Abstract
OBJECTIVES: 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 accelerator 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 A(35)/B(35), 35 Gy; group A(40)/B(40), 40 Gy; and group A(45)/B(45), 45 Gy. The left mandibular molars of the rats were extracted 1 week after irradiation. The rats were sacrificed 3 weeks after tooth extraction, and the mandible specimens were obtained for gross observation, 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 A(35) and A(40). However, failed gingival healing and bone exposure were found in groups A(45) and B. Hematoxylin and eosin staining showed necrotic bone of the irradiated mandible in groups A(40), A(45),and B, with success modeling rates of 40% in group A and 93.3% in group B. CONCLUSIONS: Small-animal irradiator irradiation is an ideal device for establishing ORNJ model.