Document Type

Thesis

Date of Degree

Spring 2016

Degree Name

MS (Master of Science)

Degree In

Orthodontics

First Advisor

Lina M. Moreno-Uribe

Abstract

Introduction: The purpose of this study was to examine phenotypic expression of craniofacial form, shape, and size as it relates to the genotype of an individual. Shape analyses were completed on 3-D images of each subject's craniofacial structure by landmarking 45 points of interest on the cranial base, facial bones, and upper and lower jaws. A candidate gene analysis was undertaken focusing on specific genes in the Hippo Signaling Pathway to examine genotype-phenotype correlations that play a role in craniofacial development. This study is a continuation of a larger project aimed at the identification of candidate genes associated with human dento-skeletal bite problems led by Dr. Lina Moreno-Uribe.

Methods: The sample size for our study included 166 individuals who had never been treated orthodontically at the time of records. Each individual was genotyped and a CBCT of the craniofacial complex was captured. Each CBCT image was landmarked by a single observer using 45 points to mark points on the cranial base and facial bones including the maxilla and mandible. General Procrustes superimposition was used to find correlations with phenotype and genotype. Size analysis was completed with average Euclidean Distances and ANOVA analysis.

Results: 2 SNP's from the FOX03 gene had significant associations with size. The AA genotyped individuals appeared larger in overall size than AB genotyped individuals. 3 SNP's had statistically significant associations with facial form. The FOX06 SNPs had significant associations with increased anterior-posterior growth of the maxilla. The AJUBA SNP had significant associations with increased overall craniofacial breadth.

Conclusion: Genes in the Hippo signaling pathway have specific roles in the development of facial form and size.

Public Abstract

The purpose of this study is to examine a select number of genes and determine whether or not these genes correlate with facial form, shape, and size. The genes that will be examined belong to a specific genetic pathway that help control organ size, i.e. the size of an individual’s skull. 3D radiographs were made of 166 individuals whom had never received any orthodontic treatment at the time and were analyzed with their genetic information to determine whether any relationships exist between specific facial characteristics and the genes that were examined. Two genes were found to have a significant relationship with size. Three more genes had a significant association with facial shape. Further research is needed to understand the mechanism of its exact involvement in craniofacial growth.

Keywords

publicabstract, Candidate Gene Analysis, Craniofacial, Genotype, Phenotype

Pages

vii, 45 pages

Bibliography

Includes bibliographical references (pages 42-45).

Copyright

Copyright 2016 Jed Arbon

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