Methods: This research was a descriptive retrospective study and was performed on 33 specimens of Ameloblastomas, 4 of which were excluded due to the loss of expression of the markers. As a result, the specimens were dropped to 29 (17 benign, 5 recurrent, 7 malignant). They were examined Immunohistochemically using the Streptavidin-Biotin method with anti-PCNA and anti-Ki-67 antibodies.
Results: The Ki-67 was expressed below 10% in 75.9% of the cases (22 cases), below 39% in 20.7% (6 cases) and above 3% in 3.4% (1 case). This showed that there was no significant relationship between the type of ameloblastoma and presence of Ki-67 (P<0.927). The average positivity percentage of PCNA expression was 42.05% in benign types, 65% in malignant types, and 25% in the recurrent types. The average positivity of PCNA expression in the malignant type was higher than the recurrent and benign types, but there was no difference between the recurrent and the benign types. This showed a statistically difference in PCNA expression among different types of Ameloblastomas (P<0.023).
Conclusions: There was no statistically significant difference between different types of Ameloblastomas and expression of Ki-67, so it cannot be used as a diagnosis means for different types of Ameloblastomas, but there is strong relation between the positivity percentage of PCNA and different types of Ameloblastomas; therefore, it can be used to differentiate between the different types.