Aim. The aim of this study was to examine the changes in the levels of interleukine-1 beta (IL-1 beta), tumor necrosis factor alpha (TNF-alpha), malondialdehyde (MDA), nitric oxide (NO), and 8-hydroxydeoxyguanosine (8-OHdG) in saliva and IL-1 beta, TNF-alpha, and NO in gingival crevicular fluid (GCF) samples of patients with fixed orthodontic appliances. Material and Method. The subject population consisted of 50 volunteers who were in need of orthodontic treatment with fixed orthodontic appliances. GCF and saliva samples were obtained from all individuals before treatment, at 1st month of treatment and at 6th month of treatment. Periodontal clinical parameters were measured. Samples were investigated to detect IL-1 beta, TNF-alpha, and 8-OHdG levels using ELISA method and NO and MDA levels using spectrophotometric method. Results. Since IL-1 beta level detected in GCF at the 6th month of orthodontic treatment is statistically significant according to baseline (P < 0.05), all other biochemical parameters detected both in saliva and in GCF did not show any significant change at any measurement periods. Conclusion. Orthodontic tooth movement and orthodontic materials used in orthodontic treatment do not lead to a change above the physiological limits that is suggestive of oxidative damage in both GCF and saliva.