We have a just 8 month cavalier and we have`nt seen one of his puppy teeth, he has eaten them all!, he did have a retained puppy tooth and the big tooth had fully grown, we were a big worried about this and we thought it was making the adult tooth crooked, but the vet said it was fine and would not interfere with his big teeth and if necessary they would take it out if ever he needed anaesthetic, he was just over 6 months and the vet said he had all his big teeth then. The tooth dropped out on it`s own in the end.
With my older cavalier who is nearly 11 yrs old we found a few of his on the carpets and I kept them and put them in a little pot, which we still have, just a little momento. I wished I had just a few of the pups teeth to keep.
and my two special boys Jasper age 14 and Ollie age 4.