Search results for "Ameloblast"
showing 10 items of 85 documents
Outline and arrangement of enamel rods in human deciduous and permanent enamel. 3D-reconstructions obtained from CLSM and SEM images based on serial …
2001
Human enamel rods were made visible continuously from the dentino-enamel junction (DEJ) up to the enamel surface. From 12 teeth (1st and 2nd dentition) enamel blocks from the cervical third were prepared with perpendicular planes, embedded in resin, and ground down in steps of 15 microm parallel to the enamel surface. Enamel rods were made visible by acid etching (35% H3PO4, 45 s), sputtered and examined in the scanning electron microscope (SEM). Prior to this, the enamel blocks were viewed under the CLSM and optical sections at distances of 2 microm were obtained, starting in the same plane as the grinding surface. The outlines of the rods were digitized and reconstructed three dimensional…
Odontoameloblastoma: descripción de un caso y revisión de la literatura
2004
El odontoameloblastoma (OA) es un tumor odontogénico mixto extremadamente raro que aparece en los huesos maxilares y que presenta tanto componentes epiteliales como mesenquimales. El término odontoameloblastoma fue incluido en la clasificación de 1971 de la OMS. Tan solo 23 casos bien documentados han sido publicados. Debido a su rareza, existe controversia en cuanto al tratamiento de este tumor. Presentamos un nuevo caso de OA que afecta a la mandíbula y simula un odontoma compuesto, así como una breve revisión de la literatura. Odontoameloblastoma (OA) is an extremely rare mixed odontogenic tumor appearing within the maxillary bone, with both epithelial and mesenchymal components. The ter…
Appraisal of jaw swellings in a Nigerian tertiary healthcare facility
2012
Introduction: The mandible and maxilla can be the site of myriads of lesions that may be categorized as neoplastic, cystic, reactive and infective or inflammatory. Literature reviewing jaw swellings in an amalgamated fashion are uncommon, probably because aetiologies for these swellings are varied. However, to appreciate their relative relationship, it is essential to evaluate the clinico-pathologic profile of jaw swellings. The aim of this appraisal is to describe the array of jaw swellings seen at our hospital from 1990 to 2011, to serve as a reference database. Methodology: Biopsy records of all histologically diagnosed cases of jaw swellings seen at the department of Oral Pathology, Uni…
Comparison of the value of PCNA and Ki-67 as markers of cell proliferation in ameloblastic tumors
2012
Objectives: The aim of this study was to compare among PCNAand Ki-67 as the most reliable immunohisto chemical marker for evaluating cell proliferation in ameloblastic tumors. Study Design: Observational, retrospective, and descriptive study of a large series of ameloblastic tumors, com- D esign: Observational, retrospective, and descriptive study of a large series of ameloblastic tumors, com- esign: Observational, retrospective, and descriptive study of a large series of ameloblastic tumors, com posed of 161 ameloblastomas and four ameloblastic carcinomas, to determine and compare PCNA and Ki-67 expression using immunohistochemistry techniques. Results: When analyzing Ki-67 positivity, the…
Peripheral ameloblastoma of the upper gingiva: Report of a case and literature review
2014
According to the 2005 histological classification of odontogenic neoplasms by the World Health Organization, ameloblastoma is a benign, locally invasive epithelial odontogenic tumor of putative enamel organ origin. There are four distinct subgroups in which this neoplasm can be gathered: the solid/multicystic type, the unicystic type, the desmoplastic and the peripheral type. Peripheral ameloblastoma is believed to be the rarest subgroup, making up for 2 to 10% of all ameloblastomas. From its first description by Kuru in 1911 to date, less than 200 cases of PA have been described in literature. PAs commonly affect the mandible, in the maxilla the most common location is the soft palatal tis…
Desmoplastic ameloblastoma of maxilla: a case report
2010
Ameloblastoma is the most common neoplasm affecting the jaws, arising from the odontogenic epithelium. Despite its locally aggressive nature, it is considered to be benign. The chief histopathological variants of ameloblastoma are the follicular and plexiform types, followed by the acanthomatous and granular cell types. Uncommon variants include desmoplastic, basal cell, clear cell ameloblastoma, keratoameloblastoma and papilliferous keratoameloblastoma. When the desmoplastic type co-exists with other types, it is called as “hybrid” ameloblastoma. There are significant anatomic, histopathological and radiological differences between desmoplastic ameloblastoma and the classical type. The pur…
Molecular markers of cell adhesion in ameloblastomas. An update
2013
Ameloblastoma is the most common odontogenic tumor of epithelial origin, and though it is of a benign nature, it frequently infiltrates the bone, has a high rate of recurrence and could potentially become malignant. Cellular adhesion potentially plays an important role in the manifestation of these characteristics and in the tumor biology of ameloblastomas. Losses of cell-cell and extracellular matrix adhesion and cohesion are among the first events that occur in the invasion and growth of tumors of epithelial origin. The present review includes a description of the molecules that are involved in cell adhesion as reported for various types of ameloblastomas and discusses the possible roles …
CD166 expression in dentigerous cyst, keratocystic odontogenic tumor and ameloblastoma.
2015
Background CD166 is a glycoprotein of an immunoglobulin super family of adhesion molecules that has been associated with aggressive characteristics and high recurrence rate of tumors. Different odontogenic lesions exhibit considerable histological variation and different clinical behavior. In an attempt to clarify the mechanisms underlying this different behavior, the present study investigates the immunohistochemical expression of CD166 in these lesions. Material and Methods In this study 69 formalin-fixed, paraffin embedded tissue blocks of odontogenic lesion consist of 15 unicystic ameloblastoma (UA), 17 solid ameloblastoma (SA), 18 keratocystic odontogenic tumors (KCOT), and 19 dentiger…
Granular cell ameloblastoma of jaw: report of a case with an emphasis on its characterization
2013
Ameloblastoma is a neoplasm of odontogenic epithelium, especially of enamel organ-type tissue that has not undergone differentiation to the point of hard tissue formation. It accounts for approximately 10% of all tumors originating from gnathic bones. It exhibits diverse microscopic patterns which occurs either singly or in combination with other patterns. Granular cell ameloblastoma is a rare condition, accounting for 3.5% of all ameloblastoma cases that shows marked transformation in the cytoplasm of tumor cells, which are usually stellate reticulum like cells. The transformed cells possess very coarse, granular, eosinophilic cytoplasm. The “granular change” is thought to be due to a dysf…
Ameloblastic fibroma: a rare case appearing as a mixed radiographic image
2014
Ameloblastic fibroma (AF) is a benign tumor of mixed odontogenic origin, which affects predominantly young individuals. AF appearing as a mixed radiographic image is very rare. This report describes a case of AF in a 12-year-old male identified during a routine radiographic exam for orthodontic treatment planning. The panoramic radiography revealed a well-defined multilocular mixed image located in the mandible between the roots of the left mandibular second premolar and first molar. The lesion was excised under local anesthesia. Histopathological analysis revealed islands of epithelial cells and columnar peripheral cells showing a nucleus in inverted polarization, interspersed with spindle…