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Orthognathic surgery outcome analysis: 3-dimensional landmark geometric morphometrics
Banu Cakirer1, David Dean, Juan Martin Palomo
1Hacettepe University, School of Dentistry, Department of Orthodontics, Ankara, Turkey. bcakirer@hacettepe.edu.tr
The International Journal of Adult Orthodontics and Orthognathic Surgery
|July 9, 2002
Summary
Geometric morphometrics using Procrustes superimposition offers a superior method for analyzing craniofacial shape changes. This technique provides a single, reliable measure for surgical outcomes and normative comparisons, overcoming limitations of traditional cephalometric analysis.
Area of Science:
- Orthodontics and Dentofacial Orthopedics
- Biomedical Engineering
- Anthropology
Background:
- Traditional 2D cephalometric analysis relies on distances, indices, and angles, which are baseline-dependent.
- Existing geometric morphometric methods often assume equal information content across all landmarks.
- 3D landmark coordinate data allows for comprehensive shape comparison and outcome assessment.
Purpose of the Study:
- To evaluate the utility of Procrustes superimposition for analyzing 3D craniodental and soft tissue landmark data.
- To compare the effectiveness of Procrustes shape analysis against traditional cephalometric methods.
- To assess pre- and postoperative surgical changes and compare patient data to normative standards.
Main Methods:
- Collected 3D hard and soft tissue landmark coordinates from pre- and postoperative cephalograms and stereophotograms.
- Performed Procrustes superimpositions on patient data and normative Bolton standards (18-year-old male and female).
- Utilized scatter plots to visualize surgical shape changes for individual patients.
Main Results:
- Procrustes shape analysis yielded a single, useful measure of surgical shape change.
- This method facilitated both qualitative and quantitative evaluations of patient craniodental data.
- The analysis allowed for a more precise determination of necessary orthodontic treatment.
Conclusions:
- Procrustes shape analysis provides a baseline-independent and comprehensive approach to evaluating craniofacial morphology.
- It offers a significant advantage over traditional cephalometric methods for assessing surgical outcomes and treatment planning.
- This technique enhances the ability to compare individual patient shapes to normative data effectively.