Ocular echobiometry and relationship with cranial and body morphometric parameters in Shih Tzu dogs / [Ecobiometria ocular e relação com a morfometria craniana e corporal em cães Shih Tzu]

The purpose of this paper is to determine the ocular echobiometry and investigate its correlation with cranial and body morphometric parameters in 50 adult Shih Tzu dogs. The echobiometric measurements of the anterior chamber (AC), vitreous chamber (VC), lens axial thickness (LTA), transverse lens thickness (LTT), and axial length of the eyeball (ALE) were obtained by two-dimensional ultrasonography. Morphometric measurements of bizygomatic distance (BDIST), frontal-occipital distance (FOD), withers height (WH), thoracic circumference (TC), and body length (BL) were also obtained. The mean of the AC depth was 2.83±0.50mm, the VC was 9.18±0.54mm, the LTA was 6.42±0.32mm and the LTT was 9.17±1.18mm, while the mean of the ALE was 18.82±0.66mm. There was no correlation between ocular echobiometric variables and cranial and body morphometric variables in adult dogs of the Shih Tzu breed, as well as no significant difference of these variables when considering gender and age of the dogs (p ≥ 0.05).

Objetivou-se, com este estudo, a determinação da ecobiometria ocular e a investigação de sua correlação com parâmetros morfométricos cranianos e corporais em 50 cães Shih Tzu adultos. As medidas ecobiométricas da câmara anterior (CA), da câmara vítrea (CV), da espessura axial (ELA), da transversal da lente (ETL) e do comprimento axial do globo ocular (CGO) foram obtidas por meio da ultrassonografia em modo bidimensional. As medidas morfométricas do distanciamento bizigomático (DBZ), do distanciamento fronto-occipital (DFO), da altura de cernelha (AC), da circunferência torácica (CT) e do comprimento corporal (CP) também foram obtidas. A média da profundidade de CA foi de 2,83±0,50mm, da CV foi de 9,18±0,54mm, da ELA foi de 6,42±0,32mm e da ETL foi de 9,17±1,18mm, enquanto a média do CGO foi de 18,82±0,66mm. Não foi verificada correlação entre as variáveis ecobiométricas oculares e as morfométricas cranianas e corporais em cães adultos da raça Shih Tzu, assim como não houve diferença significativa dessas variáveis quando considerado o gênero e a idade dos cães (P≥0,05).

Skull of capybara (Hydrochoerus hydrochaeris) - morphometric parameters

Background: The capybara (Hydrochoerus hydrochaeris) is the largest rodent in the world. They are territorial animals,and live in social groups, commonly occurring in anthropized area, what has attracted the attention of researchers in relation to this animal species, since it is the host of the Amblyomma cajennese tick that transmits spotted-fever to humansand are responsible for severe impact on livestock and public health. The skull is a part of the axial skeleton that enclosingthe brain, sensory organs and digestive and respiratory structures. Moreover, the phenotypic appearance of the capybarahead depends on the shape of the skull. Thus, the aim of this study was to describe the reference values of cranial measurements of capybaras. The knowledge of morphometric parameters of skull is pivotal for veterinary treatment of pathologicalconditions and taxonomic affiliation.Materials, Methods & Results: Eight capybaras (Hydrochoerus hydrochaeris) skulls were used in this study, irrespectiveof age and sex. The skulls belonging to the anatomical collection of the Laboratory of Wildlife Anatomy and AnatomicalMuseum, Department of Anatomy, Universidade Estadual Paulista Júlio de Mesquita Filho, UNESP, Botucatu, São Paulo.A total of 35 morphometric parameters were performed using a digital caliper and 6 cranial indices were calculated. Allinvestigated features were expressed as mean ± standard deviation. Anatomically, capybara skull were elongated, rectanglelike and consisted of cranial and facial bones. The morphometric parameters were used to calculate the following craniometrics indices: skull index (57.86 ± 3.62), cranial index (50.49 ± 2.08), facial index (49.22 ± 3.82), basal index (33.98 ±0.86), nasal index (26.73 ± 3.1), and the foramen magnum index (149.61 ± 1.07). Moreover, the facial part length (mean137.90 mm) and cranium part length (mean 87.76 mm) also were calculated. The facial part...(AU)

Skull of capybara (Hydrochoerus hydrochaeris) - morphometric parameters

Background: The capybara (Hydrochoerus hydrochaeris) is the largest rodent in the world. They are territorial animals,and live in social groups, commonly occurring in anthropized area, what has attracted the attention of researchers in relation to this animal species, since it is the host of the Amblyomma cajennese tick that transmits spotted-fever to humansand are responsible for severe impact on livestock and public health. The skull is a part of the axial skeleton that enclosingthe brain, sensory organs and digestive and respiratory structures. Moreover, the phenotypic appearance of the capybarahead depends on the shape of the skull. Thus, the aim of this study was to describe the reference values of cranial measurements of capybaras. The knowledge of morphometric parameters of skull is pivotal for veterinary treatment of pathologicalconditions and taxonomic affiliation.Materials, Methods & Results: Eight capybaras (Hydrochoerus hydrochaeris) skulls were used in this study, irrespectiveof age and sex. The skulls belonging to the anatomical collection of the Laboratory of Wildlife Anatomy and AnatomicalMuseum, Department of Anatomy, Universidade Estadual Paulista Júlio de Mesquita Filho, UNESP, Botucatu, São Paulo.A total of 35 morphometric parameters were performed using a digital caliper and 6 cranial indices were calculated. Allinvestigated features were expressed as mean ± standard deviation. Anatomically, capybara skull were elongated, rectanglelike and consisted of cranial and facial bones. The morphometric parameters were used to calculate the following craniometrics indices: skull index (57.86 ± 3.62), cranial index (50.49 ± 2.08), facial index (49.22 ± 3.82), basal index (33.98 ±0.86), nasal index (26.73 ± 3.1), and the foramen magnum index (149.61 ± 1.07). Moreover, the facial part length (mean137.90 mm) and cranium part length (mean 87.76 mm) also were calculated. The facial part...

