Orthodontic treatment requires carefully controlled forces to reposition teeth within the jawbone. Traditional methods use some teeth as anchors to move others, but this often causes unwanted movement of the anchor teeth, known as anchorage loss. The need for more precise and efficient tooth movement led to the development of tools that provide a non-moving anchor point. This advancement introduced Temporary Anchorage Devices (TADS), which are now a valuable part of contemporary orthodontics. TADS offer a way to straighten teeth with a degree of control and predictability that was previously unattainable.
What Are Temporary Anchorage Devices
Temporary Anchorage Devices are miniature, screw-like fixtures designed to be temporarily secured into the jawbone. They are typically fabricated from medical-grade titanium alloy, a biocompatible material. TADS are significantly smaller than permanent dental implants, generally measuring between 1.2 to 2 millimeters in diameter and 6 to 12 millimeters in length.
Their size allows orthodontists to place them strategically in specific locations in the mouth. Common placement sites include the dense bone between the roots of teeth (inter-radicular bone) or in the palate. The defining characteristic of a TAD is its temporary nature; it is removed once its function in the treatment plan is complete. Unlike permanent implants, TADS rely on mechanical retention in the bone rather than a biological fusion process called osseointegration.
How TADS Provide Orthodontic Stability
The core function of a TAD is to establish a fixed, stable point from which orthodontic forces can be applied. This concept is referred to as absolute or skeletal anchorage, meaning the anchor point does not shift when force is applied to move teeth. Traditional anchorage methods often struggle with Newton’s Third Law, where the force used to move one tooth causes an equal and opposite, undesired reaction in the anchor tooth.
By bypassing the teeth and anchoring directly into the bone, TADS absorb this reactionary force, ensuring that only the target teeth move. This capability allows for highly specific tooth movements that were once difficult or impossible to achieve without headgear or jaw surgery. The clinical applications of this absolute stability greatly expand the scope of non-surgical treatment options.
One common application is the bodily movement of entire segments of teeth, such as moving a whole arch backward (distalization) or forward (mesialization). TADS are also employed to close large gaps in the dental arch with greater control than traditional braces, such as after a tooth extraction. They allow for the vertical adjustment of teeth, including the intrusion of molars to correct an open bite or the extrusion of anterior teeth to address a deep bite. This mechanical advantage helps the orthodontist achieve the intended outcome with high predictability and often reduces overall treatment time.
Patient Experience: Placement and Care
The procedure for placing a Temporary Anchorage Device is minimally invasive and is typically completed quickly in the orthodontic office. The insertion site is numbed using a local anesthetic, similar to a routine dental filling, ensuring minimal pain during the process. Since the jawbone contains very few nerve endings, patients usually report feeling only a sensation of pressure as the device is inserted.
Following placement, a patient may experience mild tenderness or soreness at the site for the first one to two days. This temporary discomfort is managed with common over-the-counter pain relievers. Maintaining proper oral hygiene around the TAD is important to prevent irritation or infection of the surrounding gum tissue.
Patients are instructed to gently brush the area with a soft-bristled toothbrush. They may also be advised to use an antimicrobial mouthwash or a simple salt water rinse. The duration a TAD remains in place varies, but it is removed as soon as its function is complete. The removal process is simpler than placement, often requiring no anesthesia, and the site heals rapidly.