Dentists divided over removing wisdom teeth.(Knight Ridder Newspapers)

Your dentist has just advised you to have your wisdom teeth removed, even though they are not causing any problems.

Is this a word to the wise, or jumping the, er, gum?

Wisdom teeth, of course, are the molars that sit farthest back in the mouth, two in the upper jaw and two in the lower. Technically called third molars, these are the last teeth to develop, usually appearing in the late teens or early twenties _ supposedly about the time wisdom shows up.

For decades, dentists and oral surgeons have urged young adults to get rid of wisdom teeth that are "impacted" _ below the gum and blocked from growing in normally _ in order to avoid trouble down the line.

But the wisdom of this practice has never been proven. In fact, in recent years some experts have argued that the costs and surgical risks of preemptive extraction outweigh the benefits of preventing problems that may never develop.

"Careful analyses of the published research show that routine removal of impacted or unerupted, disease-free third molars cannot be justified," E. Preston Hicks, professor of orthodontics at the University of Kentucky, wrote in the ...