Papers by Sylvia Frazier-Bowers
Impacts of Skeletal Anterior Open Bite Malocclusion on Speech
FACE, 2022
Introduction: Articulation problems are seen in 80% to 90% of dentofacial deformity (DFD) subject... more Introduction: Articulation problems are seen in 80% to 90% of dentofacial deformity (DFD) subjects compared with 5% of the general population, impacting communication and quality of life, but the causal link is unclear. We hypothesize there are both qualitative (perceptual) and quantitative (spectral) differences in properties of stop (/t/ or /k/), fricative (/s/ or /ʃ/), and affricate (/tʃ/) consonant sounds and that severity of anterior open bite (AOB) jaw disharmonies correlates with degree of speech abnormality. Methods: To test our hypotheses, surgical orthodontic records and audio recordings were collected from DFD patients (n = 39 AOB, 62 controls). A speech pathologist evaluated subjects, and recordings were analyzed using spectral moment analysis (SMA) to measure sound frequency distortions. Results: Perceptually, there is a higher prevalence of auditory and visual speech distortions in AOB DFD patients when compared to controls. Quantitatively, a significant ( P
The Angle orthodontist, 2021
Orthodontics & Craniofacial Research, 2019
Marfan Syndrome (MFS) is a life-threatening connective tissue disorder characterized by multi-sys... more Marfan Syndrome (MFS) is a life-threatening connective tissue disorder characterized by multi-system organ involvement with cardinal features occurring in the cardiovascular, ocular and skeletal systems. 1 It is caused by a mutation in the gene coding for the protein fibrillin-1 (FBN1). 2 The morbidity and mortality associated with the clinical presentation of MFS highlight the importance of early diagnosis and management. The characteristics found within the cardiovascular system (aortic dilatation and/or aortic dissection) are the primary source of morbidity and early mortality, 1 (ie undiagnosed adult patients have well-established cardiovascular pathology and suboptimal clinical outcomes). 3 Within the ocular system, the hallmark feature is ectopia lentis (dislocation of the lens of the eye), and observed in approximately 60% of patients. 1 While the features in the skeletal system are not a major source of morbidity/mortality and do not account for sudden or premature death, they are essential for diagnosis. 4 Skeletal features are the most striking physical features of MFS and may lead to a suspicion for this syndrome in undiagnosed patients. These features include excessive linear growth
European Journal of Orthodontics, 2021
Summary Introduction Patients with dentofacial disharmonies (DFDs) seek orthodontic care and orth... more Summary Introduction Patients with dentofacial disharmonies (DFDs) seek orthodontic care and orthognathic surgery to address issues with mastication, esthetics, and speech. Speech distortions are seen 18 times more frequently in Class III DFD patients than the general population, with unclear causality. We hypothesize there are significant differences in spectral properties of stop (/t/ or /k/), fricative (/s/ or /ʃ/), and affricate (/tʃ/) consonants and that severity of Class III disharmony correlates with the degree of speech abnormality. Methods To understand how jaw disharmonies influence speech, orthodontic records and audio recordings were collected from Class III surgical candidates and reference subjects (n = 102 Class III, 62 controls). A speech pathologist evaluated subjects and recordings were quantitatively analysed by Spectral Moment Analysis for frequency distortions. Results A majority of Class III subjects exhibit speech distortions. A significant increase in the cen...
Journal of Dental Research
Tooth agenesis is one of the most common developmental anomalies affecting function and esthetics... more Tooth agenesis is one of the most common developmental anomalies affecting function and esthetics. The paired-domain transcription factor, Pax9, is critical for patterning and morphogenesis of tooth and taste buds. Mutations of PAX9 have been identified in patients with tooth agenesis. Despite significant progress in the genetics of tooth agenesis, many gaps in knowledge exist in refining the genotype-phenotype correlation between PAX9 and tooth agenesis. In the present study, we complete genetic and phenotypic characterization of multiplex Chinese families with nonsyndromic (NS) tooth agenesis. Direct sequencing of polymerase chain reaction products revealed 9 novel (c.140G>C, c.167T>A, c.332G>C, c.194C>A, c.271A>T, c.146delC, c.185_189dup, c.256_262dup, and c.592delG) and 2 known heterozygous mutations in the PAX9 gene among 120 probands. Subsequently, pedigrees were extended, and we confirmed that the mutations co-segregated with the tooth agenesis phenotype (with ...
