1 Have the equivalent of at least two years clinical experience as a dentist. 2  Complete an accredited three year full-time university degree in orthodontics. 3  Be registered as a Specialist in Orthodontics.
It opened on January 4, 2010. Soaring 828 meters (2,717 feet) the Burj Dubai in the United Arab Emirates is now considered the world's tallest building. Keep in mind, however, that these statistics include the skyscraper's enormous spire.
Willis tower is the oldest building in the list and the construction of the building completed in 1974. It stands 442 meters or 1,450 feet high and composes 108 floors. Willis Tower is also the longest building that held the longest tallest worldâs record in the list. It held the record for a quarter decade. This tower is also the tallest building in north America.