This study was undertaken to examine effects and biocompatibility of a new internalized distraction device made from newly developed Ti-Nb-Al shape memory alloy (SMA). Crania of Wistar rats were expanded using a U-shaped wire of this SMA set on each cranium in an experimental group. At 2 or 4 weeks after operation, the rats were killed; width measurements and three-dimensional observations of crania were conducted using soft x-ray and microfocus x-ray computed tomography photography. After photography, histologic sections were made and stained with hematoxylin and eosin. No pathologic change in the experimental duration was observed macroscopically or histologically. Significantly increased size was found for the rat crania in the experimental group compared with the control group. Results demonstrated the feasibility and biocompatibility of internalized distraction osteogenesis using Ni-free, Ti-based SMA in craniofacial plastic surgery for craniofacial deformities.