Multi-step finite element simulation for clear aligner space closure: a proof-of-concept compensation protocol

Area of Science:

• Orthodontics
• Biomedical Engineering
• Computational Mechanics

Background:

• Clear aligners are revolutionizing orthodontic treatment but struggle with extraction space closure due to cumulative errors and tipping.
• Existing methods lack precision in simulating sequential aligner movements for complex orthodontic cases.

Purpose of the Study:

• To introduce and evaluate an adaptive iterative finite element method (FEM) for simulating clear aligner treatment in extraction space closure.
• To compare the precision and tipping reduction of a novel compensation protocol against a conventional approach.

Main Methods:

• Development of a multi-step finite element method (FEM) for sequential clear aligner simulation.
• Implementation of an adaptive iterative FEM-based compensation protocol.
• Analysis of movement precision, tipping, and crown-root synchronization.

Main Results:

• The compensation protocol significantly reduced tipping to ≤1°, compared to >6° with the conventional protocol.
• Minimized mismatch between crown and root movements, ensuring more accurate bodily tooth movement.
• Maintained high movement efficiency and controlled vertical displacement, reducing extrusion.

Conclusions:

• The adaptive FEM compensation protocol enhances predictability and accuracy in clear aligner orthodontic treatment for extraction cases.
• This method allows systematic aligner design adjustments based on actual tooth movement, optimizing biomechanics.
• Potential for improved clinical outcomes in orthodontics through more precise clear aligner therapy.