A temporary anchorage device (TAD) is a temporary mini screw implant used by orthodontists to assist with complex movement of teeth. Newton's third law says that for every action or force, there is an equal and opposite force or reaction. Traditionally, when orthodontists wanted to move a certain tooth, they did it by pulling from other teeth. In most cases, this is still the method used.
There are, however, some cases where it would be beneficial to move a tooth without anything else moving. This is where TADs come in. TADs are mini implants that are temporarily placed to assist with such movements. They are usually 1-2 mm in diameter and 6-8mm (about 1/2 to 1/3 of an inch) in length. The are placed through the gums and into the bone, and usually requires no anesthesia. The picture below shows what a TAD looks like in the mouth.
There are many cases where these mini screws can be very beneficial. Some include:
- Avoiding extraction of teeth
- Closing spaces where teeth have been taken out, in many cases eliminating the need for an implant replacement
- Closing open bites
- Fixing deep overbites
- Avoid surgery
- Avoid headgear and other extraoral appliances
The placement of TADs usually takes 5-10 minutes and is pain free. The TAD usually stays in place until the desired movement is completed, usually for a few months.
TAD mini screws provide fast and reliable treatment outcomes, usually reducing the time needed in treatment. It also gives orthodontists a lot of new treatment options that weren't available before. While the majority of patients will not need one, for the ones that do, it can make a world of difference. In the example below, a TAD and a stainless steel spring are being used to move a back molar forward, something that was impossible to do before without side effects.
Most orthodontists are becoming proficient in the use of TADs, although some orthodontists might refer their patients to a different specialist to place the TAD, usually an oral surgeon. If your orthodontist recommends the use of mini screw TADs during treatment, make sure you discuss with them all the benefits and possible side effects of such treatment. In the right patients, it can provide many benefits to make treatment shorter, easier, and more effective.