A dental extraction is the removal of teeth from the dental alveolus in the alveolar bone. Extractions are performed for a wide variety of reasons, but most commonly to remove teeth which have become unrestorable through tooth decay, periodontal disease or dental trauma, especially when they are associated with toothache. Sometimes wisdom teeth are impacted and may cause recurrent infections of the gum. In orthodontics, if the teeth are crowded, sound teeth may be extracted to create space so the rest of the teeth can be straightened.