Distraction osteogenesis in the dog mandible under 60-Gy irradiation.
OBJECTIVE
The objective of this study was to explore the probability of distraction osteogenesis (DO) in the irradiated dog mandible after 60-Gy irradiation.


METHODS
Fourteen Chinese dogs were randomly divided into 2 groups. Twelve dogs received a preoperative unilateral irradiation from (60)Co (group R) in the mandible with a total dose of 24.8 Gy in four 6.2-Gy fractions (biologically equivalent to 60 Gy/25 fractions). The other 2 dogs without irradiation served as the control (group C). Bilateral corticotomies were made 6 months after completion of irradiation. Bone distraction was activated at a rate of 0.5 mm twice daily for 10 days after a 1-week latency period, followed by a consolidation phase of 8 weeks. The inferior alveolar nerve (IAN) underwent electrophysiologic analysis. Dog mandibles were subsequently subjected to histologic and radiographic analysis.


RESULTS
All the animals had successful distractions. After 8 weeks of consolidation, no difference was found between the percentage area of new bone in both groups. New bone was more mature and organized in group C than in group R. The action potential of IAN showed corresponding alternation during the irradiation and distraction process.


CONCLUSIONS
Based on this study it seems that DO may be feasible in dog mandible under 60-Gy irradiation. Further research is indicated.
Department of Oral and Maxillofacial Surgery, General Hospital of Jinan Military Region, Ji'nan, Shandong Province, China. liuyanpufmmu@hotmail.com
Yuxiao
Y
Liu
Guicai
G
Liu
Jianli
J
Xu
Guoxiong
G
Zhu
Zhaoling
Z
Wang
Yanpu
Y
Liu
D000818:Animals; D016723:Bone Remodeling / Q000528:radiation effects*; D004285:Dogs; D005071:Evoked Potentials / Q000502:physiology / Q000528:radiation effects; D005260:Female; D008297:Male; D008334:Mandible / Q000528:radiation effects* / Q000601:surgery; D008340:Mandibular Nerve / Q000502:physiology / Q000528:radiation effects; D009416:Nerve Regeneration / Q000502:physiology / Q000528:radiation effects; D019857:Osteogenesis, Distraction / Q000379:methods*; D011829:Radiation Dosage; D011833:Radiation Injuries, Experimental / Q000503:physiopathology*; D011897:Random Allocation