For most people, their wisdom teeth will be blocked from erupting completely in the mouth by the permanent second molars or the surrounding bone and/or gums due to the smaller jaw space. These wisdom teeth are considered to be impacted. Treating impacted wisdom teeth is the most common reason why your dentist will recommend wisdom tooth extraction.
The impacted wisdom tooth may partially emerge (partially impacted), showing only the crown of the tooth, or never emerge through the gums at all (fully impacted). The wisdom tooth may also grow at an angle towards or away from the second molar, or grow at a right angle, almost as if it is “lying” down.
Wisdom teeth are the last adult teeth to come into the mouth (erupt). Most people have four wisdom teeth at the back of the mouth — two on the top, two on the bottom.