Robert De Niro once paid dentist £4,000 to have his teeth ground down to look more menacing for movie role

It goes without saying that Robert De Niro is one of the greatest actors of his generation, but his commitment to one particular role helps set him apart even further.

For those unfamiliar with the film, it centres on convicted rapist Cady (played by De Niro), who is released from prison and hatches a plot to track down and exact revenge from public defender Sam Bowden (played by Nick Nolte) whom he blamed for sending him to prison.

To get into character, De Niro opted to undergo costly - and painful sounding - unnecessary dental work to look the part. Ouch.

De Niro went through a complete transformation for the role, alongside his teeth being filed, he worked out to give Cady a prison-gym-honed physique and covered his body in fake tattoos.

Of course, De Niro didn’t want to be stuck with the teeth he’d had designed for Cady, so once the movie wrapped, he had to splash out another $20,000 to have them fixed. Rather you than me, pal.

For what it’s worth, the movie went on to become a box office smash and De Niro earned himself a best actor nomination at the Oscars - so arguably the effort and expense was all worth it.

De Niro’s commitment to a character doesn’t end with what he’s willing to put his body through, either.

When filming The Deer Hunter, released in 1978, De Niro insisted on using a real bullet during the tense Russian roulette scene.

However Cazale is said to have ‘obsessively’ checked and rechecked the gun before each and every take to make sure that the live round was not next in the chamber. I mean, I can’t say I blame him there.