oral fixation eh? i know what you mean i LOVE chewing and will go through bag on bag of popcorn just for the eating part! here are some alternatives (DO NOT TAKE UP SMOKING!

haha)
chew gum (sugar free)
chew ice (dont tell your dentist i told you to do this and fyi i cracked a tooth doing this but.... i love it!)
chew on a tooth pick
get one of those ring pops (like 80 cals and it lasts the WHOLE day....)
chew on lemon/lime wedges (again dont tell your dentist i told you too! can eat through enamel)
have a diet drink
drink water
distract yourself with other things (ie call a friend)
the hardest part for me is once i start chewing/eating/snacking i want to prolong the feeling. walk away and tell yourself if you still want it in an hour you can come back... by that time you prob wont want it!
also i think over eating messes with your blood sugar and causes you to want to eat more... try eating a diabetic diet (whole grains, lean protein, lots of veggies) for a week and see if these cravings (oral or otherwise) go away!
good luck! im right there with you!