Orthodontic Dictionary

Archwire
The arch-shaped wire that is tied to the brackets and connects them.

Band
A stainless steel ring that fits around a tooth. Bands have a hole through which the archwire is inserted and a hook for attachment of other components of the braces such as elastics.

Bracket
The steel or porcelain button is bonded to the tooth. With excessive force, brackets can become detached from teeth and come off or feel loose.

Coil Spring
Metal springs are on the archwire so as to move the teeth apart or closer together.

Colours
Coloured ‘modules’, which are little circular rubber rings which tie the archwire into the bracket slots.

Elastics
Small rubber bands worn between upper and lower brackets to bring about desired tooth movements. They are usually attached to hooks on brackets, bands or tubes.

Hooks
Small posts that are found on bands, molar tubes, brackets, and some archwires. Hooks are used to attach other components of the braces.

Ligature Wire
Thin small piece of wire used either to tie a number of teeth together (usually in a criss-cross pattern), or to tie the archwire into the bracket slots.

Lingual Arch
Arch-shaped metal bar which connects bands on lower back teeth. It fits just on the inside of the teeth in front and to the sides of the tongue, and it holds space further back within the lower set of teeth for the purpose of straightening crowded lower front teeth.

Module
Little round rubber rings used to hold the archwire into the bracket slots. Modules can come in all sorts of fun colours or they can blend in with the colour of your brackets.

Molar Tube or Buccal Tube
A longer sort of bracket which is attached to the back teeth; or the channel that is welded to a molar band. The end of the archwire is inserted through the buccal tube.

O-Lig
A thin wire which is threaded through an elastic module: the module end is usually on a hook on a molar tube, and the end of the wire is usually tied to a hook on a thick archwire. It fits on the sides of the brace and is used to close gaps between side teeth.

Power Chain
A continuous and stretchy rubber chain that fits over the brackets and connects a number of teeth so as to close gaps between those teeth.

Quadhelix
This is a metal brace which fitted on the roof of the mouth side of the upper teeth, and connects bands on the upper back teeth. It has four coils (helices) which make it flexible, and arms that push the upper side teeth away from each other in order to widen a narrow upper dental arch.

Transpalatal Arch
A metal bar that crosses the back of the palate and is connected to bands on top back teeth. Its job is to hold spaces between the back teeth for straightening of the crowded top front teeth.

Acrylic
Hard plastic material that forms the majority of the brace. It sometimes rubs against the soft tissues of the mouth which may hurt, and if so it needs to be adjusted by your orthodontist.

Aligner
A colourless horse-shoe shaped removable brace which is a little bit like a mouthguard and is made of clear bendy plastic. For example, the removable braces used in Invisalign are called aligners.

Baseplate
The acrylic (hard plastic) part of a removable brace. The wire components of a removable brace are attached to the baseplate. It sometimes rubs against the soft tissues of the mouth which may hurt, and if so it needs to be adjusted by your orthodontist. The baseplate can often be ordered in different fun colours.

Labial Bow
Arch-shaped wire part of a removable brace that wraps around the front teeth. A labial bow usually has loops which are U-shaped by the canine teeth. They help hold the brace tightly on the teeth, and can also be used to push front teeth back.

Clasp
A wire clip to fasten the removable brace to teeth so that the removable brace is held firmly in place.

Expansion Screw
A component of the brace which is used to widen a narrow dental arch and is usually found in the centre of the baseplate. Whenever there is an expansion screw in place, there is a split in the baseplate. A removable brace is usually expanded 1-3 times a week by inserting a key in the expansion screw and turning the key.

Key
A firm inch-long wire which is inserted into an expansion screw and turned, thus activating it and helping to widen a narrow jaw.

Retainer
It is not uncommon for people to call all removable appliances ‘retainers’. However, retainer is any type of appliance which is used after the completion of orthodontic treatment to hold the result, maintain stability, and minimise the risk of relapse. Retainers can be made of acrylic and wire, or clear flexible mouthguard-shaped plastic; or be fixed wires that are glued to the back of the front teeth.

Spring
Thin flexible wires attached to the baseplate used for moving teeth.