Hi @emilyelliott321 ONJ stands for Osteonecrosis of the Jaw. People undergoing bisphosphonate treatment such as taking Prolia or other meds to reduce bone loss have a rare but slightly elevated risk of developing osteonecrosis of the jaw following a tooth extraction. This can be due an area of bone that is exposed and not receiving a steady blood supply. That can damage and destroy that area of bone.
https://www.healthline.com/health/osteonecrosis-of-the-jaw
Are you on a bone-loss drug such as Prolia or fozamax?