A machine learning approach to determine the prognosis of patients with Class III malocclusion
American Journal of Orthodontics and Dentofacial Orthopedics
Educational debt and the gender gap: Understanding factors influencing orthodontists’ career decisions
American Journal of Orthodontics and Dentofacial Orthopedics
Seminars in Orthodontics, 2015
Primary tooth resorption and its role in the normal tooth eruption process
Endodontic Topics, 2010
Sylvia A. Frazier-Bowers, DDS, PHD, Associate Professor, Department of Orthodontics, School of Dentistry, University of North Carolina, Chapel Hill, NC, USA
Endodontic Topics, 2010
Mentoring and Career Development in Dental Research
Orthodontics & Craniofacial Research, 2009
Objectives-While some eruption disorders occur as part of a medical syndrome, primary failure of ... more Objectives-While some eruption disorders occur as part of a medical syndrome, primary failure of eruption (PFE) -defined as a localized failure of secondary tooth eruption -exists without systemic involvement. Recent studies support that heredity may play an important role in the pathogenesis of PFE. The objective of our human genetic study is to investigate the genetic contribution to PFE. Materials and Methods-Four candidate genes POSTN, RUNX2, AMELX, and AMBN) were investigated due to their relationship to tooth eruption or putative relationship to each other. Families and individuals were ascertained based on the clinical diagnosis of PFE. Pedigrees were constructed and analyzed by inspection to determine the mode of inheritance in 4 families. The candidate genes were directly sequenced for both unrelated affected individuals and unaffected individuals. A genome wide scan using 500 microsatellite markers followed by linkage analysis was carried out for one family.
An interview with Sylvia Frazier-Bowers
Dental press journal of orthodontics
Dr. Frazier-Bowers is an associate professor at the University of North Carolina, Chapel Hill (UN... more Dr. Frazier-Bowers is an associate professor at the University of North Carolina, Chapel Hill (UNC-CH), in the Department of Orthodontics. She received a BA from the University of Illinois, Urbana-Champaign, and a DDS from the University of Illinois, Chicago. After completing the NIH Dentist-Scientist Program at UNC-CH in Orthodontics (Certificate, 97’) and Genetics and Molecular Biology (PhD, 99’), she completed a post-doctoral fellowship at the University of Texas Health Science Center, Houston (UTHSC), in the Department of Orthodontics. Leadership positions include president of local NC-AADR (North Carolina (2005-2006); director of the AADR Craniofacial Biology group (CBG) 2004-2007; IADR/AADR councilor for NC-AADR (2007, 2008, 2012) and for the CBG (2012-2015); member of Southern Association of Orthodontists Scientific Affairs Committee (2005-2013) and the American Association of Orthodontists Council on Scientific Affairs (2014 – Present). Dr. Frazier-Bowers also serves various...
Mutational Analysis of MSX1 and PAX9 in Human Tooth Agenesis
Tooth agenesis (hypodontia or oligodontia) in its most severe form adversely impacts the quality ... more Tooth agenesis (hypodontia or oligodontia) in its most severe form adversely impacts the quality of life for affected individuals and their families. Characterized by the congenital absence of primary teeth, it is a hereditary disorder affecting up to 10% of the population. Mutations in two genes, MSX1 and PAX9, have been frequently reported as causative for hypodontia/oligodontia. Previous studies have shown the presence of genetic mutations within exons 1 and 2 of MSX1 and 1, 2 and 4 of PAX9. There have been multiple studies documenting sequence variations in the coding region of PAX9 exon 3; however, none are proven to be functional and/or causative mutations that results in tooth agenesis. Objective: The objective of this study is to determine a genotype/phenotype correlation with PAX9 exon 3 single nucleotide polymorphisms (SNPs) and the tooth agenesis phenotype. Methods: From a database of 41 individuals affected with tooth agenesis, we sequenced the entire coding regions of M...
Changes in Chronological Age of Third Molar Development Over Time
Tooth development represents a chronologically specific process but third molar development has s... more Tooth development represents a chronologically specific process but third molar development has shown great variability across gender and ethnicity with increasing evidence of more precocious development in recent years. Data is lacking on the current trends in third molar development in a US population. Objective: The objective of our study is to test the hypothesis that third molars are present in an earlier developmental stage than in the past. Method: We utilized panoramic radiographs and the Demirjian staging criteria to evaluate the presence and developmental stage of third molars in children ranging from 7 to 13 years of age. Result: In comparison to a previous study (average age of occurrence of stage D about 16 years), our analysis of 62 panoramic radiographs showed that 100% of developing maxillary third molars in males had reached or surpassed stage D by 12 years of age and 43.75% had reached stage D at age 11. In females, 100% of developing maxillary third molars had rea...