Craniometric geographical variation in Hylaeamys megacephalus populations / Variação geográfica craniométrica em populações de Hylaeamys megacephalus

Hylaeamys megacephalus (G. Fisher, 1814) presents great genetic diversity and wide geographical distribution, and occurs in both the Amazon and Cerrado biomes. Because of its generalist aspect, this species tolerates different eating habits and habitats. It occurs in flooded and dry areas and is predominantly terrestrial, which allows greater gene flow between populations even over long distances. Studies that seek a better understanding of morphological variations resulting from differences imposed by the environment throughout this species' distribution are still lacking. This study aimed to analyze the differences between H. megacephalus populations based on craniometry, investigating whether the environment has an influence on morphology. We analyzed a total of 142 specimens from three scientific mammal collections: National Museum, "Universidade Federal do Rio de Janeiro" (MN-UFRJ); "Laboratório de Biologia e Parasitologia de Mamíferos Reservatórios Silvestres", "Instituto Oswaldo Cruz", "Fundação Oswaldo Cruz"(LBCE-Fiocruz); and "Laboratório de Biodiversidade", "Universidade Federal de Goiás", "Regional Jataí" (LZE-UFG), and took 20 craniometric measurements. Craniometry was explored using unweighted pair group method with arithmetic mean (UPGMA), canonical variate analysis, and principal component analysis (PCA). The results led us to conclude that there are three craniometric groups of H. megacephalus with a tendency to differentiate as a result of geographical influences.(AU)

Com grande diversidade genética e distribuição geográfica, Hylaeamys megacephalus (G. Fisher, 1814) ocorre tanto na Amazônia quanto no Cerrado. Visto seu aspecto generalista, esta espécie tolera diversos hábitos alimentares e habitats, ocorrendo em áreas inundadas ou não, sendo predominantemente terrestre, permitindo maior fluxo de genes entre as populações, mesmo em longas distâncias. Apresenta ampla distribuição, e carece de estudos que busquem um melhor entendimento sobre as variações morfológicas resultantes das diferenças impostas pelo meio ao longo de sua distribuição. O estudo teve como objetivo, analisar as diferenças entre as populações de H. megacephalus, com base na craniometria investigando se o ambiente interfere na morfologia. Analisamos um total de 142 espécimes oriundos de coleções científicas de mamíferos, do Museu Nacional, Universidade Federal do Rio de Janeiro (MN-UFRJ), Laboratório de Biologia e Parasitologia de Mamíferos Reservatórios Silvestres, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz (LBCE-Fiocruz) e Laboratório de Biodiversidade, Universidade Federal de Goiás, Regional Jataí, nos quais foram tomadas 20 medidas craniométricas. A craniometria foi explorada nas análises estatísticas de agrupamento de pares não ponderados com médias aritméticas (UPGMA), variação canônica e análise dos Componentes Principais (PCA). Os resultados encontrados nos levaram a concluir a existência de três grupos craniométricos da espécie de H. megacephalus com tendência a se diferenciarem, por influências geográficas.(AU)

Craniometric geographical variation in Hylaeamys megacephalus populations / Variação geográfica craniométrica em populações de Hylaeamys megacephalus

Hylaeamys megacephalus (G. Fisher, 1814) presents great genetic diversity and wide geographical distribution, and occurs in both the Amazon and Cerrado biomes. Because of its generalist aspect, this species tolerates different eating habits and habitats. It occurs in flooded and dry areas and is predominantly terrestrial, which allows greater gene flow between populations even over long distances. Studies that seek a better understanding of morphological variations resulting from differences imposed by the environment throughout this species' distribution are still lacking. This study aimed to analyze the differences between H. megacephalus populations based on craniometry, investigating whether the environment has an influence on morphology. We analyzed a total of 142 specimens from three scientific mammal collections: National Museum, "Universidade Federal do Rio de Janeiro" (MN-UFRJ); "Laboratório de Biologia e Parasitologia de Mamíferos Reservatórios Silvestres", "Instituto Oswaldo Cruz", "Fundação Oswaldo Cruz"(LBCE-Fiocruz); and "Laboratório de Biodiversidade", "Universidade Federal de Goiás", "Regional Jataí" (LZE-UFG), and took 20 craniometric measurements. Craniometry was explored using unweighted pair group method with arithmetic mean (UPGMA), canonical variate analysis, and principal component analysis (PCA). The results led us to conclude that there are three craniometric groups of H. megacephalus with a tendency to differentiate as a result of geographical influences.(AU)

