I have always kept good care of my teeth. I am 19. I never had cavities. However, in the past week, I notice some swelling on my gums under my lower front teeth. A few heads emerged, and pus started to appear, and my teeth above it were sore. A few days past, an I noticed it 'popped' and pus came out. Not too much though. This is all with in a week. I went to my dentist, and she used an x-ray to see my teeth. What I saw was like little halos on 2-3 teeth and one a little bigger halo on a tooth next to it. Like I thought, they were infections, and she said I need root canals. I was in utter shock. I don't deserve this. She said it must have been some kind of trauma. I remember a year or 2 ago I crashed by bike and my lower jaw hit the concrete pretty hard. Now I ask you what is your opinion and advice?