The paroxysmal pain at night in the posterior alveolar portion of the tooth is likely to be the occurrence of acute pulpitis, caused by tooth decay inflammation reaching the pulp cavity, and may also be trigeminal neuralgia. 1. Acute pulpitis. Tooth decay acute pulpitis attack, there will be a characteristic night pain symptoms, and the pain is more intense, usually can not clearly point out the affected tooth, oral examination can be found dental disease, the need for root canal treatment to remove the pulp. 2. Trigeminal neuralgia. When the second and third branches of trigeminal neuralgia attack, there will be cut-like tear-like pain, the pain lasts for a few seconds and then disappears immediately. However, there are trigger points during the pain attack, and oral examination is generally free of dental disease. Partial night paroxysms of pain in the posterior alveolar teeth are recommended to go to the hospital in time to check the cause of the disease and deal with it in time, so as to avoid affecting your life.