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1.
Int J Nanomedicine ; 15: 10059-10073, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33335394

RESUMO

Introduction: Vertical bone augmentation without osseous walls to support the stability of clots and bone grafts remains a challenge in dental implantology. The objectives of this study were to confirm that cortical perforation of the recipient bed is necessary and to evaluate whether nanohydroxyapatite (nHA) block grafts coated with recombinant human vascular endothelial growth factor165 (rhVEGF165) and cortical perforation can improve vertical bone regeneration. Materials and Methods: We prepared nHA blocks coated with or without rhVEGF165 on the rabbit calvarium through cortical perforation, and designated the animals as the nonperforated group (N-nHA), rhVEGF165 group (NV-nHA), perforated group (P-nHA) and rhVEGF165 on perforated group (PV-nHA). Micro-computed tomography (micro-CT) and fluorescence microscopy were selected to evaluate parameters of vertical bone regeneration at 4 and 6 weeks. Results: The ratio of the newly formed bone volume to the titanium dome volume (BV/TV) and the bone mineral density (BMD) were significantly higher in the PV-nHA group than in the N-nHA group at 4 and 6 weeks, as determined using micro-CT. The fluorescence analysis showed slightly greater increases in new bone regeneration (NB%) and vertical height (VH%) gains in the P-nHA group than in the N-nHA group. Greater increases in NB% and VH% were observed in groups treated with rhVEGF165 and perforation than in the blank groups, with significant differences detected at 4 and 6 weeks (N-nHA compared with PV-nHA, p<0.05). A greater VH% that was observed at the midline of the block in the PV-nHA group than in the other three groups at both time points (0.75±0.53% at 4 weeks and 0.83±0.42% at 6 weeks). Conclusion: According to the present study, cortical perforation is necessary and nHA blocks coated with rhVEGF165 and decoration could work synergistically to improve vertical bone regeneration by directly affecting primary osteoblasts and promoting angiogenesis and osteoinduction.


Assuntos
Regeneração Óssea/efeitos dos fármacos , Durapatita/farmacologia , Regeneração Tecidual Guiada/métodos , Nanoestruturas/química , Crânio/efeitos dos fármacos , Crânio/fisiologia , Fator A de Crescimento do Endotélio Vascular/química , Animais , Durapatita/química , Osteoblastos/efeitos dos fármacos , Porosidade , Coelhos , Proteínas Recombinantes/química , Crânio/citologia , Crânio/diagnóstico por imagem , Titânio/química , Microtomografia por Raio-X
2.
Cient. dent. (Ed. impr.) ; 17(2): 87-92, mayo-ago. 2020. ilus, tab
Artigo em Espanhol | IBECS | ID: ibc-195096

RESUMO

En la actualidad la relación entre oclusión y posturología despierta un gran interés científico, sobre todo de cara a la instauración de un tratamiento multidisciplinar. Sin embargo, la diversidad de estudios se refiere sobre todo a la población adulta y no hay un consenso común entre las diferentes investigaciones. En base a ello nos planteamos como objetivo estudiar la posición craneocervical en diferentes oclusiones en población en desarrollo. Mediante un diseño de carácter transversal fueron seleccionados 64 pacientes pediátricos con historia clínica completa y radiografías laterales de cráneo de calidad. Las variables analizadas mediante el software de ImageJ® y Nemoceph® fueron FP-MP, ángulo ANB, OPT-SN, CVT-SN y Ad1-Ba. El análisis estadístico descriptivo y comparativo se llevó a cabo mediante el programa programa IBM SPSS® hallan-do posteriormente la fiabilidad intraexaminador. Los valores p obtenidos para cada una de las variables fueron 0,846 para FP-MP, 0,008 para el ángulo ANB, 0,155 para OPT-SN, 0,415 para CVT-SN y 0,221 para Ad1-Ba. Por todo ello, creemos que la posición craneofacial en las diferentes oclusiones podría estar determinada por el hecho de que el desarrollo todavía no ha finalizado


Currently, the relationship between occlusion and posture arouses great scientific interest, especially during the establishment of a multidisciplinary treatment. However, the diversity of studies refers mostly to the adult population and there is no common agreement among the different investigations. Based on this, we aimed to study the craniocervical position in different occlusions in the developing pediatric population. Through a cross-sectional design, 64 pediatric patients with complete clinical history and high-quality lateral skull radiographs were selected. The variables analyzed by ImageJ® and Nemoceph® software's were FP-MP, ANB angle, OPT-SN, CVT-SN and Ad1-Ba. Descriptive and comparative statistical analysis was carried out with IBM SPSS Statistics® software, subsequently finding intra-examiner agreement. P-values obtained for each of these variables were 0.846 for FP-MP, 0.008 for ANB angle, 0.155 for OPT-SN, 0.415 for CVT-SN, and 0.221 for CVT-SN. Based on these results, we believe that the craniofacial position in the different occlusions could be determined by the fact that the development has not yet been completed


