In orthodontics, the term "active unit" refers to:

In orthodontics, the term "active unit" specifically refers to the tooth being moved. This concept centers around the idea that when orthodontic forces are applied, they directly act on the teeth to initiate movement towards a desired position. The active unit is responsible for the changes observed in the dental alignment as it is influenced by the forces generated by the appliance, such as braces or aligners.

Understanding the role of the active unit is crucial because it highlights how targeted forces are essential for effective tooth movement. The application of these forces allows orthodontists to strategically plan treatment according to individual dental arch and occlusal discrepancies, ensuring that the teeth move effectively while taking into account the biological responses involved in tooth movement. This understanding also allows orthodontists to adjust forces appropriately based on the specific needs of the patient’s case.

The other concepts mentioned, such as anchorage units, passive units, and brackets, all play significant roles in the overall orthodontic treatment plan but do not define the active unit itself. Anchorage units are crucial for stabilizing certain teeth while others are being moved, the passive unit typically refers to components that do not directly participate in the movement, and brackets serve as a means to apply forces to the teeth. These aspects support the function of the