Objective: To quantify the acceptability of facial asymmetry to plastic surgeons, orthodontists and the lay population. Methods: Facial images were animated with one of six asymmetries: jaw and nasal deviation, interocular distance, ocular height, angulation, and shape. Evaluators were asked to judge the faces based on their visual acceptability. Results: There were no differences between the groups except for in the evaluation of ocular shape. Mandibular deviation of 4mm, and nasal deviation of 3mm was judged as unacceptable. 9% rounder and 18% flatter eyes were considered unacceptable. Hypertelorism and inferior ocular dystopia was unacceptable after a change of 2mm. Hypotelorism and superior vertical dystopia was unacceptable after a change of 2.5mm. Ocular angulations of 5.5 degrees superiorly and 3.5 degrees inferiorly were unacceptable. Conclusions: Plastic surgeons, orthodontists, and lay people find specific facial asymmetries to be unacceptable at similar levels of deviation.

Objective: To quantify the acceptability of facial asymmetry to plastic surgeons, orthodontists and the lay population. Methods: Facial images were animated with one of six asymmetries: jaw and nasal deviation, interocular distance, ocular height, angulation, and shape. Evaluators were asked to judge the faces based on their visual acceptability. Results: There were no differences between the groups except for in the evaluation of ocular shape. Mandibular deviation of 4mm, and nasal deviation of 3mm was judged as unacceptable. 9% rounder and 18% flatter eyes were considered unacceptable. Hypertelorism and inferior ocular dystopia was unacceptable after a change of 2mm. Hypotelorism and superior vertical dystopia was unacceptable after a change of 2.5mm. Ocular angulations of 5.5 degrees superiorly and 3.5 degrees inferiorly were unacceptable. Conclusions: Plastic surgeons, orthodontists, and lay people find specific facial asymmetries to be unacceptable at similar levels of deviation.

Thesis (M.S.)--University of Michigan, 1938.

Thesis (MSD) --Boston University, Henry M. Goldman School of Dental Medicine, 2015 (Department of Orthodontics and Dentofacial Orthopedics). / Includes bibliographic references: leaves 43-50. / Background: Mirror imaging in identical twins has long been noted and suggests that left-right asymmetry may become established early in embryogenesis. However, it is not known whether the clinical reports of “mirroring” in twins are annulled by an equal number of cases lacking mirroring. As left-right patterning is a key component of laterality-based birth defects, it is important to determine whether aspects of left-right asymmetry are in fact set prior to the splitting event that produces monozygotic twins. We aimed to determine whether significant mirror imaging occurs in transverse facial asymmetries in monozygotic and dizygotic twins. Material and Methods: The sample included PA cephalograns from 56 pairs of monozygotic twins and 57 pairs of dizygotic twins from the Forysth/Moorrees Twin Study (females age 14-1 5 and males age 15-16). The films were digitized and anatomical landmarks identified. Using Geometric Morphometric analyses including Procrustes superimposition, the landmark configuration of one individual twin was reflected (mirrored) and superimposed using Procrustes superimposition. Principal components analysis (PCA) and MANOVA tests 1V were performed to determine the differences between monozygotic and dizygotic twins. A secondary Procrustes superimposition was then conducted without reflection. If mirroring asymmetry was present, the average Procrustes distance within reflected twin sets (D1) would be smaller than those superimposed without reflection (D2). T tests were performed to determine the differences between reflected and non-reflected regions in monozygotic and dizygotic twins. Results: After reflection, no statistically significant differences were found for any regions (with the exception of Mandible A Right, p=0.0258) between monozygotic and dizygotic twins. When comparing reflected versus non-reflected regions, Midface D Left and Mandible C Right in dizygotic twins yielded negative values for D1-D2; however permutation tests revealed these values are not significant. T tests showed 15 out of 20 regions had significant smaller mean values for D2 versus Dl in monozygotic twins, while only 7 out of 20 in dizygotic. A Z test comparing these two proportions revealed this difference between twin types is significant (p=0.011), With the monozygotic twins having significantly more regions that fit better when non-reflected than the dizygotic twins. Conclusion: No statistically significant differences in mirroring were found between monozygotic and dizygotic twins in any craniofacial regions except for Mandible A Right, in which dizygotic twins showed a better fit when mirrored. Upon examination of the differences between reflected and non-reflected regions, monozygotic twins showed a statistically significantly greater number of regions that fit better when superimposed versus reflected in comparison to dizygotic twins. From this study we conclude that no significant mirroring occurs in craniofacial asymmetries, perhaps due to the biological stability of neural crest cells that derive the cranial cartilage and skeleton.

