Losing a baby tooth can be fun for a kid. You can put it under your pillow and look forward to finding some money there in the morning. And then you can watch your new permanent(永恒的) tooth grow in its place.
But if a permanent tooth falls out, that’s a problem. There isn’t another one under the gum(齿龈)that can replace it. Unfortunately, this happens to some older people. And if permanent teeth fall out or need to be pulled, an older person might need dentures.
