Objective To explore certain principle of how osteoprotegerin（OPG） and osteoprotegerin ligand（OPGL） take part in the periodontal tissues remodeling under the combined influence of inflammation and orthodontic force. Methods The positive signals of OPG and OPGL mRNA were measured with in situ hybridzation after orthodontic tooth movement in the experimental periodontitis groups and control ones. Results The OPG and OPGL mRNA expression intensity in the experimental group showed difference from control. All their optical density index reached a peak in day 2, respectively. Conclusion OPG and OPGL play important roles in the periodontal reconstruction induced by inflammation irritation and orthodontic force, and complex interaction could exist between the two factors.
