archives@tulane.edu / The goal of this project was to examine patterns of craniofacial ontogeny in three species of baboons, Papio anubis (n = 55), P. cynocephalus (n = 43), and P. ursinus (n = 42), and three species of macaques, Macaca. cyclopis (n = 34), M. fascicularis (n = 55), and M. mulatta (n = 59) to determine the degree to which they exhibited similarities and differences in ontogeny, and then to apply those findings to Neandertals (n = 12) and modern humans (n = 42) to better understand ontogenetic variation within Homo. Macaques and baboons were chosen as model species because, like Neandertals and modern humans, they have relatively large geographic ranges, and this study aimed to investigate whether that had any impact on shifts in ontogeny. First, virtual 3D models of each individual were created in Agisoft Photoscan. Then 3D coordinates from 39 type I and type II landmarks representing the entire cranium from each individual were collected in Stratovan Checkpoint. Missing landmarks were estimated in R and statistical analyses were conducted in Paleontological Statistics (PAST). The results indicate that Neandertals and modern humans share parallel postnatal growth trajectories, which is in agreement with existing literature. However, there was some indication of non-parallel trajectories among baboons and macaques. Specifically, in some, though not all, aspects of shape, P. anubis and P. ursinus have divergent trajectories, as does M. cyclopis compared to both M. fascicularis and M. mulatta. One possible explanation for these differences lies in their geographic ranges. Although there is interspecific overlap in baboon ranges and baboons are known to hybridize, P. anubis and P. ursinus ranges do not touch. Similarly, although there is overlap in the ranges of M. fascicularis and M. mulatta and evidence of interbreeding between the two species, M. cyclopis is isolated on the island of Taiwan. Thus, while additional data, especially in terms of larger juvenile sample sizes are needed to confirm this pattern, the results of this study suggest possible subtle divergences in ontogeny of species whose ranges do not overlap and who therefore do not hybridize in their natural environments. / 1 / Whitney Karriger

Thesis advisor: Sarah McMenamin / Thyroid hormone (TH) facilitates developmental transitions, particularly by modulating cell proliferation and differentiation. Its role in regulating skeletal growth is well documented. Previous work from our lab and others have demonstrated that hypo- and hyperthyroid fish display changes in bone shape, ossification and the timing of ossification5. Zebrafish (Danio rerio) develop bone quickly, grow indefinitely throughout their lives, are highly amenable for imaging, and are a valuable model for skeletal biology research. Using Danio rerio, we sought to study the long-term effects of TH on bone density by rearing and comparing normal euthyroid (Eu) with a transgenically thyroid-ablated hypothyroid (TH-) and mutant hyperthyroid (TH+) fish. We found that TH strongly affects bone density and volume. We further hypothesize that TH is critical for the timing and fidelity of skeletogenesis. In hormone-dysregulated fish, we found that massive bone and cartilage exostoses grow on the dentary. Thyroid hormone’s effects are highly bone-specific: in TH- fish, we see reduced density in many craniofacial bones, but also increased volume and mineralization in other regions of the dentary. These data suggest that TH plays a critical role in coordinating bone mineralization with growth. / Thesis (MS) — Boston College, 2019. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Biology.

No description available.

Thesis advisor: Sarah K. McMenamin / Thesis advisor: Vicki Losick / Proper bone development requires coordination and timing of specific morphogenetic events, and relative shifts in these temporal processes can change morphology. Thyroid hormone (TH) plays an important role in regulating the timing of vertebrate skeletogenesis, and the hormone induces the profound skeletal shape changes that occur during amphibian metamorphosis. Like humans, zebrafish do not undergo an ecological metamorphosis; yet TH is essential in coordinating postembryonic developmental processes. In particular, several elements of the craniofacial skeleton that continue to ossify and remodel during later stages of development are sensitive to TH titer. My aims focus on the role of TH in regulating skeletal growth and shape changes in zebrafish. To examine changes in the entire zebrafish skeleton during normal postembryonic development, I generated a skeletal reference of microCT scans of zebrafish ranging from early juvenile through adult stages (Chapter 2). After defining the normal changes that wild-type zebrafish undergo, I hypothesized that TH coordinates the developmental shape changes and determined the role of TH in stimulating developmental shape change in zebrafish skulls and its effects on skeletogenic cell populations (Chapter 3). Finally, I investigated whether phenotypes induced by altered TH levels mirror some of the evolutionary diversity seen across Danioninae craniofacial skeletons (Chapter 4). My research elucidates the role of TH in the regulation of bone growth and shape change in a vertebrate system and provides new insights into the natural craniofacial diversity of Danioninae. / Thesis (PhD) — Boston College, 2024. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Biology.

