We often don’t think about our teeth unless they are bugging us, but they are extremely important to our overall health and well being. After all, they help us eat, chew, talk and smile. And they are an incredibly complex and often misunderstood part of our anatomy. Here’s 10 interesting facts about your teeth that you might not know:

1. At First Glance

The first feature people notice about another person is their smile, according to a survey done by the American Academy of Periodontology. And good teeth are kind of important to a good smile.

2. In the Womb

 Although a child’s teeth don’t start to appear until the child is six to 12 month’s old, they actually begin forming before they are born. Baby teeth, also called milk teeth, begin forming when the child is in the womb.

3. 40 Sets of Teeth?

While humans only have two sets of teeth (32 teeth total), other species vary widely in the number of sets of teeth. Sharks top the list with around 40 sets of teeth!

4. That’s A Lot of Toothpaste!

US consumers buy more than 14 million gallons of toothpaste annually. The typical person spends 38 days of their lifetime using that toothpaste to brush their teeth!

5. Name All Four Types of Teeth

There are four different types of teeth used by humans to cut, tear and grind their food. They are incisors, canines, premolars, and molars.

6. The Power of Saliva

Your saliva is critical to your oral health because it protects your teeth from bacteria in your mouth (and bacteria are the first ingredient in the formation of a cavity) and helps you digest your food. The typical person produces 25,000 quarts of saliva in their lifetime.

7. Undercover

More than one-third of the length of your tooth is hidden out of sight underneath your gums. The part that is hidden is the root.

8. Now That’s A Valuable Tooth

Sir Isaac Newton holds the record for the most valuable tooth. It sold for $3,633 in 1812, which today would be worth $35,700. Why would someone want to buy his tooth? To set in a ring!

9. Inflation From the Tooth Fairy

In 1950, the Tooth Fairy left on average 25 cents. That went up to $1.00 in 1988, and now the rate is up to almost $2.00!

10. No Self Repair

The bones and tissue in your body can repair themselves – but your teeth can’t. That’s why fillings and other dental work are necessary to protect your teeth from further damage once you have an oral health problem.