Below is an instruction from Human. Write a response.
    ### Instruction:
    What is (are) Gum Disease ?
    ### Response:
    If you have gum disease, you're not alone. Many U.S. adults currently have some form of the disease. It ranges from simple gum inflammation, called gingivitis, to serious damage to the tissue and bone supporting the teeth. In the worst cases, you can lose teeth.
    