Teeth Grinding

I have a one year old cat, and recently I have been noticing him grinding his teeth. When I open his mouth the bottom of his teeth seem to be crooked and smaller the the upper part of his teeth. Is it normal for cats to grind their teeth? How do I stop him from doing it? 

Has he been eating and everything else normally?  Teeth grinding can be an indication of an upset tummy.  Have you mentioned this to the vet?

His eating habits haven't changed in the least bit, he doesn't seem at all effected by it. I have noticed however, that he has been chewing at a lot of stuff that he normally doesn't chew on. I thought that maybe it his gums hurting him. I haven't took him to the vet yet because I just noticed this afternoon that he has been doing this. 

I think a vet visit to rule out anything wrong with his teeth is definitely in order.  Good job noticing!