I agree with carolinalima - you might want to get teeth checked out. My Holland started kind of biting at air and pawing her mouth when she was having teeth problems.
Does your cat make a noise as if it was grinding it's teeth?. Rosie's has done this now and again for about 5 years now. The vet checked her teeth but said her teeth were fine, and they've been fine on every checkup. He did say that it could be a bit kibble that was stuck to her teeth that she was getting rid of, but it's best to have them checked just incase.