Assuntos
Humanos , Masculino , Feminino , Criança , Vértebras Cervicais/diagnóstico por imagem , Vértebras Cervicais/fisiologia , Crânio/diagnóstico por imagem , Crânio/fisiologia , Cefalometria/métodos , Deformidades Dentofaciais/diagnóstico por imagem , Intervalos de Confiança , Assimetria Facial/diagnóstico por imagem
3.
PLoS Biol ; 18(8): e3000801, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32810126

RESUMO

The evolutionary radiation of birds has produced incredible morphological variation, including a huge range of skull form and function. Investigating how this variation arose with respect to non-avian dinosaurs is key to understanding how birds achieved their remarkable success after the Cretaceous-Paleogene extinction event. Using a high-dimensional geometric morphometric approach, we quantified the shape of the skull in unprecedented detail across 354 extant and 37 extinct avian and non-avian dinosaurs. Comparative analyses reveal fundamental differences in how skull shape evolved in birds and non-avian dinosaurs. We find that the overall skull shape evolved faster in non-avian dinosaurs than in birds across all regions of the cranium. In birds, the anterior rostrum is the most rapidly evolving skull region, whereas more posterior regions-such as the parietal, squamosal, and quadrate-exhibited high rates in non-avian dinosaurs. These fast-evolving elements in dinosaurs are strongly associated with feeding biomechanics, forming the jaw joint and supporting the jaw adductor muscles. Rapid pulses of skull evolution coincide with changes to food acquisition strategies and diets, as well as the proliferation of bony skull ornaments. In contrast to the appendicular skeleton, which has been shown to evolve more rapidly in birds, avian cranial morphology is characterised by a striking deceleration in morphological evolution relative to non-avian dinosaurs. These results may be due to the reorganisation of skull structure in birds-including loss of a separate postorbital bone in adults and the emergence of new trade-offs with development and neurosensory demands. Taken together, the remarkable cranial shape diversity in birds was not a product of accelerated evolution from their non-avian relatives, despite their frequent portrayal as an icon of adaptive radiations.


Assuntos
Evolução Biológica , Aves/anatomia & histologia , Dinossauros/anatomia & histologia , Crânio/anatomia & histologia , Animais , Fenômenos Biomecânicos , Aves/classificação , Aves/fisiologia , Dinossauros/classificação , Dinossauros/fisiologia , Extinção Biológica , Comportamento Alimentar/fisiologia , Fósseis/anatomia & histologia , Filogenia , Crânio/fisiologia
4.
Proc Natl Acad Sci U S A ; 117(35): 21251-21257, 2020 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-32817513

RESUMO

A large brain combined with an upright posture in humans has resulted in a high cephalopelvic proportion and frequently obstructed labor. Fischer and Mitteroecker [B. Fischer, P. Mitteroecker, Proc. Natl. Acad. Sci. U.S.A. 112, 5655-5660 (2015)] proposed that the morphological covariations between the skull and pelvis could have evolved to ameliorate obstructed labor in humans. The availability of quantitative data of such covariation, especially of the fetal skull and maternal pelvis, however, is still scarce. Here, we present direct evidence of morphological covariations between the skull and pelvis using actual mother-fetus dyads during the perinatal period of Macaca mulatta, a species that exhibits cephalopelvic proportions comparable to modern humans. We analyzed the covariation of the three-dimensional morphology of the fetal skull and maternal pelvis using computed tomography-based models. The covariation was mostly observed at the pelvic locations related to the birth canal, and the forms of the birth canal and fetal skull covary in such a way that reduces obstetric difficulties. Therefore, cephalopelvic covariation could have evolved not only in humans, but also in other primate taxa in parallel, or it could have evolved already in the early catarrhines.


Assuntos
Desproporção Cefalopélvica/fisiopatologia , Pelve/anatomia & histologia , Crânio/anatomia & histologia , Animais , Antropologia Física/métodos , Evolução Biológica , Desproporção Cefalopélvica/genética , Parto Obstétrico , Feminino , Feto , Hominidae , Humanos , Macaca mulatta/embriologia , Macaca mulatta/crescimento & desenvolvimento , Parto/fisiologia , Pelve/fisiologia , Gravidez , Crânio/fisiologia
5.
Sci Rep ; 10(1): 6793, 2020 04 22.
Artigo em Inglês | MEDLINE | ID: mdl-32322020

RESUMO

An on-going debate concerning the dietary adaptations of archaic hominins and early Homo has been fuelled by contradictory inferences obtained using different methodologies. This work presents an extensive comparative sample of 30 extant primate species that was assembled to perform a morpho-functional comparison of these taxa with 12 models corresponding to eight fossil hominin species. Finite Element Analysis and Geometric Morphometrics were employed to analyse chewing biomechanics and mandible morphology to, firstly, establish the variation of this clade, secondly, relate stress and shape variables, and finally, to classify fossil individuals into broad ingesta related hardness categories using a support vector machine algorithm. Our results suggest that some hominins previously assigned as hard food consumers (e.g. the members of the Paranthropus clade) in fact seem to rely more strongly on soft foods, which is consistent with most recent studies using either microwear or stable isotope analyses. By analysing morphometric and stress results in the context of the comparative framework, we conclude that in the hominin clade there were probably no hard-food specialists. Nonetheless, the biomechanical ability to comminute harder items, if required as fallback option, adds to their strategy of increased flexibility.


