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Morphological changes of human mandibular bone during fetal periods
1Department of Anatomy, Saga Medical School.
Okajimas Folia Anatomica Japonica
|October 1, 1994
Summary
Fetal mandibular shape changes significantly with growth, particularly in the gonial angle and coronoid process, as analyzed by Fourier descriptors. These prenatal changes anticipate postnatal mandibular development.
Area of Science:
- Biomedical Engineering
- Anthropology
- Developmental Biology
Background:
- Fetal mandibular development is crucial for craniofacial structure.
- Understanding prenatal shape changes aids in predicting postnatal morphology.
Purpose of the Study:
- To analyze fetal mandibular shape changes during prenatal growth.
- To identify specific morphological alterations using Fourier analysis.
Main Methods:
- Standardized photographs of 80 fetal mandibles were analyzed.
- Fourier series analysis was applied to outline segments (gnathion-condylion, coronoid process, infradentale-gnathion, inferior margin).
- Statistical analysis (t-test, canonical discriminant analysis) was performed on groups stratified by body length (BL).
Main Results:
- The gnathion-condylion outline showed greater constant and first term phase values in the largest fetuses (BL4), indicating an anteroinferior shift and acute gonial angle.
- The coronoid process outline's first term phase decreased with increasing stature.
- The infradentale-gnathion outline's shape contribution shifted from the first to the second term with growth.
- The inferior margin's constant increased significantly with fetal growth.
Conclusions:
- Prenatal mandibular development involves an anteroinferior shift at the gonial angle, preceding postnatal changes.
- The coronoid process tip shifts forward as fetal body length increases.
- Fourier analysis effectively quantifies fetal mandibular shape transformations.