Introduction of a novel internal spring-driven craniofacial bone distraction device

A study of craniofacial bone distraction using an internal self-expanding bone device designed by the authors was performed in a young rabbit skull model. Ten 30-day-old New Zealand white rabbits were divided into two groups: 5 underwent distraction with the device, and 5 served as controls. Serial cephalograms, defleshed skull measurements, and histological examinations were performed on the study animals. The distracted group demonstrated a significant midface lengthening and overbite compared with the control group. Histologically, more fibroblasts and osteoblasts were seen in the front nasal bone in the distracted group in comparison with the nondistracted controls. The self-expanding internal bone distractor can effectively lengthen certain facial bones in an animal model and avoid some of the disadvantages associated with the external distraction techniques. This new device offers clinical potential as a useful distraction technique, but further work is needed to determine the effects of continuous postoperative tension loads on bone healing, the amount of tension generated by certain spring loads and lengths' and the feasibility of applying this concept in confined bone spaces.