Third molars or wisdom teeth may have served a useful purpose in prehistoric humans, according to Anthony R. Silvestri, Jr., D.M.D., clinical professor and director, Dental Anatomy, and Iqbal Singh, B.D.S., M.D.S., D.M.D., associate professor and director, Preclinical Studies at Tufts University's School of Dental Medicine in Boston.

But during the last century, they wrote, defining a useful purpose for third molars has become more difficult, especially given that so many people experience pain and disease caused either by the teeth themselves or by having them extracted.

"As dental research develops new techniques to reduce and possibly eliminate the loss of more functional teeth resulting from caries and periodontal disease," they wrote, "the usefulness for third molars in the dentition will decrease further."

They say third molar-related morbidity likely will continue to affect people and that the potential elimination of the problems caused by third molars by preventing their development is an area worthy of investigation.

In the article, the authors say 65 percent of 20-year-olds have at least one impacted (unable to come in or misaligned) third molar. In addition, they say, wisdom teeth that do come in are frequently out of position, making them difficult to clean.

In the past 30 years, there has been intense interest in the biomolecular events involved in tooth development, according to the authors. The result has been heightened research interest in growing new teeth.

"Perhaps, it is time to develop techniques to stop their development as well," they write.