LAUSR

OBJECTIVE To explore the safe zone for micro-implants of the maxillary molar region by oblique plane cutting mode of cone beam computed tomography (CBCT). METHODS Thirty-nine patients with orthodontic alignment were enrolled with CBCT. In this study, the areas between the maxillary second premolar and the first molar were analyzed by the image reconstruction with CS 3D Imaging Software. The alveolar ridge bone width and the minimum interradicular space were measured at the height of 8, 10, and 12 mm from archwire under the 2 cutting modes of the oblique plane and coronal plane, respectively. The statistical analysis was performed. RESULTS The bone widths of alveolar ridge between the maxillary second premolar and the first molar were statistically significant under the 2 cutting modes of the oblique plane and coronal plane. The bone width was gradually decreased to the cranial side with the fixed measurement point and the interradicular space was gradually increased. The differences were statistically significant. CONCLUSION The oblique plane cutting of CBCT is more representative of the alveolar bone than the coronal plane. There is sufficient safe zone between the maxillary second premolar and the first molar for most patients to implant the micro-implants. However, the individual differences present large and CBCT needs to be taken before the implantation.