One of the questions I hear most often in orthodontic practice is, “Can I straighten my teeth without having any removed?”
Once a natural tooth has been extracted, it cannot be put back. Preserving natural teeth whenever possible also helps retain the gums and periodontal tissues that surround them. That is why, when planning orthodontic treatment, we first consider whether a good result can be achieved without removing teeth.
The key to non-extraction orthodontics is not simply avoiding tooth removal. It is finding enough room for the teeth to move without the space that extractions would create.
For example, crowded teeth may be straightened without extractions, but if there is not enough space, aligning them alone can push the front teeth forward. This may make the lips look more prominent, producing a change the patient did not expect. Before aligning the teeth, we therefore need to plan how much space is required and how to create it.
Creating space is especially important when the lips protrude
For prominent lips to move back naturally, there must be room for the front teeth to move backward. However, the front teeth cannot always be moved back on their own. The canines and premolars, and sometimes even the rearmost molars, need to move as well.
If the teeth are simply aligned without creating enough space, the front teeth may instead move forward and make the lips appear more prominent. This is why straightening crowded teeth alone does not necessarily mean that non-extraction treatment has been successful.
MARPE (Miniscrew-Assisted Rapid Palatal Expansion): a rapid palatal expansion appliance
The way we create space differs from patient to patient
There is more than one way to gain space in non-extraction orthodontics.
If the teeth can move within the boundaries of the supporting bone, appropriate expansion of the dental arch can create space. When the upper jaw itself is narrow, MARPE, a miniscrew-assisted appliance for skeletal expansion, may also be considered.
If space is available farther back, the teeth can be moved backward. Depending on the patient's condition, we may use orthodontic elastics, appliances placed on the palate or on the inner side of the teeth, or miniscrews.
When the front teeth are excessively tilted inward, bringing them to a suitable angle can also create some space. Rather than looking only at whether the front teeth move forward, we need to consider their original angle and the accompanying changes in lip shape.
If these methods still do not provide enough space, interproximal reduction may be used alongside them.
Interproximal reduction is limited to the amount and areas needed
Interproximal reduction, also known as IPR, creates space by carefully removing a small, planned amount of enamel from the surfaces where adjacent teeth meet. Reshaping the teeth in this way can also help reduce the triangular gaps near the gums known as black triangles.
The description “shaving the teeth” often raises concerns about weakened teeth, cavities or sensitivity. However, the amount of enamel that can be removed is not the same for every tooth. The size and shape of each tooth and the thickness of its enamel must be assessed, and only the necessary amount should be removed within safe limits.
In a long-term follow-up study by Zachrisson and colleagues, patients who underwent appropriately performed IPR were observed for more than 10 years, with no marked increase in caries, periodontal problems or alveolar bone loss. These findings depend, however, on carefully planning the amount of reduction and thoroughly finishing and polishing the tooth surfaces afterward.
It is not appropriate to remove enamel uniformly from multiple teeth at the outset. The principle is to first calculate how much space can be gained through expansion and backward tooth movement, then use IPR only where additional space is still needed.
Ultimately, the important question is not simply whether to perform IPR. What matters more is which teeth need it, how much is needed and for what purpose.
Non-extraction orthodontics is a treatment worth considering
Non-extraction orthodontics means more than simply keeping all the teeth. It combines expansion, backward tooth movement, adjustments to tooth angulation and interproximal reduction to create the necessary space within the limits of the supporting bone.
Of course, non-extraction treatment is not suitable in every case. If the required space cannot be obtained within safe limits of tooth movement, extraction treatment may be more appropriate.
However, if enough space can be created and both the teeth and the balance of the face and lips can be improved in the way the patient hopes for, non-extraction orthodontics is a treatment option worth considering. Rather than deciding on extractions in advance, an accurate diagnosis can first establish what changes are possible without them, helping preserve natural teeth while aiming for a satisfying treatment result.
References
Zachrisson BU, Nyøygaard L, Mobarak K. Dental health assessed more than 10 years after interproximal enamel reduction of mandibular anterior teeth. American Journal of Orthodontics and Dentofacial Orthopedics. 2007;131:162–169.