Com grande diversidade genética e distribuição geográfica, Hylaeamys megacephalus (G. Fisher, 1814) ocorre tanto na Amazônia quanto no Cerrado. Visto seu aspecto generalista, esta espécie tolera diversos hábitos alimentares e habitats, ocorrendo em áreas inundadas ou não, sendo predominantemente terrestre, permitindo maior fluxo de genes entre as populações, mesmo em longas distâncias. Apresenta ampla distribuição, e carece de estudos que busquem um melhor entendimento sobre as variações morfológicas resultantes das diferenças impostas pelo meio ao longo de sua distribuição. O estudo teve como objetivo, analisar as diferenças entre as populações de H. megacephalus, com base na craniometria investigando se o ambiente interfere na morfologia. Analisamos um total de 142 espécimes oriundos de coleções científicas de mamíferos, do Museu Nacional, Universidade Federal do Rio de Janeiro (MN-UFRJ), Laboratório de Biologia e Parasitologia de Mamíferos Reservatórios Silvestres, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz (LBCE-Fiocruz) e Laboratório de Biodiversidade, Universidade Federal de Goiás, Regional Jataí, nos quais foram tomadas 20 medidas craniométricas. A craniometria foi explorada nas análises estatísticas de agrupamento de pares não ponderados com médias aritméticas (UPGMA), variação canônica e análise dos Componentes Principais (PCA). Os resultados encontrados nos levaram a concluir a existência de três grupos craniométricos da espécie de H. megacephalus com tendência a se diferenciarem, por influências geográficas.(AU)

Estudo descritivo e morfométrico do crânio do Ramphastos toco (Aves: Piciformes) / A descriptive and morphometric study of the skull of the Ramphastos toco (Aves: Piciformes)

O estudo de caracteres morfológicos e suas funções biomecânicas na estrutura craniana das aves levanta debates de cunho filogenético, taxonômico e morfofuncional. O objetivo deste trabalho foi descrever e analisar caracteres morfológicos e morfométricos do esqueleto do Ramphastos toco e confrontá-los com a bibliografia disponível. Foram analisados 13 crânios de indivíduos adultos e de um espécime dissecado fixado em formol (4%). As carcaças foram submetidas à técnica de maceração para o preparo dos esqueletos, com a retirada dos tecidos moles, desengorduramento e clareamento em água oxigenada (50%) e hipoclorito de sódio (50%). O formato e amplitude da sutura naso-frontal e zona flexora craniofacial, a presença dos sesamóides intracapsulares rostral e caudal na articulação quadrática e a presença do ligamento pós-orbital foram fatores que desafiaram a bibliografia existente e os modelos de transferência de força propostos durante estudos da cinética craniana da espécie. A discussão que emerge é a possibilidade dessas características limitadoras da cinética craniana descritas nos espécimes possuírem, em conjunto, a função de promover estabilidade funcional para uma estrutura cuja natureza dimensional, em si, gera instabilidade. Os resultados morfométricos também apresentaram divergências significativas quando comparados à bibliografia disponível, o que pode estar relacionado a variáveis como especiação alopátrica, hibridização e amostragem.(AU)

The study of morphological traits and their biomechanical roles in the cranial structure of birds raises phylogenetic, taxonomic and morphofunctional debates. The aim of this study was to describe and analyze morphological and morphometric data of the skull of Ramphastos toco and to compare the results with the available bibliography. Thirteen adult skulls and one folmaldehyde-fixed dissected specimen were analyzed. For skeletal preparation, the carcasses were submitted to maceration with the removal of soft tissues, degreasing and bleaching in hydrogen peroxide (50%) and sodium hypochlorite (50%). The shape and size of the naso-frontal suture, the presence of the rostral and caudal intracapsular sesamoids in the quadratic joint and the presence of the orbital ligament were altogether elements that challenged the available data. It also challenges the strength transferring models proposed in kinetic studies for the species. The discussion that emerges is the possibility of these limiting characteristics of the cranial kinetics described on the specimens have, together, a single role promoting functional stability to a structure that has a dimensional nature that generates instability. The morphometric results also presented significant divergences when compared to the available bibliography, which may be related to variables such as allopatric speciation, hybridization and sampling.(AU)

Estudo descritivo e morfométrico do crânio do Ramphastos toco (Aves: Piciformes) / A descriptive and morphometric study of the skull of the Ramphastos toco (Aves: Piciformes)

O estudo de caracteres morfológicos e suas funções biomecânicas na estrutura craniana das aves levanta debates de cunho filogenético, taxonômico e morfofuncional. O objetivo deste trabalho foi descrever e analisar caracteres morfológicos e morfométricos do esqueleto do Ramphastos toco e confrontá-los com a bibliografia disponível. Foram analisados 13 crânios de indivíduos adultos e de um espécime dissecado fixado em formol (4%). As carcaças foram submetidas à técnica de maceração para o preparo dos esqueletos, com a retirada dos tecidos moles, desengorduramento e clareamento em água oxigenada (50%) e hipoclorito de sódio (50%). O formato e amplitude da sutura naso-frontal e zona flexora craniofacial, a presença dos sesamóides intracapsulares rostral e caudal na articulação quadrática e a presença do ligamento pós-orbital foram fatores que desafiaram a bibliografia existente e os modelos de transferência de força propostos durante estudos da cinética craniana da espécie. A discussão que emerge é a possibilidade dessas características limitadoras da cinética craniana descritas nos espécimes possuírem, em conjunto, a função de promover estabilidade funcional para uma estrutura cuja natureza dimensional, em si, gera instabilidade. Os resultados morfométricos também apresentaram divergências significativas quando comparados à bibliografia disponível, o que pode estar relacionado a variáveis como especiação alopátrica, hibridização e amostragem.

