Evaluation of en-masse retraction using microimplant versus conventional techniques : an in vitro study

Abstract EN

Background: The study aimed to investigate the effect of different techniques of en masse retraction on the vertical and sagittal position, axial inclination, rate of space closure, and type of movement of maxillary central incisor.

Materials and methods: A typodont simulation system was used (CL II division 2 malocclusion).

Three groups were used group 1(N=10, T-loop), group 2(N=10, Time-Saving loop), and group 3(N=10, Microimplant).

Photographs were taken before and after retraction and measurements were made using Autodesk AutoCAD© software 2010.

Kruskal- Wallis one-way analyses of variance and Mann-Whitney U test (p≤0.05) were used.

Results: The rate of space closure showed no significant difference among the three groups (p≤0.05), while results regarding type of tooth movement showed a significant difference among the three groups (p≤0.05), where group 3(0.59±0.09) showed a more degree of controlled tipping than group1(0.33±0.19) while group 2(-0.50±0.09) showed an uncontrolled tipping movement.

Conclusions: It is concluded that microimplant anchored sliding mechanics gives better control over the en masse retraction mechanics and greater retraction.

Conventional techniques result in extrusion and move the teeth in less degree of translation movement.