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A method based on 3D affine alignment for the quantification of palatal expansion
Andrea Maggiordomo1, Marco Farronato2, Gianluca Tartaglia2,3,4
1Department of Computer Science, Università Degli Studi di Milano, Milano, Italy.
Plos One
|December 30, 2022
Summary
A new affine alignment method improves 3D digital model analysis for quantifying palatal expansion in young patients. This technique offers a more accurate assessment of treatment outcomes compared to traditional rigid superimposition methods.
Area of Science:
- Orthodontics
- Biomedical Engineering
- Craniofacial Research
Background:
- Quantifying palatal expansion typically relies on rigid superimposition of 3D models, which can be imprecise.
- Accurate measurement of 3D structural changes is crucial for evaluating palatal expansion efficacy.
Purpose of the Study:
- To introduce and evaluate a novel affine alignment method for quantifying palatal expansion.
- To compare the accuracy of affine alignment against the gold standard rigid superimposition.
Main Methods:
- Developed an affine alignment technique implemented in MeshLab.
- Applied the method to 40 3D digital models from young patients (mean age 10.7) undergoing palatal expansion (Rapid Maxillary Expander and NiTi self-expander).
- Compared results with traditional rigid alignment.
Main Results:
- The affine alignment method provided a single numeric value for overall expansion (9.3% mean).
- Observed differential expansion: 10.3% for Rapid Maxillary Expander (RME) and 8.4% for NiTi self-expander (NiTiSE).
- Reduced average error from 0.91 mm to 0.58 mm compared to the gold standard.
Conclusions:
- Affine alignment enhances the quantification of 3D structural changes in palatal expansion.
- This method offers clinicians valuable, precise information on morphological changes in growing patients.
- Improved accuracy in digital model alignment leads to better assessment of treatment effectiveness.
