In order to practice, all orthodontists must be licensed by their state. To receive a dental license, candidates must graduate from an accredited dental school, successfully complete the written National Board Dental Examinations and pass state clinical tests.
The world's tallest artificial structure is the 829.8 m (2,722 ft) tall Burj Khalifa in Dubai . The building gained the official title of Tallest Building in the World and the tallest self supported structure at its opening on January 9, 2010. The second tallest self-supporting structure and the tallest tower is the Tokyo Skytree. The tallest guyed structure is the KVLY-TV mast.
The international non-profit organization Council on Tall Buildings and Urban Habitat (CTBUH) was formed in 1969 and announces the title of The World's Tallest Building and sets the standards by which buildings are measured. It maintains a list of the 100 tallest completed buildings in the world. The organization currently ranks Burj Khalifa in Dubai as the tallest at 828 m (2,717 ft).