Swelling and infection of the tissues around your teeth is called periodontal disease. Some people have problems with their gums. Others have problems with the bones that support their teeth. You may also have trouble with both the gums and the bones. This is a common issue. Not caring for your teeth properly is the main cause of periodontal disease. Good teeth and mouth care may help prevent this problem. You may not know you have periodontal disease until you see your dentist.