Assuntos
Adaptação Fisiológica/fisiologia , Dieta , Alimentos , Fósseis , Mandíbula/anatomia & histologia , Mastigação/fisiologia , Animais , Evolução Biológica , Análise de Elementos Finitos , Hominidae , Arcada Osseodentária/anatomia & histologia , Arcada Osseodentária/fisiologia , Mandíbula/fisiologia , Primatas/anatomia & histologia , Primatas/classificação , Primatas/fisiologia , Crânio/anatomia & histologia , Crânio/fisiologia , Máquina de Vetores de Suporte
6.
Sci Rep ; 10(1): 4224, 2020 04 09.
Artigo em Inglês | MEDLINE | ID: mdl-32273522

RESUMO

Dinosaur embryos are among the rarest of fossils, yet they provide a unique window into the palaeobiology of these animals. Estimating the developmental stage of dinosaur embryos is hindered by the lack of a quantitative method for age determination, by the scarcity of material, and by the difficulty in visualizing that material. Here we present the results of a broad inquiry, using 3D reconstructions from X-ray computed tomography data, into cranial ossification sequences in extant saurian taxa and in well-preserved embryos of the early branching sauropodomorph dinosaur Massospondylus carinatus. Our findings support deep-time conservation of cranial ossification sequences in saurians including dinosaurs, allowing us to develop a new method for estimating the relative developmental percentage of embryos from that clade. We also observe null-generation teeth in the Massospondylus carinatus embryos which get resorbed or shed before hatching, similar to those of geckos. These lines of evidence allow us to confidently estimate that the Massospondylus carinatus embryos are only approximately 60% through their incubation period, much younger than previously hypothesized. The overall consistency of our results with those of living saurians indicates that they can be generalized to other extinct members of that lineage, and therefore our method provides an independent means of assessing the developmental stage of extinct, in-ovo saurians.


Assuntos
Evolução Biológica , Dinossauros/embriologia , Dinossauros/fisiologia , Osteogênese , Óvulo/fisiologia , Crânio/embriologia , Crânio/fisiologia , Animais , Dinossauros/anatomia & histologia , Fósseis , Filogenia
7.
Sci Rep ; 10(1): 7122, 2020 04 28.
Artigo em Inglês | MEDLINE | ID: mdl-32346021

RESUMO

Although isolated Champsosaurus remains are common in Upper Cretaceous sediments of North America, the braincase of these animals is enigmatic due to the fragility of their skulls. Here, two well-preserved specimens of Champsosaurus (CMN 8920 and CMN 8919) are CT scanned to describe their neurosensory structures and infer sensory capability. The anterior portion of the braincase was poorly ossified and thus does not permit visualization of a complete endocast; however, impressions of the olfactory stalks indicate that they were elongate and likely facilitated good olfaction. The posterior portion of the braincase is ossified and morphologically similar to that of other extinct diapsids. The absence of an otic notch and an expansion of the pars inferior of the inner ear suggests Champsosaurus was limited to detecting low frequency sounds. Comparison of the shapes of semicircular canals with lepidosaurs and archosauromorphs demonstrates that the semicircular canals of Champsosaurus are most similar to those of aquatic reptiles, suggesting that Champsosaurus was well adapted for sensing movement in an aquatic environment. This analysis also demonstrates that birds, non-avian archosauromorphs, and lepidosaurs possess significantly different canal morphologies, and represents the first morphometric analysis of semicircular canals across Diapsida.


Assuntos
Sistema Nervoso Central/anatomia & histologia , Dinossauros/anatomia & histologia , Fósseis , Sensação , Crânio/anatomia & histologia , Animais , Sistema Nervoso Central/fisiologia , Canais Semicirculares/anatomia & histologia , Crânio/diagnóstico por imagem , Crânio/fisiologia , Tomografia Computadorizada por Raios X
8.
PLoS One ; 15(4): e0231760, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32348315

RESUMO

The decline of the Roman rule caused significant political instability and led to the emergence of various 'Barbarian' powers. While the names of the involved groups appeared in written sources, it is largely unknown how these changes affected the daily lives of the people during the 5th century AD. Did late Roman traditions persist, did new customs emerge, and did both amalgamate into new cultural expressions? A prime area to investigate these population and settlement historical changes is the Carpathian Basin (Hungary). Particularly, we studied archaeological and anthropological evidence, as well as radiogenic and stable isotope ratios of strontium, carbon, and nitrogen of human remains from 96 graves at the cemetery of Mözs-Icsei dulo. Integrated data analysis suggests that most members of the founder generation at the site exhibited burial practises of late Antique traditions, even though they were heterogeneous regarding their places of origin and dietary habits. Furthermore, the isotope data disclosed a nonlocal group of people with similar dietary habits. According to the archaeological evidence, they joined the community a few decades after the founder generation and followed mainly foreign traditions with artificial skull modification as their most prominent characteristic. Moreover, individuals with modified skulls and late Antique grave attributes attest to deliberate cultural amalgamation, whereas burials of largely different isotope ratios underline the recipient habitus of the community. The integration of archaeological and bioarchaeological information at the individual level discloses the complex coalescence of people and traditions during the 5th century.


