Osteonecrosis of the Jaw Associated with Obinutuzumab in a Patient with Preceding Follicular Non-Hodgkin’s Lymphoma

<b>Background:</b> Obinutuzumab is a glycoengineered type II anti-CD-20 monoclonal antibody, which can be applied as immunotherapy in patients with follicular lymphoma. To our knowledge, this is the first reported case in the literature describing osteonecrosis of the jaw associated with CD20 monoclonal antibody therapy. <b>Methods:</b> The following case report describes a 39-year-old female patient under maintaining therapy with Obinutuzumab developing osteonecrosis of the jaw after tooth extraction. The necrotic area was located in the right mandible and was rated as a stage II osteonecrosis. <b>Results:</b> This case report should draw attention to the importance of dental follow-ups during aftercare of patients with Non-Hodgkin's Lymphoma as well as to the relevant precautions for performing tooth extractions in such patients. <b>Conclusions:</b> As Obinutuzumab seems to be a contributing factor in the development of MRONJ, special attention has to be drawn to tooth extractions in such patients, which should only be performed with perioperative antibiosis, the least amount of trauma possible, always including the smoothening of sharp residual bone segments and a saliva-proof wound closure, as well as constant dental follow-ups.