Abstract
<title>Abstract</title> <p>This study analyzed the oral microbial characteristics of populations at risk of medication-related osteonecrosis of the jaw (MRONJ), preliminarily clarified its etiological association with the pathogenesis of MRONJ, and provided evidence for clinical prevention and treatment of the disease. This study enrolled 20 patients who attended our hospital from 2022 to 2024 and were at risk of MRONJ. They were grouped according to whether they had used MRONJ-inducing drugs (zoledronic acid, denosumab) and whether they suffered from MRONJ. Oral mucosal swabs from the subjects were subjected to 16S rRNA gene sequencing, and linear discriminant analysis effect size (LEfSe) and heatmap analysis were applied to explore the differences in the diversity and abundance of oral microbiota. The results showed that compared with the non-medication and MRONJ-free groups, the diversity of dominant oral microflora in subjects from the medication group and MRONJ-affected group decreased significantly, with concomitant alterations in microflora composition: the medication group was dominated by Weeksellaceae and Bergeyella (Both belong to phylum Bacteroidota), whereas the MRONJ-affected group was characterized by the predominance of Bacteroidaceae and Prevotella heparinolytica. Additionally, existing studies have demonstrated that these microbial taxa can indirectly induce MRONJ; thus, it is speculated that drug-induced changes in the dominant oral microflora may be one of the major pathogenic factors for MRONJ. MRONJ patients and drug users exhibit distinct oral dominant microbiota structures versus non-diseased/non-medicated individuals. Oral microbial characteristics can serve as a key entry point for etiological research, offering a novel theoretical basis for early prevention and targeted intervention.</p>