Expression Of Noggin In Periodontal Tissues During Orthodontic Tooth Movement In An Animal Experimental Study

Objective: Noggin is an extracellar antagonist of BMPs'signaling. Noggin acts by binding BMPs, thus preventing them from binding to their receptors and subsequently blocking the actions of BMPs.The main purpose of this study is to examine the expression of Noggin in periodontal tissues during orthodontic tooth movement in rats.Method: Selected 21 8-week-old male SD rat(180-220g),which were randomly divided into 7 groups. Established orthodontic tooth movement model and chose the left side of the maxillary as the experimental side. The right side was taken as control side. The mini-implant was used as the anchorage part. A coil spring was placed between the maxillary first molar and mini-implant. The first molar was moved mesially by about 40g force. Rats were killed after 1,3,5,7,14 ,21,28 days. The tissue was stained with HE to observe the histological changes of periodontal tissues. Immunohistochemical assay was used to determine Noggin levels. And the result was analyzed by statistic test.Results:Noggin has a specific temporal and spatial expression profiles during the orthodontic tooth movement. The expression of Noggin was clearly upregulated in the early phase and then decreased thereafter.It reached the peak on 7 day,then decreased gradually ,the expression is almost equal to the control group on 28 day group.Conclusion:Noggin involved in the rat bone remodeling and orthodontic tooth movement, and played a very important role.As an antagonist,noggin often is expressed in conjunction with BMPs,conceivably defining boundaries of BMP induced structures.The upregulation of the Noggin expression points to the possibility of a negative feedback mechanism for BMPs induced bone formation.