A Comparison Study On Distraction Osteogenesis In The Rat's Mandible According To Distraction Rhythm

ABSTRACT

distraction osteogenesis according to different distraction rhythm in the rat 's mandible. Forty-five adult male rats underwent open osteotomy between the second and third molars and external unilateral distraction device was applied.Latency was allowed for 5 days before distraction began.The distraction device was activated with same rate of 0.5mm per day and varying distraction rhythms of once daily,twice daily,four times daily until 3mm length gain was achieved.Tissues were harvested after 4 days,2 weeks,and 4 weeks after distraction for Western blot analysis,RT-PCR analysis and harvested 3 weeks,6 weeks after distraction for clinical,radiographic,and histologic studies.Three animals were killed at each time point. The results obtained from this study were as follows No significant difference was found on clinical examination according to distraction rhythms,and increasing the frequency of distraction was shown to improve regenerate bone formation on radiographic and histologic examination,and TGF-beta 1 expression increased when small,more frequent distractions were performed. From these results,it could be stated that more frequent distraction is shown to significantly improve and accelerate bone formation and has considerable effects on TGF-beta 1 expression.