An orthodontic appliance is a type of fixed or removable device used during the process of tooth alignment and arch expansion. In some cases, the dentist may recommend a fixed lingual expander in combination with clear aligners to help achieve optimal arch correction.

Types of orthodontic appliances:

• Transverse expander: Uses an expansion spring to increase the distance between the canines, helping to relieve crowding and widen a narrow dental arch.
• Anterior-posterior expander: Operates on a sliding mechanism to extend the dental arch and create space for the six front teeth to move forward, improving bite alignment and overall aesthetics.