Establishment of a modified rat model for osteoradionerosis of the jaws using a linear accelerator

doi:10.3877/cma.j.issn.1674-1366.2026.01.008

Abstract

Abstract:

Objective

To investigate the effects of different irradiation schemes (single-dose 20 Gy and fractionated 5 × 7 Gy) on a rat model of osteoradionecrosis of the jaws (ORNJ) , to optimize the modeling protocol.

Methods

Twenty-seven male Sprague-Dawley (SD) rats were randomly divided into a single-dose irradiation group (20 Gy) , a fractionated-dose irradiation group (5 × 7 Gy) , and a control group. Prior to irradiation, the subcutaneous depth and buccolingual diameter of the left mandible in rats were measured. A linear accelerator was used to precisely target the left mandibular molar region, supplemented with a compensator membrane to enhance superficial dose delivery. One week after irradiation, all left mandibular molars were extracted with the aid of a microscope. Twelve weeks post-extraction, gross observation, micro-CT scanning and reconstruction, as well as histopathological analyses (H & E, Masson's trichrome and TRAP staining) were performed to assess bone destruction, sequestrum formation, fibrosis, and osteoclast. Survival rate and modeling success rate were analyzed.

Results

The single-dose group exhibited acute radiation reactions (skin redness, hair loss) and significant occlusal disorder after four weeks, with a modeling success rate of 71%. The fractionated -dose group showed milder acute reactions but more severe late-stage fibrosis, with a modeling success rate of 78%. Micro-CT revealed more obvious trabecular fractures, cortical bone disruption, and pathological fractures in the single-dose group, while the fractionated group exhibited deeper bone defects. Histologically, both experimental groups displayed necrotic bone formation, fibrous tissue hyperplasia, empty bone lacunae, increased fatty vacuoles, and osteoclast infiltration. The fractionated group demonstrated marked bone marrow fat vacuolization, fibrosis, and osteoclast infiltration.

Conclusions

The fractionated irradiation scheme (5 × 7 Gy) is more consistent with the pathological features of ORNJ. The optimized modeling method demonstrates high reproducibility and controllability, providing a reliable platform for investigating ORNJ mechanisms and developing prevention/therapeutic strategies.

Key words: Linear accelerator, Osteoradionerosis of the jaws, Animal model

Ke Liu, Chenyu Zeng, Yikun Li, Yuxin Qian, Mingzhe Xin, Lei Jin. Establishment of a modified rat model for osteoradionerosis of the jaws using a linear accelerator[J]. Chinese Journal of Stomatological Research(Electronic Edition), 2026, 20(01): 51-60.

/ / Recommend

Add to citation manager EndNote|Ris|BibTeX

URL: https://zhkqyxyjzz.cma-cmc.com.cn/EN/10.3877/cma.j.issn.1674-1366.2026.01.008