Bones of the cranial vault protect the underlying brain but preserve flexibility to allow brain growth. The edges of skull bones are joined by fibrous sutures, which provide structural support and are the sites of bone growth. Craniosynostosis (CS), premature fusion of bones at the sutures, causes skull deformity and secondary problems in brain development. Bone morphogenetic protein (BMP) signaling is critical in regulating osteoblast differentiation and ossification. Several components of the BMP signaling pathway are associated with increased risk of CS, supporting a central role for BMP signaling in suture formation and development of CS. However, the specific factors involved and disease mechanisms remain largely unknown. To address the gaps in our knowledge, we identified regulatory elements active in skeletal tissues associated with the risk of CS. Briefly, we selected conserved noncoding elements within the genomic regions near the CS risk genes, BMP2 and BMPER (BMP Binding Endothelial Regulator), and performed zebrafish transgenesis to screen for enhancer activities in cranial skeletal tissues. We found multiple enhancers that directed transgene expression consistent with the expression of endogenous bmp2 and bmper genes. Using confocal microscopy, we demonstrated activity of the enhancer, -707BMPER, in cartilage closely associated with developing frontal bones, suggesting its involvement in cranial bone growth, suture formation and the risk of CS. We also performed an enhanced yeast one-hybrid (eY1H) assay to determine the transcription factors that interacted with the identified enhancers, implicating the underlying signaling pathways in regulation of their activity. Compelling human genetic evidence has revealed a role for SMAD6 (mothers against decapentaplegic homolog 6), a negative regulator of BMP signaling, in craniosynostosis. SMAD6 mutations are also associated with cardiovascular abnormalities and nonsyndromic radioulnar synostosis. However, there are significant unanswered questions about the mechanisms linking specific SMAD6 mutations to any of these defects. To create a tractable animal model to address these questions, we used CRISPR targeting to mutate the zebrafish ortholog, smad6a and smad6b. In addition, we developed a zebrafish assay to evaluate the functional consequences of SMAD6 sequence variants, based on the ability of Smad6 to disrupt dorsal-ventral patterning of zebrafish embryos in a dose-dependent manner. We anticipate that the zebrafish assay can provide a convenient approach to verify the disease risk of SMAD6 variants, and that zebrafish lacking smad6 function will be a tractable genetic model to study the role of Smad6 in development.

O objetivo deste trabalho foi avaliar diferentes aspectos da displasia fibrosa por meio da tomografia computadorizada (sítio ósseo da lesão, padrões de imagem, expansão e/ou destruição óssea) e correlacioná-los com a classificação da lesão (displasia fibrosa monostótica e craniofacial) e o sexo dos pacientes, além de sugerir uma padronização da classificação destas imagens. Foram avaliados 52 pacientes com displasia fibrosa monostótica e craniofacial por meio de cortes axiais e coronais de tomografia computadorizada. Os padrões de imagem na tomografia computadorizada foram divididos em três aspectos: hiperdenso e homogêneo (“vidro despolido"); pagetóide (hipo e hiperdenso); hiperdenso e esclerótico e hipodenso (Apesar de não ter encontrado na minha tese, este foi um padrão citado). Quando comparados os sexos, observou-se maior proporção de imagens padrão pagetóide e esclerótico no sexo feminino e padrão de imagem “vidro despolido" no sexo masculino. O padrão de imagem “vidro despolido" predominou entre as displasias fibrosas monostóticas; entre as displasias fibrosas craniofaciais, as imagens padrão “vidro despolido" e pagetóide apresentaram igual freqüência. As imagens escleróticas apresentaram proporção semelhante nos dois casos. Nos sítios ósseos com displasia fibrosa monostótica, o padrão “vidro despolido" foi predominante no esfenóide e na maxila. Além disso, foi o único padrão observado nos ossos frontal e temporal. O padrão pagetóide foi predominante na mandíbula e foi o único padrão encontrado no occipital. O padrão esclerótico só foi encontrado no temporal. Nos sítios ósseos com displasia fibrosa craniofacial, foram observados todos os três padrões de imagem no esfenóide, zigomático, maxila, etmóide, frontal e osso temporal. O padrão pagetóide foi encontrado em todos os sítios ósseos com displasia fibrosa craniofacial. O teste de Fisher mostrou não haver nenhuma associação estatística entre padrões de imagem e classificação da lesão para cada sítio ósseo (p > 0,05). Independentemente do padrão de imagem, todas as lesões apresentaram expansão da cortical. No entanto, somente as lesões com padrão pagetóide apresentaram destruição da cortical. A tomografia computadorizada é essencial na avaliação da extensão e do padrão de imagem da lesão. Uma nova padronização da classificação das imagens foi sugerida para um melhor entendimento e tratamento da doença quando correlacionada com o sítio ósseo. / The aim of this study was to determine the different computed tomography aspects (site of involvement of the lesion per bone, pattern of imaging and behavior (expansive and/or destructive) of patients with monostotic fibrous dysplasia and craniofacial fibrous dysplasia considering sex and the bone locations and to suggest a standard imaging classification. 