American Association of Orthodontists

The American Association of Orthodontists (AAO) is a U.S.-based professional membership organization serving the orthodontic dental specialty. Founded in 1900, it is the world's oldest and largest dental specialty organization, representing nearly 19,000 orthodontist members throughout the United States, Canada, and abroad. Its headquarters are in Creve Coeur, Missouri, near St. Louis.

Membership is limited to orthodontists—dentists who have completed two to four years of advanced training in an accredited orthodontic residency program in the diagnosis, prevention, and treatment of orthodontic problems. All orthodontists are dentists and may simultaneously hold membership in the American Dental Association. The AAO is also affiliated with the Canadian Association of Orthodontists.

The AAO is dedicated to promoting the highest standards of orthodontic care and education. It advocates for the profession at state and federal levels—addressing patient health and safety, access to care, and regulations affecting the field—and provides clinical guidelines and evidence-based best practices, supported by research collaborations that give members access to the latest scientific advancements.

Because the AAO disseminates clinical guidelines, evidence-based best practices, and the latest scientific advancements to its members, innovation in orthodontic care and technology is directly relevant to its educational and advocacy mission. In 2013, Gayle Glenn was elected as the AAO's first female president.