Having worked in an Ortho office I've seen many brackets off due to eatting the wrong things...
Things to avoid:
Hard/Brittle Crunchy Crusty Sticky/Gooey
Ice, Potato Chips, Pizza Crusts, Caramels, Nuts- Peanuts, Almonds, Tortilla Chips, Toasted Bagels/Breads, Chewing Gum
Jolly Rancher Candies, Apples with Front Teeth, Starburst
Pens and Pencils, Fresh Carrots, Sugar Daddies, Snickers or similar, Pretzels Kaiser Dinner Rolls, Jelly Beans, Corn on the Cob, Hard Taco Shells, Popcorn, Licorice, fruit snacks
I know thats a long list of everything they currently love to eat... Things will get better with time. Even the slurping will go away..