Thesis (M.S.)--University of Michigan, 1955.

Symmetry is considered an attractive facial characteristic, though it is very rare as most humans have some degree of asymmetry. Though most cases are subtle enough to go undetected, more severe cases of asymmetry can result in marked facial deformity. It has been found that facial asymmetry presents as a comorbid condition with other severe malocclusions. While many causes of facial asymmetry have been thoroughly investigated, such as cleft lip/palate, unilateral craniosynostosis and hemifacial microsomia, the genetic cause of asymmetries associated with dentofacial malocclusions has yet to be investigated. Studies have shown that muscle strength, size, and fiber type can influence bone size and density. The masseter muscle is frequently involved in development of sagittal malocclusion, and left/right fiber-type differences have been previously found in subjects with facial asymmetry. Still, the contribution of muscle function to the development of facial asymmetry is unclear. Symmetry is a genetically controlled human characteristic, as is the careful breaking of symmetry during development to allow for appropriate organ formation necessary for life. Many genes have been identified to play a role in this initial breaking of symmetry, as well as the maintenance of left-right differential expression. Among these genes, the Nodal Pathway plays a particularly important role. Expression of Nodal Signaling Pathway (NSP) genes, which provide positional and patterning information during embryogenesis, vary significantly in facial asymmetry subjects. PITX2, a downstream NSP effector, patterns changes in gene expression on left-right sides through gradient density signaling. PITX2 is reportedly expressed in adult human skeletal muscle satellite cells suggesting NSP gene activity is a key factor in both development and maintenance of facial asymmetry in adulthood. A human transcript microarray was used to evaluate whether these genes involved with normal coding of symmetry during development were differentially expressed in masseter muscle from patients with or without facial asymmetry. This study evaluated orthognathic surgery patients with varying skeletal malocclusions. The patients were categorized based on vertical, transverse, and sagittal discrepancies, as well as the presence or absence of facial asymmetry (n= 93). The subjects were appropriately diagnosed as open or deep bite, class I, II, or III, and treatments planned for the appropriate surgical correction. All of the patients required bimaxillary sagittal split osteotomy, at which point masseter muscle samples were collected. Eleven patients were included in this study. Of the eleven, two of the patients were classified with facial asymmetry. Samples were disrupted in QIAzol Lysis Reagent, RNA was isolated using a Qiagen miRNeasy Mini Kit according to the manufacturer’s instructions, and quality of the total RNA was tested by Agilent Bioanalyzer and Nanodrop spectrophotometry. Samples were used for quantitative Reverse Transcriptase Polymerase Chain Reaction (RT-PCR) and protocols for microarray analysis were conducted as described in the Ambion WT Expression Manual and the Affymetrix GeneChip Expression Analysis Technical Manual. The eleven samples were analyzed by Principal Components Analysis (PCA) to detect fold-changes for each transcript. From this, differences in global gene expression between the two asymmetric and eight remaining subjects were evident, as the two asymmetric patients clustered separately from the malocclusion patients without asymmetry. To find differentially expressed transcripts step-up t-tests were performed to correct for false discovery rate (FDR) comparing the two asymmetric samples to the eight symmetric samples. Differences were considered significant if step-up p-values were ±2 between groups. Differential gene expression was confirmed with ten of the 22 Nodal Pathway genes in asymmetric patients. Extracellular mediators Nodal and Lefty expression was 1.39 and 1.84 fold greater (P< 3.41 x 10-5) whereas integral membrane Nodal-modulators NOMO1,2,3 were -5.63 to -5.81 (P < 3.05 x 10-4) less in asymmetric subjects. Two of the three Nodal Pathway mediators decreased significantly with negative fold differences (-7.02, -2.47; P < 0.003). PPM1a, one of the two negative intracellular mediators, had a significantly decreased fold difference of -3.79 with asymmetry (P , 4.59 x 10-6). PITX2, an asymmetry factor known to influence the size of type II skeletal muscle fibers in adults was also decreased in facial asymmetry (P< 0.05). The down regulation of Nodal Pathway genes suggests its involvement in development of asymmetry. PITX2 expression differences also contribute to skeletal and muscle development in this condition. The overall data trend was for moderate to large decreases in gene expression for approximately 60% of the Nodal pathway genes. Further histological analysis of masticatory muscle fiber types will be necessary to determine how variations in bilateral masticatory muscle phenotype contribute to jaw asymmetry in subjects with posterior facial asymmetry. Finally, the methods used in this study should be conducted with a larger sample population, including a wider variety of different types of asymmetry. / Oral Biology