The study of morphological traits and their biomechanical roles in the cranial structure of birds raises phylogenetic, taxonomic and morphofunctional debates. The aim of this study was to describe and analyze morphological and morphometric data of the skull of Ramphastos toco and to compare the results with the available bibliography. Thirteen adult skulls and one folmaldehyde-fixed dissected specimen were analyzed. For skeletal preparation, the carcasses were submitted to maceration with the removal of soft tissues, degreasing and bleaching in hydrogen peroxide (50%) and sodium hypochlorite (50%). The shape and size of the naso-frontal suture, the presence of the rostral and caudal intracapsular sesamoids in the quadratic joint and the presence of the orbital ligament were altogether elements that challenged the available data. It also challenges the strength transferring models proposed in kinetic studies for the species. The discussion that emerges is the possibility of these limiting characteristics of the cranial kinetics described on the specimens have, together, a single role promoting functional stability to a structure that has a dimensional nature that generates instability. The morphometric results also presented significant divergences when compared to the available bibliography, which may be related to variables such as allopatric speciation, hybridization and sampling.

Craniometria em lobos-guará Chrysocyon brachyurus Illiger, 1815 (Carnivora, Canidae) / Craniometric measurements in maned wolves Chrysocyon brachyurus Illiger, 1815 (Carnivora, Canidae)

Os objetivos do presente trabalho foram obter mensurações em crânios de Chrysocyon brachyurus adultos, caracterizar valores craniométricos para a espécie e observar se a classificação craniométrica de cães domésticos é adequada para o lobo-guará. Foram utilizados sete crânios de lobo-guará adultos, sem distinção de sexo. Determinou-se a localização de nove pontos craniométricos utilizados em cães domésticos para o lobo-guará. Os pontos foram referência para as 18 medidas craniométricas utilizadas para o cálculo de seis índices craniométricos. Os índices craniométricos são: cefálico 96,147 ± 3,89 mm, crânio facial 1,06 ± 0,20 mm, do neurocrânio 61,68 ± 1,83 mm, facial 100,06 ± 3,36 mm, basal 29,79 ± 1,18 mm, e do forame magno 89,25 ± 7,82 mm. A classificação em braquicefálico, dolicocefálico ou mesaticefálico não se adequa a Chrysocyon brachyurus.(AU)

The aim of this study was to obtain craniometric measures in adult Chrysocyon brachyurusskulls, establish craniometric values for the species, and determine if the craniometric classification of domestic dogs is suitable for the maned wolf. Seven skulls of adult maned wolves were used, with no gender distinction. Nine craniometric points used in domestic dogs were used for the maned wolf. The points served as reference to 18 craniometric measurements used subsequently to calculate six skull indices. Craniometric indeces were: cefalic 96.147 ± 3.89 mm, craniofacial 1.06 ± 0.20 mm, neurocranium 61.68 mm ± 1.83, facial 100.06 ± 3.36 mm, basal 29.79 ± 1.18 mm, and foramen magnum index of 89.25 ± 7.82 mm. The usual classification in brachicephalic, dolichocephalic, and mesaticephalic is not valid for Chrysocyon brachyurus.(AU)

Craniometria em lobos-guará Chrysocyon brachyurus Illiger, 1815 (Carnivora, Canidae) / Craniometric measurements in maned wolves Chrysocyon brachyurus Illiger, 1815 (Carnivora, Canidae)

Os objetivos do presente trabalho foram obter mensurações em crânios de Chrysocyon brachyurus adultos, caracterizar valores craniométricos para a espécie e observar se a classificação craniométrica de cães domésticos é adequada para o lobo-guará. Foram utilizados sete crânios de lobo-guará adultos, sem distinção de sexo. Determinou-se a localização de nove pontos craniométricos utilizados em cães domésticos para o lobo-guará. Os pontos foram referência para as 18 medidas craniométricas utilizadas para o cálculo de seis índices craniométricos. Os índices craniométricos são: cefálico 96,147 ± 3,89 mm, crânio facial 1,06 ± 0,20 mm, do neurocrânio 61,68 ± 1,83 mm, facial 100,06 ± 3,36 mm, basal 29,79 ± 1,18 mm, e do forame magno 89,25 ± 7,82 mm. A classificação em braquicefálico, dolicocefálico ou mesaticefálico não se adequa a Chrysocyon brachyurus.

The aim of this study was to obtain craniometric measures in adult Chrysocyon brachyurusskulls, establish craniometric values for the species, and determine if the craniometric classification of domestic dogs is suitable for the maned wolf. Seven skulls of adult maned wolves were used, with no gender distinction. Nine craniometric points used in domestic dogs were used for the maned wolf. The points served as reference to 18 craniometric measurements used subsequently to calculate six skull indices. Craniometric indeces were: cefalic 96.147 ± 3.89 mm, craniofacial 1.06 ± 0.20 mm, neurocranium 61.68 mm ± 1.83, facial 100.06 ± 3.36 mm, basal 29.79 ± 1.18 mm, and foramen magnum index of 89.25 ± 7.82 mm. The usual classification in brachicephalic, dolichocephalic, and mesaticephalic is not valid for Chrysocyon brachyurus.

