DS, 5, has a bad habit that he inherited from DH, thumb sucking. We have tried so much to stop him but he doesn't realise he is doing it so it makes it even more difficult. I freaked out this morning because after staying with his grandparents for a week I noticed a huge difference with his teeth! The top ones are bending out, bottom ones leaning in. I swear his teeth looked nothing like that 1 week ago! He has (had) such lovely teeth.
Now I'm so angry with DH's parents - they always go on about how we shouldn't be so strict on trying to stop him, so I can imagine how much DS was sucking his thumb whilst staying with them. But in saying that, I can't image that much damage can possibly be done in only 1 week?? Or can it?

Does anyone have any tips on how to help stop DS from doing any more damage?!