All the dogs I have had have been rescues over one year old, so I have never seen this. I have a nine month old Maltese/Yorkie mix who weighs three lbs and was the runt of the litter. We have had her since she was 12 weeks old. She has her adult teeth in now, but the long pointed ones at the front upper and lower (canines?) came in without the baby ones falling out. So, she has two at each corner currently. Is this uncommon? They don't seem to be bothering her, but what's the latest age for when they should fall out?
When she yawns she looks like something out of a science fiction movie.
1. I don't have pooches, (kitteh person here).....
When I was a kid, the same thing happened to me; my adult two front teeth grew in before I lost the two front baby teeth. The dentist just extracted the two baby teeth. I was the only kid who was never missing the two front teeth.