Unlike reptiles and fish, which usually replace their fangs on a regular basis, it is widely accepted that humans and most other mammals only grow two sets of teeth.

But hidden underneath our gums are the dormant buds of a third generation, according to Katsu Takahashi, head of oral surgery at the Medical Research Institute Kitano Hospital in Osaka.

[…]

Tests on mice and ferrets suggest that blocking a protein called USAG-1 can awaken the third set, and the researchers have published lab photographs of regrown animal teeth.

In a study published last year, the team said their "antibody treatment in mice is effective for tooth regeneration and can be a breakthrough in treating tooth anomalies in humans".