52 patients with monostotic fibrous dysplasia or craniofacial fibrous dysplasia were studied through CT (axial and coronal slices). The images were categorized in four patterns: 1) “ground glass", 2) pagetoid, 3) sclerotic and 4) hypodense. When the two sexes were compared, a greater proportion of pagetoid and esclerotic patterns was observed in the female while “ground-glass" in the male. The “ground-glass" pattern was predominant in the cases of monostotic fibrous dysplasia . In addition, the ground-glass" and pagetoid patterns showed equal frequency. The sclerotic images showed similar proportion in both cases. In the bone locations with monostotic fibrous dysplasia, the “ground-glass" pattern was predominant in the sphenoid and maxilla. In addition, it was the only pattern observed in the frontal and parietal bones. The pagetoid pattern was predominant in the mandible and it was the only pattern observed in the occipital. The sclerotic pattern was only found in the temporal bone. In the bone locations with craniofacial fibrous dysplasia, all patterns of imaging in sphenoid, zygoma, maxilla, ethmoid, frontal and temporal bones were observed. Furthermore, all the bone locations with craniofacial fibrous dysplasia showed the pagetoid pattern. When the Fisher test was used, statistically significant association between imaging pattern and lesion classification considering bone location was not observed (p>0.05). All lesions showed expansion of the cortical and only the lesions with the pagetoid pattern showed destruction of the cortical. Computed tomography determined the extension and imaging patterns of the bone affected with monostotic fibrous dysplasia and craniofacial fibrous dysplasia. A standard imaging classification could be established in order to clarify the diagnosis and treatment of these lesions.

Com cerca de 35,3 milhões de pessoas vivendo com HIV/AIDS no mundo, não foram encontrados estudos cefalométricos realizados em grupos de pacientes com HIV/AIDS e portanto não há como estimar se a doença ou seu tratamento podem influenciar o crescimento craniofacial de crianças e adolescentes soropositivos. Estudos sobre o desenvolvimento deste grupo de pacientes, que utilizam a terapia antirretroviral (TARV-HAART), comprovam que ocorrem alterações que podem afetar o crescimento normal dessa população, seja em peso e/ou altura. Assim foi feita uma pesquisa sobre a morfologia craniofacial, através da avaliação do perfil cefalométrico esquelético, de pacientes HIV positivos infectados por transmissão vertical e submetidos à terapia antirretroviral, através de um estudo com 21 pacientes HIV positivos com idade entre 6 anos a 17 anos, comparados com 21 pacientes normorreativos pareados por sexo e idade. Embora as diferenças não sejam estatisticamente significantes, encontramos na morfologia craniofacial, medidas lineares diminuídas de crianças HIV positivas, particularmente na faixa etária de 13 a 17 anos de idade, quando comparadas às crianças normorreativas. / With around 35.3 million people living with HIV/AIDS in the world, it hasn´t been found cephalometric studies performed in groups of patients with HIV/AIDS, therefore it can´t be estimated if the disease or its treatment can have influence on HIV positive children and adolescents\' craniofacial growth. Studies about the development of this group, which use HAART, have proved that there are alterations that can affect the regular growth of this population, either in terms of weight and/or height. Thus, there has been done a research about craniofacial morphology evaluating the skeletal chephalometric profile of HIV positive patients infected via vertical transmission and submitted to antiretroviral therapy, in a study with 21 HIV positive patients, ages between 6 to 17 years old, compared to 21 normoreactive patients, paired according to sex and age. Although the differences are not statistically significant, we have found in craniofacial morphology, linear measurements diminished in HIV positive children, particularly in the age range between 13 to 17 years old, when compared to normoreactive children.

