1 Private practice of orthodontics at Clínica Balut, Pafnuncio Padilla #13, 201/202, Cto. Comercial Satélite, Mexico City, Estado de México 53100, Mexico; Professor, Department of Orthodontics, Universidad del Valle, Cali, Colombia, and Department of Orthodontics, Universidad de Baja California, Mexicali, Mexico. E-mail: nbalut@prodigy.net.mx.
2 Private practice of Orthodontics at Clínica Balut, Comercial Satélite, Mexico City, Mexico.
3 In the private practice of Orthodontics in Mexico City.