Nucleolar organiser regions in odontogenic cysts and ameloblastomas.

Silver nucleolar organiser region (AgNOR) counts were performed on apical periodontal cysts, dentigerous cysts, odontogenic keratocysts, ameloblastomas and basal cell carcinomas. Significant differences, but with excessive overlap, were shown between dentigerous cysts and apical periodontal cysts and between odontogenic keratocysts and apical cysts. The mean AgNOR counts for all odontogenic cysts ranged between 2.02 and 2.65, and for ameloblastomas were 2.24, indicating that the method has neither a diagnostic nor a prognostic value in these lesions. Control oral squamous cell carcinoma tissues had significantly higher AgNOR counts than any other lesion tested.