Anatomical and radiographic study of the white-eared opossum (Didelphis albiventris) skull / Estudo anatômico e radiográfico do crânio no gambá-de-orelha-branca (Didelphis albiventris)

This study was made to investigate the anatomical features of the white-eared opossum skull, by osteology and radiographic anatomy. For this, five animals were used without sexual distinction. The skull was examined by radiographic and macroscopic characteristics. The skulls were then subjected to maceration. The skull was described macroscopically according to standard views, i.e. dorsal and caudal, lateral, ventral, and midsagittal. The skull can be divided into facial (viscerocranium) and cranial (neurocranium) regions. The facial region was elongated and more developed than neurocranium. The supraorbital foramen was absent. The tympanic bulla is not well developed. The zygomatic arch was formed by zygomatic process of the temporal bone, zygomatic process of the maxilla, and temporal process of the zygomatic bone. There was no significant difference between bones found in this study when compared with those described for others mammals. These findings may contribute to the better understanding of the anatomy and biology of the white-eared opossum.(AU)

Este estudo objetivou investigar as características anatômicas do crânio do gambá-de-orelha-branca, através da anatomia óssea e radiográfica. Para tanto, cinco animais foram usados sem distinção sexual. O crânio foi estudado através de análises radiográficas e macroscópicas. Para esta última, os crânios foram macerados. O crânio foi descrito macroscopicamente de acordo com as vistas ou normas rotineiras, isto é, dorsal e caudal, lateral, ventral e sagital. O crânio pode ser dividido em regiões facial (viscerocrânio) e cranial (neurocrânio). A região facial se mostrou alongada e mais desenvolvida que o neurocrânio. O forame supraorbital estava ausente. A bula timpânica não era bem desenvolvida. O arco zigomático era formado pelo processo zigomático do osso temporal, processo zigomático da maxila, e pelo processo temporal do osso zigomático. Não houve diferenças significativas entre os ossos estudados quando comparados com os já descritos para outros mamíferos. Estes resultados podem contribuir com um melhor entendimento da anatomia e biologia deste animal.(AU)

Anatomical and radiographic study of the white-eared opossum (Didelphis albiventris) skull / Estudo anatômico e radiográfico do crânio no gambá-de-orelha-branca (Didelphis albiventris)

This study was made to investigate the anatomical features of the white-eared opossum skull, by osteology and radiographic anatomy. For this, five animals were used without sexual distinction. The skull was examined by radiographic and macroscopic characteristics. The skulls were then subjected to maceration. The skull was described macroscopically according to standard views, i.e. dorsal and caudal, lateral, ventral, and midsagittal. The skull can be divided into facial (viscerocranium) and cranial (neurocranium) regions. The facial region was elongated and more developed than neurocranium. The supraorbital foramen was absent. The tympanic bulla is not well developed. The zygomatic arch was formed by zygomatic process of the temporal bone, zygomatic process of the maxilla, and temporal process of the zygomatic bone. There was no significant difference between bones found in this study when compared with those described for others mammals. These findings may contribute to the better understanding of the anatomy and biology of the white-eared opossum.(AU)

Este estudo objetivou investigar as características anatômicas do crânio do gambá-de-orelha-branca, através da anatomia óssea e radiográfica. Para tanto, cinco animais foram usados sem distinção sexual. O crânio foi estudado através de análises radiográficas e macroscópicas. Para esta última, os crânios foram macerados. O crânio foi descrito macroscopicamente de acordo com as vistas ou normas rotineiras, isto é, dorsal e caudal, lateral, ventral e sagital. O crânio pode ser dividido em regiões facial (viscerocrânio) e cranial (neurocrânio). A região facial se mostrou alongada e mais desenvolvida que o neurocrânio. O forame supraorbital estava ausente. A bula timpânica não era bem desenvolvida. O arco zigomático era formado pelo processo zigomático do osso temporal, processo zigomático da maxila, e pelo processo temporal do osso zigomático. Não houve diferenças significativas entre os ossos estudados quando comparados com os já descritos para outros mamíferos. Estes resultados podem contribuir com um melhor entendimento da anatomia e biologia deste animal.(AU)

Measurement of Incisor Overjet and Physiological Diastemata Parameters in Quarter Horse Foals.

Cephalometric studies are important to quantify abnormalities of jaw length and positioning. In this study, 4 to 7-month-old Quarter horse foals (n = 51) were examined to determine overjet (horizontal overlap) prevalence and measure the size of the physiological diastemata. Results were analyzed in relation to age, sex, and lineage. Another aim of this study was to develop a simple field technique for measuring incisor malocclusion and physiological diastemata dimensions that could be used to monitor the growth of the rostral components of maxilla, incisive bone, and mandible. The overall prevalence of overjet lesions in these foals was 51%. Females were overrepresented (61.5%). Overjet occurred more commonly in show foals (50% prevalence) than other working (7.7%) and race (42.3%) lineage foals. Significant differences were found between maxillary and mandibular physiological diastemata lengths in foals of all ages and, as expected, there was a positive statistical correlation between age and maxillary and mandibular physiological diastemata measurements. Incisor overjet was present in 44.4% of 4-month-old foals, 45.5% of 5-month-old foals, 58.3% of 6-month-old foals, and 60% of 7-month-old foals. There was a weak positive correlation between age and the presence of incisor overjet. It was concluded that incisor overiet was common among Quarter horse foals, especially those from show and race lineages. The field technique for physiological diastema measurements was considered effective.

