The effects of fiberotomy were evaluated in alleviating dental relapse of incisors after orthodontic treatment. The study sample consisted of 23 patients with crowded maxillary and mandibular incisors before orthodontic treatment. The amount of initial crowding was determined according to Little's irregularity index. Fiberotomy procedures were performed on ii of the patients 1 week before debonding, The other 12 subjects served as the control group. All patients wore Hawley retainers. Lateral cephalometric headfilms and dental casts of the patients were taken at the beginning (T1) and at the end (T2) of treatment, 6 months into the retention phase (T3), and 1 year after orthodontic treatment (T4). Significant increase of irregularity index was noted in the control group at T3 and T4 for both maxillary and mandibular anterior segments (P < .05, P < .01). Meanwhile, in the group where circumferential supracrestal fiberotomy was performed, no significant increase of the irregularity index was noted.