Clear aligners, custom-made, clear plastic trays, are a popular method for straightening teeth. They offer an aesthetic alternative to traditional metal braces for correcting various alignment issues. A common issue people seek to address is dental gaps, medically known as diastemas or generalized spacing. The effectiveness of aligners in closing these spaces is a frequent question for those considering this treatment.
Aligners and Gap Closure Mechanics
Clear aligners can effectively close many types of gaps by applying controlled, continuous forces to the teeth. Each aligner tray is fabricated to be slightly different from the previous one, representing an incremental step toward the final desired tooth position. When the aligner is seated over the teeth, the plastic material naturally exerts a gentle force on the teeth that need to be moved.
The fundamental mechanical principle involves the aligner pushing the spaced teeth together. This pressure stimulates a biological process where bone tissue is dissolved where pressure is applied and rebuilt where tension is created. This cycle of bone remodeling allows the tooth to migrate through the jawbone over time. For space closure, the forces are typically directed to translate the teeth bodily, moving the entire tooth structure, including the root.
Factors Influencing Treatment Success
The success of using clear aligners to close gaps depends heavily on specific characteristics of the patient and the spacing itself. Small to moderate spacing, often defined as a few millimeters, is generally considered ideal for aligner treatment. Cases with mild spacing have a significantly lower probability of requiring refinement compared to those with severe spacing.
The root cause of the gap also influences the treatment approach. Gaps caused by natural tooth size discrepancies or previous tooth movement are often more straightforward to address than those resulting from missing teeth or persistent habits like tongue thrusting. Healthy periodontal tissues are necessary to support the bone remodeling required for safe and effective tooth movement. The type of movement required, such as a full bodily movement versus a simple crown tip, impacts the complexity and predictability of the outcome.
Necessary Orthodontic Accessories
While the clear aligner trays provide the primary force, specific auxiliary tools are often necessary to ensure precise and predictable gap closure, especially in more complex cases.
Attachments
Attachments are small, tooth-colored composite resin bumps bonded directly to the teeth’s surface. These attachments improve the grip of the aligner and modify the force transmission. This allows for complex movements like controlling root position during space closure.
Elastics
For more powerful or distant tooth movements, elastics (rubber bands) may be used in conjunction with aligners. These elastics hook onto buttons bonded to the teeth or into small precision cuts made directly in the aligner tray.
Interproximal Reduction (IPR)
Interproximal Reduction (IPR) involves carefully polishing away a minute amount of enamel from the sides of the teeth. This creates the small amount of space necessary for achieving tight, precise contact points when the gap is fully closed.
Maintaining Space Closure
After the active phase of gap closure is complete, a long-term commitment to retention is necessary to preserve the new alignment. Teeth have a natural tendency to revert to their original positions, a phenomenon known as relapse, because the surrounding bone and periodontal ligaments require time to stabilize. This post-treatment phase is crucial.
To counteract relapse, a retainer must be worn indefinitely. Retention strategies typically involve either removable retainers (such as clear plastic trays or Hawley retainers) or a fixed retainer. Fixed retainers use a thin wire bonded to the back surfaces of the front teeth, providing a permanent solution that does not rely on patient compliance for continuous wear.