Distraction Osteogenesis in Maxillary Deficiency Using a Rigid External Distraction Device

Abstract

Distraction osteogenesis is an effective method of bone regeneration. McCarthy et al.1 were the first to report success in human mandible lengthening using distraction osteogenesis. The primary cleft lip and palate repair performed during infancy and early childhood improves the facial appearance, speech, and deglutition, but these early surgical interventions cause an impairment of maxillary growth, producing secondary deformities of the jaw and malocclusion.2,3 The hypoplastic maxilla can be advanced later by Le Fort I osteotomy, with or without bone graft, to re-establish the facial balance and occlusion.4–6 However, the maxilla in these patients is often difficult to mobilize because of the scarring from previous operations. Despite improvements in surgical fixation, there is greater tendency to relapse in cleft patients compared with noncleft patients with maxillary hypoplasia.4,7,8 Patients with severe cleft maxillary deficiency are difficult to treat with standard surgical orthognathic surgery. Treatment of severe maxillary hypoplasia with conventional Le Fort I maxillary advancement, especially in patients with orofacial cleft, has been unstable. The extreme discrepancies between the bony segments make stabilization difficult, and the added effect of palatal scarring can result in significant postsurgical relapse. Maxillary distraction is believed to be especially effective for cleft lip and palate patients with severe maxillary hypoplasia.9–11 Maxillary advancement may benefit articulation, but it compromises velopharyngeal closure by increasing the nasopharyngeal distance. It is known that velopharyngeal closure could be compromised after conventional maxillary advancement (not maxillary distraction) exceeding 10 mm.12–14 The purpose of this study was to present our experience in the treatment of maxillary deficiency in cleft patients using rigid external distraction devices. Patients received 2 years of clinical and cephalometric follow-up, and preoperative and postoperative changes in velopharyngeal function in cleft lip and palate patients were evaluated. In this article, we discuss the advantages of distraction osteogenesis for the treatment of major maxillary deficiency in cleft patients compared with the conventional Le Fort I advancement, in terms of stability and relapse and postoperative changes in velopharyngeal function.