Failure of a tooth to emerge completely from the gum. It can arise because of overcrowding or when a tooth grows in the wrong direction.
Impacted wisdom teeth are normal when the teeth come through in early adulthood. If they do not cause any symptoms it is not necessary for them to be removed. In certain cases, however, impacted wisdom teeth partially penetrate the gum, leaving a flap of tissue over the majority of the crown. Bacteria, plaque, and food debris can then collect between the gum and the tooth, creating inflammation of pain in the gum tissues. If the problem persists the affected teeth will need to be removed.