Wisdom teeth are called the 3rd molars, because they erupt behind the 2nd molars in the mouth. Wisdom teeth are the last teeth to erupt in the mouth. We have 4 wisdom teeth, two in the upper arch and two in the lower. The wisdom teeth are the ones least needed for good oral health. They may not erupt or emerge from your gums until your late teens or early twenties - if they erupt at all. Most often they are impacted or trapped in the jaw-bone and gums, usually because there is not enough room for them in your mouth. In fact, wisdom teeth often do more harm than good, and in-case of any problems related to them, we would suggest removing them.
There are 4 possible ways in which wisdom teeth may cause problems:-
Gum disease: Most people are aware of the pain experienced during the eruption of these teeth. This generally happens because the partly erupted tooth is difficult to keep clean, and the accumulated food particles cause the gums around the tooth to get infected. Such an infection is felt as swelling and pain around the area. Sometimes the tooth is trying to erupt, but has not yet broken through the gums. When the upper tooth bites down onto this gum, pain can be caused.
Crowding: An impacted or erupting wisdom tooth can push on adjacent teeth, causing them to become crooked or even damaging them structurally.
Cyst: If the sac that holds the crown of the wisdom tooth remains in the bone, it can fill with fluid, forming a cyst that can destroy the surrounding bone.
Impaction: It sometimes happens that there is not enough space in the mouth for these teeth to erupt. In such cases they may try to erupt in an abnormal direction, or may get locked into the jaw.