A note about extractions in orthodontics
It is the goal of orthodontists to achieve a healthy, stable bite and pleasing smile in a conservative and comfortable manner. In most cases this can be achieved without the need to remove teeth. In other cases, there are compelling reasons to remove teeth for braces, and in such cases the pros and cons of such treatment options must be considered by the orthodontist, the patient, and the patient’s dentist.
In which situations would one consider or choose to remove teeth for orthodontic treatment?
- In cases of protrusion or excessive prominence of the front teeth.
- In cases of significant crowding in the upper and/or lower jaw.
- When a tooth is excessively compromised due to disease or injury.
- When it is necessary to correct a bite asymmetry
- When opting to compensate for significant front-to-back discrepancies in the relationship between the upper and lower jaws
- When needed for optimal results in orthodontic cases requiring corrective jaw surgery, with respect to the bite and/or facial cosmetic (esthetic) goals
- When teeth cannot be moved due to impaction or fusion to bone, and there are disadvantages to leaving them in place.
How many teeth are typically removed for braces?
Let’s set aside consideration of wisdom teeth, as they often are removed for reasons separate from orthodontic treatment goals. Of the remaining teeth, when extraction is determined to be beneficial it is common to remove from one to four teeth, opting for the least number of teeth removed in order to meet the treatment goals. It is common to remove an odd number of teeth (1 or 3) when addressing asymmetry. Premolars, the fourth and fifth teeth from the front, are the most common teeth to be extracted. Occasionally it is advantageous to remove other teeth. The key is planning to address the unique situation presented by each patient, including that effects that extractions may have on facial esthetics or tongue position. Orthodontists often do a trial or beta version of proposed treatment using plaster models of the patient’s teeth, which is referred to as a diagnostic set-up.
What about alternatives to removal of teeth?
One such alternative is expansion of the arches to resolve crowding, which is the U-shape that the teeth fit into in each jaw. The upper jaw can actually be made wider in child and adolescent patients by activating the growth center running front-to-back through the center of the jaw with an appliance known as an expander. This growth center typically fuses during the late teens. However, in the lower jaw and in the upper jaw of adult patients, expansion is really the spreading of teeth within the existing bone dimensions. This sort of expansion is limited because the bone
This sort of expansion is limited because the bone that form covers the roots under the gums is fairly thin and does not “expand” or grow when the teeth are pushed outwardly. Excessive expansion of the teeth can lead to bone and gum recession, and less-than-stable results. There are surgical procedures designed add bone for expansion purposes, but studies regarding their effectiveness over the long-term are not conclusive. Another option is to orthodontically move the back teeth further back. Studies have shown that some methods are more effective than others, but we do not yet know the long-term stability of such movement.
Have you heard claims that it’s wrong to remove teeth for braces?
There are certainly a lot of opinions out there, and not all are based on good scientific evidence. This is why it’s important for the orthodontist to diagnose and treatment plan patients based on their unique, individual needs, and to consider what good scientific studies reveal. The key factors are whether extractions are selected appropriately and the orthodontic treatment is done properly.