If the teeth are fractured, too severely broken or inordinately infected to be saved by root canal/nerve treatment/capping, then it becomes mandatory to extract or remove such teeth.
When wisdom teeth/third molars do not get space to erupt properly, they get stuck in the bone. Such teeth are called impacted teeth. When they try to come out/erupt and are unable to do so, they cause inflammation and infection of the gums. This results in acute pain and swelling in the patient’s mouth. In such cases, these impacted teeth need to be removed by surgical extraction.