Inclusion Criteria:  Patients have  Fully erupted permanent teeth (regardless the third molar), Indication to have orthodontic treatment without extraction Fair or good oral hygiene before or after oral hygiene instruction  Exclusion Criteria:  Patients will be excluded if they had  Previous orthodontic treatment or extractions Missing teeth Active enamel caries determined by clinical examination Patients with enamel hypoplasia, dental fluorosis or tetracycline pigmentation Labial restorations Severe periodontal diseases determined according to PDI index by Sigurd P. Ramfjord (Ramfjord, 1967) Craniofacial syndromes such as clefts Xerostomia determined from clinical history of the patient Severely rotated teeth (limiting the appearance of buccal surfaces) Heavy smokers determined by accounting the number of cigarettes per day and time to the first cigarette of the day (Heatherton et al., 1989) .