Swelling under the root of the left ear and pulling the tooth pain, may be acute pulpitis or acute wisdom tooth pericoronitis caused, according to the situation to choose root canal treatment, medication, tooth extraction and so on. 1. Root canal treatment: Acute pulpitis pain has a certain degree of radioactivity, and in severe cases, it will radiate to one side of the head and face, causing pain on the same side of the head, face, temporal region, and swelling under the root of the ear, etc. The best treatment is root canal treatment. The best treatment is root canal therapy, which can quickly relieve tooth pain and swelling under the root of the ear. 2. Medication: Acute wisdom tooth pericoronitis will cause one side of the ear lymph node swelling and ear pain. You can choose local rinsing and medication, usually use 3% hydrogen peroxide solution and saline, with compound chlorhexidine gargle solution gargle; if the swelling is serious, there is pus, need to make incision and drainage, and at the same time, intravenous infusion of metronidazole injection and penicillin to relieve the swelling. 3. Tooth extraction: If wisdom teeth have recurring pericoronitis, it is best to remove them. Swelling under the root of the left ear pulling tooth pain may also have other reasons, it is best to go to the hospital in a timely manner, after the cause of the disease is clear and active treatment, the use of medication as prescribed by the doctor, so as not to delay the condition.