Margot Robbie is still wearing her retainers because she is "paranoid" something will go wrong with her teeth

Appearing on Australia's 'The Kyle and Jackie O Show', the blonde beauty confessed when asked how she coped playing a character with a lisp in 'Peter Rabbit': "This is so embarrassing, I actually have two retainers, one for the bottom teeth which is for grinding and one for my top teeth which is just so my teeth don't move.

"The orthodontist, when I got my braces off when I was 14, said, 'You'll need to wear it for two years but I am so paranoid that, 10 years later, I'm still wearing them."

The 'Suicide Squad' star revealed she took extreme measures to try and stop her teeth grinding habit by having Botox injected into her muscles inside her mouth.

She said: "I grind my teeth so bad I ended up getting Botox in the muscles there and it stops you from grinding your teeth."

Margot portrays Flopsy the bunny - who suffers from speech problems - in the big screen adaptation of the Beatrix Potter classic.

'Peter Rabbit' stars James Corden as the voice of the mischievous bunny created by British children's author Beatrix Potter and published in the early 1900s.

Meanwhile, Margot is reportedly in talks to star in the Quentin Tarantino-directed 'Once Upon a Time in Hollywood'.

The Australian-born star - who has recently emerged as one of Hollywood's most bankable stars - is being lined up to play the role of Sharon Tate in the much-anticipated new movie, which is set in Los Angeles in 1969, at the height of so-called hippy Hollywood.

The film will tell the story of the murder of Tate and several others in a killing spree instigated by Charles Manson.

Margot could line up alongside Leonardo DiCaprio - who will play a former TV star - and Brad Pitt - his long-time stunt double - in the movie, according to Deadline.