Craniometria, morfometria do encéfalo e tipologia do circuito arterial da base do encéfalo em gatos / Craniometry, morphometry of brain and arterial circuit typology in brain cats

Os objetivos deste estudo foram descrever a tipologia do circuito arterial, a craniometria e a morfometria do encéfalo em gatos de ambos os sexos. As dissecções foram realizadas em 50 cadáveres de gatos adultos, 25 machos e 25 fêmeas, com média do comprimento rostro-sacral de 47,9cm e 46,6 cm, respectivamente. Os gatos foram posicionados em decúbito lateral direito e feita uma incisão torácica para remoção da 6ª e 7ª costelas para canulação da porção torácica da aorta. Após fixação com solução de formaldeído a 10% e preenchimento do sistema arterial com solução de látex corado procedeu-se a craniometria, craniotomia, remoção e morfometria dos encéfalos e dissecção para a observação da tipologia dos vasos responsáveis pela formação circuito arterial. Na presente pesquisa foi observado que, os machos apresentaram comprimento total do crânio, comprimento do crânio, largura do crânio e largura da face maior que as fêmeas. As fêmeas apresentaram o maior comprimento da face. Machos apresentaram maior índice da face enquanto que as fêmeas apresentaram maior índice do crânio. Não houve diferença nas medidas do cerebro e cerebelo. As artérias da base do encéfalo estiveram na dependência dos sistemas carótico e vértebro-basilar, responsáveis pela formação do circuito arterial do encéfalo. O padrão vascular encefálico dos gatos apresentou tendência do subtipo 2 alfa ao subtipo 2 beta, e encontrou-se entre os estágios médio e final de seu desenvolvimento filogenético(AU)

The aims of this study were to describe the typology of the arterial circuit of brain, craniometric measures and morphometry ofthe brain in cats of both sexes. The anatomical dissections were performed in 50 cadavers of adult cats, 25 male and 25 female,with a rostrum-sacral length of 47.9 cm and 46.6 cm respectively. After fixed with 10% formaldehyde solution and performing theinjections with latex solution stained with pigment the craniometric measures, craniotomy, morphometry of the brain and dissectionwere made to identify the typology of the arterial circuit. In this study it was observed that males had total length of the skull, skulllength, skull width and face width larger than the females. Females showed the greatest length of the face. Males had higherrates of the face while females had higher rates of the skull. There were no differences in measures of brain and cerebellum. Thearteries of the base of the brain had been in the dependence of the carotid and vertebral-basilar systems, which are responsiblefor the brain arterial circuit formation. The cats brain vascular pattern tended to be from subtype 2 alpha to beta 2 subtype, andconsidered among the middle and final stages of phylogenetic development(AU)

Qual a acurácia das medidas ultrassonográficas fetais na predição da data do parto em gatas mesaticefálicas e braquicefálicas? / What is the Accuracy of the Ultrasonographic Fetal Measures in the Prediction of Parturition in Mesaticephalic and Brachycephalic Cats?

Background: Ultrasound is commonly used in queens for diagnosis and monitoring of pregnancy and may also be used to estimate the date of birth in cats with unknown date of mating, representing a valuable aid in clinical practice and in reproductive programs. The determination of gestational age can be made based on sonographic fetal measurements. In bitches, the conformation of the cranium should be considered in proportional variations in measurements because it interferes with predicting parturition date. Although domestic cats do not show a large variation in terms of size, they present variation in the cranial conformation. So far, there is no study that has produced mathematical equations for determination of gestational age in cats considering these differences. Thus, there is a widespread use of these equations that can lead to mistakes in this estimation. This study aimed to verify the accuracy of prediction of delivery date in cats of different cranial conformation through mathematical equations enshrined in clinical practice, using different sonographic measurements and verify the effect of litter size on the accuracy of determination of days to delivery. Materials, Methods & Results: Sonographic examinations were performed on pregnant brachycephalic and mesaticephalic cats. Biparietal and abdominal diameters and depth of the fetal diencephalo-telencephalic vesicle were measured. The average value of each structure was calculated and ultrasound prediction of days before delivery was obtained by applying equations derived from growth curves that have been already published. All mathematical equations used in predicting the date for delivery showed lower percentage of success, regardless of the type of the parameter and cranial ultrasound used. The biparietal diameter was the most reliable measure for estimating the date of delivery. The litter size did not influence the accuracy of determining the date of delivery. Discussion: Although queens have ovulation induced by copulation and date of birth would be more easily predicted than in bitches, with a good accuracy and subsequent birth date, it is extremely important to be able to plan clinical delivery assistance or a c-section. In this study, the application of the equations derived from the growth curves of biparietal and abdominal diameter and depth of the fetal diencephalo-telencephalic vesicle resulted in little accurate predictions of delivery date for the three and sonographic parameters for both types cranial. The generalization use of these equations for cats may lead to errors in the estimation of gestational age. Although the equations used in this study are old, we opted for their use in this work, because they are still widely used in ultrasound practice, still being cited in recent publications on this subject. Studies that performed the ultrasound monitoring of pregnancy in cats and dogs show that the fetus ordinary course follows a well-defined development with particular characteristics of development at specific times during pregnancy. This makes clear that the evaluation of these characteristics is useful for predicting the day of delivery and can also be applied in other breeds, unlike the mathematical equations that are specific to each breed standard. Thus, it is suggested that the estimate of gestational age is made in conjunction with the fetometry and observation of fetal growth and subsequent organogenesis, avoiding the use of one of the tools individually so that one has higher reliability in this prediction. Thus, it was concluded that the mathematical equations already published are not individually sufficient for accurate determination of date of birth in brachycephalic and mesaticephalic cats.

