Stem Cell Breakthrough: Regrowing Teeth and Bone Within Years

Researchers in Japan have identified specific stem cell lineages that govern the formation of tooth roots and the surrounding alveolar bone, a discovery that could eventually enable the biological regeneration of lost teeth and supporting jaw structures.

The findings, published as companion studies in Volume 16 of Nature Communications on July 1 and July 2, 2025, are the result of a collaboration led by Assistant Professor Mizuki Nagata of the Institute of Science Tokyo and Dr. Wanida Ono of the University of Texas Health Science Center at Houston, with support from the University of Michigan.

Mapping the Origins of Tooth and Bone

Using genetically modified mice and advanced lineage-tracing techniques, the research team focused on the apical region, or the tip, of tooth roots. By employing fluorescent cellular tags and gene silencing, they were able to observe how specific signaling proteins direct cell fate during the development of a tooth.

The study identified a previously unknown population of mesenchymal progenitor cells that split into two distinct lineages:

• One lineage is strongly associated with the development of the tooth root, originating from cells in the apical papilla within the epithelial root sheath. These cells express CXCL12, a protein typically associated with bone formation in bone marrow.
• The second lineage is responsible for the formation of the alveolar bone, which is the specialized bone that anchors the teeth into the jaw.

The researchers found that these processes are orchestrated through the canonical Wnt signaling pathway, a critical mechanism that directs how stem cells specialize and organize themselves during growth.

The Shift Toward Biological Regeneration

Current dental medicine relies heavily on artificial substitutes, such as dentures and dental implants, to treat edentulism, or toothlessness. While these tools restore function and appearance, they do not replicate the biological integration or structural complexity of a natural tooth.

The ability to regrow teeth is complex because it requires the coordinated activity of the enamel organ, dental pulp, and jawbone cells. By uncovering the specific stem cell lineages and the signaling networks that control them, scientists hope to move beyond artificial replacements toward treatments that stimulate the body’s own regenerative capabilities.

Clinical Progress and Human Trials

Parallel to the stem cell research at Science Tokyo, other Japanese researchers are testing a pharmaceutical approach to tooth regrowth. Human trials for an experimental drug began in September 2024.

This treatment targets a protein called Uterine sensitization–associated gene-1 (USAG-1), which inhibits tooth growth. Scientists from Kyoto University developed a monoclonal antibody designed to disrupt the interaction between USAG-1 and bone morphogenetic protein (BMP), thereby potentially triggering the growth of new teeth.

The current trial involves 30 males between the ages of 30 and 64, each missing at least one tooth. The drug is administered intravenously to assess safety and efficacy.

“We want to do something to help those who are suffering from tooth loss or absence,” Katsu Takahashi, head of dentistry at the medical research institute at Kitano Hospital in Osaka

If these trials prove successful, Kitano Hospital plans to extend the treatment to children between the ages of 2 and 7 who are missing at least four teeth. The researchers aim to make a tooth-regrowing medicine available for all forms of toothlessness by the year 2030.

Remaining Challenges

Despite these advancements, significant hurdles remain. Regenerating a tooth is not simply about growing the crown; the new tooth must be successfully integrated into the jawbone and connected to the body’s vascular and nervous systems.

Other research, such as studies published in the International Journal of Oral Science, has identified GLDN+ odontogenic stem cells as crucial for regenerating vascularized dental pulp. These findings suggest that the future of regenerative dentistry will likely require a combination of stem cell therapy to rebuild the tooth’s internal structure and pharmacological interventions to trigger the initial growth process.