Two-dimensional radiographic and clinical references of the tooth crown for orthodontic mini-implant insertion: a guide-free technique - Barros, Sérgio Estelita; Janson, Guilherme; Chiqueto, Kelly; Garib, Daniela Gamba (Oral Surgery, Oral Medicine, Oral Pathology, Oral Radiology, and Endodontology, 2010)