An ear tooth, also known as a dentigerous cyst, heterotrophic polydontia, temporal teratoma, or temporal odontoma, is a cyst containing a tooth or tooth material in a location where teeth should not occur. This is a relatively rare developmental anomaly where a few cells that were programmed to become teeth essentially get “lost” and begin forming tooth-like structures in abnormal locations. The most common place for these cysts to occur is at the base of the ear. Generally, they appear as a focal swelling at the base of the ear and often are associated with a chronic draining tract. They can also occur within the skull or nasal passages, where they are much more likely to cause problems. Treatment of dentigerous cysts is complete surgical removal. This is generally a simple procedure and is curative.