So what is going on here?
Its pretty simple actually. the adult tooth has simply "missed" the baby tooth.
The idea behind losing your baby teeth is that the adult tooth is supposed to come in
right above, below, the baby tooth and push it out.
The adult tooth then takes the place of the baby tooth.
In this instance however, the adult tooth "missed" the baby tooth.
The adult tooth came in too far towards the roof of the mouth.
The fix is fairly simple.
You need to have the baby tooth extracted.
The idea is that the adult tooth can then slide into the place of the
baby tooth and all will be well.