Department of Oral and Maxillofacial Surgery, General Hospital of Jinan Military Region, Ji'nan, Shandong Province, China.
Oral Surg Oral Med Oral Pathol Oral Radiol. 2012 Feb;113(2):183-7. doi: 10.1016/j.tripleo.2011.01.041. Epub 2011 Apr 20.
The objective of this study was to explore the probability of distraction osteogenesis (DO) in the irradiated dog mandible after 60-Gy irradiation.
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.
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.
Based on this study it seems that DO may be feasible in dog mandible under 60-Gy irradiation. Further research is indicated.
本研究旨在探讨 60Gy 照射后犬下颌骨发生牵张成骨（DO）的可能性。
14 只中国犬随机分为 2 组。12 只犬在接受术前单侧照射（60）Co （组 R），总剂量为 24.8Gy，分为 4 个 6.2Gy 剂量（生物学等效剂量为 60Gy/25 个剂量）。另外 2 只未照射的犬作为对照（组 C）。照射完成后 6 个月行双侧骨切开术。在潜伏期 1 周后，每天以 0.5mm 的速度激活骨牵张 10 天，然后进行 8 周的巩固期。对下牙槽神经（IAN）进行电生理分析。随后对犬下颌骨进行组织学和影像学分析。
所有动物均成功进行了牵张。在 8 周的巩固期后，两组的新骨面积百分比无差异。与组 R 相比，组 C 中的新骨更成熟、更有组织。IAN 的动作电位在照射和牵张过程中表现出相应的变化。
根据本研究，60Gy 照射下犬下颌骨的 DO 似乎是可行的。需要进一步研究。
