[Preliminary study on the etiological characteristics and clinical treatment of medication-related osteonecrosis of the jaws].

Objective: To summarize the etiological characteristics and clinical treatment effects of 17 patients with medication-related osteonecrosis of the jaw (MRONJ). Methods: The clinical data of 17 patients with MRONJ admitted to the Department of Oral and Maxillofacial Surgery, the First People's Hospital of Jinzhong, Shanxi Province, from July 2016 to December 2019 were retrospectively analyzed, including 9 males and 8 females, aged (63.6±9.6) years old (43-82 years old). Descriptive analysis of the primary disease, onset factors, site of disease, clinical manifestations, treatment methods, and treatment effects was conducted through follow-up for at least 1 year. Results: Among the primary diseases of the 17 cases, 12 were malignant tumors, and 5 were osteoporosis. There were 13 cases with a history of a trigger event (tooth extraction or unsuited removable denture). Six cases occurred in the maxilla, 10 cases occurred in the mandible, and 1 case involved both the upper and lower jaws. For the most common medication used, bisphosphonate was used in 16 cases including 5 cases with concomitant use of angiogenesis-inhibiting drugs. There was 1 case resulted from receptor activator of NF-κB ligand (RANKL) monoclonal antibody application. The duration of medication application was (10.1±3.9) months (3-18 months). All 17 cases were treated surgically. Totally 15 patients healed well after surgical treatment and the other 2 patients, who had poor soft tissue healing after surgery, healed well after a second operation. Conclusions: Tooth extraction might be a major trigger factor for the onset of MRONJ in the mandible. The disease was more possibly occured in the mandible than in the maxilla. Appropriate surgical treatment could achieve a good clinical outcome.