Deshpande Sagar S, Monson Laura A, Cavaliere Christi M, Ayzengart Alexander L, Buchman Steven R
Craniofacial Research Laboratory, Section of Plastic Surgery, University of Michigan, Ann Arbor, MI 48104, USA.
J Oral Maxillofac Surg. 2013 Aug;71(8):1465-70. doi: 10.1016/j.joms.2013.02.011.
The investigators hypothesized that low-dose hyperfractionated radiation would impair mandibular distraction osteogenesis (DO) in a murine mandibular model.
Male Sprague-Dawley rats underwent fractionated radiation (30 Gy) of the left mandible. After a 2-week recovery period, an external frame distractor was applied and gradual distraction of the mandible was performed. Tissue was harvested after a 28-day consolidation period. Gross, radiologic, and histologic evaluations were undertaken. Control animals underwent surgery for an identical time frame without preoperative radiation.
Animals subjected to preoperative radiation (n = 10) showed suboptimal bone formation, including bone atrophy, incomplete bridging of the distraction gap, and gross bony defects or nonunion, compared with controls (n = 10). Although physical lengthening was achieved, irradiation consistently led to a detrimental effect on the normal process of DO.
This set of experiments establishes a valuable rodent model to evaluate the effects of radiation on DO and may help to formulate strategies to optimize DO before it is widely applied in oncologic reconstruction.
研究者们推测，低剂量超分割放疗会损害小鼠下颌骨模型中的下颌骨牵张成骨（DO）。
雄性Sprague-Dawley大鼠接受左侧下颌骨的分割放疗（30 Gy）。经过2周的恢复期后，应用外部框架牵张器并对下颌骨进行逐步牵张。在28天的巩固期后采集组织。进行大体、放射学和组织学评估。对照动物在相同时间范围内接受手术，但无术前放疗。
与对照组（n = 10）相比，接受术前放疗的动物（n = 10）显示出骨形成欠佳，包括骨萎缩、牵张间隙的不完全桥接以及明显的骨缺损或骨不连。尽管实现了物理延长，但放疗始终对正常的DO过程产生有害影响。
这组实验建立了一个有价值的啮齿动物模型，用于评估放疗对DO的影响，并可能有助于制定策略，以便在DO广泛应用于肿瘤重建之前对其进行优化。
