Kesterke, Matthew J.
(2016)
The Effects of In-utero Thyroxine Exposure On Mandibular Shape in Mice.
Doctoral Dissertation, University of Pittsburgh.
(Unpublished)
This is the latest version of this item.
Abstract
An estimated 3% of U.S. pregnancies are affected by maternal thyroid dysfunction, with between one and three of every 1,000 pregnancies being complicated by overactive maternal thyroid levels. Overactive maternal thyroid hormones have been linked to neurological impairment and craniofacial development dysmorphogenesis, affecting both endochondral and intramembranous bone. Using both Euclidean Distance Matrix Analysis (EDMA) and geometric morphometric approach, this study evaluates the role of in utero thyroxine overexposure on the growth of offspring mandibles in a sample of 241 mice. Principle component analysis (PCA) and canonical variate analysis (CVA) utilized 16 unilateral mandibular landmarks obtained from 3D microCT to assess shape changes between unexposed controls (n=63) and exposed mice (n=178). By evaluating shape changes in the mandible between different age groups (15, 20, and 25 days postnatal) and different dosage levels (low, medium, and high), this study found that maternal thyroxine alters offspring mandibular shape in both age- and dosage-dependent manners, particularly within the high dosage individuals in the oldest age group. The EDMA results demonstrate marked shape changes throughout the mandible, with the gonial angle and alveolus undergoing significant (p <0.10) changes. Geometric morphometric analysis revealed that group differences in overall shape were significant (p <0.001 for both PCA and CVA) and showed major changes in regions of the mandible associated with muscle attachment (coronoid process, gonial angle) and regions of growth largely governed by articulation with the cranial base (condyle) and occlusion (alveolus). These results compliment recent studies demonstrating that maternal thyroxine levels can alter the cranial base and cranial vault of offspring, contributing to a better understanding of both normal and abnormal mandibular development and facilitating a fuller understanding of evolutionary and medical implications of craniofacial growth and development.
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Details
| Item Type: |
University of Pittsburgh ETD
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| Status: |
Unpublished |
| Creators/Authors: |
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| ETD Committee: |
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| Date: |
22 November 2016 |
| Date Type: |
Publication |
| Defense Date: |
21 October 2016 |
| Approval Date: |
22 November 2016 |
| Submission Date: |
27 October 2016 |
| Access Restriction: |
No restriction; Release the ETD for access worldwide immediately. |
| Number of Pages: |
196 |
| Institution: |
University of Pittsburgh |
| Schools and Programs: |
Dietrich School of Arts and Sciences > Anthropology |
| Degree: |
PhD - Doctor of Philosophy |
| Thesis Type: |
Doctoral Dissertation |
| Refereed: |
Yes |
| Uncontrolled Keywords: |
Craniofacial Growth and Development, Maternal Environment, Mandible, Thyroxine, Bone Growth |
| Date Deposited: |
24 Jan 2017 15:41 |
| Last Modified: |
25 Jan 2017 06:15 |
| URI: |
http://d-scholarship.pitt.edu/id/eprint/30345 |
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The Effects of In-utero Thyroxine Exposure On Mandibular Shape in Mice. (deposited 24 Jan 2017 15:41)
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