Abstract
Recently, distraction osteogenesis has been used for patients with hypogrowth of bones. Distraction osteogenesis is a technique of lengthening hypogrowth bones with a mechanical distraction device to regenerate bone and soft tissue.
This is a clinical report on a bilateral cleft lip and palat e patient with severe undergrowth of the maxilla, using maxillary distraction osteogenesis by a rigid external distraction system (RED system). The patient was a girl 9 years and 11 months old, with malocculusion due to a bilateral cleft lip and palate. Although the lst stage treatment used a facial mask due to the acceleration of the maxillary forward growth, the maxilla still showed extreme undergrowth. Therefore, we changed our treatment plan to maxillary distraction osteogenesis by a RED system, combined with a mandibular set back osteotomy and genioplasty.
Maxillary movements were evaluated using lateral cephalometr ic analysis, and endosseous metal implants were inserted into maxillary bone as a marker. During maxillary distraction, maxillary forward movement was less than the extension distance of the distraction screw. The amount of distraction screw extension was 34 mm, but the marker moved only about 7.5mm, caused by tooth movement and sway of the head-frame. The problem with the RED system was deformation of the distraction hook and head-frame movement because of heavy tension of the scar tissue in this cleft lip and palate patient. However, the position of the maxilla after distraciton osteogenesis was stabilized, and relapse was hardly observed. As a consequence, stable occlusion and profile improvement could be obtained by this treatment.
