Abstract:

BACKGROUND: Compared with traditional orthodontic anchorage, bone implant anchorage displays advantages in treating intractable cases. However, the failure rate exists. To extend and apply the miniscrew anchorage system, the key methods  improved the stability of miniscrews, which is based on accurate diagnosis and analysis to the local alveolar bone.
OBJECTIVE: To evaluate the accuracy of various multi-slice spiral CT (MSCT) images assisting implant anchorage surgery and explore the factors associated with the accuracy.
METHODS: Following design of the implant anchorage angles in various MSCT images accurately, 32 titanium miniscrews were implanted in procine skull. The anchorage angles on MSCT images again and the buccalingual breaths of alveolar process by insert angle were measured. The skulls were dissected, and the implant anchorage angles and the breadths of alveolar process were measured on anatomic bone samples. The various MSCT images data and pits’ skull sample data were compared.
RESULTS AND CONCLUSION: Their concordance correlations between MSCT length and angle measurement data and the anatomic bone samples were good. But all MSCT data were smaller than the anatomic samples data. The accuracy of 2D images was better than 3D images. The measurement accuracy of angles was better than lengths. The accuracy of axial sections were better than that of cross-sections in 2D and 3D MSCT images. MSCT images can provide accurate quantity information in the ration 1:1 to material object. It is accurate and reliable that MSCT images assist implant anchorage surgery. On measurement, the 2D axial and 2D cross-sectional images play the most important role on clinical application. The measurement accuracy of cross-sectional images is affected by scanning plane of MSCT radio active rays.