不同辐照仪对大鼠下颌骨放射性颌骨坏死模型建立的影响

Effects of different irradiators on the establishment of osteoradionecrosis model of rat mandible

目的比较不同辐照仪对大鼠放射性颌骨坏死(ORNJ)模型建立的影响,探索理想建模方法。方法将33只成年SD大鼠随机分为CN组(空白对照,3只)、A组(直线加速器照射,15只)、B组(小动物辐照仪照射,15只)。A、B组再次随机分为3组:A35/B35、A40/B40、A45/B45,各组左侧下颌骨分别接受每天7、8、9 Gy照射,连续5 d。照射结束后1周,所有大鼠行左侧下颌骨照射区拔牙创伤,3周后处死,获取下颌骨标本,进行大体观察、micro-CT扫描和组织病理学观察,评估建模成功率。结果拔牙后3周,A35、A40组拔牙创愈合,A45、B组拔牙创未愈合、明显骨外露。苏木精-伊红染色见A35组无死骨形成,A40、A45和B组明显死骨形成。A组建模成功率为40%,B组建模成功率为93.3%。结论小动物生物辐照仪是理想的大鼠ORNJ建模照射方式。

Objective To compare the effects of different irradiators on the establishment of osteoradionecrosis of jaw model(ORNJ)to explore an ideal modeling method.Methods A total of 33 adult SD rats were included and randomly divided into three groups according to the radiation equipment,namely,the blank control(CN,3 rats),group A(linear ac‐celerator irradiation,15 rats),and group B(small-animal irradiator irradiation,15 rats).Groups A and B were irradiated with daily fractions of 7,8,and 9 Gy for 5 days and further divided into three subgroups as follows:group A35/B35,35 Gy;group A40/B40,40 Gy;and group A45/B45,45 Gy.The left mandibular molars of the rats were extracted 1 week after irradia‐tion.The rats were sacrificed 3 weeks after tooth extraction,and the mandible specimens were obtained for gross observa‐tion,micro-CT scanning,and histological detection to evaluate the success rate of modeling.Results At 3 weeks after dental extractions,complete gingival healing was found in the regions of dental extractions in groups A35 and A40.Howev‐er,failed gingival healing and bone exposure were found in groups A45 and B.Hematoxylin and eosin staining showed ne‐crotic bone of the irradiated mandible in groups A40,A45,and B,with success modeling rates of 40%in group A and 93.3%in group B.Conclusion Small-animal irradiator irradiation is an ideal device for establishing ORNJ model.