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.
Since its completion in 2010, the world's tallest skyscraper has been Burj Khalifa in Dubai, United Arab Emirates. The building, which was designed by the architects Skidmore, Owings & Merrill, is a mighty 828 meters tall and has 163 floors. Burj Khalifa is one of Dubai's most famous buildings.