Morfometria e morfologia da articulação temporomandibular por meio do exame de tomografia computadorizada em Canis familiaris mesaticefálicos e braquicefálicos / Temporomandibular morphometry and morphology by means of computed tomography in brachycephalic and mesaticephalic Canis familiaris

A articulação temporomandibular do cão é considerada como uma articulação condilar verdadeira ou sinovial, conformada por duas superfícies articulares: a fossa mandibular e processo condilar, as quais permitem abrir e fechar a boca. [...] O objetivo desta pesquisa foi determinar por meio de exame de tomografia computadorizada, tanto as características morfométricas das superfícies articulares quanto a relação existente entre as mesmas, em cães adultos mesaticefálicos e braquicefálicos. Foram mensuradas a profundidade e largura da fossa mandibular, e sequencialmente 5 diferentes ângulos relacionando as superfícies articulares em 34 articulações temporomandibulares de 17 cães mesaticefálicos e 62 articulações temporomandibulares de 31 cães braquicefálicos. As mensurações realizadas permitiram estabelecer as características morfológicas e o grau de relação articular temporomandibular nos cães deste estudo. As articulações temporomandibulares dos cães mesaticefálicos e braquicefálicos de pequeno e médio porte apresentaram fossas mandibulares pouco profundas, processos retroarticulares pouco desenvolvidos e processos condilares irregulares. Já os cães mesaticefálicos e braquicefálicos de grande porte apresentaram articulações mais congruentes, com fossas mandibulares mais profundas, processo retroarticulares bem evidentes e processos condilares mais uniformes. A mediana do ângulo de relação articular variou para os cães mesaticefálicos entre 123° e 172°, e para os cães braquicefálicos entre 96° e 167°. A tomografia computadorizada demostrou ser uma ferramenta de grande valia tanto na identificação dos pontos de referência quanto na obtenção das mensurações propostas neste trabalho

The temporomandibular joint (TMJ) in the dog is regarded as a true or synovial condylar joint, formed by two articular surfaces: the mandibular fossa and the condylar process, which allows opening and closing of the mouth. This joint could be affected by congenital, traumatic, neoplastic and degenerative disorders that may affect the animals ability to prehend or eat food. Although several imaging techniques have been used to describe the anatomical conformation of the TMJ in the dog, there are no morphometric studies using computed tomography to describe the TMJ structures or the anatomical relationship between them. The aim of this study was to determine measurable parameters that detail the morphometry of the temporomandibular bony structures and their anatomical relationship by means of computed tomography performed in normal adult mesaticephalic and brachycephalic dogs. In 17 mesaticephalic dogs (34 TMJs) and 31 brachycephalic dogs (62 TMJs), measurements were taken of the depth and width of the mandibular fossa as well as five different angles relating the mandibular fossa, retroarticular process and condylar process. The temporomandibular joints of small and medium-sized brachycephalic and mesaticephalic dogs showed shallow mandibular fossas, poorly developed retroarticular processes and irregular mandibular heads. On the other hand, large brachycephalic and mesaticephalic dogs showed more congruent temporomandibular joints with deeper mandibular fossas, marked retroarticular process and more uniform condylar processes. The median value range of the temporomandibular joint relationship angle in mesaticephalic dogs was between 123° and 172°, and for brachycephalic dogs between 96° and 167°. Computed tomography Computed tomography proved to be a valuable tool for identifying normal reference points for measuring TMJ depth, width and anatomical conformation

Virtual reconstructions of the endocranial cavity of Rhea americana (Aves, Palaeognathae): postnatal anatomical changes.

We examined the external anatomy of the endocast of the Greater Rhea (Rhea americana, Palaeognathae), during 3 main stages of its postnatal life, and compared it with information available on other palaeognathous birds. Series of scans with spiral computed tomographies were obtained from 3 skulls of different ages (chick, juvenile and adult) of R. americana; digital 3-dimensional reconstruction was performed and brain volumes were calculated from the models obtained. Qualitative assessment of the brain anatomy of R. americana indicates a conical and ventrally located bulbus olfactorius, laterally expanded hemispherium telencephali, well-developed eminentia sagittalis, and conspicuous cerebellum and tectum mesencephali. Anatomy of the chick brain was markedly different: less lateral expansion of the hemispherium telencephali, and lesser development of the eminentia sagittalis and auricula cerebelli. Little change between chicks and adults was observed in some brain regions such as the tectum mesencephali, while the eminentia sagittalis showed great increase in size. The large size of the eminentia sagittalis coupled with its increasing development during ontogeny could reflect its importance for visual processing functions and the way these improve during growth. Finally, the brain of R. americana is similar to that of Struthio and Dromaius, but differs from that of the Tinamidae and of Apteryx, allowing recognition of 3 distinct brain morphologies among the Palaeognathae.

Using a specially designed cephalostat for longitudinal cephalometric studies in rats.

To better understand and observe craniofacial growth, researchers carry out longitudinal cephalometric studies on animals. The authors constructed a cephalostat specially designed to study craniofacial growth in rats. They describe and validate a cephalometric technique using this cephalostat. They carried out cephalometric radiography and analysis of 62 Wistar rats. By using this method, the authors were able to take repeated, reproducible intracranial, intramandibular and craniomandibular measurements of the rats. The proposed method is a useful tool for studying the craniofacial growth process.

Head morphology and degree of variation in lacerta bilineata: podarcis muralis and podarcis sicula / Morfología de la cabeza y el grado de variación en lacerta bilineata: podarcis muralis y podarcis sicula

The morphology of cephalic scales in Lacertids is organised in well defined geometrical structures. The variation of these elements is related to the underlying bone growth and morphogenesis, but it is also associated with the muscular system and the sutural dynamics. In this paper, the patterns of variation of the cephalic scales have been compared between three common Mediterranean species: Podarcis muralis, Podarcis sicula and Lacerta bilineata. The morphospace generated by the morphological relationships within the cephalic system in these three species is investigated in order to consider their degree of variation and their anatomical peculiarities. Generally, Lacerta is 64 percent larger than Podarcis, shows a relative reduction of the frontal scale, enlarged fronto-parietal structures, and stretched occipital area. L. bilineata shows the smaller degree of variation within the shape space, while P. muralis shows the highest values. The morphology of the two genera is definitely different mostly because of allometric variation. Non-allometric distinctions between the three species are subtle but detectable. The degree and pattern of variation are interpreted in terms of possible environmental pressures and of functional cranial dynamics associated with the fronto-parietal suture, respectively. In this sense, the structural relationships between bones and scales are of particular interest to further investigate ontogeny and phylogeny in reptiles.

