Abrasion

Abrasion is the loss of tooth substance due to friction caused by hard food components.

Acceledent

Acceledent is a product designed to accelerate orthodontic treatment. It is an electrically operated device for intraoral use which transfers the instrument’s vibrations directly onto the recipient’s teeth. Acceledent has been introduced to orthodontics with great marketing effort. However, several high quality scientific studies have not indicated any particular benefit deriving from Acceledent, so orthodontic […]

Activator

The Activator was the first “functional orthodontic” brace that has been internationally recognized. Before that there was already the “jumping-the-bite appliance” of Kingsley (1879) and the monobloc of Robin (1902), but without much influence. It was originally introduced in 1935 by Viggo Andresen. The Activator is a removable appliance that encloses both teeth quadrants simultaneously […]

Active Plate

The active plate is a removable brace for just one jaw that was first devised in the 1920’s and was later improved by A.M.Schwarz. It consists of a plastic body, wire fasteners and active components such as springs and screws. Active plates, like all other removable appliances, are only useful for a small variety of […]

Active Plate (Single Brace)

An obsolete orthodontic appliance: First introduced by Charles Nord in 1929 and later improved by A.M. Schwarz, this is a removable brace for just one jaw. It consists of a plastic body, wire fasteners and active components such as springs and screws. With active plates, as with removable appliances, only very simple tooth movements are […]

Agenesis

Agenesis is the congenital absence of an organ or organ part. This term refers to the failure of a tooth or several teeth to develop during embryonic growth and development due to the absence of primordial tissue. The German word for this finding is „Nichtanlage“.The most commonly congenitally absent teeth are the upper lateral incisors, […]

Aligner

Ever since the Positioner first appeared in 1944, it has been possible to provide orthodontic treatment by using plastic, removable braces. Since then, both the Positioner, that resembles a sports mouth-protector, and the thinner, transparent Aligner have been continuously improved. The very first feasible treatment procedure using a thin, transparent aligner was described by Sheridan […]

Alveolar process

The alveolar process is the part of the jaw that surrounds the tooth roots. When the teeth are lost, the alveolar processes recede and only the jawbone bases remain.

Alveolar socket

The alveolar socket is the bony compartment of the tooth root.

Angle Classification

The Angle Classification was conceived by E. H. Angle, the founding father of orthodontics, for classifying orthodontic deviations after the first molars have appeared: Angle-Class I refers to a neutral occlusion (normal bite), Angle-Class II refers to a distal occlusion (back-bite) and Angle-Class III refers to a mesial occlusion in the lower molars (forward bite). […]

Angulation

The term angulation refers to the angular position of the dental crown or root, mostly in a mesiodistal direction.

Ankylosis

This refers to the growing together of the tooth root with the jaw bone. If this occurs during the growth phase, it results in the affected tooth not being able to keep up with the jaw growth and then seeming to slowly disappear into the jaw itself (infra-occlusion). Sometimes, children’s milk-teeth are affected, when there’s […]

Antagonist

A tooth is called antagonist which is opposite to another tooth and makes contact.

Apex

In dentistry, the root tip is called apex.

Apical

Apical is a directional term for: in the direction of the root tip.

Aplasia

Aplasia is the congenital absence of an organ or organ part. In dentistry, this term refers to the natural non-development of teeth. See agenesis

ARS

Abbreviation for Air Rotor Stripping. In American English a common name for interproximal enamel reduction with a high-speed angled handpiece.

Arthritis

Arthritis refers to the inflammation of joints which is usually associated with pain and functional impairments.

Arthroscopy

Arthroscopy is the examination of a joint with a slim optic device directly introduced under anesthesia. The arthroscopy of the temporomandibular joint is an occasionally useful examination technique with reasonable risks. During arthroscopy the temporomandibular joint can be irrigated at the same time and any particles from the discus can be removed (lavage and lysis).

Arthrosis

Arthrosis is a degenerative joint disease characterized by the disappearance of cartilage covering the healthy joint surfaces. In most cases, arthritis (joint inflammation) which leads to the breakdown of the cartilage is a precursor of arthrosis. In older people, a certain arthrotic remodeling of the temporomandibular joint is relatively normal and it can be interpreted […]

Articulator

The articulator is a hinged rack for assembling jaw models and simulating jaw function. It’s necessary for making dental prostheses in the orthodontic laboratory. At the height of Gnathology, this was regarded as essential for functional diagnosis but this device is usually superfluous for this process. Moreover, it’s particularly superfluous and involves additional costs when […]

ASR

In German the abbreviation ASR is used for interproximal enamel reduction, see there.

Attachment

Regarding the orthodontic treatment with aligners, attachments are used as small plastic buttons on the teeth which improve aligner retention.

Attrition

Attrition is the loss of tooth substance due to tooth-to-tooth friction, e.g. with teeth grinding or pressing.