Madonna has diamond-encrusted grills made to conceal her "ugly" teeth.

During an appearance on The Tonight Show Starring Jimmy Fallon on Wednesday night, the superstar asked host Jimmy if she was lisping because she was wearing her new dental jewellery.

"I designed them - they are my birthday grills. It's almost my birthday, so I got myself a pair of grills," she shared.

Jimmy went on to ask how long Madonna has worn grills.

"Decades," the 63-year-old replied. "People have a problem with my grills, I don't know why? I just like the way it looks - mouth jewellery. And I have really ugly teeth."

Without adjusting his tone, the TV host stated, "You do."

"Don't agree with me!" she exclaimed, while Jimmy tried to backtrack quickly as Madonna playfully slapped him on the wrist.

The Like a Prayer hitmaker was on the talk show to promote her new compilation album, Finally Enough Love: 50 Number Ones, which will be released on 19 August.

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