The American Academy of Periodontology has developed the following parameter on the treatment of aggressive periodontitis. Patients should be informed of the disease process, therapeutic alternatives, potential complications, expected results, and their responsibility in treatment. Consequences of no treatment should be explained. Failure to treat aggressive periodontitis appropriately can result in progressive and often rapid loss of periodontal supporting tissues. This may have an adverse effect upon prognosis and could result in tooth loss. Given this information, patients (or their parents or guardians, as appropriate) should then be able to make informed decisions regarding their periodontal therapy.