Yes / Although facial symmetry correlates with facial attractiveness, human faces are often far from symmetrical with one side frequently being larger than the other (Kowner, 1998). Smith (2000) reported that male and female faces were asymmetrical in opposite directions, with males having a larger area on the left side compared to the right side, and females having a larger right side compared to the left side. The present study attempted to replicate and extend this finding. Two databases of facial images from Stirling and St Andrews Universities, consisting of 180 and 122 faces respectively, and a third set of 62 faces collected at Abertay University, were used to examine Smith¿s findings. Smith¿s unique method of calculating the size of each hemiface was applied to each set. For the Stirling and St Andrew¿s sets a computer program did this automatically and for the Abertay set it was done manually. No significant overall effect of gender on facial area asymmetry was found. However, the St. Andrews sample demonstrated a similar effect to Smith, with females having a significantly larger mean area of right hemiface and males having a larger left hemiface. In addition, for the Abertay faces handedness had a significant effect on facial asymmetry with right handers having a larger left side of the face. These findings give limited support for Smith¿s results but do also suggest that finding such an asymmetry may depend upon some as yet unidentified factors inherent in some methods of image collection.

Objective: Genetic loci for ATP2A2 kinase, NUAK1, and phosphatase PPP1CC are associated with skeletal muscle strength phenotypes. ATP2A2 is a calcium ion transport ATPase in sarcoplasmic reticulum that is predominantly expressed in cardiac and slow-twitch fibers. NUAK1, an AMP-activated protein kinase, and PPP1CC, a subunit of protein phosphatase 1, are involved in glycogen metabolism during skeletal muscle contraction. The aim of this study is to investigate whether these genes are associated with masseter muscle composition and function in the development of skeletal malocclusion. Methods: A total of 56 orthognathic surgery patients were classified as having skeletal Class I, Class II, or III sagittal malocclusions with normal, open, or deep bites vertically, with or without facial asymmetry. Masseter muscle samples were collected during the mandibular osteotomies, frozen, and sent to the Kornberg School of Dentistry. Tissue from eleven patients was used for gene expression analysis on Affymetrix HT2.0 microarray chips and a principle components analysis. Then, these plus an additional 45 masseter samples were used for quantitative RT-PCR. Expression data for the three genes of interest were evaluated in the microarray and corroborated and expanded upon with RT-PCR data. ANOVA and unpaired t-tests were performed to determine correlations between ATP2A2, NUAK1, and PPP1CC expression levels and vertical and sagittal malocclusion classifications. Additional ANOVA and unpaired t-tests were performed to determine correlations between ATP2A2 expression level and signs and symptoms of temporomandibular disorder (TMD) with and without pain and facial asymmetry, and relative to the expression levels of a second gene associated with muscle strength phenotypes (ACTN3). Finally, Kendall Tau analyses were performed to compare ATP2A2 expression levels in subjects grouped by malocclusion classification to masseter muscle composition, including mean fiber area (MFA) and mean percent occupancy (MPO) of each fiber type. Results: Principle component analysis revealed two patients with genetic expression levels that deviated from the group. These were the only patients diagnosed with facial asymmetry. Microarray data showed that in these patients ATP2A2 and PPP1CC were significantly decreased. NUAK1 was decreased to a lesser extent. Also, among other genes in the same functional categories, ATP2A1 expression was -30.45 fold (P<6.11X10-6) and PPP3CC expression was -2.96 fold (P<2.03X10-5) in the patients with facial asymmetry. RT-PCR results showed NUAK1 and PPP1CC were differentially expressed at lower, but not statistically significant levels in subjects with craniofacial asymmetry. However, RT-PCR did verify that ATP2A2 expression is down regulated in subjects with mild to severe forms of asymmetry as compared to subjects with facial symmetry (p=0.022). ANOVA and unpaired t-test analyses illustrated that there was no significant differences in ATP2A2 expression in patients with different vertical, saggital, or combined vertical/sagittal malocclusion diagnoses. There was a significant association between the lateral differences in ATP2A2 expression, between right- and left-sided masseter biopsies within the same individual, in subjects with Class III malocclusions with different vertical diagnoses. Here, lateral differences were greatest in open bite, intermediate in deep bite, and lowest in normal Class III subjects. Kendall tau analyses were performed to compare ATP2A2 expression levels and masseter composition (MFA/MPO of type I, hybrid, and type II fibers) in all subjects, subjects with Class II malocclusions, and subjects with Class III malocclusions. Regardless of sagittal malocclusion, all subjects showed a negative correlation with type IIA MPO that was highly significant (r=-0.46; p=0.004). Also, ATP2A2 associations in Class II subjects were positive with type I MFA (r=0.36; p=0.04) and negative with type IIA MPO (r=-0.59; p=0.001). Correlations for Class III subjects were typically negative and not significant. Also, Kendall tau correlations were performed to compare ATP2A2 expression with the composition of each fiber type in patients grouped by both sagittal and vertical malocclusion classification. These found decreased type IIA fiber MPO correlated significantly (p = 0.024) with increased relative ATP2A2 expression in subjects with Class II, normal bite malocclusions (n = 6, R2 = 0.8127). Finally, ATP2A2 expression was not associated with most phenotypic traits exhibited by the surgery subjects such as presence of signs/symptoms of TMD with and without pain and facial asymmetry. However there was an association between decreased lateral differences in ATP2A2 expression in subjects with asymmetry with the TC ACTN3 genotype as compared to subjects with the TC ACTN3 genotype and facial symmetry. Conclusions: ATP2A2 promotes calcium transport in slow twitch and cardiac muscle contraction-relaxation cycling. Decreased expression of this gene in patients with asymmetries suggests that down regulation of the calcium handling capacities of muscle fibers may influence the development of abnormal craniofacial phenotypes. Both NUAK1 and PPP1CC are thought to play metabolic regulatory or responsive roles to muscle contraction. Decreased expression of these genes may accompany alterations of fiber-type form and metabolic properties to adversely affect jaw development. Additionally, ATP2A2 correlations indicate that this calcium channel protein may be important for type I fiber function, but not type IIA in masseter muscle from Class II subjects, suggesting a functional influence on malocclusions. ATP2A2 does not appear to function differentially in fiber types that influence development of Class III malocclusion. Further studies with more subjects are needed to increase experimental power. / Oral Biology

