1Hey, it's Esther.
2I wanna show you something my dentist gave me.
3Check it out.
4It's a model of my teeth.
5It shows the exact spot of each tooth in my mouth.
6My dentist made the model so they could design mouth guards that would be a perfect fit for my teeth.
7Someone named Drew has a question about teeth.
8Let's give Drew a call now.
9Hi Esther.
10Hi Drew.
11I have a question for you.
12How do braces work?
13That's a great question.
14You know, I've never had braces
15but some of my friends wore braces like these.
16Do you see how there's a piece glued to each tooth
17and a wire that goes through all the pieces?
18A dentist put the braces on
19and then, my friends wore them for months, sometimes years.
20A lot happens when people wear braces
21but it can be hard to see the changes right away because it's a slow process.
22Check out this video.
23It shows more than a year of wearing braces in just a few seconds.
24This way, we can see what happens really sped up.
25...
26That's so cool. Let's see it again.
27Try watching these teeth all the way through and see what you notice.
28Here we go.
29...
30Did you see that? The teeth moved?
31Here they are at the start and at the end.
32They're in new spots.
33Now, you might wonder why a dentist would move someone's teeth?
34Well, think about the things we do with our teeth.
35We bite and chew,
36we brush and floss to keep them clean.
37We even use our teeth when we talk.
38Braces help some people do these things by moving teeth to new spots.
39For example, a dentist might move teeth so less food gets stuck between them
40or so teeth line up when a person chews.
41Okay, so braces move teeth.
42But when I watch that video it isn't clear to me how the braces do that.
43I'm curious.
44So how do braces move teeth?
45Maybe you thought about how you move things.
46Let's say you need to move a big box that's in your way.
47It's way too heavy to pick up.
48What can you do?
49Maybe you try pulling on it or pushing on it.
50You keep pushing and pushing and slowly the box moves.
51It takes time and hard work, but...
52inch by inch, you finally move it to a new spot.
53That's what braces do too.
54Braces, push and pull on teeth.
55Remember that wire we saw, the one that connects across each tooth?
56That wire is gently pushing and pulling on teeth all the time.
57And over time, the teeth slowly move with the wire.
58But looking at that skinny wire makes me curious.
59Maybe it makes you curious too.
60Is that skinny wire really strong enough to move teeth?
61Teeth seem pretty stuck in place and that's true.
62It would be hard to bite and chew if they weren't.
63We can even see how teeth are held in place.
64Maybe you've seen a picture like this before.
65It's an X-ray.
66It shows what's inside your body.
67Solid parts like teeth and bones, show up white on an X-ray.
68Here is one whole tooth.
69Looks a little different, huh?
70This is the part you usually see
71and this part is actually inside your body.
72That part is called the root.
73It holds the tooth in place.
74Here's another whole tooth
75and another
76each with its own roots.
77Maybe you notice these white areas around the roots.
78That part of the X-ray shows bone.
79Can you see how each root has its own spot in the bone?
80Now wait.
81You probably know bones are hard
82and these hard bones are really good at holding the roots in place.
83But if bone is holding the roots in place
84and the roots are holding the whole tooth in place
85what's going on with braces?
86Braces have to move the whole tooth.
87How can braces move the whole tooth if bone is in the way?
88It almost sounds impossible.
89I mean, try feeling the bones in your shoulder.
90You can feel how hard they are under your skin.
91And because they're hard,
92your bones can support and protect your body.
93Two very important jobs.
94But another important thing your bones can do is change.
95Have you ever wondered how your baby bones became your kid bones?
96Your tiny baby bones had to change and grow to become bigger bones.
97In fact, your body is changing your bones right now to keep them healthy
98and your body will keep changing them throughout your life.
99Changing bones is something your body does naturally.
100And it turns out if you wear braces,
101your body will change the bones in your mouth so teeth can move.
102Isn't that wild?
103Here's how it works.
104Braces keep pushing and pulling on the whole tooth.
105That causes the root to press on the bone that's holding it.
106So, your body starts changing the bone.
107It makes a new space.
108Now, as the braces push and pull,
109the tooth and its root can slowly move over.
110Then your body changes the bone again to hold the tooth in its new spot.
111When dentists take the braces off,
112your teeth are in new spots
113and the bones in your mouth are in new shapes.
114So in summary, braces push and pull on teeth to move them.
115But for teeth to move, our bodies have to change the bones in our mouth.
116That's pretty cool.
117Braces are an invention that works by using something our bodies are already good at doing:
118changing our bones.
119That's all for this week's question.
120Thanks Drew for asking it.