Premaxillary Repositioning in the Severe Form of Bilateral Cleft Lip and Palate

Severe forms of bilateral cleft lip and palate remain a challenging issue. Although nasoalveolar molding dramatically improves overall treatment success, the position of the premaxilla often remains dislocated. The authors attempted to relocate the malpositioned premaxilla into the correct position to obtain the correct three-dimensional (3D) maxillary arch structure and growth. Eight patients with severe bilateral cleft lip and palate were treated with premaxillary osteotomy for premaxilla repositioning. The position of the premaxilla was measured directly using cephalometry. Two raters including orthodontists evaluated the 3D (anteroposterior, transverse, and sagittal) outcomes. Regarding the long-term effects of premaxillary repositioning on midfacial growth, 3D computed tomography scan data were used, including the measurement of the SNA, SNB, and ANB angles according to the time period (T0: preoperative; T1: immediate postoperative; T2: long-term postoperative). All bilateral cleft lips and palates were satisfactorily repaired without any complications, including any premaxillary vascular compromise, nonunion, and occlusal instability. The average visual analog scale scores (0-5) of the anteroposterior, vertical, and transverse dimensions were 3.9, 3.7, and 3.2, respectively. Regarding the effect of premaxillary repositioning on midfacial hypoplasia, the change in the ANB between T1 and T2 was not significant, implying that premaxillary repositioning did not affect the long-term harmony between the maxilla and mandible (ANB of T2-T1: P=0.1016) based on interim growth data at the time of follow-up and study completion. Premaxillary repositioning effectively corrected the malpositioned premaxilla and repaired the accompanying wide alveolar cleft, achieving successful restoration of maxillary arch coordination. In addition, premaxillary osteotomy after 8 years of age does not seem to cause significant maxillary retrusion.