If you’ve seen Netflix’s new Ted Bundy biopic Extremely Wicked, Shockingly Evil and Vile, you’ll know that Zac Efron strikes an extremely unnerving resemblance to the serial killer he’s playing.

What’s even more unnerving is that, according to director Joe Berlinger, it took just minimal hair and makeup to achieve the look.

Oh, and a set of false teeth.

Ted Bundy's crooked lower teeth helped convict him of two murders. Image: Getty

Speaking to POPSUGAR at the film's New York premiere, Berlinger said: "The only thing we did is we put in false lower teeth to match Bundy's because bite mark evidence plays a role in how he was ultimately convicted so I wanted the teeth to be similar".

So, how exactly did Bundy's slightly crooked lower teeth and chipped incisor help send him to the electric chair in 1989?

In the early hours of January 15, 1978, Ted Bundy crept into the Chi Omega sorority house at Florida State University and attacked four women.

Two of them - Lisa Levy, 20, and Margaret Bowman, 21 - were bludgeoned to death. Levy was found with a very deep double bite mark on her left buttock.

In her 1980 book, The Stranger Beside Me, Ann Rule, who worked with Bundy, wrote: "Her killer had literally torn at her buttocks with his teeth, leaving four distinct rows of marks where those teeth had sunk in".

When Bundy was later arrested and charged with those two murders, the bite mark evidence would be crucial.

According to Oxygen, forensic odontologist Dr. Richard Souviron testified at the trial. He produced a display board which had a photo of the bite marks on Levy. He put a transparent sheet, which showed Bundy’s teeth impression, on top of that photo and stated, "They line up exactly!"

Despite the fact that Bundy's defence team described the bite mark evidence as "primitive" the jury were convinced, convicting Bundy of two counts of first degree murder, three counts of attempted first-degree murder, and two counts of burglary.

Trial judge Edward Cowart imposed death sentences for the murder convictions.

The night before his execution in January 1989, Bundy confessed to 30 more murders, but the true total remains unknown.