Estudos investigativos sobre a influência da hereditariedade nas fissuras orofaciais têm sugerido que indivíduos não-afetados com filhos portadores de fissura labiopalatina apresentam morfologia craniofacial distinta da população geral. O objetivo desta pesquisa foi, por meio de antropometria direta da face, estudar as dimensões faciais dos pais de fissurados em relação a indivíduos sem histórico familiar de fissura, com a finalidade de determinar características faciais que possam inferir uma predisposição à fissura. A amostra foi constituída por 244 indivíduos leucodermas, com média de idade de 34,1 anos, sendo 50 pais e 94 mães de crianças com fissura de lábio com ou sem envolvimento do palato, registrados na Faculdade de Odontologia da Universidade de São Paulo, formando o grupo de estudo, que foi subdividido em grupo pais, grupo mães e grupo casal; e 50 homens e 50 mulheres com ausência de história familiar de anomalias craniofaciais, compondo o grupo controle. Após a marcação de pontos antropométricos na face, foram realizadas 38 medidas antropométricas, correspondendo às dimensões faciais de altura, largura e profundidade, com auxílio de paquímetro digital e compasso facial. Para a análise estatística foi utilizado o teste t de Student com correção de Levene para igualdade de variâncias. Os resultados estatisticamente significantes, para o grupo pais, foram: largura da testa; largura da face e distâncias inter-orbital interna e externa menores, enquanto que a largura da base do nariz, a altura do perfil inferior e a profundidade da mandíbula do lado esquerdo foram maiores. No grupo mães, a distância pupila-linha média lado direito, a largura da base do nariz, a largura do nariz, a largura anatômica do nariz, a largura da columela, a altura do terço superior da face e a profundidade da mandíbula do lado esquerdo apresentaram-se maiores. Os resultados do grupo casal foram pouco consistentes porque reproduziram os registrados nos subgrupos individuais. Embora diversas medidas tenham mostrado diferenças entre o grupo de estudo e o controle, apenas a largura da base do nariz e a profundidade da mandíbula do lado esquerdo se apresentam com as dimensões aumentadas nas respectivas subdivisões: pais, mães e casal. Concluiu-se que, pais e mães de crianças portadoras de fissuras labiopalatinas apresentam morfologia craniofacial distinta em relação à população geral; entretanto, não foi possível definir um padrão facial característico. / Recent studies concerning the influence of inheritance in orofacial clefts suggest that non-affected parents of children that present cleft lip and palate show distinctive craniofacial morphology compared to the overall population. The main objective of this research was to analyze and compare the facial dimensions of non-affected parents of affected children and individuals with no history of clefting in the family. The method used was the direct facial anthropometry, since it can determine facial characteristics that may be related to predisposition to cleft. The sample used comprised 244 leukoderms, averaging 34,1 years old, registered at the Dentistry School of the University of São Paulo. The sample was divided in study group and control group. The study group was composed of 50 fathers and 94 mothers of children affected by cleft lip and/or palate and was sub-divided in three sub-groups: fathers, mothers and couples. The control group was composed of 50 man and 50 women with no history of craniofacial anomalies. To evaluate the distinctive facial dimensions, a set of 38 anthropometric measurements were made using a sliding caliper and a spreading caliper to determine the length, width and depth. For statistical analysis the Student t test was used with Levene\'s correction for equal variances. The statistically significant results were: - Fathers group: smaller width of the forehead; smaller width of the face; smaller intercanthal width and biocular width as well as larger width of the nasal root, larger height of the lower profile and larger depth of the left lower jaw. - Mothers group: larger pupil-facial midline right distance, larger width of the nasal root, larger width of the nose, larger width between the facial insertion points of the alar base, larger width of the columella, larger height of the upper profile and larger depth of the left lower jaw. For the parents group, no statistical differences were identified, with results similar to the other two study groups. Although several measurements showed differences from the study group to the control group only width of nasal root and depth of the left lower jaw showed bigger dimensions in the three subgroups, fathers, mothers and couples. In conclusion, this study showed that fathers and mothers of children with cleft lip and palate show different craniofacial morphology compared to the overall population, but it was impossible to delineate a pattern.

