Gingival enlargement commonly occurs in patients treated with fixed orthodontic appliances. In a study, 25 patients were monitored during and after treatment with fixed orthodontic appliances. The extent of the enlargement of the gingiva was determined by means of intra-oral photographs made shortly before the placement of the appliances, immediately after their removal and at 3 and 6 months after the appliances had been removed. The enlargement of the gingival was determined using a Visual Analogue Scale. During orthodontic treatment the average degree of gingival enlargement increased significantly. After removal of the appliances a significant decrease in the degree of gingival enlargement occurred. Within 3 months after debonding the gingival enlargement was at the same level as before starting the orthodontic treatment. The conclusion was that the enlargement of the gingiva that takes place during treatment with fixed orthodontic appliances was reversible.