The success of orthodontic treatments applied in adolescence lies in maintaining a good oral hygiene, which favors a good functioning and avoids the appearance of complications in patients, associated with a proper brushing of teeth and orthodontic appliances, which it is an essential and important element for a successful treatment, together with the healthy maintenance of the gums, prevention of caries and peridontitis. A descriptive study was carried out in 50 patients of either sex and race, aged 12-16 years, from the Orthodontic Consultation of the Stomatology Clinic H and 21, in the period March-August 2006, which receive orthodontic treatment, in order to determine oral hygiene during treatment. The male sex and the 12-14 year old group predominated. It was observed that 92% of the patients studied were categorized with good simplified oral hygiene index and only 8% with a regular simplified oral hygiene index. Finally the simplified oral hygiene index of the collective was good. It is recommended to increase and further encourage the maintenance of oral hygiene, to obtain a good success during orthodontic treatment and therefore, that the patient can enjoy a beautiful smile without psychological effects.