Long-term skeletal stability of computer-assisted maxillary distraction osteogenesis for patients with cleft lip and palate-related midfacial hypoplasia

Abstract

Distraction osteogenesis (DO) has gained acceptance for treating cleft-related deformities involving severe maxillary hypoplasia. Modern computer-assisted surgery (CAS) has progressed rapidly and has been incorporated into oral-maxillofacial surgery. In this retrospective study, we evaluated the long-term skeletal stability of the maxilla repositioned using DO with CAS in patients with cleft-related midfacial hypoplasia. Three female patients (mean age, 21.0 years) requiring a mean maxillary advancement with DO of 11.0 (range, 10-12) mm were included. Based on preoperative computed tomography data, virtual reality surgical planning for maxillary DO with selection of the actual distractor components was done using three-dimensional rapid prototyping models. Surgery entailed a Le Fort I osteotomy and application of semi-custom-made intraoral distraction devices. DO was activated after a 5-day latency period at a rate of 1 mm/day until the appropriate amount of distraction was obtained. After a 4-week retention period, rigid internal fixation and distractor removal were performed (T1). Lateral cephalometric films taken before DO (T0), at T1, 6 months after T1 (T2), and 3 years after T1 (T3) were analyzed. Maxillary point A in the Frankfort horizontal reference plane was used to assess skeletal changes in the maxillary position (x, y) at each time point (T1–T3). In all 3 patients, maxillary DO was safe and CAS with preoperative virtual image-guided simulation was feasible in terms of dental and skeletal relationships and facial profile, with a mean change at maxillary point A of 10.7 mm (7.0 mm horizontally, 8.1 mm inferiorly). Point A showed a moderate amount of skeletal relapse by T2 (1.0 mm, 13.8%, horizontally; 1.3 mm, 16.5%, superiorly; P < 0.05), with a small amount of further relapse at T3 (P > 0.05). DO with CAS can achieve long-term skeletal stability and is a promising minimally invasive bone regenerative treatment for cleft-related midfacial hypoplasia.