Toothache is the worst pain! Because... Well, why is that? After all, it is a common misconception that trigeminal neuralgia is considered to be the worst pain. The trigeminal nerve is the 5th pair of cranial nerves, which innervates the skin of the face, teeth, tongue (front two-thirds) and other parts of the head and neck. Therefore, the pain when it is inflamed is felt on an extremely "large scale".