Establishment of an animal model of distraction osteogenesis in the irradiated dog mandible / 实用口腔医学杂志

ABSTRACT

Objective:To establish an animal model of bone distraction in the irradiated dog mandible.Methods:1 0 Chinese dogs were used.8 dogs received a unilateral irradiation of 60 Co(Group R)in the mandible with a total dose of 22.8 Gy in four 5.7 Gy frac-tions (biologically equivalent to 50 Gy/25 fractions).The other 2 dogs without irradiation served as the controls(Group C).Bilateral corticotomy was made 3 months after completion of irradiation.After a 1 -week latency period,bone distraction was activated at a rate of 0.5 mm twice daily for 1 0 days,followed by a consolidation phase of 8 weeks.New bone was evaluated by radiographic,histological and single photon emission computed tomography(SPECT)analysis.Results:One dog was excluded from the study due to anaesthetic death in group R.After 8 weeks of consolidation,no difference was found between the percent area of new bone of both groups.New bone was more mature and organized in Group C than that in Group R.SPECT analyses showed that there was active osteogenic activity in Group R.Conclusion:Distraction osteogenesis can be achieved in the irradiated dog mandible.