(4):1-9. doi:10.1016/j.job.2024.10.002. Retrieved via PubMed.

3. Japan Registry of Clinical Trials. Phase I single-administration study of TRG035 in healthy adults (jRCT2051240154). Retrieved October 6, 2026.

About the author. CJ Henley, DMD, is a general dentist in Jacksonville whose practice focuses on cosmetic and restorative dentistry, dental implants and dental care around head and neck cancer. Meet Dr. Henley.
CJ Henley, DMD, PA · 3675 Hendricks Avenue, Jacksonville, FL 32207 · 904-398-1549
Updated October 2026.

Why Are So Many Teeth Crooked? What Ancient Skulls Suggest

Crowded and crooked teeth are much more common in people today than in skulls from earlier centuries. The main explanation is that soft, processed modern food gives the jaws less chewing work while children are growing, so jaws end up slightly smaller than the teeth they need to hold. Genes still matter, and diet is not the whole story, but the evidence for a dietary influence is consistent.

What do old skulls show?

A study from the University of Oslo compared 146 skulls from abandoned medieval graveyards in Oslo, Norway, with a modern Norwegian sample assessed with the same orthodontic index.

• About 36 percent of the medieval skulls showed an objective need for orthodontic treatment.

• In the modern sample, the figure was 65 percent.

• Severe cases were also more common today: 20 percent of the modern sample showed great need, compared with 7 percent of the medieval skulls.

The authors concluded that both how often malocclusion occurs and how severe it is have increased over the last several hundred years in that population.

Why would diet change jaw size?

Bone responds to the forces placed on it. Chewing tough, raw or lightly processed food puts more strain on the jaws and face than chewing soft, cooked food, and that strain helps drive growth.

• In 1984, anthropologist Robert Corruccini reviewed populations around the world and described a rapid rise in crooked teeth and bite problems as groups moved to urban, industrialized diets. He argued the speed of the change pointed to environmental causes rather than genetic ones.

• In 2004, a team led by Harvard's Daniel Lieberman raised rock hyraxes, small animals with a short face somewhat like ours, on either raw and dried food or cooked food. The animals fed cooked food had about 10 percent less growth in the lower and back parts of the face, where chewing strain was highest.

Lieberman later described this pattern for a general audience in his 2013 book The Story of the Human Body, as one example of a mismatch between modern life and the bodies we inherited.

What are the limits of this evidence?

• Skull studies compare populations, not individual people. They cannot tell you why your own teeth are crowded.

• Genes influence tooth size, jaw shape and bite. Habits such as thumb sucking and mouth breathing may also play a part.

• The animal research shows a plausible way diet affects jaw growth. It does not show that a tougher diet today would straighten an adult's teeth.

What does this mean for you?

Crowding is common, and having it does not mean anyone did something wrong. Crooked teeth can be harder to clean, which raises the risk of decay and gum disease, and a poor bite can wear teeth unevenly. Whether treatment makes sense depends on your teeth, your bite and your goals.

If you are weighing options, you can read about clear aligners, how smile design compares with orthodontics, and why wisdom teeth sometimes have too little room. In Jacksonville, a dental examination is the place to start.

Sources

1. Evensen JP, Øgaard B. Are malocclusions more prevalent and severe now? A comparative study of medieval skulls from Norway. Am J Orthod Dentofacial Orthop. 2007;131(6):710-716. doi:10.1016/j.ajodo.2005.08.037. Retrieved via PubMed.

2. Corruccini RS. An epidemiologic transition in dental occlusion in world populations. Am J Orthod. 1984;86(5):419-426. doi:10.1016/s0002-9416(84)90035-6. Retrieved via PubMed.

3. Lieberman DE, Krovitz GE, Yates FW, Devlin M, St Claire M. Effects of food processing on masticatory strain and craniofacial growth in a retrognathic face. J Hum Evol. 2004;46(6):655-677. doi:10.1016/j.jhevol.2004.03.005. Retrieved via PubMed.

4. Lieberman DE. The Story of the Human Body: Evolution, Health, and Disease. New York: Pantheon; 2013.

About the author. CJ Henley, DMD, is a general dentist in Jacksonville whose practice focuses on cosmetic and restorative dentistry, dental implants and dental care around head and neck cancer. Meet Dr. Henley.
CJ Henley, DMD, PA · 3675 Hendricks Avenue, Jacksonville, FL 32207 · 904-398-1549
Updated October 2026.