An internal distraction device for midface distraction osteogenesis: The NAVID system type Z'gok

Abstract

Midface advancement with distraction osteogenesis is more routinely used for faciocraniosynostosis. Distraction devices are generally classified into external and internal types. Compared with external distractors, internal distractors are smaller and better tolerated, but their removal is complicated. Here, we introduce a refined internal distraction device and describe its applicability. Unlike the previous anterior fixation plate that utilises screws, the refined internal distraction (type Z'gok) has 3 claws. This anterior point of the distractor is positioned behind the malar eminence, or the lateral orbital wall. Eight patients with syndromic craniosynostosis underwent midface distraction osteogenesis using the type Z'gok between 2016 and 2017 (Z'gok group). Twelve patients were treated using conventional internal distractors (control group). Patient age ranged from 6 to 21 years. Among them, 4 patients underwent Le Fort III distraction osteogenesis, while the others underwent Le Fort IV distraction osteogenesis. The operative time to remove the distractors in the Z'gok group was 65 ± 18min, shorter than 89 ± 12min in the control group. The blood loss per kilogram of body weight in the Z'gok and control groups was 3.6 ± 3.3 mL/kg and 4.7 ± 1.7 mL/kg, respectively. In conclusion, the type Z'gok is a reliable and effective internal distractor for midface distraction osteogenesis.