https://zhkqyxyjzz.cma-cmc.com.cn/EN/Y2026/V20/I01/51

Figures/Tables 12

References 30

[1]	Gundestrup AK，Lynggaard CD，Forner L，et al. Mesenchymal stem cell therapy for osteoradionecrosis of the mandible：A systematic review of preclinical and human studies[J]. Stem Cell Rev Rep，2020，16（6）：1208-1221. DOI：10.1007/s12015-020-10034-5.
[2]	Ruaro A，Taboni S，Chan HHL，et al. Development of a preclinical double model of mandibular irradiated bone and osteoradionecrosis in new zealand rabbits[J]. Head Neck，2025，47（2）：625-634. DOI：10.1002/hed.27955.
[3]	Guan Z，Zhang J，Jiang N，et al. Efficacy of mesenchymal stem cell therapy in rodent models of radiation-induced xerostomia and oral mucositis：A systematic review[J]. Stem Cell Res Ther，2023，14（1）：82. DOI：10.1186/s13287-023-03301-y.
[4]	Yamasaki MC，Roque-Torres GD，Peroni LV，et al. A modified protocol of mandibular osteoradionecrosis induction in rats with external beam radiation therapy[J]. Clin Oral Investig，2020，24（4）：1561-1567. DOI：10.1007/s00784-019-03054-0.
[5]	Li J，Yin P，Chen X，et al. Effect of alpha2-macroglobulin in the early stage of jaw osteoradionecrosis[J]. Int J Oncol，2020，57（1）：213-222. DOI：10.3892/ijo.2020.5051.
[6]	Guo Z，Wang Z，Liu Y，et al. Carbon dots from Lycium barbarum attenuate radiation-induced bone injury by inhibiting senescence via METTL3/Clip3 in an m⁶A-dependent manner[J]. ACS Appl Mater Interfaces，2023，15（17）：20726-20741. DOI：10.1021/acsami.3c01322.
[7]	dos Santos M，Demarquay C，Ermeneux L，et al. Refining the mandibular osteoradionecrosis rat model by in vivo longitudinal μCT analysis[J]. Sci Rep，2021，11（1）：22241. DOI：10.1038/s41598-021-01229-y.
[8]	Wang Y，Wang X，Liu Z，et al. Establishment of an osteoradionecrosis model and its mechanism via single ionizing radiation exposure[J]. Int Dent J，2025，75（3）：1672-1682. DOI：10.1016/j.identj.2025.03.006.
[9]	Bagi CM，Berryman E，Moalli MR. Comparative bone anatomy of commonly used laboratory animals：Implications for drug discovery[J]. Comp Med，2011，61（1）：76-85.
[10]	de Oliveira SV，Dos Reis T，Amorim J，et al. Efficacy of photobiomodulation therapy on healing of ionizing irradiated bone：A systematic review of in vivo animal studies[J]. Lasers Med Sci，2022，37（9）：3379-3392. DOI：10.1007/s10103-022-03649-2.
[11]	Nguyen TTH，Eo MY，Seo MH，et al. Effects of pentoxifylline and tocopherol on a rat-irradiated jaw model using micro-CT cortical bone analysis[J]. Eur Arch Otorhinolaryngol，2019，276（12）：3443-3452. DOI：10.1007/s00405-019-05600-8.
[12]	Murphy CK，Fey EG，Watkins BA，et al. Efficacy of superoxide dismutase mimetic M40403 in attenuating radiation-induced oral mucositis in hamsters[J]. Clin Cancer Res，2008，14（13）：4292-4297. DOI：10.1158/1078-0432.Ccr-07-4669.
[13]	Frankart AJ，Frankart MJ，Cervenka B，et al. Osteoradionecrosis：Exposing the evidence not the bone[J]. Int J Radiat Oncol Biol Phys，2021，109（5）：1206-1218. DOI：10.1016/j.ijrobp.2020.12.043.
[14]	Cabrera AR，Yoo DS，Brizel DM. Contemporary radiotherapy in head and neck cancer：Balancing chance for cure with risk for complication[J]. Surg Oncol Clin N Am，2013，22（3）：579-598. DOI：10.1016/j.soc.2013.02.001.
[15]	Tchanque-Fossuo CN，Monson LA，Farberg AS，et al. Dose-response effect of human equivalent radiation in the murine mandible：Part Ⅰ. A histomorphometric assessment[J]. Plast Reconstr Surg，2011，128（1）：114-121. DOI：10.1097/PRS.0b013e31821741d4.
[16]	Niehoff P，Springer IN，Açil Y，et al. HDR brachytherapy irradiation of the jaw：As a new experimental model of radiogenic bone damage[J]. J Craniomaxillofac Surg，2008，36（4）：203-209. DOI：10.1016/j.jcms.2008.01.003.
[17]	Little JB. Cellular，molecular，and carcinogenic effects of radiation[J]. Hematol Oncol Clin North Am，1993，7（2）：337-352. DOI：10.1016/S0889-8588(18)30244-2.
[18]	Yamasaki MC，Roque-Torres GD，Peroni LV，et al. Does the administration of meloxicam before head and neck radiotherapy reduce the risk of mandibular osteoradionecrosis? An animal model study[J]. Clin Oral Investig，2021，25（6）：3739-3745. DOI：10.1007/s00784-020-03701-x.
[19]	Janus JR，Jackson RS，Lees KA，et al. Human adipose-derived mesenchymal stem cells for osseous rehabilitation of induced osteoradionecrosis：A rodent model[J]. Otolaryngol Head Neck Surg，2017，156（4）：616-621. DOI：10.1177/0194599816688647.
[20]	Seo MH，Myoung H，Lee JH，et al. Effects of pentoxifylline and tocopherol on an osteoradionecrosis animal model[J]. J Craniomaxillofac Surg，2020，48（7）：621-631. DOI：10.1016/j.jcms.2020.02.008.
[21]	Dréno M，Bléry P，Guicheux J，et al. Development of a rat model of mandibular irradiation sequelae for preclinical studies of bone repair[J]. Tissue Eng Part C Methods，2020，26（8）：447-455. DOI：10.1089/ten.TEC.2020.0109.
[22]	Li J，Kong XB，Chen XY，et al. Protective role of α2-macroglobulin against jaw osteoradionecrosis in a preclinical rat model[J]. J Oral Pathol Med，2019，48（2）：166-173. DOI：10.1111/jop.12809.
[23]	Page EE，Deshpande SS，Nelson NS，et al. Prophylactic administration of Amifostine protects vessel thickness in the setting of irradiated bone[J]. J Plast Reconstr Aesthet Surg，2015，68（1）：98-103. DOI：10.1016/j.bjps.2014.08.054.
[24]	Deshpande SS，Gallagher KK，Donneys A，et al. Parathyroid hormone therapy mollifies radiation-induced biomechanical degradation in murine distraction osteogenesis[J]. Plast Reconstr Surg，2013，132（1）：91e-100e. DOI：10.1097/PRS.0b013e3182910ae7.
[25]	Deshpande SS，Gallagher KK，Donneys A，et al. Stem cells rejuvenate radiation-impaired vasculogenesis in murine distraction osteogenesis[J]. Plast Reconstr Surg，2015，135（3）：799-806. DOI：10.1097/PRS.0000000000001024.
[26]	Sapir-Koren R，Livshits G. Osteocyte control of bone remodeling：Is sclerostin a key molecular coordinator of the balanced bone resorption-formation cycles?[J]. Osteoporos Int，2014，25（12）：2685-2700. DOI：10.1007/s00198-014-2808-0.
[27]	Tamplen M，Trapp K，Nishimura I，et al. Standardized analysis of mandibular osteoradionecrosis in a rat model[J]. Otolaryngol Head Neck Surg，2011，145（3）：404-410. DOI：10.1177/0194599811400576.
[28]	Mullender MG，van der Meer DD，Huiskes R，et al. Osteocyte density changes in aging and osteoporosis[J]. Bone，1996，18（2）：109-113. DOI：10.1016/8756-3282(95)00444-0.
[29]	Seo MH，Lee MY，Eo MY，et al. Development of a standardized mucositis and osteoradionecrosis animal model using external radiation[J]. J Korean Assoc Oral Maxillofac Surg，2020，46（4）：240-249. DOI：10.5125/jkaoms.2020.46.4.240.
[30]	Moreno AC，Watson EE，Humbert-Vidan L，et al. International expert-based consensus definition，classification criteria，and minimum data elements for osteoradionecrosis of the jaw：An interdisciplinary modified delphi study[J]. Int J Radiat Oncol Biol Phys，2025，122（2）：341-354. DOI：10.1016/j.ijrobp.2024.12.017.

