Why Are Teeth Extracted in Orthodontic Treatment?
The degree of dental discrepancy (crowding) and patient age play important roles in the decision to treat a malocclusion (poor bite) with or without the extraction of permanent teeth. A patient who presents in the permanent dentition with a severe enough discrepancy in arch length (the size of the teeth versus the size of the jaw) might very well require extraction treatment. There are also situations in which the upper front teeth need to be retracted in order to reduce the horizontal space (overjet) between the upper and lower front teeth.
Which Teeth Are Extracted?
Approximately 20 to 25 percent of patients require extraction of permanent teeth with their orthodontic treatment. The teeth extracted will vary depending on the specific and individual needs of the patient. A combination of teeth may be extracted. This may include four premolar teeth, two upper or two lower premolar teeth, a single lower incisor tooth, or upper and lower second molar teeth. Generally speaking, any tooth in the mouth can be extracted in order to help the orthodontist achieve a proper bite and soft tissue profile while eliminating the crowding that exists.
What If Teeth Are Not Extracted?
In cases where teeth should be extracted but are not, the crowding may not be resolved or the teeth may need to be placed in an unstable position. This means that crowding may occur as the patient ages and dental relapse occurs. Another possibility may be that the malocclusion (bite) is not corrected with treatment or the horizontal overjet is not reduced.
How About Wisdom Teeth?
Removal of the wisdom teeth does not create space in the mouth that is needed to eliminate crowding. The molar teeth move from the back to the front of the mouth, and not vice versa.
Eruption of wisdom teeth often occurs simultaneously with the appearance or increase in lower anterior (front teeth) crowding. It is a common belief that this is because of pressure created by the erupting wisdom teeth. However, current evidence suggests that wisdom teeth play a minor role, if any, in the late lower incisor crowding. Thus, there is no evidence to support a recommendation to extract wisdom teeth in order to prevent late incisor crowding.