Displacement patterns of the maxillary anterior teeth during total distalization and en masse anterior retraction using interradicular and infrazygomatic crest mini-implants with varying power arm heights: A finite element analysis

Abstract

Aim: To evaluate the initial displacement of the maxillary anterior teeth during distalization of the whole maxillary dentition and en masse retraction of the maxillary anterior teeth using interradicular MIs (IRMIs) and infrazygomatic crest mini-implants (IZCMI) with varying power arm heights. Materials and Methods: The study is a finite element (FE) study. Two FE models were created for total distalization of the maxillary dentition and en masse retraction of the maxillary six anterior teeth. Mini-implants (MIs) were placed in the IZC and IR areas. The power arms were placed on the arch wire between the lateral incisors and canines at heights of 5, 8, and 12 mm. Total distalization (3N) and en masse anterior retraction (2N) forces were applied to the power arm. Results: The von Mises stress increased as power arm height increased with no significance, but the values were significantly greater in the IRMI than IZCMI in both models. Initial backward displacement of the maxillary anterior teeth increased as power arm height increased with no significance, but the values were significantly greater in IZCMI than IRMI in both models. Initial upward displacement of the maxillary anterior teeth decreased as power arm height increased with no significance, but the values were significantly greater in IRMI than IZCMI in both models. Conclusions: A careful consideration of the MI location and the power arm height should be preceded to obtain a desired tooth movement when planning to retract or distalize the maxillary dentition.