Trigeminal neuralgia is anatomically divided into three branches: the first branch is the ophthalmic branch, the second branch is the maxillary branch, and the third branch is the mandibular branch. The scope of pain can be used to roughly determine which branch is affected. Generally, pain located in the forehead area is caused by the first branch, the ophthalmic branch. Pain in the area from the tip of the nose to the lips is caused by the second branch, the maxillary branch. Pain from the lips to the angle of the jaw is caused by the third branch, the mandibular branch. Therefore, we can understand which branch is in pain by the distribution area and scope of the trigeminal neuralgia.