State of the field, first pass

One antibody has been given to adults. Everything else is upstream of a person.

Written 2026-07-28. This is the first pass; it supersedes nothing. Superseded passes are kept, never edited, and every future pass will state what it replaces and what it changes. Every entry here is dated and cited; corrections are logged, never silently edited.

Tier ladder

• Tier 5: Replicated human efficacy. Nothing in this field holds it. Held by: nothing.
• Tier 4: Human efficacy or safety data, single programme. Held by: anti-USAG-1 / TRG-035.
• Tier 3: Small or single-centre human data, narrow endpoint. Held by: pulp and dentin repair.
• Tier 2: Animal result, no human protocol proposed. Held by: bioengineered tooth germ, tooth epithelial organoids, tooth-root organoids.
• Tier 1: In vitro only, or mechanism without a tissue result. Held by: nothing at this pass.

Per-program assessment

Anti-USAG-1 / TRG-035 (Toregem BioPharma, Kyoto University): tier 4

A humanised monoclonal antibody against USAG-1, given once. In mice and ferrets, removing USAG-1 raises BMP signalling in tissue already attempting to form a tooth, and a tooth that would not have formed does (Murashima-Suginami et al., Sci Adv 2021). That is a rescue of a suppressed programme, not the installation of a new one.

The human programme has so far answered one question: whether a single ascending dose is tolerated in adults. Phase I at a university hospital in Kyoto enrolled adults with a safety primary endpoint (registry entry; Kitano Hospital trial announcement, 3 May 2024). The sponsor’s disclosure of 19 May 2026 describes Phase I as complete and Phase II as in preparation. No peer-reviewed human result set is public, and no efficacy endpoint has been tested in anyone. Human data exists, but for safety, and not in the population of interest.

What would change this assessment: an efficacy endpoint in the intended population, children with congenital anodontia, reported with its statistical plan rather than by press release; or a dated human image showing a tooth in a site that was radiographically empty before treatment.

Bioengineered tooth germ: tier 2

A transplanted bioengineered tooth germ erupted, occluded, and responded to mechanical and pain stimuli in an adult mouse (2009). A functional organ replacement in an animal, and still the most complete demonstration in the field. Human cell sourcing and control of development remain open, and no human protocol has been proposed.

What would change this assessment: a stated, ethically obtainable human cell source, and a first-in-human design built on it.

Tooth epithelial organoids: tier 2

Human cells in vitro that recreate enamel-forming developmental tissue. A powerful model of cell behaviour, not a replacement tooth: no implantation into an animal jaw has been reported, and no route to a human protocol exists in the record.

What would change this assessment: implantation into an animal jaw producing mineralised tissue of the correct architecture.

Tooth-root organoids: tier 2

Root-like organisation of dentin, cementum, pulp, and ligament components from human cells in vitro. The organisation is encouraging; eruption, crown formation, innervation, and integration with bone are unresolved, and nothing has been placed in an animal.

What would change this assessment: an implanted construct that integrates with bone and supports a functional tooth structure in an animal.

Pulp and dentin repair: tier 3

Pulp is where human data actually is. Autologous pulp stem cells, taken from a patient’s own shed deciduous tooth and placed into an injured immature permanent incisor: a 26-patient series reports continued root development on imaging at 24 months, restored pulp sensibility, and no graft-related serious adverse events. This is real regenerative dentistry, and it is almost never what a headline about growing teeth is describing. It regenerates the inside of a tooth the patient still has. The evidence is a small, single-centre series with a narrow endpoint, not yet independently replicated, which is what holds it at tier 3.

What would change this assessment: independent replication at a second centre with a pre-registered endpoint and a comparison arm.

Myth vs record

1. Claim: a tooth-regrowth drug will be available in 2030. Verdict: unsupported. A 2030 availability date circulates widely. No filing, guidance or trial schedule in the record supports it. The date is a developer projection carried without attribution; no regulator, protocol, or filing has adopted it.
2. Claim: the Phase I trial is enrolling children aged 2 to 6. Verdict: misstated. Phase I enrolled adults with a safety primary endpoint, as a first-in-human study must. Children with congenital anodontia are the planned later population.
3. Claim: the antibody works by blocking both BMP and Wnt. Verdict: misstated. The 2021 proof-of-concept paper reports field-selective BMP action. The Wnt half is an inference carried forward from earlier reviews, not a finding of the paper.
4. Claim: humans can be made to grow a third set of teeth. Verdict: not established. Established in mice and ferrets. In humans, only tolerability in adults has been tested. No human has grown a tooth in the record.

What would change the field-level assessment

1. A dated human image showing a tooth in a site that was radiographically empty before treatment.
2. An efficacy endpoint, in children, reported with its statistical plan rather than by press release.
3. Independent replication of tooth formation in a large animal by a group with no commercial stake.

Corrections applied this pass

None. This is the first pass; the corrections log opens empty. When corrections occur they are appended with what was said, what the record shows, and why the error happened. Nothing here is ever edited silently.

Cited here

• Murashima-Suginami et al., Sci Adv 2021: anti-USAG-1 antibody rescues tooth agenesis in mice.
• Phase I trial registry entry, Kyoto University Hospital: single ascending dose, adult participants, safety primary endpoint.
• Kitano Hospital, trial announcement, 3 May 2024.
• Toregem BioPharma, Phase II financing disclosure, 19 May 2026.
• Peer-reviewed pulp-graft series, 26 patients with immature permanent incisors, 24-month imaging.
• Bioengineered tooth-germ transplant in an adult mouse, 2009.