Accuracy of Two Variants of 3D-Printed Insertion Guides for Orthodontic Mini-Implants: An Ex Vivo Study in Human Cadavers

Insertion guides are becoming popular for orthodontic mini-implant positioning. The aim of this study was to evaluate and compare the accuracy two different insertion guides, with or without pre-drilling, in a human cadaveric model. Maxillary casts six fresh frozen specimens were digitized create guides. Sixty mini-implants randomly inserted full-arch skeletonized either predrilling. Pre- post-treatment CBCTs superimposed using rigid registration. Transformation matrices planned real positions obtained, distances at neck apex, as well angular deviation, calculated. Kruskal–Wallis test performed, followed by post hoc when indicated. Out 60 mini-implants, 46 could be evaluated. Of these, 10 initially assigned no pre-drilling required procedure due very high bone density. Therefore, 32 implants (n = 15 full-arch; n 17 skeletonized) 14 7 skeletonized). lowest mean deviation 1.22 ± 0.6 mm, registered full-arch/pre-drilling group. skeletonized/no group presented values i.e., 1.72 8.23 4.24°. Significant differences among groups observed only neck, higher skeletonized/pre-drilling than one (p 0.014). In conclusion, within limitations study, rather deviations between found. Further studies needed on how improve vivo settings.