There is no conflict of interest related to the submitted manuscript. This research protocol was reviewed and approved by the Institutional Ethics Committees from University of Taubaté (2008/0098) and Guarulhos University (09/2005). “
“The authors regret that the units of Table 3 were incorrect. It should be as below The authors would like to apologise for any inconvenience caused. “
“Orthodontic tooth movement (OTM) occurs through remodelling of alveolar bone after mechanical stimuli. The orthodontic forces generate and propagate signalling cascades through all paradental selleck tissue cells, triggering important changes in the homeostatic periodontal environment.1 and 2

The orthodontic loading leads to a focal tissue injury and, consequently, an aseptic inflammatory

find more response characterised by the release of several important inflammatory mediators on periodontal tissues,2 and 3 such as the cytokine interleukin-1 (IL-1).4 IL-1 is directly involved in bone resorption by taking part in the survival, fusion and activation of osteoclasts and it exerts its activities by binding to two types of receptors, IL-1-RI and IL-1-RII.5 Whilst the latter has no described signalling properties and acts as a “decoy” target for IL-1, the former develops pro-inflammatory functions, such as cell recruitment and release of other cytokines, which also are involved in bone resorption.6 However, IL-1 functions are physiologically ID-8 controlled by the naturally occurring interleukin-1 receptor antagonist (IL-1Ra), which competitively blocks the interactions of IL-1 with its receptors and inhibits its activity.7 and 8 IL-1Ra has long been studied in clinical and experimental surveys as a physiological and therapeutic target in inflammatory conditions related to bone resorption, such as rheumatoid arthritis9 and 10 and periodontal disease.11 and 12 These studies reported that administration of exogenous IL-1Ra may be a useful strategy to control bone resorption, mainly for its anti-inflammatory properties related to the antagonism of IL-1.9, 10,

11 and 13 However, only a few studies have investigated the effect of IL-1Ra on OTM, showing a positive correlation between decreased IL-1Ra gingival expression and faster OTM in humans.14, 15, 16 and 17 Despite these findings, there is a lack of evidence describing the effects of IL-1Ra therapy on bone remodelling after mechanical loading. Therefore, the aim of this study was to investigate the effects of IL-1Ra administration on OTM in a mouse model. Thirty five ten-week-old wild-type mice (WT) (C57BL6/J) were used in this study. For histomorphometric analysis, 10 mice with orthodontic appliance were used. In this set of experiments, the left side of maxillae (without orthodontic appliance) was used as control.