Quantitative evaluation of training method in placing miniscrews in orthodontic graduate program

Background The purpose of this study was to assess the effectiveness of training residents in an orthodontic program in the placement of miniscrews by using cone beam computed tomography (CBCT) images. A total of 90 miniscrews were placed in 15 pig mandibles over a 3-year period by 15 first-year orthodontic residents. Miniscrews were divided into three groups (Control group: no radiographs; 2D group: placement with 2D radiographs; CBCT group: placement with CBCT). Proximity of the miniscrew to the neighboring root was measured. The miniscrew success rate was examined in the graduate clinic from 2015 to 2021. Results The percentage of root contact for each group was: 36.7% (11/30), 20.0% (6/30), 0% (0/30), for the Control, 2D, and CBCT groups, respectively. The CBCT group was significantly different from the Control and 2D groups ( p < 0.05). For root proximity, the miniscrews were significantly closer to the roots in the Control ( p < 0.001) and 2D ( p < 0.001) groups compared with the CBCT group. No significant difference was observed between the Control and 2D groups ( p = 0.80). There was no significant difference among the years in the miniscrew success rate. Conclusions Training the residents in an orthodontic graduate program using CBCT may be helpful to avoid root damage and to decrease the miniscrew failure rate.