Straighter teeth in children may improve their smile but there is no guarantee of happiness and improved self-esteem - says a new study. The study results were published in the British Journal of Health Psychology.

Scientists in Britain in their 20-year long study looked at the impact of braces on more than 300 children in Wales showed that straightening their teeth had little positive impact on their psychological health later in life.

When they were questioned as adults, none of them regretted for having braces and most of them were satisfied with the way they looked. But there was no difference in their psychological well-being when compared to other people who have never had braces.

Professor William Shaw, an orthodontist at the University of Manchester in England, said: "On the basis of our research if there are irregularities, and especially if they are not severe, then there will be no harm to dental health and it wouldn't change their life happiness in the future if they don't wear braces."

In 1981, Shaw and his team assumed that there would be social or psychological benefits for children having their teeth straightened. But when the participants, who had quite significant dental irregularities and had received braces free through the NHS, were asked some psychological questions 20 years later to assess their well-being, the researchers found nothing that seems to have been derived from having orthodontic treatment.

Shaw concluded that, although in general participants' self-esteem increased over the 20-year period, it was not as a result of receiving braces and didn't relate to whether an orthodontist treatment need existed in 1981.