I am 21 yrs old. I have had an extra tooth in my upper left jaw, a canine, at the age of 12 or somewhere there. So my mom brought me to the dentist and had it removed. I haven't been to the dentist since then. Now a 2-3 months ago I went to the dentist to get a cleaning and a checkup , only to find out that there is bone missing below my incisors in my lower jaw, below all 4. He says it's bacteria eating away the bone. I mean, my incisors are shaky, but I thought that was normal until he told me it wasn't. Anyway, he gave me a mouthwash to use twice per day and that I should schedule a surgery with him to inject something into the jawbone to promote healing and to kill the bacteria. But I have been reading online that osteonecrosis is diagnosed when a teeth is removed and the bone didn't get a chance to heel. I didn't remove any of my incisors, so is my diagnosis correct? There are risks of taking the injection and it's pretty expensive.