Possible Crowding
Wisdom teeth may impair the normal eruption of second molars and can cause other teeth to crowd or shift. Aside from cosmetic issues, a patient's bite may become uneven, causing chewing problems. The molars and other teeth may become difficult to clean and prone to cavities and gum disease.

Damage
Impacted wisdom teeth can cause damage to the bony support of the adjacent teeth, including root fracture and bone loss. Bone grafting may be required to restore the affected teeth.

Cyst Formation
The area surrounding an impacted tooth can fill with fluid and form a balloon-like cyst in the jawbone. An untreated cyst can expand and ultimately cause nerve damage and bone loss, which may require additional surgery and grafting. Cysts often progress asymptomatically but are an obvious indication for third molar removal.

Infection
Overcrowding and impacted teeth are prone to the collection of food and bacteria in areas that are difficult to clean. This could possibly lead to a serious and life-threatening condition if the infection spreads to the soft tissue of the face and neck. Oral infections have also been linked to other major health conditions such as heart disease. In addition, infection can ultimately cause bone loss.

Impacted
The degree of impaction can be classified as either "soft tissue," "partial" or "complete." Regardless, impacted teeth do not have enough room to adequately erupt into the mouth and become fully functional and cleansable. Their inability to fully erupt inhibits them from functioning in the chewing process.

Impacted (before roots form)
There is often insufficient anatomical space to accommodate normal third molar eruption. The optimal time to extract is when the roots are approximately one-third to one-half formed. At this time, the mouth is mature but the roots of the third molars do not yet encroach upon the inferior alveolar nerve canal, which can mean fewer complications.