[Changes of distal-less homeobox genes 5 and Msh homeobox 1 in a rat model of bisphosphonate related osteonecrosis of the jaw].

Objective: To further study the effects of distal-less homeobox gene 5 (Dlx-5) and Msh homeobox 1 (Msx-1) in the pathogenic mechanism of bisphosphonate related osteonecrosis of the jaw (BRONJ) . Methods: Twenty-four SD rats were divided into two groups, the experimental group was injected intraperitoneally with zoledronic acid for 12 weeks (0.2 mg/kg, three times a week), and the control group was injected with saline solution for 12 weeks. The first mandibular molars were extracted after 12 weeks. All of the animals were sacrificed eight weeks after teeth extraction. The BRONJ was diagnosed by gross observation, X-ray examination and histopathlolgical examination. Through real-time PCR, the expression level of Dlx-5 and Msx-1 were detected in the mandible of BRONJ samples and normal samples. Results: X-ray examination and histopathlolgical analysis showed the presence of BRONJ. The results of real-time PCR showed that the expression levels of Dlx-5 were increased ( P= 0.001) and the expression level of Msx-1 was decreased ( P= 0.001) in the experimental group compared with the control group. Conclusions: Dlx-5 and Msx-1 genes play roles in the pathogenic mechanism of BRONJ.