Methods Six adult dogs were used in this experiment.On the area of mandibular premolars, the cortical bone was removed and distractor was installed.

• 方法成年杂种犬6只,在下颌骨双尖牙区制备一个单皮质缺损区,安装牵引器,将其远中的骨皮质向骨缺损区牵引。