Kids Hygiene

So I know in some way, this is my fault. I probably didn’t encourage them to take care of themselves the right way when they were younger but I really need help at this point.

I have a 10 year old and an 8 year old who both hate showering and brushing teeth. My 8 year old is not as bad as my 10 year old, he’s more lazy than anything but he will do it with less complaining. My 10 year old, who is about to go to middle school in the fall, will actually lie about brushing his teeth and get a super nasty attitude when I tell him he has to shower. His teeth get gross where I can just look at him talking and see gunk between his teeth and I’m like wtf dude is it really so hard to brush and use a little flosser?? (I don’t say those exact words but I do get frustrated) And when he goes a day or two without showering, he stinks to high heaven. And I tell him, “If I can smell you that means other people can smell you.” He just doesn’t care.

I’m trying to explain to him that middle school is a whole new world. And even though he says he doesn’t care what people say, teasing will get to him and hurt his feelings. And more importantly, it’s hard to reverse damage done to your teeth. I’ve also shown them pictures of what can happen when you don’t take care of your teeth but it shocks them for like a day and then it’s back to the same foolishness. They both already have had bad cavities and the hideous silver caps. I’ve tried making it fun and brushing with them. I’m just at a loss.

Please help.