Invisalign aligners are a prize in a contest offered by a US dentist.

Teenage competitors have been asked to submit a video or essay explaining why they feel they need the invisible braces and how they would improve their life.

The entries will later be used for marketing by the dental surgery, which is also holding an open day later this month to highlight the benefits of Invisalign braces.

Paula Zimmerman of Grove City Family Dentistry in Ohio said it was a “very special opportunity” for local youngsters.

“The Invisalign Teen Open House and contest will encourage teens to share their story with us and allow us to show how effective the Invisalign braces are for a teen’s lifestyle,” she added.

Young people aged between 13 and 19 are eligible for the competition and will also be given a chance to use computer technology to see how their teeth will look when the cosmetic dentistry is complete.

Over one million patients have already tried Invisalign or Invisalign Teen braces.