Purpose: To determine the long-term outcomes of maxillary distraction osteogenesis (DO) on skeletal and dental structures of growing children with cleft lip and palate.
Patients and methods: Severe maxillary deficiencies were treated with a rigid external distractor device followed by a consolidation period. Preoperative and postoperative orthodontic treatment lasted a mean of 14 months and 16 months, respectively. The landmarks on standard lateral cephalometric x-rays were digitized and angular and linear measurements were compared by Student's t test to assess the changes before distraction, after distraction, after consolidation, at 1-year follow-up, and at 2-year follow-up. Long-term follow-up (5 years) was interpreted according to mean values because of the small sample size.
Results: During DO, the maxilla was horizontally advanced and moved downward as indicated by the significant changes at the SNA and ANB angles (13 degrees) and at maxillary points A, ANS, and PNS. The increase at the divergence between the maxilla and mandible (ANS-PNS/Me-Go) was found to be significant. The mandible (B, Pg, Me) also moved downward (2-4 mm) and backward (Gn) significantly because of mandibular autorotation. The overjet increased (mean increase, 13.7 mm) and the overbite decreased significantly. The advancement of the upper incisors (13.3 mm) and upper molars (12.3 mm) was slightly more than the skeletal points. In a long-term follow-up (5 years), the ANB angle and horizontal overjet continued to decrease but both values remained positive, indicating a Class I relationship.
Conclusions: This cephalometric study of young adolescents with cleft lips and palates found great improvement in dentofacial structure after maxillary DO and stability in maxillary skeletal advancement. During a 5-year follow-up, the achieved dentoskeletal treatment outcome was partly diminished. The extreme need for maxillary advancement or facial correction because of psychosocial stress and providing an easier approach for finalizing osteotomy are the major 2 indications for DO treatment.
2010 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.