25 August 2015

How Many Teeth Does The Tooth Fairy Pick Up Each Night in Utah?


Somebody asked me a question about my Tooth Fairy post the other day that got me thinking. How many baby teeth are lost every day in Utah?

I began with Googling. Surely someone else has thought of this and run some numbers, right? Lo, there is a tooth fairy site that claims that the Tooth Fairy collects 300,000 teeth per night.

That's a lot; however, when I ran the numbers, it started to seem awfully low.

Let's assume that the Tooth Fairy collects all baby teeth regardless of quality and we assume that all children lose all their baby teeth. The world population of children sits at 2.2 billion, with 74.2 million of them in the United States. Of those, approximately 896,961 of them are in Utah. This means that somewhere around .04077% of the world's children are in Utah.

If we assume that kids in Utah lose teeth at the same rate as all other children in the world and that each day in the year is just as likely as the rest to lose a tooth, then we have that of the alleged 300,000 daily collection, around 120 are collected in Utah.

No way.


That seems *way* too low! That means that of the 501 elementary schools in Utah, there is only one tooth lost in four schools a day. No way.

So, I decided to try digging up some numbers myself.

There are 668.3 million primary school-aged children in the world. I had trouble finding the same information for the United States, and for Utah, so I went with my already calculated .04077% and used it as a proportion, assuming that the proportion of primary school-aged children to other kids would be about the same throughout the world.

This gives us 272,472 primary school-aged children in Utah. Since I'm in the business of making sweeping intuitive-based assumptions, I will further assume that the average child loses nearly all of their teeth in elementary school, or, let's say, all of their 24 baby teeth and that they lose them at the same rate throughout those six years. This means that they will lose on average 4 teeth per year.

With 272,472 school children each losing 4 teeth a year, we have 1,089,888 teeth lost in Utah each year or about 3,000 every day. With 501 schools, this gives us about 6 teeth lost at school per day which seems more intuitive. The NCES states that the average number of elementary school kids per school is 523. If they are all losing teeth on average 4 per year, that means 5.7 teeth per day which is in the ballpark of 6. So, at least we are in the right order of magnitude.

So, now you can answer your childrens' penetrating questions with greater confidence. You are welcome.

More Silly Musings

  • Based on all of this, that means that an astonishing 7.3 million teeth are collected by the Tooth Fairy conglomerate every single day or 2.6 billion a year. That is a pretty big tooth palace.
  • If we assume that the one night that Tooth Fairy Rita mentioned in her letter was a typical night and that Rita is a typical Tooth Fairy, then there are roughly 30 tooth fairies assigned to Utah alone.
     
  • Of course, there is the problem of distance travelled. Certainly, the tooth fairy in Southern Utah will need to travel further distances to reach 100 teeth per night than the tooth fairy in baby booming areas like where we live. So, perhaps it is the case that Rita has a relatively high number of teeth to collect since her geographical area is smaller meaning that there are several more than 30.