I had this question yesterday in my office so I figured I
would address it here today.
In the picture below you will see some arrows that are
pointed to teeth that look like they are actually 2 teeth hooked together.
This is called a fusion.
2 teeth are, in fact, hooked together.
It usually happens in baby teeth.
And there is absolutely nothing wrong with it.
There is also another term called gemination (the above graph).
This is when 1 tooth appears to be splitting into 2.
With both fusions and geminations there is typically nothing to be concerned about.
The teeth should be noted and kept under observation over time.
But this would strictly be for the same precaution that
any other teeth would be kept a watchful eye over.
Please inform your dentist when you notice anything that may seem
out of the ordinary, but this out of the ordinary isn't too bad.