La morfología de las escamas cefálicas en Lacértidos se organiza en estructuras geométricas bien definidas. La variación de estos elementos está relacionada con el crecimiento y la morfogénesis del hueso subyacente, pero está también es asociada con el sistema muscular y sutural dinámico. En este trabajo, son comparados los patrones de variación de las escamas cefálicas de tres especies mediterráneas comunes: Podarcis muralis, Podarcis sicula y Lacerta bilineata. El morfoespacio generado por las relaciones morfológicas con el sistema cefálico en estas tres especies se investigó con el fin de examinar su grado de variación y sus peculiaridades anatómicas. En general, Lacerta es 64 por ciento más grande que Podarcis, muestra una reducción relativa de la escama frontal, alargamiento de la estructura fronto-parietal, y estrechamiento del área occipital. L. bilineata muestra el menor grado de variación en la forma del espacio, mientras que P. muralis muestra los valores más altos. La morfología de los dos géneros es diferente principalmente debido a variaciones alométricas. Diferencias no alométricas entre las tres especies son sutiles pero detectables. El grado y el patrón de variación son interpretados en términos de las posibles presiones del medio ambiente y la dinámica funcional craneal asociada a la sutura fronto-parietal, respectivamente. En este sentido, las relaciones estructurales entre los huesos y las escamas son de particular interés para seguir investigando ontogenia y filogenia de los reptiles.

Sexual dimorphism with respect to the macro-morphometric investigations of the forebrain and cerebellum of the grasscutter (Thryonomys swinderianus) / Dimorfismo sexual en relación con la investigación macro-morfométrica del cerebro y cerebelo del grasscutter (Thryonomys swinderianus)

This study was carried out to record the morphometric parameters of the brain of male and female grasscutters. Ten healthy grasscutters (5 males and 5 females) were used in this study. The mean brain weights were 9.80 + 0.50 g and 10.27 + 0.45 g for males and females respectively. The olfactory bulb mean weight was 0.57 + 0.05 g for males and 0.43 + 0.10 g for females. The cerebral and cerebellar mean lengths of 3.14 + 0.04 cm and 1.34 + 0.04 cm for males, 6.26 + 0.10 cm and 3.80 + 0.32 cm for females were observed. The cerebrum, cerebellum and olfactory bulb account for 70%, 12% and 6% of the total brain weight in males and 64%, 13% and 4% in the females respectively. The mean brain lengths were 5.63 + 0.07 cm and 6.26 + 0.1 cm for males and females respectively. There were significant differences in the body and olfactory bulb weights and also, in the whole brain and cerebral lengths between the males and females. In our present research, the ratios of 0.01 for males and 0.006 for females were observed. This suggests a relatively low brain weight in the ruminants. The olfactory bulb in the male is larger than that in the females. Females in turn have longer brain dimension than the males. Cerebellum has no sex variation both in weight and in length.

Este estudio se llevó a cabo para registrar los parámetros morfométricos del cerebro de grasscutters machos y hembras. Diez grasscutters sanos (5 machos y 5 hembras) fueron utilizados en este estudio. La media de peso del cerebro fueron 9,80 +/- 0,50 g y 10,27 +/- 0,45 g para los machos y hembras respectivamente. El peso medio del bulbo olfatorio fue 0,57 +/- 0,05 g para los machos y 0,43 +/- 0,10 g para las hembras. La longitud media del cerebro y del cerebelo fue de 3,14 +/- 0,04 y 1,34 cm +/- 0,04 cm para los machos, y 6,26 +/- 0,10 cm y 3,80 +/- 0,32 cm para las hembras, en las muestras observadas. El cerebro, cerebelo y el bulbo olfatorio representaron un 70%, 12% y el 6% del peso total del cerebro en machos y 64%, 13% y 4% en las hembras, respectivamente. La media de las longitudes del cerebro fueron 5,63 +/- 0,0 y 6,26 cm +/- 0,1 cm para los machos y hembras respectivamente. Hubo diferencias significativas en el peso del cuerpo y el bulbo olfatorio, y también en la longitud total del cerebro de machos y hembras. En nuestra actual investigación, los índices de 0,01 para los machos y de 0,006 para las hembras fueron observados. Esto sugiere un peso relativamente bajo en el cerebro de rumiantes. El bulbo olfatorio en los machos es mayor que en las hembras. A su vez, las hembras presentan una dimensión cerebral mayor que los machos. El cerebelo no tuvo variación según el sexo tanto en peso como en longitud.

A reliable positioning device for dorsoventral cephalometric radiography of the rat.

In dental research, dorsoventral cephalometric radiography is often used to assess skull growth and dental movement in rat models. To ensure that images can be reproduced, radiographers must use a cephalostat to maintain the rat's head in a consistent position across imaging sessions. The authors describe a positioning device they designed that connects easily to a standard dental X-ray machine. The device enabled researchers to position rats repeatedly for radiographic imaging with very little variation.