Facial muscle pain during tooth clenching may be caused by long-term chewing, trauma, temporomandibular joint disorder syndrome and other reasons. 1. Long-term chewing: If patients chew hard food for a long time, the chewing muscles may not get rest for a long time, which may cause muscle pain and soreness, resulting in facial muscle pain during tooth clenching. 2. Trauma: If the patient suffers from trauma, such as collision, blows, etc., it may cause damage to the biting muscle, so when the patient’s teeth bite, the facial muscles may have symptoms of pain. 3. Temporomandibular Joint Disorder Syndrome (TMJDS): If the patient is emotionally tense or under too much pressure in daily life, it may lead to clenching and grinding of teeth at night, which will lead to TMJDS in the long run, and the facial muscles will be painful when biting the teeth. It is recommended that patients go to the hospital for relevant examinations, and according to the cause of the disease to do the appropriate treatment, do not treat privately, so as not to cause danger.