Children treated for childhood cancers with both radiation and chemotherapy often exhibit disturbances in dental development. A retrospective analysis of treatment outcome in 10 orthodontically treated children was performed. A questionnaire was sent to each child's orthodontist, and 5 orthodontists reported that the patient's medical condition influenced their choice of treatment plan. Three orthodontists, all treating patients with severely disturbed root development, reported using lighter forces than they used with the average patient. With regard to complications related to orthodontic treatment, 1 of the 10 patients showed evidence of root resorption. In 4 of the 10 patients, the treatment result was judged to be unsatisfactory. This study showed that, although ideal treatment results were not always achieved, orthodontic treatment did not produce any harmful side effects in children who are long-term survivors of childhood cancer.