The effects of palatal anchorage device on molar distalization with clear aligner: Three-dimensional finite element analysis.

INTRODUCTION

This study aimed to analyze the biomechanical effects of the combined use of clear aligner and palatal anchorage devices (transpalatal arch [TPA], combination of TPA and microimplant [MI]) during maxillary molar distalization.

METHODS

Three-dimensional finite element models were established to simulate molar distalization, incorporating 7 configurations: Without-TPA, TPA-no-MI, TPA-with-MI1, TPA-with-MI2, TPA-with-MI3, TPA-with-MI4, and TPA-with-MI5. The 3-dimensional displacements of upper teeth and von Mises stress distribution in the periodontal ligament were evaluated.

RESULTS

The use of palatal anchorage devices enhanced the anchorage of anterior teeth and improved molar distalization. The efficacy of anchorage enhancement is related to the relative position of MI and the center of resistance of the maxillary dentition.

CONCLUSIONS

TPA placed on the first premolars effectively reinforces anterior anchorage during molar distalization with clear aligner. The combination of TPA and palatal MI can strengthen anterior tooth anchorage further.