Lymphangioma occurs frequently in the head and neck region. Lymphangioma of the tongue appears frequently in the front two-thirds of the tongue. It may cause an open-bite related to the tongue posture and tongue size. Though lymphangioma is not malignant, frequent recurring is problematic. This article presents two cases report: orthodontic treatment of patients with lymphangioma of the tongue. The first case, a 12 years 11months old boy who had been treated for lymphangioma visited the orthodontic department for correcting crowding and open-bite. Rapid palatal expansion was performed to correct transverse discrepancy. When he was 13 years 10 months, fixed orthodontic treatment was started after extraction of upper and lower premolars. After aligning the dentition ,intrusion of upper and lower molars was performed using MEAW and microscrews. Orthodontic appliance was removed without detail finishing due to the generalized root resorption. After debonding, open bite was relapsed due to recurrence of ulceration on dorsal tongue surface and subsequent depression of tongue posture. The second case, a 6-year-old girl who had a macroglossia and open-bite due to lymphangioma visited orthodontic department after receiving lingual frenoplasty at oral and maxillofacial surgery department. Considering the recurrence of lymphangioma, active treatment was postponed until growth completion. When she bacame 18 years 6 months, orthognathic surgery and tongue reduction was ferfomed. After 12 months postsurgical orthodontic treatment a good alignment of teeth was obtained. During the treatment myofunctional therapy was instructed. After 2 years follow up, the result was stable. The special considerations for orthodontic treatment of the patient with lymphangioma are discussed with comparing these two cases.