Soft tissue changes during distraction osteogenesis

This study aimed to investigate soft tissue changes in distraction osteogenesis depending on various distraction and consolidation periods. Fifteen male rabbits were divided into three groups and evaluated for five parameters. An external custom-made device was placed on the right side of the mandible. The postoperative latent period was 4 days. The groups were distracted for different periods (6 days, 3mm; 11 days, 5.5mm, 16 days, 8mm). For histomorphometric analyses, specimens were retrieved from both study and control sides of the mandible and were examined with light microscopy. The number of muscle fibres and nuclei on the study side increase proportionally with the distraction period. Regeneration in the first group continued in its natural pattern; in the second group, there seemed to be degeneration rather than regeneration; and in the third group there seemed to be a balance between regeneration and degeneration processes. In conclusion, when a massive amount of bone is to be obtained, instead of distracting the bone at once, it is thought to give better results if the total amount of distraction is divided into several time periods.