A gene that controls production of tooth enamel

24 Feb 2009, 1054 hrs IST, PTI

NEW DELHI: It may not be long when our grandparents can retain their 'closeup' smiles even at advanced stages of their life as scientists have
identified a gene that controls production of tooth enamel, promising replacement of teeth which can be grown on demand.

The identification of the gene opens new vistas in the dental sciences as it could make possible repair of damaged enamel, a new concept in cavity prevention, restoration and even the production of replacement teeth.

The gene known as Ctip2 was known for several functions including immunity and development of skin and nervous system in the body. The researchers at Oregon State University in the US have found that this gene is also responsible for the development of tooth as well.

The findings were published in the latest edition of the journal 'Proceedings of the National Academy of Sciences' in the US.

"It's not unusual for a gene to have multiple functions, but before this we didn't know what regulated the production of tooth enamel," one of the researchers Chrissa Kioussi said.

Scientists used mice whose Ctip2 gene was "silenced" as such animals come as an important tool for scientists to study what systems are present and what are missing.

"This is the first transcription factor ever found to control the formation and maturation of ameloblasts, which are the cells that secrete enamel," Kioussi said.

"In this case, the mice had rudimentary teeth ready to erupt, but they lacked a proper enamel coating, and never would have been functional," Kioussi said.

Enamel is one of the hardest coatings found in the nature which helped the carnivores have tough and long-lasting teeth they needed to survive.

"The problems with eroded tooth enamel are very common in India. Smokers, people who drink and especially some who use illegal drugs such as Yaba (methamphetamine) are prone to such cavities. And most cavities start as a hole in tooth enamel that allows decay to begin," Dr C P Kohli, a dental surgeon in Lucknow said.

The understanding of genetic functions, Kioussi said, may help in using tooth stem cells to stimulate the growth of new enamel.

"Some groups are already having success growing the inner portions of teeth in laboratory animal experiments, but those teeth have no hard coatings. The scientists lacked the genetic material that makes enamel," Kioussi pointed out.