Investigators at the Tufts University School of Dental Medicine have noticed something quite peculiar when they looked into the possibilities of why some people develop wisdom teeth and some do not. For years, most experts have attributed not developing wisdom teeth on genetics, but now it turns out that (at least in some cases) childhood dental care may be to blame.

Examining data, the researchers found that children who received injections of anesthesia in their gums between the ages of two and six from dentists were significantly more likely to be missing their wisdom teeth as they got older.

Regular teeth are fully formed when people reach infant age and erupt from beneath the gums during early childhood. Wisdom teeth are different, in that they are not formed until later in life. Instead, they begin as small buds that grow and develop into teeth, erupting during the late teenage years. Wisdom teeth are often removed because they can become impacted or affect the alignment of other teeth in the mouth.

"It is intriguing to think that something as routine as local anesthesia could stop wisdom teeth from developing. This is the first study in humans showing an association between a routinely- administered, minimally-invasive clinical procedure and arrested third molar growth," said corresponding author, Anthony R. Silvestri, D.M.D., clinical professor in the department of prosthodontics and operative dentistry at Tufts University School of Dental Medicine.

The "bud" that turns into the wisdom tooth is quite small before it actually develops into a tooth -- until a certain point it is just about the same diameter of an anesthesia needle.

Researchers at Tufts went through dental records of 220 patients who had received treatment between the ages of two and six and had X-rays three or more years after to monitor the development of the wisdom teeth.

The data showed that kids that had anesthesia injections were 4.35 times as likely to have no wisdom tooth development compared to kids that had no injections. The lack of bud formation increased from 1.9 percent in children who had no injections to 7.9 percent in those that did.

"The incidence of missing wisdom teeth was significantly higher in the group that had received dental anesthesia; statistical evidence suggests that this did not happen by chance alone. We hope our findings stimulate research using larger sample sizes and longer periods of observation to confirm our findings and help better understand how wisdom teeth can be stopped from developing," Silvestri continued. "Dentists have been giving local anesthesia to children for nearly 100 years and may have been preventing wisdom teeth from forming without even knowing it. Our findings give hope that a procedure preventing third molar growth can be developed."

One day we may have a simple minimially invasive procedure during childhood to prevent wisdom tooth growth, sparing millions from extraction surgery later on in life when problems happen.

The research published in the Journal of the American Dental Association can be found here.