Effect of the Increasing Operator’s Experience on the Miniscrew Survival Rate

Abstract

The aim of our study was to determine the learning curve of orthodontic miniscrew insertion in novices, unsupervised and supervised by experts. Three inexperienced orthodontists, two unsupervised (JA-S, MS) and one supervised (JŁ) by the experts, inserted 404 AbsoAnchor® miniscrews (Dentos, SH131208) into 202 patients for en masse retraction or distalization purposes. Miniscrews were inserted symmetrically on both sides of the maxilla between the 2nd bicuspid and the 1st molar. Then, the miniscrew survival rate and the orthodontists’ learning curves were estimated. After first 40 insertions JA-S, MS, and JŁ achieved 73, 70, and 83% of stable miniscrews, respectively. The overall outcome showed that after 74 and 118 insertions, the miniscrew survival rate reached 80% and 85%, respectively, and from that point the learning curve still presented an ascending trend. The success rate increased significantly: by 1.016 times with every procedure (odds ratio = 1.016, p = 0.006). Since the success rate significantly increased after each miniscrew insertion in the buccal maxillary area, this finding might encourage hesitating clinicians to introduce the miniscrews to the daily practices. Obtained data could also help to plan an effective training system for novice orthodontists.