Immunoexpression of RANK, RANKL, OPG, VEGF, and vWF in radicular and dentigerous cysts.

Background: Radicular (RC) and dentigerous cysts (DC) can show a range from little to quite extensive primary/secondary inflammation and it is possible that the variation seen in the fibrous capsule of these cysts might reflect differences in the osteolytic activity. Moreover, the presence of hemorrhagic areas in the fibrous capsule of DC could also contribute to the increase in osteolytic activity. The aim of this study was to compare immunohistochemical expression of nuclear factor κappaB (RANK), RANK ligand (RANKL), and osteoprotegerin (OPG), vascular endothelial growth factor (VEGF) and angiogenic index in RC and DC.

Methods: These proteins were evaluated in 20 RC and DC by immunohistochemistry. Angiogenic index was determined by microvessel count (MVC) using anti-von Willebrand factor antibody.

Results: RANK and RANKL were higher in DC than RC in fibrous capsule. RC showed higher expression of VEGF in the epithelium and capsule. DC exhibited higher MVC than RC.

Conclusions: Ours results suggest that RANK and RANKL play an important role in bone resorption in DC and the hemorrhagic areas in the capsule of DC could be explained by increased vessel's number. The higher VEGF expression in RC might be related to nature of these lesions, where the inflammatory process contributes significantly to these findings.