Objectives: determination of the effect of five oral hygiene teaching method in patients with orthodontic appliances. The study population: patients with fixed orthodontic appliances (age range 12 -25 years old) referred to two specialist orthodontic offices located in Hamadan. Design: randomized, single-blind, multicenter. Inclusion criteria: patient should be started their fixed orthodontic treatment during previous 3 months, and no special oral health education at the time of orthodontic treatment, is never given. Patients should have no systemic disease that affect their periodontal conditions; like Diabetes. Also patients must have normal levels of psychological and learning. Exclusion criteria: lack of patient cooperation in principles of education and failure to follow up referral appointment. Target sample size: 125. Setting and conduct: The first group receive orthodontic oral hygiene instruction in the form of face to face training, the second group in the form of face to face training with pamphlet, the third group in the form of face to face training with videotape, the fourth group in the form of face to face training with use of disclosing agent, The fifth group in the form of pamphlet and use of disclosing agent, receive oral hygiene instruction. Time of intervention: one week later orthodontic appliance installation, plaque Index and gingival index will be recorded and oral hygiene instruction will be presented. A week later oral hygiene instruction and one month later oral hygiene instruction, plaque Index and gingival Index will be recorded again. Main outcome measure: plaque Index, gingival Index.