Permanent teeth were intended to last a lifetime, but there are a few reasons why you might need a tooth extracted.
Crowding is a common cause for the need for dental extraction. Most people simply do not have the space in their mouths to allow wisdom teeth to fit properly. Extraction of wisdom teeth is very common. In fact, some people have such limited space that premolars need to be taken out to allow for proper alignment of all of their teeth. This is usually done just before braces are placed by their orthodontist.
Deep decay allows bacteria to enter and kill the pulp of the tooth. This results in an abscessed, or infected tooth. Many times this can be treated with root canal therapy. If there is not enough tooth structure to allow restoration, the tooth will need to be extracted.
Periodontal disease causes loosening of the teeth due to bone loss. When this has continued untreated for many years, it will cause the teeth to need to be extracted. This happens most rapidly in people with diabetes.
Other health conditions may necessitate the discussion of extraction. Patients needing head and neck radiation sometimes have teeth taken out before their cancer treatment.