Cytokines play an important role in intercellular signaling and have been implicated in the pathology of periodontal diseases, bone destruction, and bone response to orthodontic treatment. One of the most important breakthroughs of bone biology has been the identification of the role of cytokines in bone remodeling. Bone remodeling is used by orthodontists when forces transmitted to the surrounding tissues of the periodontium initiate the remodeling process. The aim of the study is to evaluate the changes in the clinical parameters and gingival crevicular fluid levels of interleukin 8 after placement of orthodontic appliances. subjects starting orthodontic therapy with fixed appliance will be selected, the study subjects should be systemically healthy, no smokers, with no pre-existing periodontal diseases.GCF was sampled separately from the labial gingival crevices of each central teeth where the orthodontic forces were applied. The GCF samples will be collected before initiation of orthodontic therapy, 3-5 days, 2 weeks, and 1 month after therapy for evaluation of levels of IL-8 using ELISA.clinical parameters will be recorded before initiation of orthodontic therapy then month later Level of interleukin -8 elevated during 3-5 days and 2 weeks, and returns back to baseline after 1 month. There was a significance change in the Periodontal pocket depth and plaque index of Oral cavity. Minimal changes was seen in the Gingival index, no changes in CAL or in gingival recession. The results obtained suggested that IL-8 has an important role in periodontal tissue remodeling in response to initial leveling orthodontic force.