Gum disease, also known as periodontal disease, is the No. 1 cause of tooth loss in adults. Tooth loss in adults can be especially devastating, causing embarrassment and self-consciousness and leading to expensive dental repair work. It’s important to take great care of teeth from childhood into adulthood to prevent decay and disease. Here are the three main stages pf gum disease so you can understand it better and hopefully prevent it with good oral hygiene and regularly scheduled dental exams and cleanings.