Comparison of 3 different mandibular dental midline correction mechanics: A finite element analysis study

Introduction

This study aimed to compare the effects of three different mandibular dental midline correction mechanics on the dental arch using the finite element analysis method.

Methods

In the first scenario, two forces parallel to the occlusal plane (without a vertical component) were applied, anchored by two miniscrews in the mandibular arch. In the second scenario, a Class II elastic was applied in the right quadrant, a Class III elastic in the left quadrant, and diagonal intermaxillary elastics were applied from the maxillary left lateral to the mandibular right lateral in the anterior region. In the third scenario, bilateral Class II intermaxillary elastics were used, along with a z-shaped diagonal intermaxillary elastic extending from the maxillary anterior to the mandibular posterior. The amount of tooth movement and the highest and lowest von Mises stress values were compared across all three scenarios.

Results

The mandibular incisors exhibited consistent movement in the same direction along the transverse axis across all three scenarios; however, the first scenario demonstrated the greatest degree of movement. Because of the elastics, the maxillary incisors in the second and third scenarios shifted in the opposite direction compared with the mandibular incisors. Movement of the maxillary incisors was more pronounced in the third scenario compared with the second. A significant development of occlusal cant was observed in the second scenario.

Conclusions

Miniscrew-assisted midline correction has proven to be effective for preventing occlusal cant. Modifying the traditional elastic configuration can reduce or eliminate the risk of developing occlusal cant.