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Updated: Jun 17, 2026
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Finite Element Analysis Model for Assessing Expansion Patterns from Surgically Assisted Rapid Palatal Expansion
Published on: October 20, 2023
Occlusal plane rotation and vertical control using high-pull palatal gear: A finite element study.
Sheng-Chin Lin1, Rungsi Thavarungkul2, Leslie Yen-Peng Chen3
1Private practice, Chinmei Dental Clinic, Chupei, Taiwan.
Summary
The position of miniscrews in high-pull palatal gear (HPPG) mechanics significantly impacts orthodontic outcomes. Posterior placement offers better control over whole-arch intrusion and distalization with minimal occlusal plane changes compared to anterior placement.
Area of Science:
- Orthodontics
- Biomechanics
- Finite Element Analysis
Background:
- High-pull palatal gear (HPPG) mechanics are utilized in orthodontics.
- Miniscrew placement is a critical factor in HPPG efficacy.
- Understanding the biomechanical effects of different miniscrew positions is essential for optimizing treatment outcomes.
Purpose of the Study:
- To evaluate the biomechanical effects of anterior versus posterior miniscrew placement in HPPG mechanics.
- To analyze 3-dimensional tooth displacement and occlusal plane rotation.
- To assess the clinical applicability of each miniscrew configuration.
Main Methods:
- Finite element analysis was employed to simulate HPPG mechanics.
- A midpalatal miniscrew was placed at either the first premolar (anterior HPPG) or first molar level (posterior HPPG).
- A force of approximately 200g was applied for incisor retraction, and tooth displacement/occlusal plane rotation were compared.
Main Results:
- Both anterior and posterior HPPG configurations resulted in significant incisor intrusion.
- Anterior HPPG produced greater incisor intrusion, pronounced counterclockwise occlusal plane rotation, and lingual root displacement.
- Posterior HPPG led to similar intrusion of anterior and posterior teeth, whole-arch intrusion/distalization, and minimal occlusal plane alteration.
Conclusions:
- HPPG is effective for vertical control of maxillary dentition.
- Miniscrew position critically influences the line of force, affecting occlusal plane rotation.
- Anterior HPPG causes greater incisor intrusion and counterclockwise rotation; posterior HPPG offers more controlled intrusion with minimal occlusal changes, guiding clinical miniscrew selection.
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