Genes that make teeth grow in a row

Ever wonder why sharks get several rows of teeth and people only get one? Some geneticists did, and their discovery could spur work to help adults one day grow new teeth when their own wear out.
A single gene appears to be in charge, preventing additional tooth formation in species destined for a limited set. Scientists at University of Rocheste bred mice that lacked that gene and the rodents developed extra teeth next to their first molars.

Also intriguing is the fact that all the mice born without this gene, called Osr2, had cleft palates severe enough to kill. So better understanding of this gene might play a role in efforts to prevent that birth defect.
Teeth may not be visible until long after birth, but they start to form early in embryo development. Teeth ultimately erupt from a thickened band of tissue along the jaw line called the dental lamina, a band that forms in a top layer of the gum called the epithelium. Scientists have long thought the signals for tooth formation must lie in that tissue layer as well. But the Rochester team found that all the action takes place instead in a deeper cell layer called the mesenchyme.

Dr. Rulang Jiang, a geneticist at Rochester’s Center for Oral Biology showed that the Osr2 gene is like a control switch, it turns on and off the downstream actions of other genes and proteins. In that mesenchymal tissue, the Osr2 gene works in concert with two other genes to make sure budding teeth form in the right spot. Knocking that molecular pathway out of whack causes either missing or extra teeth to result, Jiang showed in a series of mouse experiments.
Time alone will tell us what lies in the future but we sure can hope for a day when becoming edentulous is no longer a concern.

Pregnancies Linked To Tooth Loss

According to a nationwide study of 2,635 women by Dr. Stefanie Russell, an Assistant Professor of Epidemiology & Health Promotion, women who have more children are more likely to have missing teeth.

Profound biological and behavioral changes related to pregnancy and child birth are likely to be a factor in tooth loss, according to Dr. Russell. For example:
* Pregnancy can make women prone to gingivitis (gum inflammation). Repeated pregnancies are likely to result in more frequent outbreaks of gingivitis that may lead to tooth loss in women with periodontitis.
* A woman may postpone seeking dental treatment because of financial concerns related to having children.
* Caring for more children may lead a mother to cut back on the time she devotes to her own oral health.

Although further research is needed on the specific reasons for the link between pregnancy and tooth loss, it is clear that women with multiple children need to be especially vigilant about their oral health

Source:www.Sciencedaily.com