While many people believe periodontal (gum) disease is an adult problem, in fact studies indicate that gingivitis (the first stage of periodontal disease) is nearly a universal problem among children and teens. Advanced forms of periodontal disease are more rare in children than adults, but can occur. Chronic gingivitis is not uncommon in children. It can cause gum tissue to swell, turn red and bleed easily. Gingivitis is preventable and treatable with a regular routine of brushing, flossing and professional dental care. If left untreated, it can eventually advance to more serious forms of periodontal (gum) disease.