Early orthodontic treatment and long-term observation in a patient with Morquio syndrome

Early orthodontic treatment and long-term observation in a patient with Morquio syndrome were demonstrated. To date, there are no case reports describing orthodontic treatment in such a patient. The patient showed spaced maxillary and mandibular arches with a tongue thrust habit at age seven years eight months. She also showed a protruded upper lip, labial inclination of the upper and lower anterior teeth, and thin enamel. The tongue thrust habit disappeared after the application of a removable orthodontic appliance. The spaced dentition in the upper and lower arches improved after treatment with a fixed appliance with closing loop arch wire (0.017 x 0.025'') and bands on the upper and lower molars. We did not use an edgewise appliance because of the thin enamel. The protruded upper lip and labial inclination of the upper and lower anterior teeth were also improved after treatment, but optimal intercuspation of the teeth was not achieved. However, optimal intercuspation of the teeth was achieved after long-term observation and the masticatory function was improved. It was suggested that early orthodontic treatment could improve the malocclusion in a patient with Morquio syndrome and that improvement of masticatory function could be achieved during a long-term retention period.