Made available in DSpace on 2014-06-11T19:27:45Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-02-21Bitstream added on 2014-06-13T18:56:27Z : No. of bitstreams: 1 santos_rr_me_araca.pdf: 2959746 bytes, checksum: e5d7502015f079eb913a0892cecdaa2e (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Atualmente a má oclusão se destaca entre os problemas de saúde pública, devido a sua alta prevalência na população, fato evidenciado por meio de estudos epidemiológicos. Estes estudos são importantes ferramentas para auxiliar os gestores na organização dos serviços de saúde, pois avaliam as necessidade da população, identificam os grupos e fatores de risco, fornecem as informações para programas de prevenção, determinam a prioridade nos serviços odontológicos, estimam o número de profissionais necessários, o planejamento de recursos e ações de intervenção. Ressalta-se que dentro da área de atenção dos serviços públicos deveria ocorrer o tratamento das oclusopatias, em decorrência das alterações fisiológicas na cavidade bucal. Dessa forma, realizou-se um trabalho no município de Araçatuba-SP, dividido em três partes. Na primeira, executou-se um estudo epidemiológico para identificar as oclusopatias e hábitos bucais dos escolares deste município, na segunda, analisou-se a relação entre mordida cruzada posterior, desvio de linha média e assimetria facial e na última, um relato de caso clínico, no qual foi realizado o tratamento de mordida cruzada posterior unilateral, utilizando as Pista Diretas Planas, como uma alternativa de tratamento viável no serviço público. No estudo epidemiológico, a população foi constituída por todos os escolares de 5 a 6 anos, matriculados nas 56 escolas da rede pública de ensino do município de Araçatuba, e adotou-se a mesma metodologia de exames utilizada na Pesquisa Nacional de Saúde Bucal (SB 2010). Já a segunda parte do estudo realizou-se no Serviço Extra-Muro Odontológico da Faculdade de Odontologia de Araçatuba, no qual foram examinadas e fotografadas 70 crianças, verificando o trespasse horizontal e vertical, a presença de mordida cruzada posterior, e ainda, o tipo de arco e o... / Actually, the malocclusion received attention among public health problems, due its high prevalence on population, evidenced fact by epidemiological studies. Malocclusions stay among principal oral health problems being behind only of dental caries and periodontal problems. It‘s considered like a public health problem due its high prevalence. It‘s important to point that in attention area of public health services should have the treatment of malocclusions, because of physiological aspects about oral cavity. Epidemiological studies compose na important research area, because it shows diseases incidence and prevalence, evaluate necessities of health, identify groups and risks factors, give information for development of prevention programs, determine priority on dental services, calculate number of professionals that are necessary and planning of recouses and actions of intervention. So, it was realized a work in Araçatuba City, São Paulo State, Brazil, divided in tree parts. On first, it was performed an epidemiological study to identify malocclusions and bad habits. On second, it was analyzed the relation between posterior crossbite and facial assimetry, and on the third part, a clinical case, where it was executed a treatment of unilateral posterior corssbite, using Planas Direct Tracks, like na alternative on possible treatment in public health. On epidemiological study, population was constituted by all scholar children between 5 and 6 years-old, enrolled on 56 schools of educational public system from Araçatuba City. The parents should authorize the participation of their suns in research. It was used the same methods that were used in Oral Health Brazilian Research (SB-Brasil 2010). It was possible to detected a significative prevalence of malocclusions and sucling habits and a positive association among them. On second part, the study was ... (Complete abstract click electronic access below)

