If gingivitis is left untreated, it can lead to periodontitis. Over time, plaque will extend to the gum line and irritate the soft tissue there. The toxins produced by the bacteria trigger a chronic inflammatory response in which the body turns on itself and start destroying the gum tissue and the supporting tooth structure. As a result, gums start receding from the teeth, forming deep pockets, which become filled with bacteria and infection. As the disease progresses, the pockets become larger and more and more gum, and bone tissue is destroyed. Eventually, teeth may become loose and fall out.

Periodontitis has many forms. The most common ones are:

• Aggressive Periodontitis: Generally, gum disease is rare in children, but some children and adults do develop aggressive periodontitis, even though they may be otherwise healthy. This disease can occur in children even younger than 3 years old. By age 20, people with aggressive periodontitis lose their teeth. Subtypes of aggressive periodontitis include localized juvenile periodontitis that results in excessive bacterial colonization. Another rare condition is known as prepubertal periodontitis, which impacts children shortly after their baby teeth start to appear. Common symptoms include swollen, red and bleeding gums, pus, and unpleasant breath.
• Chronic periodontitis occurs in adults and is the most common form of periodontitis. This gum disease is characterized by severely swollen gums that bleed profusely and gum recession. Formation of deep pockets can occur slowly, but rapid progression can also occur.
• Necrotizing Periodontal Disease: Also referred to as acute necrotizing ulcerative gingivitis, this is the most severe form of gum disease. The condition can result in the death of gingival tissue, ligaments, and the alveolar bone. This disease is most commonly seen in people who are malnourished or who have compromised immune systems, like HIV/AIDS patients.