A gap between teeth, clinically known as a diastema, is a common feature that often widens or becomes more noticeable as a person ages. This change is typically a gradual process resulting from a mix of natural physiological forces and external factors. Understanding the mechanisms behind this shifting helps in managing the progression of a diastema.
Primary Drivers of Tooth Movement Over Time
Teeth are not rigidly fixed in the jawbone; they are suspended by fibers that allow for slight, continuous movement throughout life. A primary physiological reason for shifting is mesial drift, the natural, slow, forward migration of all teeth toward the midline of the face. This phenomenon occurs to compensate for the wear that happens on the sides of teeth where they touch, ensuring chewing efficiency is maintained. While mesial drift often causes teeth to crowd, in the presence of existing space, it can sometimes exacerbate the widening of a gap instead.
Another contributing factor is attrition, the physical wear and tear on the chewing surfaces. Years of biting and grinding flatten the biting edges of teeth, reducing the surface area where adjacent teeth make contact. This reduction in contact points lessens the mechanical stability of the dental arch, making it easier for teeth to shift and for existing spaces to expand.
The supporting structures of the teeth also undergo subtle, age-related changes. Over time, the density of the jawbone can decrease, which may reduce the secure anchorage of the teeth. This change in the supportive bone structure, combined with the daily forces of chewing, can influence tooth position and contribute to a gradual increase in the size of a diastema.
Pathological and Behavioral Causes of Widening
While some movement is natural, pathological conditions and behavioral habits can accelerate the widening of gaps. Periodontal disease is one of the most destructive factors for tooth stability. As the disease advances, inflammation destroys the alveolar bone supporting the tooth roots. This loss of supporting bone causes the teeth to loosen and drift—a process known as pathological tooth migration—which can rapidly enlarge spaces. Addressing the underlying infection is necessary before any cosmetic correction can be stable.
Certain oral habits also exert constant, abnormal pressure that pushes teeth out of alignment. Tongue thrusting, an orofacial myofunctional disorder, involves the tongue pressing against the back of the front teeth during swallowing. The repetitive force from this muscle can gradually push the front teeth forward, creating or enlarging a gap.
The loss of a back tooth, even one not adjacent to the gap, can destabilize the entire dental arch. When a tooth is missing, opposing and adjacent teeth drift and tilt into the empty space. This shifting of the bite transfers forces to the front of the mouth, causing existing gaps to widen or new ones to form.
Strategies for Preventing Gap Progression
Preventing gaps from worsening centers on stabilizing supporting tissues and controlling external forces. Maintaining excellent oral hygiene is the most important defense against disease-caused progression. Consistent brushing and flossing prevent periodontal disease, a major cause of bone loss and subsequent tooth migration. Regular professional cleanings and check-ups allow a dentist to monitor the health of the gums and bone structure.
Identifying and modifying destructive oral habits can halt gap expansion. For habits like tongue thrusting or bruxism (clenching and grinding), professional intervention, such as myofunctional therapy or a custom-fitted night guard, may be required. Reducing the force exerted on the teeth prevents further wear and movement.
For individuals who have had previous orthodontic treatment to close spaces, the consistent, lifelong use of a retainer is necessary. Teeth have a strong tendency to return to their original positions, and a retainer provides the passive force needed to maintain alignment against the natural forces of mesial drift and chewing. Failure to wear the retention device is a common reason for a closed diastema to reopen.
Professional Corrective Treatments
If a gap has already widened, several professional treatments are available to close the space. Orthodontics, using traditional braces or clear aligners, remains the most comprehensive solution. It closes gaps by physically moving the teeth into a new, stable alignment, and is often necessary for larger gaps or when the problem involves a larger bite misalignment.
For smaller spaces, a dentist may suggest composite bonding. This procedure involves applying a tooth-colored resin material to the sides of the teeth bordering the gap, then sculpting and hardening it to effectively reduce the space in a single visit. Porcelain veneers or crowns offer a durable and highly aesthetic alternative for closing gaps, particularly when the teeth have issues with shape, color, or minor damage.
If the gap is caused by an oversized piece of tissue connecting the upper lip to the gum, a procedure called a frenectomy may be performed. This minor surgery removes the excess tissue, allowing the teeth to be moved together more easily with orthodontics or bonding. Regardless of the chosen cosmetic solution, any underlying pathology, such as active gum disease or a missing tooth, must be addressed first to ensure the long-term stability of the correction.