Impactions are specialized extraction procedures. In this the tooth to be removed is either completely or partially embedded within the bone.
Teeth may become impacted because of adjacent teeth, dense overlying bone or a genetic abnormality which may cause any congentinally impacted teeth. Most often, the cause of impaction is inadequate arch length and space in which to erupt.
The third molars are frequently impacted because they are the last teeth to erupt in the oral cavity. Mandibular third molars are more commonly impacted than their maxillary counterparts. As a general rule, all impacted teeth must be removed.