Is medication related osteonecrosis of the jaw around implants a rare entity? A case series with a focus on etiopathophysiology.

Medication Related Osteonecrosis of the Jaw (MRONJ) around dental implants is a rare complication of antiresorptive drug (ARD) treatment. MRONJ has been described in patients with implants placed before, during or after ARD treatment. The aim of this study was to review our cases and to discuss a preventive approach to avoid the risk of MRONJ around implants. In a retrospective analysis of the 168 MRONJ seen in our department from 2005 to 2021, we searched for cases of patients with MRONJ around dental implants. Six patients (4 females, 2 males) presented with MRONJ around 17 implants. Median age was 64 (50-83) years. Four patients received ARD treatment for osteoporosis and 2 for cancer. The maxilla was more affected than the mandible. Six implants were placed after the initiation of ARD treatment and eleven were placed before initiation of ARD treatments. Eight implants were managed surgically while 9 implants were managed conservatively. In this series, implants were placed before or after starting ARD treatment. Despite initial successful osseointegration, MRONJ occurred months or years after initiation of ARD treatment. The role of periimplantitis should be discussed as well as the role of microcracks in the bone following implant loading. Less is known over the effect of ARD treatment after implant osseointegration. Implants could be a risk factor for MRONJ and must be checked regularly (every 3 months). It is important to check the healthy and biomechanical harmony of the implant system during the pre-treatment assessment