Mass retraction movement of the anterior upper teeth using orthodontic mini-implants as anchorage.

BACKGROUND

Several studies have demonstrated the application of mini-implants in the orthodontic treatment as anchorage during the retraction movement of the anterior teeth.

PURPOSE

This study was designed to evaluate the mass retraction movement of the anterior upper teeth using orthodontic mini-implants as anchorage.

MATERIALS AND METHODS

Nine patients with class I malocclusion and Angle's class II, needing extractions of the upper first premolars, were enrolled in this case series. The retraction was performed using sliding mechanics and orthodontic anchorage on mini-implants. Measures were taken by initial and final cephalometric X-rays of the retraction movement to evaluate whether the mini-implants remained stationary and displacements of the incisors and the upper first premolars.

RESULTS

Out of 18 mini-implants, 8 mesialized (0.45 mm, average) and 3 extruded (0.14 mm, average). The upper incisors were retracted on the average of 4.21 mm, extruded 0.33 mm, and tipped 10.3°. There were no statistical significant modifications in the placement of the posterior teeth.

CONCLUSIONS

Although there was a very small displacement of the mini-implants, they still provided an adequate anchorage for the retraction of the anterior teeth, and there was no loss in the anchorage of the posterior teeth.