Orthodontic devices can be fixed or removable.

Fixed appliances

These are the most common devices used in orthodontics. They are used when precision is important. A person can eat normally with fixed appliances, but some foods and drinks need to be avoided, such as carbonated drinks, hard candy, gum, and other sticky foods.

People who participate in contact sports need to tell their orthodontist, as they may need special gum shields. Examples of fixed orthodontic appliances include:

Braces

These consist of brackets, wires, and bands. Bands are fixed firmly around the teeth and serve as anchors for the appliance, while brackets are usually connected to the front of the teeth.

Wires in the shape of an arch pass through the brackets and are fixed to the bands. As the arch wire is tightened, tension is applied to the teeth. Over time, this moves them into the proper position.

Follow-up involves monthly visits to adjust or tighten the braces. Treatment may last from several months to a number of years. Both clear and colored braces are available.

Fixed-space maintainers

If a child loses a baby tooth, a space maintainer will stop the two teeth at either side of the space from moving into it until the adult tooth comes through. A band is fixed to one of the teeth next to the space, and a wire goes from the band to the other tooth.

Removable space maintainers

These are an alternative to fixed-space maintainers.

Special fixed appliances

These can help control tongue thrusting or thumb sucking. They may be uncomfortable, especially when eating, and so they are only used if necessary.

Removable orthodontic appliances

These may be used to treat minor problems, such as preventing thumb sucking or correcting slightly crooked teeth.

The appliance should only be taken out when cleaning, eating, or flossing. Sometimes, the orthodontist may advise the patient to remove them during certain activities, such as playing a wind instrument or cycling.

Examples of removable appliances include:

Aligners: This alternative to braces may be useful for adults. They are virtually unnoticeable by other people, and they can be removed to brush their teeth, floss, or eat. An aligner is used for 2 to 3 weeks, then changed for a tighter one.

Headgear: A strap around the back of the head is attached to a metal wire in the front, or face bow. The aim is to slow down upper jaw growth and keep the back teeth in position while the front ones are pulled back.

Lip and cheek bumpers: These are specially made to relieve the pressure of cheeks or lips on the teeth.

Palatal expander: This appliance is designed to make the arch of the upper jaw wider. It consists of a plastic plate with screws that are placed on the palate, or roof of the mouth. The screws put pressure on the joints in the bones, forcing them outward. This expands the size of the area on the roof of the mouth.

Retainers: These are used after treatment to stop the teeth from moving back to their original positions. If modified, they may also be used to stop children from sucking their thumbs.