13. Jessica Simpson

While this fresh-faced singer and entrepreneur usually has gleaming blonde locks and a glowing complexion, she doesn’t fare so well in the dental department.

The pop star confessed she only scrubs her pearly whites three times a week. Instead, she uses Listerine and rubs them clean with her shirt – 0 out of 5 dentists recommend this hygiene habit.

Reportedly, a housekeeper informed Star magazine that Simpson is also very messy and will leave her clothes and hair extensions all around the house.

Jessica went on “Ellen” and admitted to millions that she doesn’t like how slippery her teeth feel after she brushes them — so she just doesn’t. Jess flosses and uses mouthwash but doesn’t scrub more than a couple times per week.

She said: “I don’t like them to feel too slippery…I’ll use a shirt or something. I know it’s gross but I always have fresh breath.”