The restricted mouth opening that occurs after wisdom tooth extraction is usually caused by post-traumatic hematoma and is usually self-healing. The hematoma can be helped to dissipate by applying local heat, such as using a warm towel on the swollen facial skin, 48 hours after wisdom tooth extraction. In addition, inflammatory infection attacking the maxillofacial space or masticatory muscles after tooth extraction can also lead to restricted mouth opening, a condition that cannot be answered simply by whether it can heal spontaneously because it may heal spontaneously or it may be life-threatening due to uncontrolled infection. In any case, the patient should be routinely treated with adjuvant anti-inflammatory and symptomatic medications to avoid the continued spread of inflammation to other facial interstices. If an abscess forms, it needs to be incised, drained, and drained promptly. Usually, the inflammation can subside after a week or so of treatment, and the restriction of mouth opening can be relieved, and the mouth can move normally with the extension of time.