Assuntos
Arqueologia , Mundo Romano/história , Mudança Social/história , Adolescente , Restos Mortais/anatomia & histologia , Restos Mortais/fisiologia , Cemitérios , Criança , Pré-Escolar , Comportamento Alimentar , Feminino , História Antiga , Humanos , Hungria , Lactente , Recém-Nascido , Masculino , Crânio/anatomia & histologia , Crânio/fisiologia , Adulto Jovem
9.
J Vis Exp ; (157)2020 03 14.
Artigo em Inglês | MEDLINE | ID: mdl-32225155

RESUMO

Bone is a connective tissue constituted of osteoblasts, osteocytes, and osteoclasts and a mineralized extracellular matrix, which gives it its strength and flexibility and allows it to fulfill its functions. Bone is continuously exposed to a variety of stimuli, which in pathological conditions can deregulate bone remodeling. To study bone biology and diseases and evaluate potential therapeutic agents, it has been necessary to develop in vitro and in vivo models. This manuscript describes the dissection process and culture conditions of calvarias isolated from neonatal mice to study bone formation and the bone tumor microenvironment. In contrast to in vitro and in vivo models, this ex vivo model allows preservation of the three-dimensional environment of the tissue as well as the cellular diversity of the bone while culturing under defined conditions to simulate the desired microenvironment. Therefore, it is possible to investigate bone remodeling and its mechanisms, as well as the interactions with other cell types, such as the interactions between cancer cells and bone. The assays reported here use calvarias from 5-7 day old BALB/C mice. The hemi-calvarias obtained are cultured in the presence of insulin, breast cancer cells (MDA-MB-231), or conditioned medium from breast cancer cell cultures. After analysis, it was established that insulin induced new bone formation, while cancer cells and their conditioned medium induced bone resorption. The calvarial model has been successfully used in basic and applied research to study bone development and cancer-induced bone diseases. Overall, it is an excellent option for an easy, informative, and low-cost assay.


Assuntos
Remodelação Óssea/fisiologia , Técnicas de Cocultura/métodos , Crânio/fisiologia , Microambiente Tumoral/fisiologia , Animais , Humanos , Camundongos
10.
Sci Rep ; 10(1): 2277, 2020 02 10.
Artigo em Inglês | MEDLINE | ID: mdl-32042021

RESUMO

Megakaryocytes (MKs) play key roles in regulating bone metabolism. To test the roles of MK-secreted factors, we investigated whether MK and promegakaryocyte (pro-MK) conditioned media (CM) may affect bone formation and resorption. K562 cell lines were differentiated into mature MKs. Mouse bone marrow macrophages were differentiated into mature osteoclasts, and MC3T3-E1 cells were used for osteoblastic experiments. Bone formation was determined by a calvaria bone formation assay in vivo. Micro-CT analyses were performed in the femurs of ovariectomized female C57B/L6 and Balb/c nude mice after intravenous injections of MK or pro-MK CM. MK CM significantly reduced in vitro bone resorption, largely due to suppressed osteoclastic resorption activity. Compared with pro-MK CM, MK CM suppressed osteoblastic differentiation, but stimulated its proliferation, resulting in stimulation of calvaria bone formation. In ovariectomized mice, treatment with MK CM for 4 weeks significantly increased trabecular bone mass parameters, such as bone volume fraction and trabecular thickness, in nude mice, but not in C57B/L6 mice. In conclusion, MKs may secrete anti-resorptive and anabolic factors that affect bone tissue, providing a novel insight linking MKs and bone cells in a paracrine manner. New therapeutic agents against metabolic bone diseases may be developed from MK-secreted factors.


