Accuracy of a dynamic guided surgery system for orthodontic miniscrew placement: an experimental in vitro study.

Objectives: To compare the accuracy and time required for orthodontic miniscrew placement using a dynamic computer-assisted surgery (d-CAS) system vs the conventional freehand (FH) approach. The effect of side, location, and operator experience was also evaluated. Materials and Methods: A randomized, in vitro experimental study was conducted using 10 maxillary resin models. After virtual planning, 40 miniscrews were randomly placed by one experienced and one novice operator. Twenty miniscrews were placed using a d-CAS system (test group) and 20 using the conventional FH method (control group). Preoperative and postoperative cone beam computed tomography scans were superimposed to measure deviations between the planned and final miniscrew position, and placement time was recorded. Results: The d-CAS group showed less deviation at the entry point (95% confidence interval [CI] = 1.79 mm to 0.16 mm; P = .019) and less angle deviation (95% CI = 8.5° to 1.7°; P = .004). No significant differences were observed in other variables. Both operators achieved similar accuracy. Placement time was significantly longer in the d-CAS group, with a mean difference of 6.3 minutes (P < .001). Conclusions: Dynamic computer-assisted surgery improves the accuracy of orthodontic miniscrew placement vs the traditional FH method. However, d-CAS takes significantly longer. Clinician experience does not seem to significantly affect accuracy.