The mouth opening is not big and accompanied by right side jaw pain, which may be caused by temporomandibular joint disorder, wisdom tooth pericoronitis, apical abscess or periodontal abscess, etc. General treatment, medication and tooth extraction treatment are feasible. 1. Temporomandibular joint disorder syndrome: limitation of mouth opening, pain and popping are the main clinical manifestations of temporomandibular joint disorder. When the symptoms are mild, it is usually necessary to improve the biting habit, insist on chewing on both sides of the teeth in turn, avoid eating too hard food, avoid excessive mental tension, avoid opening the mouth too wide for a long time, and improve the symptoms with local infrared therapy and helium-neon laser therapy. 2. Wisdom tooth pericoronitis: when the inflammation affects the chewing muscles, mouth opening will be restricted and pain will occur. In the acute stage of inflammation, local rinsing with hydrogen peroxide solution and saline can be used first, and oral anti-infective drugs, commonly used drugs are cephalosporin, with tinidazole or ornidazole, and wisdom teeth can be extracted after the inflammation is eliminated. 3. Periodontal abscess or apical abscess: when the inflammation spreads to the chewing muscles, mouth opening will be restricted. When the symptoms are serious, incision and drainage of abscess or decompression of the pulp of the tooth will be carried out, and after the inflammation is under control, root canal treatment will be carried out on the affected tooth, and if the affected tooth cannot be preserved, it will be extracted. When the mouth does not open wide jaw pain may also be other reasons, should be timely to the regular hospital consultation, active treatment, to avoid delaying the condition. All of the above drugs should be used under the guidance of a doctor.