辐照设备	辐照方案
辐照设备	辐照剂量	辐照次数
直线加速器	20/25/30/40 Gy^[7]	单次高剂量
直线加速器	20 Gy^[4,8,18]	单次高剂量
HDR	20 Gy^[19]	单次高剂量
X射线辐照仪	35 Gy^[20]	单次高剂量
⁶⁰Co	30/45 Gy^[11]	单次高剂量
X射线辐照仪	80 Gy^[21]	单次高剂量
X射线辐照仪	5 × 7 Gy^[22,23]	大剂量分割辐照
中压X射线治疗系统	5 × 7 Gy^[24,25]	大剂量分割
中压X射线治疗系统	5 × 5.91/7/8.89 Gy^[15]	大剂量分割

辐照设备	辐照方案
辐照设备	辐照剂量	辐照次数
直线加速器	20/25/30/40 Gy^[7]	单次高剂量
直线加速器	20 Gy^[4,8,18]	单次高剂量
HDR	20 Gy^[19]	单次高剂量
X射线辐照仪	35 Gy^[20]	单次高剂量
⁶⁰Co	30/45 Gy^[11]	单次高剂量
X射线辐照仪	80 Gy^[21]	单次高剂量
X射线辐照仪	5 × 7 Gy^[22,23]	大剂量分割辐照
中压X射线治疗系统	5 × 7 Gy^[24,25]	大剂量分割
中压X射线治疗系统	5 × 5.91/7/8.89 Gy^[15]	大剂量分割

动物建模	临床常规
动物建模	次数（次）	剂量（Gy）
20 Gy，单次	46	92
25 Gy，单次	70	140
30 Gy，单次	99	198
35 Gy，单次	133	266
40 Gy，单次	172	344
7 Gy/次，5次	35	70

动物建模	临床常规
动物建模	次数（次）	剂量（Gy）
20 Gy，单次	46	92
25 Gy，单次	70	140
30 Gy，单次	99	198
35 Gy，单次	133	266
40 Gy，单次	172	344
7 Gy/次，5次	35	70

Please choose a citation manager

Content to export