Related Experiment Video
Updated: Jul 6, 2026

A Finite Element Approach for Locating the Center of Resistance of Maxillary Teeth
Published on: April 8, 2020
Effects of maxillary incisor intrusion with clear aligners under ideal retention: A finite element study using local
Duy Nguyen1, Thong Tri Dang1, Thuy-Trang Thi Ho1
1Faculty of Dentistry, University of Medicine and Pharmacy at Ho Chi Minh City, Ho Chi Minh City, Viet Nam.
Objective:
This study aimed to evaluate the initial tooth displacement pattern and periodontal ligament (PDL) stress across the maxillary arch, from 0.25-mm intrusion of the maxillary right central incisor (UR1) with clear aligner therapy (CAT) under ideal retention, using finite element method (FEM).
Methods:
A 3D FEM model of the maxillary dentition, PDL, and alveolar bone was reconstructed from CBCT data in Mimics Research 21.0 (Materialise, Leuven, Belgium). A 0.7-mm scalloped aligner was generated in 3-matic Research 13.0. UR1 was extruded 0.25mm, and the aligner was seated onto this geometry to create an interference-fit activation. Materials were defined as linear elastic and isotropic; aligner-tooth contacts were set as bonded to simulate ideal retention. Tooth displacement and von Mises stress were computed in ANSYS Workbench 2025 R1 (ANSYS Inc., Canonsburg, PA, USA) using global and tooth-specific local axes.
Results:
UR1 showed primary intrusion with mild distal-lingual tipping. Adjacent incisors, canines, and premolars exhibited slight extrusion; molars showed minimal intrusion with distal tipping. All teeth displayed a distal displacement trend. Lingual tipping occurred anteriorly and buccal tipping posteriorly. UR1 had the highest PDL stress (441.462kPa), concentrated apically. Anchorage teeth showed cervical stress consistent with tipping. UR1 achieved ∼52% of the programmed intrusion.
Conclusion:
A 0.25-mm intrusion step generated light force (about 0.163N), producing 0.13-mm intrusion (52%) with mild distal-lingual tipping of UR1. The anchorage teeth were slightly extruded and tipped distally. PDL stress was concentrated apically on UR1 and cervically on adjacent teeth. Interpretation based on tooth-specific local axes in FEM studies enhances the identification of subtle, clinically relevant side effects beyond the primary movement pattern.
More Related Videos
Related Concept Videos
Plotting and Calibrating the Root Locus
The maximum gain occurs at the breakaway points between open-loop poles on the real axis, while the minimum gain is observed...
One-Compartment Open Model: Wagner-Nelson and Loo Riegelman Method for ka Estimation
On...
Mechanistic Models: Compartment Models in Algorithms for Numerical Problem Solving
In individual population analyses, different algorithms are employed, such as Cauchy's method, which uses a...
Typical Model Studies
Optimization Problems
Lagrange Multipliers: Two Constraints

