Navegando por Assunto "Dentes"

Agora exibindo 1 - 5 de 5

Acesso aberto (Open Access)
Anatomical and histological characteristics of teeth in agouti (Dasyprocta prymnolopha Wagler, 1831)
(2013-12) SILVA, Daiane Claydes Baia da; FAGUNDES, Nathália Carolina Fernandes; TEIXEIRA, Francisco Bruno; PENHA, Nelson Elias Abrahão da; SANTANA, Luana de Nazaré da Silva; OLIVEIRA, Ana Cristina Mendes de; LIMA, Rafael Rodrigues
The agouti species Dasyprocta prymnolopha (D. prymnolopha) is a medium-sized rodent, diurnal, and characteristic of northeastern Brazil, south of the Amazon. Several studies have been made on these rodents. However, there is a lack of analysis of masticatory system, in particular morphology of the teeth. Thus, this research seeks to describe anatomical and histological aspects of the agouti teeth. For this purpose, we used adult agouti, in which measurements and descriptions of teeth and dental tissues were made. It was observed that the dental arch of D. prymnolopha comprises of twenty teeth, evenly distributed in the upper and lower arch, being inferior teeth larger than their corresponding higher. The incisors are larger, and between the posterior premolars and molars, there is a gradual increase in length in the anterior-posterior arch. In microscopic examination, a prismatic appearance was observed consisting of enamel prisms arranged in different directions, behind the enamel and dentin with standard tubular dentinal tubules with variable diameter and far between, also showing a sinuous path from the inner portion to the junction with more superficial enamel. Morphological analysis of dental tissues showed that an enamel with structural organization adapted to the act of chewing and high impact dentin compatible with standard tubular function resilience and mechanical damping of masticatory forces, as found in larger animals, confirming the understanding of eating habits that define much of its ecological functions within the ecosystem they inhabit.
Acesso aberto (Open Access)
Avaliação comparativa da ultraestrutura e propriedades físicas do esmalte bovino, bubalino e humano
(2014-05) NOGUEIRA, Bárbara Catarina Lima; FERNANDES, Piero Maia; PAIVA, Augusto Cezar Justino; FAGUNDES, Nathália Carolina Fernandes; TEIXEIRA, Francisco Bruno; LIMA, Rafael Rodrigues
This study aimed to compare the morphology and physical properties of the enamel structure of bovine, buffalo and human teeth. Analysis of this tissue was performed by scanning electron microscopy, mineral composition, microhardness and surface roughness of enamel in 41 buffalo incisors (Bos taurus indicus), 41 bovine incisors (Pelorovis antiques), and 30 human permanent incisors. The results showed a significant similarity between the ultrastructure of enamel in these animal species and the one found in human samples. The chemical elements which presented higher concentration in bovine and buffalo enamel were: O,Ca and P, precisely those that form hydroxyapatite crystals - Ca10(PO4)6(OH)2. Knoop microhardness values showed no statistically significant differences between the three species. However, the surface roughness of buffalo enamel (2.16µm ±0.23) was significantly higher when compared with human (0.36µm ±0.05) and bovine teeth (0.41µm ±0.07). It is concluded that the characteristics and properties of bovine and buffalo enamel, as obtained from our analysis and testing, showed a similar morphology to that of humans. They showed a similar ultrastructural architecture, microhardness and mineral composition equivalent to the human dental tissue, becoming reference models for research.
