Self-injuries may be associated with a known disease for which the patient suffers, or be one of the first symptoms of mental disorders. In the case of injuries in the oral cavity, various forms of orthodontic appliances have been reported in the literature to protect the tongue, cheeks or lips. Six-years follow-up of a 12 years old girl with rare SWS syndrome is reported in paper, referred at the age of six due to chronic tongue and floor of the mouth self-injuries. After treatment of carious lesions in primary dentition, upper and lower removable bite-planes were inserted. Appliances were fabricated with bite construction. The patient and her parents were instructed to use them the most time. The patient accepted them very well. Significant improvement of the tongue status was achieved. New injuries occurred only when splints were not used. After two years the appliances were grinded and perforated. New biteplanes were made to continue improvement in occlusion. Those appliances allowed to avoid accidental self-injurious of the tongue and improved the quality of the patient’s life.