Discovering that teeth have started to shift after investing time and resources into straightening them can be frustrating. This phenomenon, known as orthodontic relapse, is the natural tendency of teeth to drift back toward their original positions. Understanding why this movement occurs and knowing the corrective options available is the first step toward restoring your aligned smile. This article explains why teeth shift following treatment and details the steps and devices used for correction and long-term maintenance.
Why Teeth Move After Orthodontic Treatment
Teeth are not fixed rigidly in the jawbone; they are suspended within sockets by connective tissues called the periodontal ligaments. These ligaments possess a “biological memory” of the teeth’s original position and retain the elasticity to pull the teeth back once the pressure from braces is removed. This soft tissue rebound is a primary biological driver of post-treatment shifting.
Gingival fibers, which connect the teeth to the surrounding gum tissue, also contribute to this elastic pull, resisting the newly corrected position. Because the bone and soft tissues require time to fully remodel and stabilize around the new tooth placement, the period immediately following the removal of braces is the most susceptible to movement.
Movement is continuous due to forces exerted during daily function. Activities like chewing, swallowing, and speaking place constant, subtle pressure on the teeth. Habits such as clenching, grinding (bruxism), or tongue thrusting apply greater, repeated forces that can gradually push teeth out of alignment.
Natural maturation and aging changes also influence the dental arch. As individuals age, the lower jaw continues to grow slightly, often resulting in minor crowding of the lower front teeth. The most significant factor contributing to noticeable relapse, however, remains the failure to consistently use the prescribed retention devices.
Solutions for Correcting Relapse
The solution for correcting shifted teeth depends on the degree of relapse. Your orthodontist will first assess the current position using a clinical examination and diagnostic records. If shifting is minimal and caught early, simply wearing your original retainer full-time for a few weeks can gently nudge the teeth back into place.
For minor to moderate relapses, a limited course of clear aligner therapy is a common, discreet, and efficient option. These protocols, sometimes called “express” or “refinement” treatments, use a short series of custom-made aligners to correct small movements, typically taking a few weeks to six months. This method is highly effective for correcting minor crowding or spacing that has reappeared.
In cases of significant relapse, where teeth have returned substantially toward their original malocclusion, a full retreatment may be necessary. This involves a new, comprehensive course of orthodontics, utilizing traditional braces or full clear aligner therapy. Retreatment is often shorter in duration than the initial process.
The cost of correcting relapse is highly variable based on severity and the chosen appliance. Mild relapse correction using limited aligners may cost between $1,700 and $4,500, while more complex retreatment can range from $3,000 to $6,500 or more.
The Essential Role of Retention Devices
Once teeth are in their ideal positions, using a retention device is an indefinite commitment to prevent future shifting. Orthodontists universally recommend that retention is a lifelong process, often transitioning to nighttime wear after the initial stabilization period. Failure to adhere to the prescribed wear schedule is the most frequent cause of relapse.
Removable retainers fall into two main categories: the Hawley retainer and the clear thermoplastic retainer (Essix). The Hawley device uses a metal wire across the front teeth and an acrylic plate against the palate or floor of the mouth. This design allows for minor adjustments and offers high durability, lasting five or more years with proper care.
Clear Essix retainers are molded from thin, transparent plastic that fits snugly over the entire arch. They offer superior aesthetics and comfort and generally encourage better patient compliance. However, they are more susceptible to wear and tear, typically needing replacement every six to twelve months. Both types must be kept away from hot water, which can cause the plastic to warp and lose its precise fit.
Fixed retainers offer a non-removable solution, consisting of a thin wire bonded to the back surface of the front teeth, most commonly the lower arch. This wire provides continuous, passive stability but requires meticulous oral hygiene, including the use of floss threaders or a water flosser. Avoiding hard or sticky foods helps prevent the bond from breaking, which would compromise the achieved alignment.