Exploratory Analysis of Idiopathic Short Root Malformation
Objectives: Idiopathic short root malformation (IRM) is not well documented likely because it is ... more Objectives: Idiopathic short root malformation (IRM) is not well documented likely because it is poorly understood and the etiology remains unknown. The anomaly may be misdiagnosed as resorption. This hypothesis-generating study aimed to systematically characterize individuals with idiopathic short root malformation and no history of orthodontic treatment in order to better define the condition and improve diagnosis. Methods: Sixteen individuals (ranging from 9-48 years of age) were included in this study based on the identification of shortened permanent tooth roots. Digital panorex and periapical films were analyzed to characterize the pathology (ie pattern and frequency of affected teeth). Crown-to- root ratios of the affected teeth were used to characterize the extent of malformation. When available a comparison of crown-to-root ratios at 2 ages was completed. Results: Fifteen of 16 individuals were of Latino descent and 1 individual was of Filipino descent. In all individuals e...
Evaluation of a Statistical Model for Predicting Class III Subtypes
Introduction: Class III malocclusion is often described as a challenging clinical problem to mana... more Introduction: Class III malocclusion is often described as a challenging clinical problem to manage due to difficulty in predicting timing and extent of disproportionate growth. Further, the clinical variation of the Class III dentofacial phenotype has been shown to include distinct sub phenotypes that carry treatment recommendations ranging from orthodontic camouflage to orthognathic surgery. A more systematic approach to diagnosis of Class III malocclusion will facilitate a more accurate treatment choice. Objective : We developed the Statistical Model for Prediction of Class III (SMP3) formula SMP3 based on a previously described five -cluster classification of Class III phenotypes using 60 cephalometric variables. In this study we aimed to test the hypothesis that the SMP3 is an accurate method to diagnose Class III patients. Methods: Sixty cephalometric measurements for a cohort (N=84) of previously clinically diagnosed Class III patients were applied to the SMP3 formula to dete...
Simultaneous sequencing of oxidized methylcytosines produced by TET/JBP dioxygenases in Coprinopsis cinerea
Proceedings of the National Academy of Sciences, 2014
TET/JBP enzymes oxidize 5-methylpyrimidines in DNA. In mammals, the oxidized methylcytosines (oxi... more TET/JBP enzymes oxidize 5-methylpyrimidines in DNA. In mammals, the oxidized methylcytosines (oxi-mCs) function as epigenetic marks and likely intermediates in DNA demethylation. Here we present a method based on diglucosylation of 5-hydroxymethylcytosine (5hmC) to simultaneously map 5hmC, 5-formylcytosine, and 5-carboxylcytosine at near-base-pair resolution. We have used the method to map the distribution of oxi-mC across the genome of Coprinopsis cinerea, a basidiomycete that encodes 47 TET/JBP paralogs in a previously unidentified class of DNA transposons. Like 5-methylcytosine residues from which they are derived, oxi-mC modifications are enriched at centromeres, TET/JBP transposons, and multicopy paralogous genes that are not expressed, but rarely mark genes whose expression changes between two developmental stages. Our study provides evidence for the emergence of an epigenetic regulatory system through recruitment of selfish elements in a eukaryotic lineage, and describes a method to map all three different species of oxi-mCs simultaneously.
Failure of Tooth Eruption: Diagnosis and Management
Craniofacial and Dental Developmental Defects, 2015
Refining the Tooth Agenesis Phenotype: Comparison of syndromic versus non-syndromic
Tooth agenesis is a common heterogeneous craniofacial anomaly that has highly variable clinical e... more Tooth agenesis is a common heterogeneous craniofacial anomaly that has highly variable clinical expressivity. Tooth agenesis may be mild or severe, with severe forms usually associated with syndromes such as Ectodermal dysplasia (ED). Objective: The objective of our study is to complete phenotypic comparisons between individuals with syndromic (ED) versus non-syndromic tooth agenesis (NSTA) to serve as a prelude to molecular comparisons. Methods: Individuals and families with tooth agenesis (ED and NSTA) were recruited to compare the patterns of missing teeth unique to ED versus NSTA. Interviews were conducted and radiographs were evaluated to determine patterns of tooth development with respect to shape, size, and number. Results: Our phenotypic analysis of 28 and 35 individuals with NSTA and ED respectively revealed that missing teeth patterns in NSTA, were restricted to posterior or anterior regions, but rarely a combination of both, whereas missing teeth patterns in ED was gener...
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Papers by Sylvia Frazier-Bowers