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Glossary of terms

The following is a glossary of some of the more common orthodontic terms.


An appointment for us to check to see how you are going and if necessary, make any adjustments to your appliance, such as change or tighten wires and replace or adjust elastics. 


Meaning ‘in front’, i.e. the canine and incisor teeth.


Any device used to reposition teeth or change the jaw position, or keep teeth in the right spot after braces are taken out. They can be permanently attached to the teeth or removable.


This term refers to the shape of the upper/lower jaw.


This term refers to the metal wire attached to brackets. Archwires move the teeth to the required position.


The Australian Society of Orthodontists (ASO) - the professional association for orthodontists in Australia ( 


A band is a circular strip of metal that is glued to back teeth using dental cement (special glue). The band supports and anchors the archwire.


How upper and lower teeth occlude or ‘bite’ together.

Bite Registration

An imprint - made by biting into wax or a rubbery material - of how teeth come together.


The process of fitting brackets to teeth using orthodontic adhesive.


Orthodontic devices used to move the teeth and/or jaws. Usually made up of brackets, bands and wires.


A metal or ceramic attachment bonded to a tooth to hold an archwire.


A condition exemplified by grinding of the teeth, often while asleep. It can cause abnormal tooth wear, and in some cases cause jaw pain.

Buccal Tube 

A small metal part welded to the outside of a molar band. The molar band contains slots to hold archwires, lip bumpers, facebows and other things used to reposition teeth.

Caephalometric X-Ray

An x-ray used to assess the position of the jaws and related structures and assisting in the diagnosis of malocclusions (see also Panoramic X-Ray)

Congenitally Missing Teeth 

Where the expected number of permanent teeth do not develop - an inherited condition.


A malocclusion where the upper teeth bite inside the lower teeth.

See: Cross-Bite.


Where there is not enough room on the jaw for the teeth.

See: Crowding.


A space between two adjacent teeth, usually with front teeth.


Small elastics or rubber bands that use continuous gentle force to allow an individual tooth to be moved or the jaw to be realigned. These elastics have to be changed every day by the wearer.

Fixed Appliances

An orthodontic device (usually braces) bonded/cemented to the teeth and cannot or should not be removed by the patient.

Functional Appliances

A removable appliance that holds the lower jaw forward to correct a bite. It uses the muscle action when speaking, eating and swallowing to produce a force to move the teeth and align the jaws.


Wire apparatus used to move upper molars backwards in the mouth to create space for crowded / protruding anterior teeth.

See: Headgear.

Impacted tooth

A tooth that does not erupt into the mouth or only erupts partially.


A mould/casting of teeth used to create sets of models of the teeth.

Ligating Module or “O”

A small doughnut shaped piece of plastic used to hold archwires in the brackets on the teeth. These may be clear or coloured.


The orthodontic term used to indicate teeth that do not fit together properly:

Class I malocclusion: A malocclusion where neither the upper nor lower teeth are prominent relative to the opposing teeth.

Class II malocclusion: A malocclusion where the upper teeth are prominent relative to the lower teeth.

Class III malocclusion: A malocclusion where the lower teeth are prominent relative to the upper teeth.


The lower jaw.


The upper jaw.

Mixed Dentition

The developmental stage in children (roughly age 6-12) when they have a mix of baby / milk and permanent / adult teeth.

Nightguard (or Occlusal Splint)

A removable device worn during the night to minimize damage / wear to teeth from tooth clenching or grinding of the teeth while asleep.


A malocclusion where the teeth don’t contact each other. An anterior open bite is where the front teeth don’t touch when the back teeth are closed together. With a posterior open bite, the back teeth don’t touch when the front teeth are closed together.

See: Open-Bite.

Orthognathic Surgery

Corrective jaw surgery to treat and correct abnormalities of facial bone structure, i.e. the jaws and teeth.

Palatal Expander

A device used to help widen your upper jaw / palate.

Panoramic X-Ray

An x-ray of the head, which shows if teeth are aligned, and growing as they should (see also Caephalometric X-Ray).


Plaque is a layer of bacteria that forms on the surfaces of your teeth. When plaque comes into contact with sugars it forms an acid that damages both teeth and gums. Plaque causes tooth decay and gum disease.


A stretchable plastic chain that holds the archwires into brackets and helps close spaces.


A device that is fixed to the molar teeth and has a zig-zag wire across the palate. Used to correct a crossbite by expanding the upper arch.

Removable Appliance

A device that can be removed by the wearer and is used to move teeth and/or align jaws.


fixed or removable device worn after braces are removed to help keep teeth in their new position.


A plastic elastic o-ring used to create space between teeth. They are generally placed between teeth 5-7 days before bands are fixed to the teeth.

Supernumerary Teeth

More teeth than the usual number.

Twin Block Appliance

A device made of an upper and lower plate that pushes the lower jaw forward and encourages lower jaw growth.

See: Twin Block Appliance.


See archwires.