Effect of orthodontic force on inflammatory periodontal tissue remodeling and expression of IL-6 and IL-8 in rats

Objective:To investigate effect of orthodontic force on inflammatory periodontal tissue remodeling and expression of IL-6 and IL-8 in rats.Methods:Eighty SD rats were randomly divided into 4 groups,blank control group(group A)with 5 rats,treatment normal group(group B)with 25 rats,inflammation control group(group(group C)with 25 rats,inflammation treatment group(group D)with 25 rats.Immunohistochemistry and histomorphometric analysis was performed to measure the expression of IL-6,IL-8 and the firet molar to the recent movement in the distance.Results:The expression of IL-8 reached a maximum on day 5 and declined thereafter in group B;the expression of IL-6 reached a maximum on day 5 in group B.The expression of IL-6 and IL-8 was gradually weakened with time in group C.The expression of IL-6 and IL-8 were high,and reached a maximum on day 5 and declined thereafter in group D.AD of positive cells in group D were higher than group B at each time point(P<0.05).The time which 0.49 N orthodontic force was loaded was longer,orthodontic tooth movement distance was greater.Movement distance in group D were longer than group B(P<0.05).Conclusions:Orthodontic force as well as inflammatory stimulus can evoke the expression of IL-6 and IL-8.Under the combined effects of inflammation and orthodontic force,the expression of IL-6,IL-8will increase.

Applied Anatomic Site Study of Palatal Anchorage Implants Using Cone Beam Computed Tomography

Aim The purpose of this study was to conduct quantitative research on bone height and bone mineral density of palatal implant sites for implantation, and to provide reference sites for safe and stable palatal implants. Methodology Three-dimensional reformatting images were reconstructed by cone beam computed tomography (CBCT) in 34 patients, aged 18 to 35 years, using EZ Implant software. Bone height was measured at 20 sites of interest on the palate. Bone mineral density was measured at the 10 sites with the highest implantation rate, classified using K-mean cluster analysis based on bone height and bone mineral density. Results According to the cluster analysis, 10 sites were classified into three clusters. Significant differences in bone height and bone mineral density were detected between these three clusters (P<0.05). The greatest bone height was obtained in cluster 2, followed by cluster 1 and cluster 3. The highest bone mineral density was found in cluster 3, followed by cluster 1 and cluster 2. Conclusion CBCT plays an important role in pre-surgical treatment planning. CBCT is helpful in identifying safe and stable implantation sites for palatal anchorage.