A gap between teeth, medically termed a diastema, is common, most frequently noticed between the two upper front teeth. While teeth shift throughout life, these spaces generally do not close on their own in adulthood. Unlike children, whose gaps often close as larger permanent teeth erupt, the adult mouth lacks the continuous growth required for spontaneous correction. For adults seeking to close a diastema, professional dental intervention is almost always necessary.
Why Gaps Appear in Adult Teeth
Diastema formation in adults stems from mechanical and biological factors that disrupt the natural balance of forces within the mouth. One common cause is a size discrepancy, where the teeth are too small for the size of the jawbone, resulting in spacing throughout the dental arch. This genetic feature means the teeth cannot fill the available space.
Another factor is an oversized labial frenum, the band of tissue connecting the upper lip to the gum line between the two front teeth. If this tissue is large or extends too low, it physically blocks the teeth from moving together, maintaining a gap. Persistent pressure from certain oral habits can also create or widen spaces. This includes tongue thrusting, an incorrect swallowing reflex where the tongue pushes against the front teeth.
Gaps may also develop later in life due to underlying dental issues, specifically advanced periodontal disease. This condition causes inflammation and the loss of supportive bone and gum tissue, leading to instability. As teeth lose their foundation, they drift and shift, creating new or expanding existing gaps. Furthermore, the loss of a tooth can cause adjacent teeth to migrate into the empty space, generating new spaces elsewhere.
The Biological Barrier to Natural Closure
The primary reason adult teeth do not spontaneously move to close gaps is the mature structure of the jaw. An adult’s alveolar bone, which anchors the teeth, is fully developed and rigid. It lacks the growth plates that make movement easier in a child’s jaw. This stable structure means that any significant tooth movement requires a sophisticated breakdown and rebuilding process.
The tooth is held in place within the jawbone by the periodontal ligament (PDL), a fibrous connective tissue that acts as a shock absorber. For a tooth to move, a sustained, controlled force must be applied to create areas of compression and tension on the PDL. On the compression side, specialized cells called osteoclasts must break down the alveolar bone to clear a path for movement.
Simultaneously, on the tension side, osteoblasts deposit new bone, stabilizing the tooth in its new position. This complex process of bone remodeling is the mechanism behind orthodontic treatment. It does not occur naturally in a balanced adult mouth without directed external force. Without a constant, deliberate force, the forces from the lips, cheeks, and tongue remain in equilibrium, meaning the gap will stabilize or continue to widen.
Professional Methods for Correcting Diastema
Since natural closure is biologically improbable for adults, professional treatment is the reliable path to correcting a diastema. The appropriate method depends on the size of the gap and its underlying cause. For large gaps or cases involving multiple spacing issues and bite misalignment, orthodontic treatment is typically the most comprehensive solution.
Traditional braces or clear aligner systems apply the continuous, controlled force necessary to activate the bone remodeling process. This gradually moves teeth together over a period ranging from several months to a couple of years. This approach addresses the root positioning, offering a stable and permanent correction. Once the space is closed, a retainer must be worn to prevent the teeth from drifting back.
For smaller, purely cosmetic gaps, restorative dentistry offers faster, less invasive options.
Dental Bonding
Dental bonding involves applying a tooth-colored composite resin directly to the edges of the teeth and sculpting it to fill the space. This procedure can often be completed in a single visit and is a cost-effective solution. However, the resin material may require maintenance over time.
Porcelain Veneers
Veneers consist of custom-made shells bonded to the front surface of the teeth. They can close a gap while also improving the tooth’s shape, size, and color. This option requires some permanent alteration of the natural tooth enamel.
Frenectomy
If an oversized labial frenum is the cause of the gap, a minor surgical procedure called a frenectomy may be performed to reduce the tissue. This is often done in conjunction with orthodontics or restorative work to ensure the gap closes fully and remains closed.