The last teeth on each side of the jaw are called the wisdom teeth. In most people, four wisdom teeth grow at the age between 17 and 21 years although, in some people, one wisdom tooth or more never occur.
That is not something you have to worry about it. In fact, maybe that is even better, because the appearance of the wisdom tooth often causes problems. Even when they are normally formed, it is difficult to clean them and are therefore more susceptible to caries. Sometimes, the wisdom tooth grows at an angle, and so the food can sometimes stay (and rot) in the space between the wisdom tooth and the adjacent tooth. Because of this rotten food, bacteriae will develop and cause painful infection, pericoronitis, in the area around the tooth.
If the wisdom tooth does not appear, there are usually no symptoms. If it grows at an angle and creates a place where food remains can be accumulated, you may feel an unpleasant taste in the mouth, accompanied by a bad breath.
The main symptoms of pericoronitis are pain while biting the food and unpleasant taste. The area around the tooth will probably be swollen. If you notice any of these symptoms, go as soon as possible to your dentist.
Self-help: you can relieve the pain with an aspirin or by washing the area around your teeth with salt water.
Professional help: the dentist will prescribe antibiotics for the treatment of infection. However, the relief will only be temporary, and the situation will be solved only by removing the wisdom tooth. Your dentist will determine the position of the wisdom tooth with radiography.
If the tooth extraction is difficult because of the tooth angle, and in case where other wisdom teeth are also affected, you will probably have to go to a hospital where your tooth (or teeth) will be removed under general anesthesia.