RESUMO
Ameloblastoma is a benign epithelial odontogenic tumor that exhibits a more aggressive behavior than odontogenic keratocyst and follicular cyst. The purpose of this study was to determine and evaluate histomorphometric characteristics and blood vessels pattern adjacent to and far from odontogenic epithelium on the clinical behavior of the above odontogenic lesions with immunohistochemistry and morphometry method. In this descriptive-cross-sectional study, 45 paraffin blocks of mentioned lesions were selected and marked immunohistochemically with CD34. From three HPFs [High Power Fields] in each slide which had more density of blood vessels in adjacent to and far from odontogenic epithelium, photography was done by a camera joined to a microscope with 40 times magnification. Through the software Motic plus 2, the internal and external diameters, section surface and thickness were determined. Also the blood vessel pattern was determined in the mentioned lesions and was compared through ANOVA, f-test and Multiple Comparison Test. The external and internal diameters and sectional surface in the regions far from the odontogenic ephithelium in ameloblastoma was greater than keratocyst [P<0.001] and dentigerous cysts [P=0.001]] but there was no significant statistical differences seen in the thickness of blood vessels in the regions far from the odontogenic ephithelium in three lesions [P=0.05]. Significant statistical difference was not seen in external [P=0.8] and internal [P=0.8] diameters, sectional [P=0.6] surface and blood vessels thickness in the adjacent regions of odontogeni ephithelium in these three lesions. The pattern of blood vessels in ameloblastoma was circumferential and in the keratocyst and follicular cyst, it was directional. It seems that morphometric characteristics of blood vessels [internal and external diameters, sectional surface] in areas far from odontogenic ephithelium and the type of blood vessels pattern affects clinical aggressive behavior of ameloblastoma more than keratocyst and follicular cyst