Orthodontic problem

Many people are familiar with traditional orthodonture, the process by which steel wires are used to straighten teeth. An orthodontist installs the steel wires, which guide the growth of teeth in some particular, desired directions. The problem with this very popular technique is that stainless steel does not stretch and adjust very well, and a patient may have to visit an orthodontist quite frequently to have adjustments made in the tensions of the wires. The use of SMA materials for orthodontic wires reduces this problem. Such wires exert the force of tension needed to direct the growth of teeth, but they do so with more elasticity and, therefore, less discomfort to patients. Patients must still visit their orthodontist for adjustments, but at much less frequent intervals. 

Jacobsen N, Hensten-Pettersen A (1989) Occupational health problems and adverse patient reactions in orthodontics. Eur J Orthod 11 254-264... 

---