It's a good thing the tooth fairly doesn't collect sharks' teeth because, if she had to leave money for every one she took, she would soon be bankrupt.
Why? Because, unlike humans, who only get one set of milk teeth and one adult set, sharks have an amazing ability to replace the ones they lose time and time again. In fact, some sharks can use, and lose, up to 30 000 teeth in a lifetime.
How do sharks' teeth work?
Rather than being embedded in a jawbone the shark's teeth are attached to a sheet of cartilage known as a tooth bed.
As the front tooth is lost, the bed rotates and the next tooth comes to the fore.
In the image of a shark's jaw on the left you can clearly see the new teeth folded behind the ones that would have been in use.
The others would have been buried in the gum until they were needed.
The teeth on the tooth bed are known as a family.
Most sharks have twenty to thirty rows, or families, but here may be as few as one in some species of ray and as many as 300 in the whale shark.
Imagine having to brush all that lot!
Shape and size
Like our teeth, those of the shark are made up of an outer layer of very hard enamel, just below that is a substance called dentine which encases the pulp, which contains the blood supply and nerves.