Effect of power arm length and attachment configuration on maxillary molar mesialization with clear aligners: a finite element analysis

Description

Ahmet Cavusoglu and Buket Erdem use computer simulation to study a hard clear-aligner job: sliding an upper first molar forward without tipping it excessively. Power arms, small posts that change where force applies, can help, but their best length and pairing were unclear. The team built six finite element models combining arm lengths of six, eight, and ten millimeters with two attachment layouts, then applied a standard forward force from a temporary anchorage screw.

In every model the molar moved mainly forward and toward the gum, with the crown traveling farther than the root tip, the signature of tipping. Longer arms consistently reduced tipping and lowered stress in the ligament that holds the tooth, yet they produced less crown movement and bent the aligner more. Shorter arms stressed the ligament most. The authors conclude arm length trades control against movement amount, and attachment choice fine-tunes the balance.

Catalog record

Source: https://europepmc.org/article/MED/PMC13617895