- Teeth, enamored by enamel, the hardest substance in the human body.

- They're just teeth!

- Just teeth?

- Yes!

- Teeth are designed to withstand hot foods, cold foods, chewy things, soft things, hard things, all of it.

Teeth are incredible.

We should probably take a bite out of this topic.

(playful music) Even before your children's teeth start to come in, we encourage parents to use a soft washcloth, and clean that gumline so kids get the idea that their mouths need to be cleaned.

And we get into the world of teething - Teething.

- Let's run through the teething timeline, how we go from a gummy, cute mouth to the rise of baby teeth, to the fall of baby teeth, and then the emergence of beautiful, pearly white adult teeth.

Now, teething starts usually in the front, bottom, and then the top in the first year of life.

And it takes about two to three years moving towards the back.

That's when teeth come in.

This is how they erupt.

When baby teeth start to fall out, they also start in the very front.

Tooth fairy, get ready.

But they fall out at the same time, roughly in the bottom and the top, and then they again start falling out towards the back.

This starts at around year six and seven and usually finishes around when kids are around 10 to 14.

And during this entire time, as toddlers are growing, so are their jaws because they have to make enough room for all those adult teeth.

And in the process, the baby teeth are almost acting like permanent little space fillers for the soon to be adult teeth.

Even before you actually see permanent teeth, they're all right below the baby teeth, pushing on those roots saying, "Get out of my way."

And if you look at this on an X-ray, try not to get alarmed, it kind of looks like a horror show.

(dramatic music) The permanent teeth literally push up on the baby teeth, dissolve the roots, and kick the baby teeth out and settle into their new home.

Now, the entire process of permanent teeth replacing baby teeth is called exfoliation.

And the eruption of permanent teeth usually happens in pairs as well.

So it's twice the fun.

By the time kids are 13 years old, they should have 28 permanent, adult, ready-to-eat-the-world teeth.

And by the time "kids" are 21, aside from probably annoying their parents a little bit more, they may also have one to four wisdom teeth as well.

But let's rewind to those first couple of years when the wonder of teething begins.

Can you tell me about what teething was like for your kids?

- First of all, no one tells you about teething.

There's so many things people don't tell you about babies, like when you go into that new baby dealership and you're like, "Oh, this one looks good!"

No one says, "Beware of teething!"

But it was tough.

We went through 1,000 styles of teething rings, teething baubles and giraffes and every kind of teething thing you can imagine.

A cold washcloth is what worked.

- [Alok] A cold washcloth?

- Yes.

Lulu loved a cold washcloth.

- [Alok] What was the recipe for the cold washcloth?

- Wet it, put it in the fridge, and wait for her to start shrieking.

Then remove the washcloth from the fridge, insert it into her mouth, baby stops shrieking.

I will say that anytime my first child cried, and there was no obvious reason, every mom around me said, "Oh, she's teething!"

'Cause she's crying.

- Default teething!

- Why is he acting, like, why is he pooping?

He's teething!

Babies poop when they teeth.

What are real symptoms of teething?

- Okay, so I'm gonna empathize with people who just attribute everything to teething because it can cause fussiness and irritability and babies have trouble eating and crying and it can make them feel warm.

It's not a real infectious fever, that's different, but it can elevate their core body temperature.

Here's another fun one.

Every now and then, a kid will get something we call referred pain, meaning he or she has pain from the gums being broken-- - It's like someone comes in and they're like, "Hello, this pain we think would be a good fit for you."

And then they, is it like that?

- I'm gonna refer you pain, and the pain is gonna be in your-- - "I think you'll like this pain very much.

This seems to be the right pain for you."

- Well, the pain you refer to your kids in that deigning sense would be ear pain, which can sometimes come from teething.

So you'll see kids and they'll sit there and tug their ears or rub their cheeks.

Or every now and again I'll get a video on social media from a parent like, "Oh my God, my kid's doing this weird thing."

And the baby will be kind of popping and locking.

But in reality rubbing their ear 'cause they're teething.

- But they're not really good at it Babies are no good at popping and locking.

- They're just-- - I know it's a generalization, but-- - But they're great at teething.

Now, baby teeth may be temporary, but they still have to be taken care of.

Not only to prevent oral pain or infections, but also because permanent teeth, which are right below them, can also get damaged or decay if the baby teeth are not well cared for.

And also, proper dental hygiene, starting young, is important for speech development.

