My brother had a root canal done when he was young. About two weeks ago, I accompanied him to the dentist for a check-up. He's been into pain for the last few weeks. The dentist, after performing some X-rays, told him that the was poorly done and it caused a cyst on the roof of his mouth. He was scheduled for another canal and a biopsy. Is a on the mouth a very serious case? I am so worried for him. I need some advice, please!
Thank you very much for your time.