Assuntos
Diferenciação Celular/efeitos dos fármacos , Meios de Cultivo Condicionados/farmacologia , Megacariócitos/metabolismo , Osteogênese/efeitos dos fármacos , Comunicação Parácrina , Animais , Reabsorção Óssea/diagnóstico por imagem , Reabsorção Óssea/tratamento farmacológico , Reabsorção Óssea/etiologia , Diferenciação Celular/fisiologia , Meios de Cultivo Condicionados/metabolismo , Modelos Animais de Doenças , Feminino , Fêmur/diagnóstico por imagem , Fêmur/fisiologia , Humanos , Injeções Intravenosas , Células K562 , Macrófagos/efeitos dos fármacos , Macrófagos/fisiologia , Células Progenitoras de Megacariócitos/metabolismo , Camundongos , Osteoclastos/fisiologia , Osteoporose Pós-Menopausa/diagnóstico por imagem , Osteoporose Pós-Menopausa/tratamento farmacológico , Osteoporose Pós-Menopausa/etiologia , Ovariectomia , Crânio/efeitos dos fármacos , Crânio/fisiologia , Microtomografia por Raio-X
11.
Anat Sci Int ; 95(3): 363-373, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32086765

RESUMO

We investigated changes in the cranial/cephalic index of the Korean population in millennia, centuries, and recent decades. Secular changes of Korean's cephalic index in history were studied using the data of archaeology literature and our measurement data of different adult skull sets for the fifteenth-nineteenth century Joseon people, the Korean War victims (1950-1953), and the Korean skeletons collected by medical schools in the 1960s. A change in head shape during the last century was also estimated by the analysis on Korean cephalometric datasets of Korean Research Institute of Standards and Science. In brief, over the past 2000 years, the crania of Korean people have steadily changed from mesocephalic to brachycephalic, mainly due to the cranial length shortening. Brachycephalization accelerated at the beginning of the twentieth century and continued until the early twenty-first century, largely caused by increased cephalic breadth. We also note that debrachycephalization began in birth cohorts around 1965 for males and around 1970 for females. Taken together, we figure out that the head shape of Korean people has been gradually shortened over millennia and then has undergone dramatic shortening in the last century. In recent decades, however, the changing pattern has reversed to debrachycephalization, for which we discussed about the possible causes in the present report.


Assuntos
Antropologia Física , Arqueologia , Cefalometria , Crânio/anatomia & histologia , Crânio/fisiologia , Feminino , Humanos , Masculino , República da Coreia
12.
Ann Biomed Eng ; 48(3): 992-1005, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31037444

RESUMO

Despite its regenerative ability, long and segmental bone defect repair remains a significant orthopedic challenge. Conventional tissue engineering efforts induce bone formation through intramembranous ossification (IO) which limits vascular formation and leads to poor bone regeneration. To overcome this challenge, a novel hybrid matrix comprised of a load-bearing polymer template and a gel phase is designed and assessed for bone regeneration. Our previous studies developed a synthetic ECM, hyaluronan (HA)-fibrin (FB), that is able to mimic cartilage-mediated bone formation in vitro. In this study, the well-characterized HA-FB hydrogel is combined with a biodegradable polymer template to form a hybrid matrix. In vitro evaluation of the matrix showed cartilage template formation, cell recruitment and recruited cell osteogenesis, essential stages in endochondral ossification. A transgenic reporter-mouse critical-defect model was used to evaluate the bone healing potential of the hybrid matrix in vivo. The results demonstrated host cell recruitment into the hybrid matrix that led to new bone formation and subsequent remodeling of the mineralization. Overall, the study developed and evaluated a novel load-bearing graft system for bone regeneration via endochondral ossification.


Assuntos
Regeneração Óssea , Células-Tronco Mesenquimais/fisiologia , Osteogênese , Crânio/fisiologia , Engenharia Tecidual/métodos , Animais , Células Cultivadas , Matriz Extracelular , Fibrina , Humanos , Ácido Hialurônico , Hidrogéis , Camundongos SCID , Porosidade
13.
Anat Rec (Hoboken) ; 303(1): 110-128, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-30365875

RESUMO

Horseshoe bats (Family Rhinolophidae) show an impressive array of morphological traits associated with use of high duty cycle echolocation calls that they emit via their nostrils (nasophonation). Delicate maxilloturbinal bones inside the nasal fossa of horseshoe bats have a unique elongated strand-like shape unknown in other mammals. Maxilloturbinal strands also vary considerably in length and cross-sectional shape. In other mammals, maxilloturbinals help direct respired air and prevent respiratory heat and water loss. We investigated whether strand-shaped maxilloturbinals in horseshoe bats perform a similar function to those of other mammals, or whether they were shaped for a role in nasophonation. Using histology, we studied the mucosa of the nasal fossa in Rhinolophus lepidus, which we compared with Hipposideros lankadiva (Hipposideridae) and Megaderma lyra (Megadermatidae). Using micro-CT scans of 30 horseshoe bat species, we quantified maxilloturbinal surface area and skull shape within a phylogenetic context. Histological results showed horseshoe bat maxilloturbinals are covered in a thin, poorly vascularized, sparsely ciliated mucosa poorly suited for preventing respiratory heat and water loss. Maxilloturbinal surface area was correlated with basicranial width, but exceptionally long and dorsoventrally flat maxilloturbinals did not show enhanced surface area for heat and moisture exchange. Skull shape variation appears to be driven by structures linked to nasophonation, including maxilloturbinals. Resting echolocation call frequency better predicted skull shape than did skull size, and was specifically correlated with dimensions of the rostral inflations, palate, and maxilloturbinals. These traits appear to form a morphological complex, indicating a nasophonatory role for the strand-shaped rhinolophid maxilloturbinals. Anat Rec, 2018. © 2018 American Association for Anatomy.


