Materials and Methods: A Simplified Oral hygiene Index (OHI-S) by Greene and Vermillion was used to determine the oral hygiene status of orthodontic patients who were on active fixed orthodontic treatment at University of Benin Teaching Hospital Dental Centre, Benin City, Nigeria. The standard six surfaces were evaluated to determine the Debris index and Calculus index for each patient. A self-administered questionnaire was also used to determine tooth brushing practices among the orthodontic patients. Statistical gender and age differences in the subject’s oral hygiene status, debris and calculus indexes were evaluated with the chi-square test and mean differences with independent t test.