You will need a clear liquid diet for several days after a chin implant, especially if the incision is made inside the mouth. For about a week after you eat or drink anything you should wash you mouth out. A mouthwash with peroxide is best but water is better than nothing.
Most doctors recommend that you eat a well balanced diet and take plenty of fluids. Some like their patients to have additional vitamin C for about six weeks after surgery. Do not take extra vitamin E at this point because it can increase bleeding. After two weeks additional vitamin E by mouth may reduce the risks of thickening of the scar.