Assuntos
Quirópteros/anatomia & histologia , Quirópteros/fisiologia , Ecolocação/fisiologia , Cavidade Nasal/anatomia & histologia , Cavidade Nasal/fisiologia , Fonação , Animais , Feminino , Crânio/anatomia & histologia , Crânio/fisiologia
14.
Anat Rec (Hoboken) ; 303(1): 44-52, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-30623594

RESUMO

Billfishes are large pelagic fishes that have an extreme elongation of the upper jaw bones forming the rostrum. Recent kinematic and biomechanical studies show the rostrum to be associated to feeding, however, it is less clear how the wide range of morphologies present among billfish may affect their striking behavior. In this study, we aim to assess the mechanical performance of different rostrum morphologies under loads that simulate feeding and to test existing hypotheses of species-specific feeding behaviors. We use finite element analysis (FEA)-a physics-based method that predicts patterns of stress and strain in morphologically complex structures under specified boundary conditions-to test hypotheses on the form and mechanical performance of billfish rostra. Patterns of von Mises stress and total strain energy suggest that distinct rostral morphologies may be functionally segregated. The rounder blue marlin rostrum may be better suited for a wide range of slashing motions to disable prey, whereas the more flattened swordfish rostrum appears to be more specialized for lateral swiping during prey capture. The almost homogenous stress distribution along each rostrum implies their possible use as a predatory weapon regardless of morphological differences between species. The mechanical implications of other less commonly reported behaviors such as spearing are discussed, as well as the potential impact of hydrodynamics in shaping the evolution of the rostrum in this lineage. Anat Rec, 2019. © 2019 American Association for Anatomy.


Assuntos
Comportamento Alimentar , Análise de Elementos Finitos , Perciformes/anatomia & histologia , Perciformes/fisiologia , Crânio/anatomia & histologia , Crânio/fisiologia , Animais , Fenômenos Biomecânicos , Hidrodinâmica
15.
IEEE Trans Neural Syst Rehabil Eng ; 28(2): 361-369, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31841414

RESUMO

Ultrasonic neuromodulation on large animals, like non-human primates, requires the array transducer to have a good steering ability to arbitrarily stimulate various brain locations. Moreover, due to the different sizes of the animal heads, the array is preferred to be conveniently adjustable to different aperture sizes. To meet these requirements, a scalable 2D plane array, which can consist of up to tens of 256-element square modules, has been designed and fabricated in this study. Arrays with large apertures, consisting of 12 and 48 modules (including 3072 and 12288 elements, respectively), have been assembled and tested. The square modules were driven at a center frequency of 1.04 MHz. The transcranial and steering abilities of the modules were verified in a water tank on an ex vivo macaque skull. A focused beam transmitted by single module could pass through the skull with its peak acoustic pressure reduced to 18.1% of that in the free-field, with an acceptable transverse steering range up to 10 mm. Moreover, a much smaller focal spot was obtained by simultaneous transmission using two vertical-placed modules. Compared to the single module, the focal zone axial size was reduced from 29.7 mm to 3.3 mm, and the "stripes" pattern in the focal zone caused by standing waves was eliminated using a difference-frequency transmitting strategy. Such scalable 2D plane array, which can provide a small-size focal spot and has a large steering range and an acceptable transcranial ability, can be useful in research on ultrasonic neuromodulation on non-human primates.


Assuntos
Encéfalo/fisiologia , Doenças do Sistema Nervoso/terapia , Terapia por Ultrassom/instrumentação , Estimulação Acústica , Algoritmos , Animais , Desenho de Equipamento , Macaca , Primatas , Crânio/fisiologia , Transdutores , Terapia por Ultrassom/métodos
16.
Mater Sci Eng C Mater Biol Appl ; 106: 110186, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31753406

RESUMO

Porosity is indispensable for a bone tissue-engineered scaffold for facilitating endogenous cell migration and nascent bone ingrowth. In large-sized cranial bone defect repair, porous scaffolds meet great challenges to match cranial bone regeneration and provide sufficient protection with structural integrity. Therefore, the pore features of the scaffolds for cranial bone regeneration should differ from those typical porous scaffolds used in tubular bone repair and be finely tuned. In this study, a series of porous mineralized collagen/PCL scaffolds with different pore features were fabricated via freeze-drying and applied in a Sprague Dawley rat cranial bone calvarial defect model. The pore size for four groups increased from 10-45 µm to 40-130 µm. As scaffold porosity increased, the compressive strength decreased from 2.09 ±â€¯0.12 MPa to 0.51 ±â€¯0.04 MPa. The micro-computed tomography three-dimensional reconstruction images showed that as pore size and porosity increased, the amount of new bone formation had a maximum in group 3 (pore size: 20-100 µm, compressive strength: 1.06 ±â€¯0.03 MPa). In addition, the histological and histomorphometric analyses showed a consistent tendency which confirmed the Micro-CT results. Meanwhile, histological findings including bony bridging, tissue response at the bone-implant interface and fibrous capsule thickness indicated that the dura mater pathway played the most important role in the regenerative process of this calvarial defect model.