As soon as a child's teeth begin to emerge, they should be brushed by an adult.

By the time kids are about one and a half or two, an adult should be brushing their teeth at least twice a day for the full two minutes.

And you want to start in the back in the molars where cavities are more likely to be formed.

For kids three and younger, use about a grain-of-rice size of fluoride toothpaste.

For kids that are three to six, you can up that a little bit to another food object, I'm not going to say golf ball, a pea-size!

Honestly, just do your best to get into a routine and a rhythm with your child.

If you can't absolutely make that two minutes, it's okay.

Take a break.

Try not to make it seem like a punishment or a chore.

Try to do it in a way where everyone gets behind it and it's all good.

(dramatic music) We recommend that parents get to the dentist at one year of age, recommended by the American Dental Association.

- Did it!

- How did that go for you and your kids?

- It was very loud.

Lulu hated the dentist.

But I will say I feel like that first visit is just like a get-to-know-the-dentist situation to see the chair and see all the little tools and kind of begin to learn what the expectations are when you go.

- Totally.

I mean, it's like a risk assessment.

You just want to meet the family, kind of get a sense for dental hygiene practices, the kid's health, and just kind of see where things are going.

- We got a book, we talked about the dentist, we showed them our mouths, which I'm not showing you, and they would go, "Aaaah!"

And I'd go, "Exactly, you have to brush your teeth every morning and every night.

We have to go to the dentist, or you'll have a mouth like Mommy and Daddy."

- And they were like, "Ohhh!"

- "Ehhhh!"

- But honestly, teething is super fascinating.

If you just look at other members of the animal kingdom, you'll appreciate how incredibly complex and awesome this process is.

Check this out.

Sharks are born with full rows of teeth.

Some sharks actually have five rows of teeth and can have thousands of teeth ready to devour other things living in the ocean.

And then there's the naked mole rat who has two teeth that they can independently control.

It's like chopsticks.

But here's what your child can do that they can't, brush and floss, which are extremely crucial for dental health.

Are your kids good brushers now?

- They're great brushers.

Nico stops the world and says, "I have to brush my teeth now," and he just goes and brushes his teeth.

It's the cutest thing watching a three-year-old handle a toothbrush and he's mimicking what he sees us do.

He's not exactly doing it, but he'll go... And it's not touching teeth yet.

Ad then he'll go...(chuckles) So we guide him.

- Kids shouldn't be left with the independent task of brushing their own teeth until they're about six or seven.

It's a big responsibility and it requires some fine motor skills, which they develop around this time.

- Flossing, your kids floss?

- Yes, they love flossing.

They're so weird.

- Dang!

- They're doing the flossing.

- When younger kids have big spaces or gaps between their teeth, you don't necessarily need to floss.

As kids get older and those gaps start to close and their teeth may touch, you will have to help your child and floss his or her teeth.

And you'll be able to check in on their progress from visits at the dentist.

- What's your favorite prize in the prize box?

- (chuckles) Do you remember the little thing that was like a square and it was like one through nine, and they'd rearranged?

- It's like pre-Sudoku.

- And you could break it and cheat, or you could do it the proper way?

- Yeah.

- That was my favorite.

- I bet you did it the proper way.

- I used to try to because if I broke it, my mom would take it from me.

- That's right.

And look, and now you're a doctor.

Wow, and I am a comedian and my favorite toy was the thing that went, "oooooooo."

- That's a pretty underrated toy.

- Yeah, so is my job.

(both laughing) - Here's what it comes down to.

Teething is a milestone.

And it doesn't come without its aches and pains.

But there's essentially a battle happening.

The bacteria want to throw a rave and party and cause cavities.

But with proper education and teaching your kid about good dental hygiene, your child's gonna blow a whistle and send the bacteria home.

- All right, let's do this and get out before she wakes up, okay?

- Being a tooth fairy is so cool.

It's like a time-honored tradition since the Middle Ages.

Every culture has their own version.

You got Ratón Pérez in Latin America, Topolino in Italy, La Petite Souris in France, in Asia sometimes they take the... - Let's just do this and get out.

- Okay.

So what do we do, put like 100 bucks under her pillow?

- 100 bucks, are you insane?

- I don't know.

Kids are demanding these days.

- How bout some NOVA stickers?

- Does any kid actually want those?

- Yes, she wants them.

- Okay.

- Let's go before she wakes up.

- [Alok] All right, done.

(dramatic music) (bright music)