For the first two days or so, stick to soft foods. Avoid tough meats, hard breads, and raw vegetables. Before long, you'll be able to chew normally. However, you'll need to protect your orthodontic appliances when you eat for as long as you're wearing braces.
When you get your braces on, you may feel general soreness in your mouth and teeth may be tender to biting pressures for two to three days. This can be relieved by rinsing your mouth with a warm salt water mouthwash. Dissolve one teaspoonful of salt in 8 ounces of warm water, and rinse your mouth vigorously. If the tenderness is severe, take aspirin or whatever you normally take for headache or similar pain. The lips, cheeks and tongue may also become irritated for one to two weeks as they toughen and become accustomed to the surface of the braces. You can put wax on the braces to lessen this. We'll show you how!
This is to be expected throughout treatment. Don't worry, it's normal. Teeth must loosen first so they can be moved. The teeth will again become rigidly fixed in their new--corrected--positions.