Active Treatment

The time while a patient is wearing braces, rather than retainers.


Bonding paste, which is used to attach the braces to the teeth.


These systems all consist of a series of clear plastic aligners worn over the teeth. They are almost invisible. Each aligner is worn for 1-2 weeks before moving onto the next aligner. These systems are not suitable for every orthodontic problem. Please see invisalign aligners in appliances section.

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The bone surrounding each tooth.

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An abnormal union between two bones or between a root surface and surrounding bone resulting in tooth immobility.
This clip shows a retained deciduous tooth , which interfered with the eruption of the permanent tooth.

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Anterior Open Bite

The lower incisors are not overlapped in the vertical plane by the upper incisors and do not occlude with them.

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This clip shows an anterior open bite.

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A wire engaged into orthodontic brackets which delivers a force to produce tooth movement.

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An instrument that mimics the movements of the lower jaw to which individual patients upper and lower dental study models can be attached.

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Attachments for Invisalign/ Aligners

To facilitate the movement of teeth with invisalign/ aligners, it is commonly necessary to place attachments on the teeth, so the aligner can grip the tooth. Please see our blog.



The metal ring that is cemented to a tooth for strength and anchorage.

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Bilateral Sagittal Split Osteotomy

A surgical procedure to reposition the lower jaw forwards, backwards or by rotation.

These clips show a mandibular ( lower jaw ) advancement.

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These clips show a mandibular ( lower jaw ) setback

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Relating to the upper and lower dental arches or jaws.

Bimaxillary Surgery

Surgery to reposition both upper and lower jaws.

This clip shows a procedure to move the maxilla ( upper jaw ) forwards, and the mandible ( lower jaw) backwards.

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This clip shows a procedure to move the maxilla (upper jaw) upwards more so at the back, and the mandible (lower jaw) forwards.

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This clip shows a procedure to move the upper jaw upwards and slightly forwards and the lower jaw backwards.

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A word commonly used to describe a fixed orthodontic appliance, usually comprised of brackets, bands and wires.

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Picture Courtesy OF A.A.O.

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A precisely fabricated fixed orthodontic attachment made from metal, ceramic or plastic that is bonded to the teeth. The bracket has a slot that the archwire fits into.

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Brushing the teeth is part of an individual’s daily home dental care. Patients with braces should brush the teeth and braces for 2-3 minutes after every meal and last thing at night.

For school children they should be brushed after breakfast , upon returning from school, after the evening meal , and last thing at night.

After brushing before you spit out it is worthwhile to swish the froth of toothpaste around your teeth and mouth for about a minute, this will act somewhat like a fluoride mouth rinse . It is best to then spit out the toothpaste but not to rinse with water after brushing.

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Grinding the teeth, usually during sleeping. Bruxism can cause abnormal tooth wear and may lead to pain in the jaw joints.


The cheek side of the teeth.


Cephalometric Radiograph

A lateral (side view) x-ray of the head.
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A stretchable series of elastic o-rings connected together and placed around each bracket to hold the archwire in place and move the teeth.

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Class 1 incisor relationship

The lower incisors bite 2-4 mm behind the upper incisors. This is the ideal relationship of the teeth.

This clip shows the ideal relationship of the teeth.

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Class 2 division 1 incisor relationship

The lower incisors bite further behind the upper incisors then normal and the upper incisors are retroclined. These clips show teeth with a class 2 division 1 incisor relationship.

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Class 2 division 2 incisor relationship

The lower incisors bite further behind the upper incisors then normal and the upper incisors are retroclined. These clips show teeth with a class 11 division 11 incisor relationship.

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Class 3 incisor relationship

The lower incisors bite further forwards of the upper incisors than normal. These clips show teeth with a class 111 incisor relationship.

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Complete Overbite

An overbite in which the lower incisors make contact with either the upper incisors or the gum tissue in the roof of the mouth.

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Comprehensive Treatment

Complete orthodontic treatment performed to correct a malocclusion.

Congenitally Missing Teeth

A genetic occurrence in which the expected number of permanent teeth do not develop.

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A birth defect that may occur as an isolated phenomenon or as part of a syndrome, consisting of premature fusion of one or more skull sutures.


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The upper incisor teeth or upper molar teeth bite on the inside on the lower teeth.



Often used to describe the loss of mineral from the tooth surface immediately surrounding an orthodontic appliance. It is caused by excessive intake of sugar and accumulation of bacteria (plaque) on the tooth surface and insufficient tooth brushing. It results in permanent discolouration of the tooth surface and cavitation if extreme.

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The process of removing dental compensations, using fixed appliances, where the teeth have attempted to naturally compensate for a mismatch in the jaw relationship. Decompensation is often carried out prior to surgical correction of jaw relationships. This may involve wearing upper and lower braces for 6-12 months prior to surgery.

Dental Arch

The arch formed by the upper and lower teeth when viewed from below or above respectively.

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Dental Council

The statutory body which regulates the practice of dentistry in the Republic of Ireland. The members are appointed from the dental profession, the universities, the medical council, the government and the public.

