Search results for " cavity"
showing 10 items of 472 documents
Radiographic Investigation of Location and Angulation of Curvatures in Human Maxillary Incisors
2008
The aim of this radiographic study was to evaluate the degree and location of root canal curvatures of human maxillary incisors. A total of 286 extracted human maxillary incisors (145 central and 141 lateral incisors) were included in this investigation. Exclusion criteria were teeth with extensive carious lesions, restorations, and root canal treatment. For this in vitro study, the teeth were fixed in a special device and digitally x-rayed with the parallel technique. The distances from the cementoenamel junction (CEJ) to the first curvature and the according angle were recorded. The results were analyzed descriptively, and p values were calculated with the Wilcoxon Mann-Whitney test. The …
In vitro comparison of root-canal measurements with conventional and digital radiology.
2002
Aim The present study compared the efficacy of digital and conventional radiology for root-canal length measurement. Methodology Seventy extracted teeth with pre-served roots were used. Root-canal length measurements were completed with K-Flexofiles (numbers 08, 10 and 15) with conventional and digital radiography using two systems (radiovisiography and photostimulate storage phosphor). All films and sensors were exposed at projections of 0 degrees and 20 degrees to the mesial. The images obtained were evaluated with and without magnification, and analysed using the Cohen's kappa test. The accuracy of the three systems to determine the root-canal length were evaluated by measuring the dista…
Canal shaping with a reciprocating system is easy to learn.
2018
To assess progressive learning of root canal shaping in order to define the number of simulated canals in resin blocks needed to reach a level of learning beyond which no further improvement in performance is observed.A total of 216 simulated canals in resin blocks were instrumented by 18 operators without experience in Endodontics and by 18 Endodontists. The R25 file of the Reciproc system (VDW, Munich, Germany) was used to prepare the canals. The blocks were photographed before and after instrumentation. An analysis was made of the variations in the dimensions of the canals at 6 locations and of the instrumentation time. A Student's t-test was used to analyse the data (P 0.05).The group …
The design of artificial nestboxes for the study of secondary hole-nesting birds: A review of methodological inconsistencies and potential biases
2010
The widespread use of artificial nestboxes has led to significant advances in our knowledge of the ecology, behaviour and physiology of cavity nesting birds, especially small passerines. Nestboxes have made it easier to perform routine monitoring and experimental manipulation of eggs or nestlings, and also repeatedly to capture, identify and manipulate the parents. However, when comparing results across study sites the use of nestboxes may also introduce a potentially significant confounding variable in the form of differences in nestbox design amongst studies, such as their physical dimensions, placement height, and the way in which they are constructed and maintained. However, the use of …
Palaeohistology and palaeopathology of an Aeolosaurini (Sauropoda: Titanosauria) from Morro do Cambambe (Upper Cretaceous, Brazil)
2021
A recent publication of fossil bones of titanosaurs assigned to Aeolosaurini from the Morro do Cambambe site (Mato Grosso state, Brazil, Upper Cretaceous) reported anomalous growth in some of them. Here, we present osteohistological sections of elements to understand not only the microstructure and growth of such bones, but also the nature of those anomalies. Among them, we selected one cervical and one mediumposterior dorsal rib, and a haemal arch. The primary bone of all specimens consisted of a variation of the fibrolamellar complex, with the inner cortex being rich in woven bone with dispersed longitudinal canals, while the outer cortex was parallel-fibred with rows of longitudinal cana…
Sinonasal respiratory epithelial adenomatoid hamartoma: A report on three cases
2018
Respiratory Epithelial Adenomatoid Hamartoma (REAH) is a rare benign lesion that may occur in the nasal cavity and paranasal sinuses. Histology is essential for the differential diagnosis with other lesions that could affect the sinonasal region. Our report focuses on three cases of male patients that were 46, 66 and 73 years old, diagnosed with REAH of the sinonasal region. All cases presented a nasal obstruction and hyposmia, and in one case cephalalgia. The definitive diagnosis of REAH was supported by the endoscopic, radiological and histological examinations. The patients underwent surgical excision with an endoscopic approach and did not experience a local recurrence at the time of wr…
Pericardium of the frog,Rana esculenta,is morphologically designed as a lymphatic space
2003
The importance of the pericardium and the pericardial fluid (PF) in the control of cardiac function has emerged over the past few years. Despite the acknowledgment that amphibians are exposed to both dehydration and excessive water accumulation, nothing is known about their pericardial structure and the morphological basis of the PF formation. We have studied the parietal pericardium (PP) morphology in Rana esculenta by electron microscopy. SEM images of the inner surface, which lines the pericardial cavity, revealed the presence of large vesicles and many small circular openings. TEM observations showed that the PP is made up of an inner mesothelial lining, often constituted by two layers …
Intraoral epithelioid hemangioendothelioma: a case report and review of the literature.
2009
The epithelioid hemangioendothelioma (EH) is an uncommon angiocentric neoplasm of borderline or intermediate malignant potential, between the hemangioma and conventional angiosarcoma. It is characterized by the proliferation of endothelial cells with epithelioid or histiocitóide morphology with vacuolated cytoplasm and occasional eosinophilic spindle cells. Shows potential for local recurrence as well as the ability to metastasize. Rarely affects the oral cavity, it have been described from 1975 until 2008 only 27 oral cases. Morphologically the EHs may be confused with other lesions, from a hemangioma to a squamous cell carcinoma, and thus immunohistochemical analysis is required. This pap…
Oral encapsulated vascular malformation: an undescribed presentation in the mouth
2016
Vascular lesions have been classified in two broad categories, hemangiomas and malformations. Encapsulated vascular lesions have not been reported in the oral cavity, but they were described in other sites, mainly in the orbit. Herein, we present a case of an oral encapsulated vascular lesion located in the right buccal mucosa of a 69-year-old male, including histological and immunohistochemical description and a literature review. Key words:Buccal mucosa, hemangioma, vascular malformation, oral cavity.
Rapid quantitative method for measuring phagocytosis of Leishmania promastigotes using a double radiolabelling method.
1990
A double radiolabelling method is described for the measurement of phagocytosis of Leishmania major promastigotes in cultures of murine resident peritoneal macrophages. L. major promastigotes were radiolabelled during exponential growth in RPMI supplemented with [125I]5-iodo-2-deoxyuridine. They were used to infect sodium [51Cr]chromate-labelled macrophages. Phagocytosis was evaluated by measuring the radioactivity of the 125IUdR-labelled parasites detectable inside 51Cr-labelled macrophages by a Beckmann gamma 5500 counting system. This was able to count simultaneously, in two different windows the radioactivity of (a) the parasites and (b) the cells. The technique compares favorably with …