Acesso aberto (Open Access)
Determinação de parâmetros para a avaliação de carcaça em bubalinos machos no Estado do Pará
(Universidade Federal do Pará, 2006-04-04) SEIXAS, Vitória Nazaré Costa; ARAÚJO, Cláudio Vieira de; http://lattes.cnpq.br/5049897507837031; CARDOSO, Elyzabeth da Cruz; http://lattes.cnpq.br/8805703740727765
This work had as objective to create a protocol for identification of carcass’ quality of male buffalo abated at the Pará State. For this purpose, the work was conducted in two stages. Firstly, were utilized 174 animals for the creation and implementation of the age identification protocol throughout the development of the incisive teeth pairs and the linear measures of hindquarters and height of anterior part, thoracic perimeter and body length. The second stage was the ratification of the preestablished protocol inserted on the evaluation of carcass characteristics through the cold and hot carcass efficiency plus five other typical parameters using 76 abated animals. Was noted the absence of the deciduous corner (fourth pair) in the animals from zero to three months. These corners were definitively noted between three and six months. From six months the incisive deciduous teeth are all presents and established. At the 24th month started the change of the “tweezers” (first tooth pair). Between the 30th and 50th month occurred the change second and third teeth pairs and from the 55th month the change of the fourth teeth pair. From the 55th to the 100th month the animals showed established all incisive permanent teeth. The live weight showed a positive and significant correlation with the linear measures. From the 25,7th to the 30th month was a reduction on the growth tax in consequence of the puberty and development of the fat layer. From 18th there was not significant difference on the carcass characteristics except in relation to the shoulder blade. Thus, we conclude that the beginning of the “tweezers” teeth change is the ideal age for abate where there is the coincidence of the reduction of growth tax and fat layer deposition in the carcass.
Acesso aberto (Open Access)
Luxation injuries in primary teeth: a retrospective study in children assisted at an emergency service
(2011-04) ASSUNÇÃO, Luciana Reichert da Silva; FERELLE, Antônio; IWAKURA, Maria Luiza Hiromi; NASCIMENTO, Liliane Silva do; CUNHA, Robson Frederico Cunha
The purpose of this study was to analyze luxation injuries in children between the ages of 0 and 5 years treated at an emergency service department. A total of 1,703 records, corresponding to a period of 10 years at the Emergency Center of the Baby Clinic at Londrina State University, Brazil, were analyzed. The age, gender, etiologic factors, type of injury, injured teeth, treatment and time interval between injury and treatment were determined for each patient. Of the examined records, 409 patients met the study criteria and included a total of 679 injured teeth. Statistical analyses were carried out using the chi-square test with the level of significance set at 5%. Trauma incidence was higher in boys (57.0%) and in children less than two years of age (40.3%). Falling while walking or running was the most predominant etiologic factor (37.7%), and the most prevalent type of injury was subluxation (32.6%). Luxation injuries decreased with increasing age (p = 0.045). Treatment usually occurred within the first 1-15 days and was significantly associated with the type of trauma (p = 0.041). "Monitor only" was the treatment most frequently observed (74.0%). In conclusion, more luxation injuries were found in younger children, predominantly in boys. Falls resulting from walking or running were the etiologic factor most observed, with subluxation as the most common type of trauma. Treatment usually occurred within the first 15 days after the injury. Despite the severity of these injuries, "monitor only" was the eligible treatment.
Acesso aberto (Open Access)
Morfologia radicular da dentição permanente de Sapajus apella: morfometria, anatomia macroscópica, ultraestrutura e propriedades físicas
(2014-08) FERNANDES, Luanna de Melo Pereira; NASCIMENTO, Elder Monteiro do; NUNES, Camila Santa Rosa; VIEIRA, Elma Pinto; LINS, Paula Dias; TEIXEIRA, Francisco Bruno; COUTO, Roberta Souza D'Almeida; LIMA, Rafael Rodrigues
This paper aimed the anatomical study including morphometric, ultrastructural and physical properties of permanent teeth of Sapajus apella primate. Ten adult male monkeys were studied. The teeth were evaluated for their length, root anatomy (external and internal considering the number of roots and canals), direction and shape of the root canal, density and diameter of the tubular root canal, dentin microhardness, and composition. The root anatomy showed specificity regarding the number of roots of the second premolar and the presence of the third premolar. We observed a decrease in the number and diameter of dentinal tubules along the root canal, a statistically significant difference when compared with the apical and cervical regions. Similarities with human teeth were found in regard to microhardness values and proportion of chemical elements in the root dentin.