Hello, about a year ago my lower first molar became inflamed; the tooth had already previously been opened. The dentist cleaned the root canals and placed medication inside. There was a small swelling on the outside of the gum the whole time. I was supposed to return after two months, but I kept postponing it. She said that the tooth was dead, but I still felt pain on pressure, and a few weeks ago the swelling became larger. The dentist extracted the tooth; most of the swelling went down, but a lump remains. It is quite visible when I yawn, for example, is about the size of a pea and moves. Even the dentist remarked that it reminded her of a lymph node. More than a week has passed since the procedure, and it does not look as though it will disappear soon. Is there any reason for concern?