Made available in DSpace on 2014-06-11T19:27:53Z (GMT). No. of bitstreams: 0 Previous issue date: 2009-03-19Bitstream added on 2014-06-13T19:36:10Z : No. of bitstreams: 1 meloti_af_me_arafo.pdf: 5104762 bytes, checksum: 0c5cfdb032ffb284707304dc3a9738ba (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / A Classe II subdivisão é composta por um relacionamento oclusal assimétrico de Classe I de um lado da arcada dentária e Classe II do outro lado. Esse relacionamento oclusal assimétrico pode ter origem esquelética, dentoalveolar ou a combinação de ambas. Existem vários métodos para diagnosticar essa assimetria, e este estudo teve por objetivo utilizar telerradiografias laterais e radiografias panorâmicas para esse fim, além de estabelecer comparação com a morfologia existente nas más oclusões de Classe I e II. A amostra foi composta por 90 telerradiografias laterais e 90 radiografias panorâmicas iniciais de indivíduos brasileiros, de ambos os gêneros, com idade cronológica entre 12 e 15 anos, que foram selecionados de forma a contemplar três grupos de indivíduos com más oclusões específicas, sendo 30 indivíduos Classe I, 30 indivíduos Classe II simétrica e 30 indivíduos Classe II subdivisão. Foram realizadas mensurações lineares horizontais em telerradiografias laterais e mensurações lineares verticais e angulares em radiografias panorâmicas. Também foi estipulado um índice de assimetria para as telerradiografias laterais e utilizado, nas radiografias panorâmicas, um índice proposto por Habets em 1988. Os resultados mostraram que a Classe II subdivisão é caracterizada por uma assimetria dentária inferior. Paralelamente foi verificado que, na Classe I, há uma assimetria esquelética na altura do ramo mandibular e que a Classe II, assim como a Classe I e Classe II subdivisão, apresenta uma assimetria na altura condilar. Os achados encontrados nessas radiografias coincidem com os observados por outros autores que utilizaram diferentes métodos de diagnóstico e, portanto, sugerem que telerradiografias laterais e radiografias panorâmicas podem ser utilizadas para diagnosticar as assimetrias nas más oclusões. / The Class II Subdivision is characterized by an asymmetrical occlusal relationship of Class I on one side of the dental arch and another of Class II on its other side. This asymmetrical occlusal relationship can be of skeletal origin, dentoalveolar origin, or a combination of both. While there are several methods of diagnosis for such asymmetry, the objective of this study was to utilize lateral cephalometric radiographs and panoramic radiographs for this purpose, as well as for comparison of its morphology with the existing morphology on Class I and II malocclusions. The sample was formed by 90 initial lateral cephalometric radiographs and 90 panoramic radiographs of Brazilian individuals, from both genders, with chronological age between 12 and 15 years old, who were selected by contemplation of three groups of individuals with specific malocclusions, 30 individuals Class I, 30 individuals Class II symmetry, and 30 individuals Class II subdivisions. Linear horizontal measurements were performed on each lateral cephalometric radiographs, along with linear vertical and angular measurements on the panoramic radiographs. An asymmetry index was stipulated for the lateral cephalometric radiographs and an index proposed by Habets in 1988, was utilized for the panoramic radiographs. The results showed that a Class II Subdivision is characterized by a lower dental asymmetry. Parallel to that, it was observed a skeletal asymmetry on the Class I at mandibular ramus height, as well as the presence of an asymmetry at condylar height on the Class II, the Class I and the Class II subdivision. The findings on these radiographs coincide with those of other authors who utilized different methods of diagnosis, thus suggesting that lateral cephalometric radiographs and panoramic radiographs can be utilized for diagnosis of the asymmetries on malocclusions.