Department of Oral Diagnosis, Division of Oral Radiology, Piracicaba Dental School, University of Campinas, Av. Limeira, 901, PO Box 52, Piracicaba, SP, 13414-903, Brazil.
Orofacial Pathologies, Imaging and Biotherapies Laboratory, Paris Descartes University, Sorbonne Paris Cité, 2496, Montrouge, EA, France.
Clin Oral Investig. 2020 Apr;24(4):1561-1567. doi: 10.1007/s00784-019-03054-0. Epub 2019 Aug 10.
To propose a modified protocol of mandibular osteoradionecrosis induction in rats with external beam radiation therapy.
A total of 45 male Wistar rats were used in this study. Firstly, 25 rats were divided into 5 groups (n = 5) according to the radiation dose protocol: without irradiation and irradiated with 15 Gy, 20 Gy, 25 Gy, or 30 Gy using a linear accelerator. Secondly, 15 other rats were divided into 3 groups (n = 5) according to the time of extraction of the three right mandibular molars: 7, 10, or 14 days after irradiation of 20 Gy. Lastly, dental extractions were performed in 5 other rats without irradiation (C-E10) for comparison with those of the group of dental extractions 10 days after irradiation (I-E10).
The irradiated animals survived throughout the study period only at single doses of 15 Gy and 20 Gy. The suitable time for dental extractions after irradiation to induce mandibular osteoradionecrosis was defined as 10 days. Macroscopic evaluation of the right hemimandibles showed presence of osteoradionecrosis in I-E10 group and complete gingival healing in C-E10 group.
A single radiation dose of 20 Gy focused on head and neck region combined with the extraction of the three mandibular molars 10 days after irradiation constitutes a feasible protocol of mandibular osteoradionecrosis induction in rats with external beam radiation therapy.
Establishing a solid and widely available protocol of mandibular osteoradionecrosis induction is essential in the search for methods to prevent this complex disease.
提出一种改良的大鼠下颌骨放射性骨坏死诱导方案，采用外照射放射治疗。
本研究共使用 45 只雄性 Wistar 大鼠。首先，25 只大鼠根据放射剂量方案分为 5 组（n=5）：不照射和照射 15Gy、20Gy、25Gy 或 30Gy 的直线加速器。其次，其余 15 只大鼠根据 20Gy 照射后拔除右侧 3 颗下颌磨牙的时间分为 3 组（n=5）：7、10 或 14 天。最后，5 只未照射的大鼠（C-E10）进行拔牙，与照射后 10 天拔牙组（I-E10）进行比较。
仅在单次照射 15Gy 和 20Gy 时，照射动物在整个研究期间存活。诱导下颌放射性骨坏死的合适拔牙时间为照射后 10 天。右侧半下颌的宏观评估显示，I-E10 组存在放射性骨坏死，C-E10 组牙龈完全愈合。
头颈部单次 20Gy 照射结合照射后 10 天拔除 3 颗下颌磨牙构成了一种可行的大鼠下颌骨放射性骨坏死诱导方案，采用外照射放射治疗。
建立一种可靠且广泛适用的下颌放射性骨坏死诱导方案对于寻找预防这种复杂疾病的方法至关重要。
