Results
No soft tissue fenestration or bone exposure was found in femur. Delayed soft tissue healing was found in both ZA group (3 in mandible, 4 in maxilla) and control group (1 in mandible, 2 in maxilla), while exposed bone was found only in the ZA group (1 in maxilla, 2 in mandible). RT-PCR analysis demonstrated no significant difference in gene expression of angiogenetic markers between ZA-treated and control groups in femur and mandible. In the maxilla, the expression of VEGFA and VEGFR-2 in medium-term ZA group was significantly down-regulated compared with that in the control. The ZA treatment does not change significantly the expression of the angiogenic factors in femur and mandible, but significantly downregulates the expression in maxilla in this rat model. The angiogenesis inhibition may contribute to the development of MRONJ but does not play a key role.