Establishment of a rabbit model for mandibular osteoradionecrosis

Abstract

Abstract: PURPOSE : The present study was performed to establish a standard animal model of mandibular osteoradionecrosis (ORN) in rabbit and to evaluate the irradiated mandibles based on clinical manifestation, single-photon emission computed tomography (SPECT), micro-CT, and histological observation. METHODS : According to the biological equivalent formula and hypofractionation radiation method, twenty-four rabbits were randomly divided into 4 groups: group 1 served as control, the left mandibles in group 2, 3 and 4 received iron irradiation at doses of 8.0, 8.9 and 9.7Gy every two days and 5 times respectively using linear accelerator. Forty-five days after irradiation, the left mandibular molars were extracted in all groups. Three months later, the mandibles in all groups were examined by clinical manifestation, SPECT, micro-CT, and histological observation to select the most suitable model. The data was analyzed with SPSS17.0 software package. RESULTS : Two rabbits died in group 4 because of malnutrition. Alopecia of the irradiated skin, sequestration and bone exposure in irradiated mandibles, and fibrosis in medulla were found in Group 3 and 4. In group 2, alopecia was less significant, and the mandibles had mainly showed medullary infection. Group 3 and 4 showed decreased BV/TV, Tb.Th, Tb.N and increased Tb.Sp compared to group 1 and 2. SPECT showed that bone metabolic rate in group 3 and 4 decreased significantly. CONCLUSION : We successfully established a reproducible rabbit model with mandibular osteoradionecrosis using iron radiation at dosage of 8.9 Gy with postradiation dental extractions. This model can serve as a platform for future studies on pathogenesis and treatment of ORN.

Key words: Osteoradionecrosis of jaws, Animal model, Biological equivalent dose, Bone histomorphometric analysis

CLC Number:

R782.4

ZONG Chun-lin¹, GUO Yu-xuan¹, DOU Gen², ZHANG Yu², TIAN Lei¹, LIU Yan-pu¹. Establishment of a rabbit model for mandibular osteoradionecrosis[J]. China Journal of Oral and Maxillofacial Surgery, 2014, 12(6): 481-486.

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