Scientists are studying how alligators renew their giant teeth in a bid to help humans who suffer dental problems.
Alligators have an average of 80 teeth at any one time – and 50 sets of replacements to last their lifetime.
The giant reptiles can go through 2,000 to 3,000 teeth in a lifetime, and researchers hope to find a way to replicate this process in humans.
Most vertebrates can renew teeth throughout their lives whereas humans’ are naturally replaced only once.
This is despite the lingering presence of a band of tissue called the dental lamina – crucial to tooth development.
To uncover the chemical mechanisms of tooth renewal Professor Cheng-Ming Chuong and colleagues studied repetitive tooth formation in American alligators.
Alligators have well-organized teeth with traits similar to those of mammals – such as secondary palates and implantation in sockets of the dental bones – and are capable of lifelong tooth renewal.
Through a combination of molecular analysis and scanning techniques the researchers showed each alligator tooth is a complex unit of three components in different developmental stages.
These are structured to facilitate replacement once they are dislodged, says the study published in Proceedings of the National Academy of Sciences.
Early on the alligator dental lamina forms a bulge at its tip that houses stem cells. Molecular analysis revealed that the initiation of the tooth cycle corresponds with the dynamic expression of an array of signaling chemicals.
The researchers believe the findings could help adults who have lost teeth or have ones that appear in addition to the regular number – a common condition called supernumerary teeth.
Professor Cheng-Ming Chuong, of Southern California University, said nature is a rich resource from which to learn how to engineer stem cells to regenerate hair, scales, nails and teeth.
He said: ‘These organs are at the interface between an organism and its external environment and therefore, face constant wear and tear.
‘Animals have evolved successful regenerative mechanisms to accommodate renewal with minimal functional interruption.
‘Feeding is critical for survival but teeth unavoidably face frequent injury and loss. Most vertebrates replace teeth throughout their lives.
‘Our goal here is to identify stem cells that can be used as a resource for episodic tooth renewal.’
Prof Chuong said reptiles and fish have robust regenerative powers for tooth renewal but living mammals can either renew their teeth one time or not at all.
He said: ‘Understanding how these signaling molecules interact in tooth development in this model may help us to learn how to stimulate growth of adult teeth in mammals.’
Attribution: Mail Online