Introdução: A DMF tipo Bauru (OMIM 604830 é uma condição genética caracterizada por hipoplasia malar, fissura orofacial, micrognatia, fendas palpebrais inclinadas para baixo e anomalia auricular. Herança autossômica dominante tem sido sugerida. Até o momento, seis casos com DMF tipo Bauru tem sido relatados e, ainda, pouco se conhece sobre os aspectos clínicos e radiológicos dessa condição. Objetivos: refinar o fenótipo da síndrome disostose mandibulofacial tipo Bauru; caracterizar clinicamente uma amostra de indivíduos com DMF tipo Bauru; investigar e caracterizar as alterações de mandíbula, maxila, arco zigomático e côndilo mandibular, presentes na amostra, por meio de avaliação radiológica. Pacientes estudados e métodos: foram incluídos neste estudo 11 indivíduos com diagnóstico clínico de DMF tipo Bauru. Todos os indivíduos foram submetidos à avaliação genético-clínica e, aqueles que ainda não tinham realizado TC foram submetidos à TC cone beam de face ou telerradiografia, dependendo da idade. As imagens de TC cone beam foram reconstruídas em terceira dimensão (3D) e obtidas telerradiografias em norma lateral, de face completa. Resultados: todos os indivíduos foram do gênero feminino. Levantamento da história familial foi observada em duas famílias, uma com padrão sugestivo de herança autossômica dominante e outra, sugestivo de herança autossômica recessiva Os principais achados clínicos incluíram frontal curto (63,6%), estreitamento bitemporal (90,9%), fácies alongado (63,6%), sobrancelhas arqueadas (90,9%), pálpebras superiores inclinadas para baixo (90,9%), ponte nasal alta (90,9%), hipoplasia de face média (100%), lábio inferior grosso e evertido (72,7%), micrognatia (100%), orelhas pequenas (54,5%), implantação baixa de orelhas (72,7%), orelhas posteriormente rodadas (81,8%), tragus hipoplásico (72,7%), lobo hipoplásico (72,7%) e perda auditiva condutiva (100%). A TC cone beam foi realizada em 8 dos 11 indivíduos e os principais achados observados na análise morfológica foram: assimetria facial (87,5%), órbitas assimétricas (100%), arco zigomático inclinado para baixo (100%), hipoplasia de maxila (100%), cavidade glenóide hipoplásica (62,5%), côndilos mandibulares hipoplásicos (75%), processo coronóide anômalo (37%), profundidade da incisura da mandíbula reduzida (62,5%), assimetria mandibular (100%), micrognatia e retrognatia (100%), meato acústico externo atópico (100%). Análise cefalométrica mostrou padrão de crescimento vertical (87,5%), dimensão da maxila reduzida (60%), mandíbula pequena (100%), ramo mandibular curto (100%), altura facial total reduzida (50%), altura facial ântero-inferior aumentada (70%). Conclusões: o padrão facial típico da DMF tipo Bauru incluiu: frontal curto, pálpebras superiores inclinadas para baixo, ponte nasal alta, hipoplasia de face média e de região zigomática, fissura orofacial, lábio inferior grosso e evertido e micrognatia acentuada. Radiograficamente é caracterizada por arco zigomático inclinado para baixo, hipoplasia de maxila, micrognatia e retrognatia, assimetria mandibular, ramo mandibular curto bilateralmente, altura facial reduzida, relação maxilomandibular deficiente, altura facial total reduzida, base anterior do crânio curto, altura facial ântero-inferior aumentada, cavidade glenóide hipoplásica, côndilos mandibulares hipoplásicos e meato acústico externo atópico. Há desvio da razão sexual para gênero feminino e a etiologia é genética com provável heterogeneidade. As alterações radiográficas são compatíveis com o observado em outras DMFs e podem auxiliar no diagnóstico