Prevalence of odontogenic keratocysts associated with impacted third molars.

In this study we analyzed the prevalence of the odontogenic keratocyst (OKC) associated with impacted third molars and evaluated OKC reactivity with the antibodies against cytokeratins (CK), particulary for CK10. Tissue samples were obtained from the proximity of the impacted molar. Differences between genders, age groups and localization of cysts were assessed using the chi2-test and relative risk (RR), and associated confidence interval. Cysts were found in 75 cases, and the radicular ones prevailed (63%), followed by follicular and OKC (13% and 12% respectively). The RR for the upper jaw cysts was almost twice greater than for the mandible. For the OKC exclusively, the upper-lower jaw RR was 1:2. The RR for all cysts increases with age, while decreases for the OKCs. The risk for the OKC occurrence decreased with age, with no significant differences between age groups. Finally, based on the results from this study we cannot suggest that the CK10 staining should be considered an useful marker in differential diagnosis of the OKCs.