Phermsang-ngarm P, et al. - A comparative analysis was conducted by the authors of the tooth movement achieved, the time required for alignment, root resorption, and alveolar bone thickness changes during initial dental alignment between groups treated with 0.012-inch preformed heat-activated or customized nickel titanium (NiTi) archwires for those having severe crowding of maxillary anterior teeth. Findings demonstrated palatal movement of the central incisors, more canine distal movement with less bone thickness changes and less root resorption. However, it took more time to achieve alignment in the experimental group than the control group.