diferencial. Ramo mandibular curto difere a DMF tipo Bauru da Sequência de Robin. / Introduction: The MFD Bauru type (OMIM 604830) is a genetics condition characterized by malar bone hypoplasia, orofacial cleft, micrognathia, downslanting palpebral fissure and auricular anomalies. Dominant autosomal inheritance has been suggested. Up to now, six cases of MFD Bauru type have been reported and yet, it is known very little about the clinical and radiologic aspects of this condition. Purpose: refine the DMF Bauru type syndrome phenotype; clinically characterize the mandible alterations from the MFD type Bauru individuals; investigate and characterize the mandible, maxilla, zigomatic arch and mandibular condyle alterations, presented on the sample, using the radiological evaluation. Studied patients and methods: 11 subjects were included on this study with the clinical diagnosis of MFD type Bauru. All the subjects were submitted to genetics and clinical assessment and, those that have not been submitted to CT Scanning were submitted to face CT cone beam or teleradiography, depending on the age. The CT cone beam images were reconstructed in third dimension (3D) and teleradiography obtained in lateral standard. Results: all the subjects were from the female gender. Recurrence was observed in two families, one with suggestive dominant autosomal inheritance and the other suggestive recessive autosomal inheritance. The main clinical finds included narrow forehead (63.6%), bitemporal narrow (90.0%), long face (63.6%), arched eyebrow (90.9%), upper eyelid inclined down (90.9%), high nasal bridge (90.9%), midface hypoplasia (100%), thick and everted lower lip (72.7%), micrognathia (100%), small ears (54.5%), low set ears (72.7%), posterior rotated ears (81.8%), hypoplastic tragus (72.7%), hypoplastic lobe (72.7%) and conductive hearing loss (100%). The CT cone beam was realized in 8 from the 11 subjects and the main finds observed on the morphological analyses were: facial asymmetry (87.5%), asymmetrical orbits (100%), zygomatic arch inclined down (100%), maxilla hypoplasia (100%), hypoplastic glenoid cavity (62.5%), hypoplastic mandibular condyle (75%), anomalous coronoid process (37%), reduced depth of the mandibular incision (62.5%), mandibular asymmetry (100%), micrognathia and retrognathia (100%), atopic external acoustic meatus (100%). The cefalometric analyses showed vertical growing pattern (87.5%), reduced maxilla dimension (60%), small mandible (100%), short madibular ramus (100%), total facial height reduced (50%), antero-inferior facial height increased (70%). Conclusions: the typical facial of the MFD Bauru type includes: narrow forehead, upper eyelids inclined down, high nasal bridge, midface and zygomatic region hypoplasia, orofacial cleft, lower lip thick and lay down and accentuated micrognathia. Radiographically it is characterized by the zygomatic arch inclined downs, maxilla hypoplasia, micrognathia and retrognathia, mandible asymmetry, bilaterally shorten mandibular ramus, reduced facial height, deficient maxilomadibular relation, total facial height reduced, shorten cranium anterior base, antero-inferior facial height increased, hypoplastic glenoid cavity, hypoplastic mandibular condyle and atopic external acoustic meatus. There is deviation of sexual rate for female gender. The etiology is genetic with probable genetic heterogeneity. The radiographic alterations were similar with those observed in other MFDs and may help on the differential diagnosis. The short mandibular ramus differ the MFD Bauru type from the Robin Sequence.

