Internal Midface Distraction in Correction of Severe Maxillary Hypoplasia Secondary to Cleft Lip and Palate

Maxillary hypoplasia is a familiar deformity in patients with cleft lip and palate. A large amount of maxilla advancement is often needed to correct the severe deformity, but local soft-tissue scars around the maxilla restrict maxilla advancement and increase the relapse rate. By gradually lengthening both the bones and the soft tissues, midface distraction can greatly increase postoperative stability and lower the relapse rate.Ten patients with severe maxillary hypoplasia secondary to cleft lip and palate were treated with midface distraction using three kinds of internal distraction devices. Among them, six patients received an alveolar bone graft from the iliac crest during their Le Fort I osteotomy, and a bilateral sagittal split ramus osteotomy was performed simultaneously to push back the mandible in five patients with prognathia, to obtain a normal soft-tissue profile and occlusal relationship.Successful maxillary advancements ranging from 5 to 15 mm were measured from preoperative and postoperative cephalograms. Patients' sella-nasion-point A angles increased from an average of 71.25 degrees preoperatively to 79.05 degrees postoperatively. Orthodontic therapies were adopted before and/or after midface distraction. After the consolidation period, dense new bone was found to have formed in the distraction gap. During the follow-up period, the position of the maxilla and the final occlusal relationship were stable and acceptable, and no obvious relapses were seen.Midface distraction is an ideal choice for the correction of severe maxillary hypoplasia secondary to cleft lip and/or palate.