Oral malignant tumours: a report on 728 cases in Chile.

The objective of this study was to describe the main clinical characteristics and the relative frequency of each type of oral malignancies received at the Oral Pathology Reference Institute (IREPO) of the Faculty of Odontology; University of Chile, since 1975 to 2006. Studies were performed of 728 cases of biopsies recorded in the IREPO data base with a diagnosis corresponding to some type of Oral Malignant Tumour (OMT) and which counted with all required clinical and demographic data. Histological sections were observed by two oral pathologists with the purpose of confirming the original diagnosis. 61.6% of OMTs were observed in males and 38.4% in females. Patients average age was 65.3 years, and the most frequent localization was the alveolar/gums ridge (20% of the cases) being the squamous cell carcinoma (SCC) the most frequent pathology (58.4%) These results are similar to the frequencies of oral malignancies reported for other countries as to distribution per gender, age, histological diagnosis. Nevertheless, frequency distribution of each of the OMTs is different to that indicated in most publications.

Nasopalatine Duct Cyst in a 31 Year-Old Male: Imaging Findings in Computed Tomography / Quiste del Canal Nasopalatino en un Hombre de 31 años: Hallazgos en Imágenes de Tomografía Computarizada

A 31-year-old man is presented and is evaluated by panoramic radiography. As a finding, an extensive lesion with a cystic appearance was detected in the anterior part of the maxilla. Computed tomography shows a lesion corresponding to the characteristics of a cyst. In the histology the combination of two types of epithelium is observed, pseudostratified columnar and stratified squamous, confirming that this was a nasopalatine duct cyst.

Se presenta el caso de un hombre de 31 años, evaluado mediante radiografía panorámica. Como hallazgo se detecta una extensa lesión de aspecto quístico en la parte anterior del maxilar. En la tomografía computada se observa una lesión que corresponde a las carácterísticas de un quiste. La histología muestra una combinación de dos tipos de epitelio, pseudostratificado columnar y estratificado escamoso, confirmando que se trataba de un quiste del canal nasopalatino.

Ameloblastin and amelogenin expression in posnatal developing mouse molars.

Ameloblastin and amelogenin are structural proteins present in the enamel matrix of developing teeth. Here we report the results of in situ hybridization analyses with DNA probes of ameloblastin and amelogenin expression in the mandibular first molars of ICR/Jcl mice from postnatal day 1 to day 15. Ameloblastin mRNA expression was observed in ameloblasts at day 2 while amelogenin mRNA was detected in secretory ameloblasts at day 3. Significant expression of both molecules was observed at days 4, 5 and 6, after which the levels decreased. Amelogenin expression ended on day 10, while ameloblastin mRNA was only weakly detected on day 12. Neither amelogenin nor ameloblastin expression was observed in day 15 mouse molars. Amelogenin and ameloblastin mRNAs were restricted to ameloblasts. We conclude that amelogenin and ameloblastin expression is enamel-specific, and suggest that these genes might be involved in the mineralization of enamel. It is possible that ameloblastin could participate in the attachment of ameloblasts to the enamel surface. In this case, the downregulation of expression may indicate the beginning of the maturation stage in which the ameloblasts tend to detach from the enamel layer.

Mouse tooth development time sequence determination for the ICR/Jcl strain.

To establish the normal dental development pattern of the ICR/Jcl strain of mouse, we analyzed a significant number of observations of the different developmental stages of the first mandibular molar, accurately recording the chronology of their daily embryonic development. Proliferation of the dental sheet began at day 12.5 in utero (E-12.5), the bud stage appeared at days E-13.5 and E-14.5, the cap stage was observed at days E-14.5, E-15.5 and E-16.5 and the early bell stage at day E-17.5. The presence of predentin was observed at day E-18.5 and dentin was observed 1 and 2 days after birth (D-1 and D-2). The late bell stage with presence of enamel was detected more than 3 days after birth. Embryonic and dental development in the ICR/Jcl strain of mouse is faster than in other well-known strains. The establishment of this developmental pattern will be useful for future investigations of transgenic mice.

The unusual evolution of a simple bone cyst in the mandible: A case report.

The simple bone cyst, as newly classified by WHO in 2005, is a lesion related to the jawbones. Therefore, it is not a cyst, since it is a cavity devoid of epithelial tissue. It is a rare pathology affecting the mandible more than the maxilla. Its onset occurs mainly during the first two decades of life, irrespective of sex. The purpose of our report is to exhibit the particular case of a 17-year-old male patient whose radiography showed an osteolytic lesion in his right mandibular body. Exploratory surgery and biopsy are performed showing a simple bone cyst. Since then, he is controlled through imaging studies, but presenting an atypical evolution, with its size increasing considerably within a 4-year follow-up. Key words:Case report, simple bone cyst, hemorrhagic bone cyst, solitary bone cyst, idiophatic bone cyst, mandible.

Oral malignant tumours: a report on 728 cases in Chile

The objective of this study was to describe the main clinical characteristics and the relative frequency of each type of oral malignancies received at the Oral Pathology Reference Institute (IREPO) of the Faculty of Odontology; University of Chile, since 1975 to 2006. Studies were performed of 728 cases of biopsies recorded in the IREPO data base with a diagnosis corresponding to some type of Oral Malignant Tumour (OMT) and which counted with all required clinical and demographic data. Histological sections were observed by two oral pathologists with the purpose of confirming the original diagnosis. 61.6% of OMTs were observed in males and 38.4% in females. Patients average age was 65.3 years, and the most frequent localization was the alveolar/gums ridge (20% of the cases) being the squamous cell carcinoma (SCC) the most frequent pathology (58.4%) These results are similar to the frequencies of oral malignancies reported for other countries as to distribution per gender, age, histological diagnosis. Nevertheless, frequency distribution of each of the OMTs is different to that indicated in most publications.

El objetivo de este estudio fue describir las principales caracteristicas clinicas y la frecuencia relativa de cada tipo de neoplasia maligna bucal recibidas en el Instituto de Referencia en Patologia Oral (IREPO) de la Facultad de Odontologia de la Universidad de Chile, entre los anos 1975 y 2006. Se seleccionaron todos los casos registrados en la base de datos del IREPO entre los anos 1975-2006 y que correspon - dieran a algun tipo de Tumor Maligno Oral (TMO) y de los que se contara con todos los datos clinicos y demograficos requeridos. Con el proposito de confirmar el diagnostico ori - gi nal, los cortes histologicos fueron observados por dos pato logos orales. El 61,6% de los TMO se presentaron en hombres y el 38,4% en mujeres. La edad promedio de los pacientes fue de 65,3 anos y la localizacion mas frecuente fue en las encias/reborde alveolar (20% de los casos), siendo el carcinoma de celulas escamosas (CCE) el tipo mas frecuente de TMO con un 58,4% de los casos. Estos resultados son similares a las frecuencias de tumores malignos orales reportadas en otros paises como tambien su distribucion por genero, edad y tipo histologico. Sin embargo, la distribucion de frecuencias de los diferentes TMO es distinta a la reportada en la mayoria de las publicaciones.