Accuracy of Miniscrew Insertion with Fully Guided Dynamic Navigation Versus Freehand: An In Vitro Experimental Study

The placement of miniscrews in orthodontics enhances dental and skeletal movements with reduced need for patient cooperation but may lead to complications such as incorrect positioning or damage to adjacent teeth. Computer-assisted surgery techniques have shown improved accuracy and reduced risks. This study aimed to compare the accuracy of the X-Guide® dynamic navigation system with the freehand method for orthodontic miniscrew insertion and to assess the influence of screw position and side on accuracy. The main hypothesis was that the X-Guide® system would yield superior accuracy in the primary variable (3D apical deviation) compared to the freehand technique. Secondary hypotheses were that the X-Guide® system would also demonstrate superior accuracy in the secondary parameters (3D entry deviation, angular deflection, apical depth, and 2D entry deviation) and that screw position and side would not significantly affect any of the outcomes. An in vitro, randomized, and blinded experimental design was used with 10 maxillary models divided into two groups: experimental (X-Guide®) and control (freehand). In each model, six miniscrews were planned using cone beam computed tomography (CBCT): three were inserted freehand and three with navigation. A trained novice clinician performed all insertions. Post-placement CBCT scans were used to compare 3D deviations between planned and actual positions. Wilcoxon signed-rank tests and Friedman’s ANOVA were applied. In conclusion, the results supported the main hypothesis regarding the primary variable: the X-Guide® system significantly improved miniscrew placement accuracy in terms of 3D apical deviation, even when used by a novice operator. However, the results partially rejected the secondary hypotheses related to precision, showing a significant improvement in 3D entry deviation with dCAS, but not in angular deflection or 2D measured parameters. Furthermore, the results supported the secondary hypothesis regarding screw position, which did not affect the outcomes. Nevertheless, with dCAS, a significantly greater deviation was found on the right side for 3D entry deviation, 2D entry deviation, and angular deflection.