Orthodontic Glossary

A

Adhesive - The dental cement used to bond brackets and bands to your teeth. It holds firm for the length of treatment and is removed cleanly at the end.

Aligner - A clear, removable tray that moves teeth gradually. Treatment uses a series of them, each shaped slightly differently, worn in sequence. Invisalign and Spark are two well-known systems.

Ankylosis - Where a tooth has fused to the surrounding bone and will not move with orthodontic force. Uncommon, but it can change the treatment plan if it occurs.

Appliance - Any device used to move teeth or guide jaw growth. It may be fixed to the teeth, removable, or a combination of the two.

Archwire - The wire running through the brackets of a fixed brace. It is the archwire, not the brackets, that actually moves your teeth. Modern wires are thin, flexible and considerably more comfortable than older ones.

B

Band - A metal ring fitted around a back tooth, usually carrying a bracket or tube. Bands give a more secure attachment than bonding alone.

Bite plane or bite ramp - A small addition to a brace that stops the upper and lower teeth meeting in their old position, allowing the bite to be corrected.

Bonding - The process of attaching brackets to teeth. Direct bonding places them straight onto the teeth; indirect bonding positions them on a model first, then transfers them in one go.

Bracket - The small attachment bonded to each tooth that holds the archwire. Available in metal or tooth-coloured ceramic.

C

Canine - The pointed tooth third from the centre, sometimes called the cuspid or eye tooth. Canines are the most common teeth to become impacted.

Cephalometric radiograph - A side-on X-ray of the head used to assess the relationship between the upper jaw, lower jaw and teeth. Standard at the assessment stage.

Clasp - The wire component that holds a removable brace or retainer securely in place.

Cone beam CT (CBCT) - A three-dimensional scan of the teeth and jaws at a much lower radiation dose than a medical CT. Used selectively, usually for impacted teeth or surgical planning.

Crossbite - Where an upper tooth bites inside its lower counterpart instead of outside it. Can affect the front or back teeth and causes uneven wear if left.

Crowding - Where there is not enough room in the jaw for the teeth, so they overlap or twist. One of the most common reasons people seek treatment.

Crown - In orthodontic terms, the part of the tooth visible above the gum.

D

Decalcification - Permanent white or brown marks on enamel caused by plaque sitting against the tooth. Entirely preventable with good brushing, which is why we are insistent about cleaning around brackets.

Deep bite - Where the upper front teeth cover too much of the lower front teeth when you bite together.

Dentofacial orthopaedics - Guiding the growth of the jaws in children, as distinct from simply moving teeth. Timing matters, which is why early assessment is worthwhile.

E

Elastics - Small rubber bands worn between the upper and lower braces to correct the bite. They only work if worn as directed, and progress stalls quickly when they are not.

Essix retainer - A clear, vacuum-formed removable retainer. The most commonly prescribed type, and close to invisible when worn.

Expander - An appliance that widens the upper jaw by applying gentle outward pressure. Most effective in children, while the jaw is still developing.

F

Fixed brace - Brackets bonded to the teeth and joined by an archwire, worn continuously until treatment finishes. Still the most versatile appliance available.

Fixed retainer - A thin wire bonded behind the front teeth to hold them in position permanently. Needs careful cleaning between the teeth.

Functional appliance - A brace that uses the patient's own jaw muscles to correct the bite. Used in growing children and teenagers, commonly for prominent upper front teeth.

H

Hawley retainer - A removable retainer with a wire across the front teeth and an acrylic plate behind. Less discreet than an Essix retainer but useful for correcting minor relapse.

Headgear - An appliance extending outside the mouth to apply backward force to the upper teeth. Used far less often than in the past.

I

Impacted tooth - A tooth that has failed to come through into the mouth, usually because it is blocked or growing in the wrong direction. Upper canines and wisdom teeth are the usual culprits.

Impression - The traditional method of recording tooth position using a soft material in a tray. Largely replaced at our clinic by digital scanning, which most patients find considerably more comfortable.

Incisor - The four flat front teeth in each jaw, used for cutting food.

Interproximal reduction (IPR) - Removing a very small amount of enamel between teeth to create space. Painless, and far less invasive than extraction where only a little room is needed.

L

Ligature - The small elastic or wire tie holding the archwire into each bracket. The coloured elastics younger patients choose are ligatures.

Lingual braces - Fixed braces bonded to the tongue side of the teeth, so they are hidden from view.

M

Malocclusion - The clinical term for teeth or jaws that do not meet as they should. Classified as Class I, II or III depending on how the jaws relate to one another.

Molar - The large grinding teeth at the back of the mouth. The first permanent molars appear around age six and are often mistaken by parents for baby teeth.

O

Open bite - Where the front teeth do not meet when the back teeth are closed, leaving a visible gap. Often linked to thumb sucking or tongue habits.

Orthognathic surgery - Jaw surgery carried out alongside orthodontic treatment to correct significant skeletal discrepancies. Only relevant to a small minority of adult patients.

Overbite - The vertical overlap of the upper front teeth over the lower ones. A small overbite is normal.

Overjet - How far the upper front teeth sit forward of the lower ones, measured horizontally. A large overjet increases the risk of the front teeth being chipped or knocked.

P

Panoramic radiograph (OPG) - A single X-ray showing all the teeth and both jaws. Taken routinely at assessment to check for missing, extra or impacted teeth.

Periodontist - A dentist specialising in the gums and supporting bone. We work alongside one where gum health needs attention before or during treatment.

Premolar - The two teeth in each quadrant sitting between the canine and the molars. Sometimes removed to create space in crowded cases.

R

Radiograph - The correct term for what most people call an X-ray.

Relapse - Teeth drifting back towards their original positions after treatment. It is the single most common cause of disappointment after braces, and retainers are what prevent it.

Removable brace - A plate that can be taken out by the patient. Useful for straightforward movements and for expansion, but less precise than a fixed brace.

Retainer - The appliance worn after active treatment to hold your teeth in their corrected position. Fixed or removable, and needed indefinitely if you want your result to last.

Root resorption - Slight shortening of the tooth roots during treatment. Usually minor and of no consequence, though a small proportion of patients experience more of it, which is why we monitor with X-rays.

S

Separator - A small rubber ring placed between back teeth for a few days to create the space needed to fit a band. They can feel like something is stuck between your teeth, which is normal.

Six-month braces - A shorter course of fixed braces aimed at aligning the front teeth only, without correcting the underlying bite. Suitable for some cases, not all.

Spacing - Gaps between the teeth, either because the teeth are small relative to the jaw or because a tooth is missing.

T

Temporary anchorage device (TAD) - A small screw placed in the bone to provide a fixed point to pull against, allowing movements that would otherwise be impossible. Placed under local anaesthetic and removed once no longer needed.

Tube - Similar to a bracket but closed, so the archwire threads through rather than clipping in. Usually fitted to back teeth.

W

Wisdom teeth - The third molars, which usually appear in the late teens or early twenties. Some people never develop them at all, and they do not, contrary to common belief, cause front teeth to crowd.