Immunohistochemical evaluation of p53 and ki-67 expression in selected developmental and inflammatory odontogenic cysts

It seems that different growth mechanisms and biologic behaviors of odontogenic cysts are related to different expressions of various proteins and molecules. The purpose of this study was to determine the expression of p53 and ki-67 in radicular cysts (RC), odontogenic keratocysts (OKC), inflamed (IDC) and noninflamed dentigerous cysts (NIDC).

In this cross-sectional descriptive study, 13 RCs, 10 NIDCs, 15 IDCs and 19 cases of OKC were selected and stained for p53 and ki-67. The slides were evaluated by light microscopy (x400 magnification) and brown-staining cells were counted. Data were analyzed by Mann-Whitney and Kruskal Wallis tests.

P53 expression was not observed in any cases of RCs and NIDCs. This marker was seen in 6.7% of IDCs and 57.9% of OKCs with an average of 0.27 ± 1.03 and 17.31 ± 27.68. There was a statistically significant difference between OKC and other cysts regarding the expression of this marker (p=0.006). Ki-67 expression was observed in 84.6%, 73.7%, 66.6% and 44% of RCs, OKCs, IDCs and NIDCs, respectively. A significant difference existed between OKC and NIDC, and also NIDC and IDC (p=0.048) and radicular cysts and inflamed dentigerous cysts (p=0.046).

Based on the results of this study, expression of p53 and ki-67 is related to clinica l behavior and growth potential of odontogenic cysts.