Dento-alveolar Compensation

The inclination of the teeth is naturally altered to help compensate for a mismatch in the jaw relationship.

Deep Bite

Also known as deep overbite, this occurs when the upper front teeth overlap the bottom front teeth in a vertical direction to an excessive amount.

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Diagnostic Records

The material and information that the orthodontist needs to properly diagnose and plan a patient’s treatment. Diagnostic records may include a thorough patient health history, a visual examination of the teeth and supporting structures, models of the teeth, a wax bite registration, extraoral and intraoral photographs, a panoramic and a cephalometric radiograph.


A space between teeth (most commonly the upper central incisors).

Disclosing tablet (Plaque)

Plaque disclosing tablets are a useful aid to help patients maintain their oral hygiene.

Click here to Read More

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Away from the midline.

Distraction Osteogenesis

A surgical technique for lengthening bones.


Ectopic Eruption

The eruption of a tooth in an abnormal position.

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Elastics or rubber bands which maybe worn during certain stages of treatment to achieve orthodontic tooth movement.

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The process by which teeth enter into the mouth. The following clips show the normal eruption process. The line at the bottom of the clips indicates the patients age in years.

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Essix retainer

A clear appliance worn after braces to keep the teeth straight. You may wish to see our entry for Retainers in our Treatments section of this website.

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Expansion Appliance

An orthodontic appliance to increase the width of the upper dental arch or jaw.

This clip shows a quadhelix which is a fixed expansion appliance. It is not removable by the patient.

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This clip shows a removable expansion appliance for the upper teeth . It is removable by the patient . The midline expansion screw is turned once a week or more by the patient or their parent.

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This clip shows a hyrax expansion appliance . It is not removable by the patient. The midline expansion screw is turned once or twice a day.

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This clip shows a Haas expansion appliance . It is not removable by the patient. The midline expansion screw is turned once or twice a day.

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The removal of a tooth . Extraction of teeth for orthodontic reasons is something which is only done after it has been considered carefully. If an equally good result or a better orthodontic result can be achieved without extracting teeth then the decision is a “no brainer”. However in some orthodontic cases the best result can only be achieved by extracting teeth. It is important to appreciate that when teeth are extracted for orthodontic reasons that the spaces created by the orthodontic extractions will be closed at the completion of orthodontic treatment. Ultimately the patient or parent can make a decision in an informed way once their options are explained to them. These clips show various cases where extractions were used to achieve specific orthodontic objectives.

This clip shows a patient with protrusive upper and lower lips , upper teeth which are sticking out too far, and crowding in the upper and lower jaws. The orthodontic objectives are to retract the protrusive upper and lower lips, to retract the upper and lower front teeth and to correct the crowding problem. To achieve these treatment objectives four first premolars were extracted.

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This clip shows a patient whose lips are in a good position there is crowding of the upper and lower teeth. The treatment objective is to correct the crowding.It was felt that sufficient space could not be created by other appropriate orthodontic means than extraction. To achieve this objective four second premolars were extracted.

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This patient had a protrusive lower lip, lower front teeth biting in front of the upper front teeth , and crowding of the upper and lower teeth . The treatment objectives were to retract the lower lip, to retract the lower front teeth so that they would bite behind the upper front teeth as is the normal relationship and to correct the crowding problem. It was felt that these treatment objectives could not be achieved without extractions. Upper second and lower first premolars were extracted.

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The following two clips describe the same case where the lower teeth are straight , but the upper lip is protrusive , the upper teeth stick out and are crowded. The treatment objectives are to create enough space to retract the upper teeth and consequently the upper lip ,and to correct the crowding of the upper teeth. In many cases which are similar to this but possibly a little less severe it is possible to create enough space in the upper jaw to achieve the treatment objectives outlined above without extractions , by using for instance headgear or a forsus type appliance amongst many other equally good appliances. It was decided here to extract both upper first premolars to achieve these objectives . Often the treatment plan reflects the patients preferences regarding which appliances they are prepared to wear.

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Occasionally under specific circumstances one lower front tooth maybe extracted

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A wire appliance used with headgear. Primarily used to move the upper first molars back, creating room for crowded or protrusive front teeth. The facebow has an internal wire bow and an external wire bow. The internal bow attaches to the buccal tube on the upper molar bands inside the mouth and the outer bow attaches to the breakaway safety strap of the headgear. These three clips illustrate a facebow being worn with three different types of headgear, cervical , combination, and high pull .

Cervical headgear.

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Combination headgear.

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High Pull Headgear

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Fixed Appliance

An appliance that is fixed to the tooth surfaces in order to produce tooth movement.

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An important part of daily home dental care. Flossing removes plaque and food debris from between the teeth, brackets and wires. Flossing keeps teeth and gums clean and healthy during orthodontic treatment.

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Forsus Appliance

This provides a constant light force to correct a situation where the upper teeth are too far in front of the lower teeth. On certain occasions it maybe an alternative to headgear.

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A fold of mucous membrane

Functional Appliances