Esta pesquisa teve dois objetivos: 1) Comparar as características craniofaciais entre crianças portadoras de perfil tegumentar do terço facial inferior equilibrado com tendência reta com crianças portadoras de perfil tegumentar do terço facial inferior equilibrado com tendêcia convexa; 2) Verificar a variabilidade entre as combinações dos componentes morfológicos na conformação craniofacial deste indivíduos. A amostra constou de 48 telerradiografias em norma lateral, de crianças leucodermas brasileiras, 24 do gênero feminino e 24 do masculino, portadoras de oclusão dentária normal, face equilibrada, lábios competentes,sem tratamento ortodôntico prévio, com dentadura mista, abrangendo faixa etária dos 7 aos 10 anos de idade. A amostra foi dividida em 2 grupos de 24 indivíduos, com igual número de componentes entre os gêneros feminino e masculino. O grupo I foi composto por indivíduos que exibiram perfil tegumentar do terço facial inferior equilibrado com tendência reta, enquanto o grupo II foi constituído por indivíduos que apresentaram perfil tegumentar do terço facial inferior equilibrado com tendência convexa. Foram utilizadas grandezas cefalométricas angulares e proporcionais para a descrição das características craniofaciais. Após a análise estatística e a interpretação dos resultados obtidos, concluiu-se que existem semelhanças morfológicas entre os grupos I e II na inclinação da base craniana posterior, ângulo goníaco; altura facial anterior, altura do ramo mandibular, altura alveolar superior e no posicionamento ântero-posterior da região posterior da maxila. Ocorreram diferenças morfológicas estatisticamente significativas nas inclinações do ramo mandibular, corpo mandibular, incisivos superiores, incisivos inferiores e, ainda, na altura facial posterior total, altura craniana posterior, altura total da face média, altura orbitária, altura maxilar basal, altura dentoalveolar inferior, largura do ramo mandibular, comprimento do corpo mandibular, posição ântero-posterior do primeiro molar superior na face média e espessura de tecidos moles na região do mento. A elevada variabilidade nas combinações entre os componentes craniofaciais, evidenciou a inexistência de padrões morfológicos específicos, tanto para o grupo de indivíduos portadores de perfil tegumentar reto como para o grupo de perfil tegumentar convexo. A hipótese de obtenção de grupos homogêneos, utilizando-se como critério de seleção a convexidade do perfil tegumentar, foi rejeitada. / This study had 2 different purposes: 1) Compare the craniofacial characteristics among children with soft tissue profile with a balanced inferior third and a straight tendency with children with a soft tissue profile with a balanced inferior third and a convex tendency; 2) verify the variability among the combinations of the morphologic components in the craniofacial conformation of those individuals. The sample was composed of 48 telerradiographs in lateral position of Caucasian Brazilian children, 24 boys and 24 girls, with normal dental occlusion, balanced face, competent lips, without previous orthodontic treatment, with a mixed dentition and age between 7 to 10 years old. The sample was divided in 2 groups of 24 individuals with equal number of both genders. Group I was composed of individuals that showed a soft tissue profile with a balanced inferior third and a straight tendency, and group II was composed of individuals with a soft tissue profile with balanced inferior third and a convex tendency. For this work, angular and proportional cephalometric variables to describe the craniofacial characteristics were used. After the statistical analysis and interpretation of the results, it was concluded that morphologic similarity was found between the groups I and II in the inclination of the posterior cranial base, gonial angle, anterior facial height, mandibular ramus height, alveolar superior height, and in the anteroposterior placement of the posterior region of the maxilla. Significant morphologic differences were found in the inclination of the mandibular ramus, mandibular body, upper and lower incisors, and in the total posterior facial height, cranial posterior height, total height of the medium face, orbital height, maxilla basal height, inferior dentoalveolar height, mandibular ramus wideness, mandibular ramus length, anteroposterior position of the first upper molar in the medium face and the thickness of the soft tissue in the pogoniun region. The high variability of combinations among the craniofacial components showed the nonexistence of specific morphological patterns for the children with a soft tissue profile with a balanced inferior third and a straight tendency and those with a convex tendency. The hypothesis to obtain homogeneous groups using the convexity of the soft tissue profile as selection criteria was rejected.