Wisdom Teeth

So I was talking to Z about my upcoming oral surgery at the end of the month and I told her that I was very excited. She replied, "Getting your wisdom teeth removed is not fun, or an enjoyable experience." I said that I was going to make some money off of the tooth fairy for my 4 teeth. She informed me that the Doctors keep the teeth because they are a biohazard. How is that possible? They are in my mouth, they belong to me, and they are not causing me any life-threatening problems. My only conclusion is that the Doctors keep the teeth because they have a deal set up with the Tooth Fairy, and hence the reason they are all rich and drive expensive cars.