I would have your vet look at his mouth and make sure that the retained teeth are not causing his bite to go wonky. That is the issue. If is bite is still fine, it’s OK to wait a bit. But if the retained teeth are making the other teeth crowd, or go in the wrong directions, or if the retained teeth are so tightly held between other teeth that there is no room for them to move and loosen, it’s a problem.At what age do retained puppy teeth need to come out? Issac just turned 8 months old and has 1 retained upper canine and 1 upper retained incisor.