Feb. 2 (iVillage Total Health) -- Parents who have spent thousands of dollars on braces for their children's teeth may have hoped the expense would pay off with straight teeth and enhanced self-confidence for their sons and daughters later in life. But a new study published recently by British researchers casts doubt on whether braces actually improve psychological well-being.

The 20-year study recruited more than 1,000 children from Cardiff, Wales, who were ages 11 to 12 in 1981. One group of children needed orthodontic treatment and received it while another group needed the braces but did not get them.

Researchers tracked both groups of children and assessed their dental health and overall psychological well-being at four intervals over the course of two decades: the initial 1981 assessment and then again in 1984, 1989 and 2001. By the end of the study participants were 31 and 32 years old. Researchers revisited 337 of them. Those who had worn braces as children had straighter teeth and were more likely to be satisfied with them than the group who did not wear the appliances.

However, what surprised many of the researchers was that the group that wore braces showed little positive improvement in psychological and emotional health and quality of life as adults. The children who did not receive orthodontic care did not appear to have psychological difficulties in adulthood.

"Although in general self-esteem increased over the 20-year period, it was not as a result of receiving braces and didn't relate to whether an orthodontic treatment need existed in 1981," co-author William Shaw, a professor at The University of Manchester School of Dentistry, said in a press release. "This runs contrary to widespread belief among dentists that orthodontic treatment improves psychological well-being, for which there is little evidence."

The researchers noted that the time a child reaches adulthood other factors may have greater significance to their self-image than teeth. They concluded that "orthodontics cannot be justified on psychological grounds alone," according to the release.

In the United States and Canada, about 6 million people -- most of them children -- receive orthodontic care each year, according to the American Association of Orthodontists. This may include braces, retainers or removable aligners.

Results of the study were published in the January 22 issue of The British Journal of Health Psychology.

Copyright 2007 iVillage Total Health.