Assuntos
Colágeno/química , Crânio/fisiologia , Tecidos Suporte/química , Animais , Regeneração Óssea/fisiologia , Carragenina/química , Masculino , Ratos , Ratos Sprague-Dawley , Prata/química , Engenharia Tecidual/métodos
17.
J Craniofac Surg ; 31(3): 838-842, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31842082

RESUMO

Existing in vitro simulators rely on external manipulation of the skull to replicate masticatory forces; however, external manipulations do not accurately represent internal loads as in physiological muscle forces.The purpose of the project is to develop an in vitro simulator that internally replicates the forces of mastication. The simulator has 3-dimensional-printed piston mounts that are reverse-engineered using a computed tomography scan of the specimen. The mounts are attached to the skull at muscle attachment sites using adhesive. The pneumatic pistons are sutured to muscle tendons; when the pistons are activated, they pull on the tendons which proportionally replicate muscle loads. The force output of the pistons can be individually modified by a custom software. Strain gauges are attached to craniofacial bones to measure deformation under replicated muscle loads. A 6 degrees-of freedom force sensor is placed intraorally to measure the generated bite force.The methodology was validated on 6 fresh-frozen cadaveric heads. Change in strain measurements was observed with change in simulated muscle loads. The simulator can validate computer simulation models and provide an experimental platform for craniofacial and dental implants. It sets the framework for a new, more physiologically consistent way of studying craniofacial stresses.


Assuntos
Força de Mordida , Mastigação/fisiologia , Crânio/fisiologia , Fenômenos Biomecânicos , Simulação por Computador , Implantes Dentários , Humanos , Crânio/anatomia & histologia , Software
18.
Int J Mol Sci ; 20(23)2019 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-31801223

RESUMO

Matrix metalloproteinase (MMP)-2 and MMP-9 are well-known gelatinases that disrupt the extracellular matrix, including gelatin. However, the advantages of modulating MMP expression in gelatin-based materials for applications in bone regenerative medicine have not been fully clarified. In this study, we examined the effects of epigallocatechin gallate (EGCG), a major polyphenol catechin isolated from green tea, on MMP expression in gelatin sponges and its association with bone formation. Four gelatin sponges with or without EGCG were prepared and implanted into bone defects for up to 4 weeks. Histological and immunohistological staining were performed. Micro-computed tomography was used to estimate the bone-forming capacity of each sponge. Our results showed that EGCG integration attenuated MMP-2 (70.6%) and -9 expression (69.1%) in the 1 week group, increased residual gelatin (118.7%), and augmented bone formation (101.8%) in the 4 weeks group in critical-sized bone defects of rat calvaria compared with vacuum-heated gelatin sponges without EGCG. Moreover, vacuum-heated gelatin sponges with EGCG showed superior bone formation compared with other sponges. The results indicated that integration of EGCG in gelatin-based materials modulated the production and activity of MMP-2 and -9 in vivo, thereby enhancing bone-forming capacity.


Assuntos
Materiais Biocompatíveis/síntese química , Regeneração Óssea/efeitos dos fármacos , Reabsorção Óssea/prevenção & controle , Catequina/análogos & derivados , Gelatina/química , Inibidores de Metaloproteinases de Matriz/farmacologia , Engenharia Tecidual/métodos , Implantes Absorvíveis , Aldeídos/antagonistas & inibidores , Aldeídos/metabolismo , Animais , Reabsorção Óssea/diagnóstico por imagem , Catequina/farmacologia , Linhagem Celular , Proliferação de Células/efeitos dos fármacos , Masculino , Metaloproteinase 2 da Matriz/metabolismo , Metaloproteinase 9 da Matriz/metabolismo , Osteoblastos/citologia , Osteoblastos/efeitos dos fármacos , Osteoblastos/fisiologia , Ratos , Ratos Sprague-Dawley , Crânio/diagnóstico por imagem , Crânio/efeitos dos fármacos , Crânio/lesões , Crânio/fisiologia , Tecidos Suporte , Microtomografia por Raio-X
19.
Rev. cuba. estomatol ; 56(4): e2110, oct.-dez. 2019. tab, graf
Artigo em Espanhol | LILACS | ID: biblio-1093251

