 The implication is that bisphosphonates may not be the initiating cause of ONJ and that other pre-existing or concurrent systemic and/or local dental factors are involved.Since ONJ has been diagnosed in many patients who did not take bisphosphonates, it is thus logical to assume that bisphosphonates are not the only factor in ONJ.While the oversuppression of bone turnover seems to play a major role in aggravating the disease process, other factors can and do initiate the pathophysiological mechanisms responsible for ONJ.