Braces and clear aligners are highly effective orthodontic treatments for closing gaps in the front teeth, a common condition known as diastema. Successful treatment requires identifying the cause of the gap and using controlled, consistent force to move the teeth into alignment. While orthodontic methods physically reposition teeth, faster non-orthodontic options exist for smaller gaps. All solutions require permanent maintenance to ensure the gap remains closed.
Understanding the Root Causes of Diastema
Gaps between the front teeth, or diastema, often result from a mismatch between the size of the teeth and the jaw. A frequent cause is a genetic predisposition where the jaw is large compared to the teeth. This size discrepancy leads to excess space in the dental arch, resulting in generalized spacing throughout the mouth.
Another factor is an oversized or low-attaching labial frenum, the band of tissue connecting the upper lip to the gum line between the central incisors. If this frenum is thick, its fibers can physically prevent the front teeth from meeting, creating a persistent midline gap.
Habits such as chronic thumb-sucking or a tongue thrust (where the tongue pushes against the front teeth during swallowing) can also apply outward pressure, forcing the teeth apart over time. Spacing can also result from missing teeth (hypodontia) or undersized teeth (microdontia), particularly the lateral incisors, which allows neighboring teeth to drift.
How Braces and Aligners Close Gaps
Orthodontic treatment works by applying continuous, light pressure to the teeth, which stimulates the surrounding bone to remodel and allows the teeth to move. Traditional braces utilize sliding mechanics, where brackets bonded to the teeth act as handles for the archwire. To close a gap, the orthodontist uses an elastic power chain—a continuous strand of elastic rings—stretched across the brackets of the spaced teeth.
The power chain delivers a steady, pulling force that slides the teeth together along the archwire until the space is eliminated. The stiff archwire and brackets ensure that the roots move along with the crowns, preventing the teeth from merely tipping into position, which can cause relapse. For a simple midline diastema, the closing phase can take three to six months, though complex cases may require 12 to 18 months of total treatment.
Clear aligners close gaps through a series of sequential, custom-fabricated plastic trays. Each new tray is slightly closer to the desired final position, incrementally pushing the teeth together. To ensure the teeth move bodily (roots and crowns moving equally), small, tooth-colored composite attachments are bonded to the teeth.
These attachments give the aligners a necessary surface to grip and apply the controlled force required for precise movement. Without the attachments, the aligners can struggle to achieve the necessary root movement for stable gap closure. Clear aligner treatment for diastema closure ranges from six to 24 months. Success depends on the patient wearing the trays for the required 20 to 22 hours per day.
Other Treatment Options Beyond Braces
For smaller gaps, especially those less than 2 millimeters wide, restorative dental procedures offer a faster, non-orthodontic alternative. Dental bonding involves applying a tooth-colored composite resin directly to the side of the gapped teeth. The dentist sculpts and hardens the resin, slightly widening the teeth to fill the space in a single appointment.
Veneers are another option, involving thin, custom-made shells of porcelain or composite material bonded to the front surface of the teeth. This procedure allows for a more significant change in the tooth’s shape and size, offering an esthetic and durable solution to conceal the space. Unlike bonding, which is conservative, veneers require a small amount of enamel preparation to ensure a proper fit and natural appearance.
When an enlarged labial frenum causes the gap, a surgical procedure called a frenectomy is necessary. This minor surgery removes or modifies the restrictive tissue band, allowing the teeth to meet. A frenectomy is performed either before or during orthodontic treatment to ensure the gap can be closed and to reduce the risk of the space reopening after appliances are removed.
Ensuring Permanent Gap Closure
The challenge after closing a diastema is preventing the space from reopening, known as relapse. The gingival fibers surrounding the tooth roots are elastic and have a memory, exerting a force that tries to pull the teeth back to their original position. This fiber memory can persist for two to three years after treatment, making a retention phase mandatory.
Retention protocols for diastema closure include two main types of appliances that must be worn long-term, often indefinitely.
Types of Retainers
- A fixed retainer is a thin, custom-fitted wire bonded directly to the tongue-side surface of the front teeth, offering continuous, invisible support.
- Removable retainers, such as clear plastic trays or wire and acrylic devices, are worn full-time initially and then typically only at night.
Due to the high risk of relapse, a fixed retainer is considered the most reliable method for maintaining permanent stability after a diastema has been closed.