RESUMO

RESUMEN Introducción: Universalmente se acepta que la radiografía postero-anterior de cráneo presenta menor grado de distorsión que otras imágenes radiográficas, por lo que las mediciones en ella son consideradas confiables. Objetivo: Determinar el porcentaje de distorsión que se presenta en las diferentes regiones faciales de la radiografía posteroanterior de cráneo. Métodos: Treinta cráneos humanos con sus mandíbulas fueron divididos por tres planos horizontales y cuatro verticales en quince cuadrantes; resultaron diez en el cráneo y cinco en la mandíbula. En cada uno de ellos se colocó un alambre de acero en posiciones vertical y horizontal y se midió su longitud (medida real). A cada conjunto se le tomó una radiografía en proyección postero-anterior y se midió la longitud de los alambres en la imagen (medida radiográfica). Resultados: No fue posible medir en los cuadrantes laterales del cráneo. La medida horizontal en los cuadrantes intermedios inferiores derecho e izquierdo del cráneo y en los cuadrantes intermedio y lateral de ambos lados de la mandíbula no es confiable; en el cuadrante mediano de la mandíbula se minimiza; en los cuadrantes medianos superior e inferior e intermedios superiores derecho e izquierdo del cráneo se magnifica. Las medidas verticales en todos los cuadrantes son confiables; en los cuadrantes intermedios superiores derecho e izquierdo del cráneo y en los intermedios y laterales derechos e izquierdos de la mandíbula se magnifica; en los cuadrantes intermedios inferiores y medianos superior e inferior del cráneo y mediano de la mandíbula se minimiza. La menor distorsión para ambas medidas se presenta en el cuadrante mediano superior del cráneo. Se reportan los porcentajes de distorsión para cada cuadrante. Conclusiones: Se presenta distorsión en la radiografía postero-anterior de cráneo y esta varía de una región a otra de la cara(AU)


ABSTRACT Introduction: Universally, it has been accepted that the postero-anterior cephalogram presents less distortion than any other x-ray radiograph; for this reason, the measurements taken on it are considered reliable. Objective: To determine for a postero-anterior cephalogram, what percentage of distortion is present in different regions of the skull and mandible. Methods: Thirty human skulls with their mandibles were divided by three horizontal and four vertical planes in fifteen quadrants, resulting ten in the skull and five in the mandible. In each quadrant, one vertical and one horizontal steel wire were fixed and their lengths were measured (real value). To each set, a postero-anterior cephalogram was taken and the wire images were measured (radiograph value). Results: No measurement could be taken in the lateral quadrants of the skull. The horizontal measurement in the right and left intermediate inferior quadrants of the skull and in the right and left intermediate and lateral quadrants of the mandible is not reliable; in the median quadrant of the mandible it is minimized; in the median superior and inferior and intermediate superior right and left quadrants of the skull it is magnified. The vertical measurement in all the quadrants is reliable; in the right and left intermediate superior quadrants of the skull and right and left intermediate and lateral quadrants of the mandible it is magnified; in the right and left intermediate inferior and median superior and inferior quadrants of the skull and median quadrant of the mandible it is minimized. The minimum distortion for both measurements is present in the median superior quadrant of the skull. The percentage of distortion in each quadrant for both measurements is reported. Conclusions: Distortion is present in the postero-anterior cephalogram and it varies from one region to another of the face(AU)


Assuntos
Humanos , Crânio/fisiologia , Radiografia Dentária/efeitos adversos , Radiografia Panorâmica/métodos , Cefalometria/métodos
20.
Proc Natl Acad Sci U S A ; 116(49): 24696-24706, 2019 12 03.
Artigo em Inglês | MEDLINE | ID: mdl-31740590

RESUMO

The avian predentary is a small skeletal structure located rostral to the paired dentaries found only in Mesozoic ornithuromorphs. The evolution and function of this enigmatic element is unknown. Skeletal tissues forming the predentary and the lower jaws in the basal ornithuromorph Yanornis martini are identified using computed-tomography, scanning electron microscopy, and histology. On the basis of these data, we propose hypotheses for the development, structure, and function of this element. The predentary is composed of trabecular bone. The convex caudal surface articulates with rostromedial concavities on the dentaries. These articular surfaces are covered by cartilage, which on the dentaries is divided into 3 discrete patches: 1 rostral articular cartilage and 2 symphyseal cartilages. The mechanobiology of avian cartilage suggests both compression and kinesis were present at the predentary-dentary joint, therefore suggesting a yet unknown form of avian cranial kinesis. Ontogenetic processes of skeletal formation occurring within extant taxa do not suggest the predentary originates within the dentaries, nor Meckel's cartilage. We hypothesize that the predentary is a biomechanically induced sesamoid that arose within the soft connective tissues located rostral to the dentaries. The mandibular canal hosting the alveolar nerve suggests that the dentary teeth and predentary of Yanornis were proprioceptive. This whole system may have increased foraging efficiency. The Mesozoic avian predentary apparently coevolved with an edentulous portion of the premaxilla, representing a unique kinetic morphotype that combined teeth with a small functional beak and persisted successfully for ∼60 million years.


Assuntos
Bico/anatomia & histologia , Aves/fisiologia , Dinossauros/anatomia & histologia , Cinese/fisiologia , Crânio/anatomia & histologia , Animais , Bico/fisiologia , Evolução Biológica , Aves/anatomia & histologia , Dinossauros/fisiologia , Fósseis/anatomia & histologia , Crânio/fisiologia
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