RANKL/OPG signaling affects the bone structure in rat model of mandibular osteoradionecrosis / A sinalização RANKL/OPG acomete estrutura óssea em modelo de rato de osteorradionecrose mandibular

Objective: Osteoradionecrosis (ORN) of the jaws is an important side effect head and neck cancer radiotherapy. The main objective this work was to evaluate expression RANK, RANKL OPG proteins, markers bone remodeling, in rats submitted Material Methods: Six-month-old male Wistar were divided into two groups: Irradiated group (IR), which received a single dose 20 Gy jaw after seven days had their three left mandibular molars extracted; Control (C), didn’t receive radiation, but underwent same procedures. Twenty one dental extractions, animals euthanized mandibles removed for analysis. volume density (Vv) immunoexpression RANK/RANKL/OPG quantified by stereology. ratio (BV/TV), trabecular thickness (Tb.Th), separation (Tb.Sp) number (Tb.N) analyzed microtomography (Micro-CT). Results: Vv were, respectively, 53% higher 50% lower IR compared C (p0.05). Micro-CT showed that there reduction mass animals. BV/TV Tb.Th 33% 38% lower, (p0.05), while Tb.Sp 37.5% these Conclusions: Ionizing irradiation high dose, followed extractions promoted ORN rats, together with changes remodeling RANK OPG.