الفهرس 
REVIEW OF LITERATUREOnly 14 pages are availabe for public view
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Abstract
Odontogenic tumors are the neoplasms that arising from epithelial, ectomesenchymal and/or mesenchymal elements of the tooth-forming apparatus. Approximately 97% of which are benign, and the frequencies of each odontogenic tumor vary according to the racial and the geographical differences.
The mechanism that triggers the proliferation of odontogenic cells or production of different tumors is unknown. Various subcellular, cellular and developmentally related factors may be responsible for this differentiation.
Nestin is one of the intermediate filaments constituting the cytoskeleton and is known as a marker of neural stem cells or progenitor cells. Human Nestin expression continues during tooth development and disappears when development is complete. In the mature tooth with caries or after cavity formation, Nestin is re‐upregulated in odontoblasts and their processes when they are stimulated by caries or when they form the secondary dentine after injury, respectively. Thus, Nestin is considered to be related to the differentiation toward odontoblasts and to the acquisition of their function to produce dentine.
The aim of the present work is to study the expression of Nestin in different odontogenic tumors and to highlight the incidence of odontogenic tumors in the Faculty of dentistry, Alexandria University in the past 10 years.
Twenty two cases of odontogenic tumors were included in the present study. Biopsies were histologically evaluated using H&E staining. The microscopical examination showed that out of the 22 cases, 9 cases were epithelial tumors, 5 cases were ectomesenchymal tumors, and 8 cases were mixed tumors.
Serial sections were immunohistochemically stained by Nestin antibody. The intensity of immunostaining of Nestin was calculated in terms of mean area percentage and mean optical density by the computer image analyzer system.
The difference in mean Nestin area percentage and mean optical density between epithelial, mixed, and ectomesenchymal odontogenic tumors revealed highly significant differences (p<0.001), except for the insignificant difference that between epithelial and ectomesenchymal group in the mean Nestin optical density.
Two hundreds and thirty four odontogenic tumors were diagnosed in the Oral Pathology Department, Faculty of Dentistry, Alexandria University, during the period from 2005 to 2014. The results revealed that keartocystic odontogenic tumors and ameloblastomas were the most prevalent cases. Approximately 95% of the all cases were benign and 5% were malignant with higher female prevalence.
This study concluded that Nestin protein is expressed in odontogenic tumors with variable intensity according to their odontogenic tissue of origin. Further studies are needed to study the possible role of Nestin as important diagnostic aid in differential diagnosis between epithelial, mixed and ectomesenchymal odontogenic tumors.