Aims: To evaluate the expression of Cyclooxygenase-2 (COX-2) in odontogenic keratocyst (OKC) and dentigerous cyst and correlate it with Ki-67 expression in these lesions.
Material and Methods: This study was carried out on 32 paraffin embedded specimens of dentigerous cyst and OKC. 16 samples obtained from healthy mucosa served as controls. Slides prepared from paraffin-embedded sections were immunohistochemically stained for Ki-67 and COX-2 and immunoreactivity of the two markers was evaluated using index of positivity and staining intensity. Statistical analysis was performed using Mann-Whitney and Spearman's correlation tests.
Results: Ki-67 and COX-2 expression in OKC and dentigerous cyst was found to be significantly higher than those observed in healthy mucosa groups (p < 0.05). The expression of the two markers was significantly higher in OKC than in dentigerous cyst. A positive correlation was found between the two markers in both lesions.
Conclusions: Increased expression of Ki-67 and COX- 2 in OKC is an indicator of the high mitotic activity of these lesions compared with dentigerous cyst. COX-2 is implicated in odontogenic epithelial proliferation in OKC and dentigerous cyst.