Morais JF, et al. - Authors evaluated the changes in the maxillary buccal alveolar bone during alignment without extractions. They also assessed the changes in arch dimensions and buccolingual inclinations of teeth and identified risk factors for bone loss. Arch expansion associated with tipping of teeth was led by nonextraction alignment with self-ligating brackets. At the incisors and mesiobuccal root of the first molars, horizontal and vertical bone loss was led by the expansion related to alignment. The risk for the buccal bone loss was increased by the thinner BTs and more severe crowding prior to the treatment.