Articulator

Articulators are devices for simulating the temporomandibular joint movement. These plaster models of the dental arches of the upper and lower jaw are mounted in occlusion on the articulator. Subsequently, the movement of the jaw can be simulated each other, which, partial and full dentures or splints is essential for the manufacturing of dental restorations.

Precursors

Precursors of the articulator are the fixator and the occluder. The fixator fixed while only the models in an invariable position to each other. It is used to look at the models in the final bite position. The occludator also allows opening and closing movements ( hinge movements ) of the two models of the maxilla and mandible. This allows simple dental work is carried out or carried out an examination of the models in the context of orthodontic treatments.

Application of the articulator

Depending on the setting of the articulator can be simulated more or less exactly the chewing movements. This results in a production of dental restorations, such as crowns and bridges, removable dentures, such as partial or full dentures or Aufbisschienen is possible.

Anatomical bases

The temporomandibular joint is the most versatile body joint, since it can perform both rotational movements ( opening and closing movements around the hinge axis), as well as sliding movements ( feeding movements ), with rotational movements are also possible during the feeding and lateral movements. The temporomandibular joints are made of a cartilage- covered condyle, also a cartilage- coated glenoid fossa, the intermediate joint fibrocartilaginous disc, which is also called the articular disc, which divides the joint into a lower and an upper chamber. Furthermore, it consists of soft tissue structures such as ligaments, vessels and nerves.

In the mouth, the condyle slides together with the discus, which is normally connected firmly to the joint head forward and down. In all movements made by the lower jaw, the temporomandibular joints and masticatory muscles are active. All this is to be imitated by means of an articulator.

Variants of the articulator

A distinction must be Mittelwertartikulatoren, semi-adjustable articulators and Vollwertartikulatoren.

Mittelwertartikulatoren

Mittelwertartikulatoren do not provide individual settings. The models are in accordance with the articulation, the incorporation of the models in the articulator to move only mean values ​​to each other. They are predetermined by the Bonwill triangle. The Bennett angle and the condylar inclination are predestined according to statistical averages. Bennett angle is measured in the horizontal plane, the angle between the sagittal and the protrusion track mediotrusion the condyle. His average is 10-15 °, that of the condylar inclination is 30 °. Both are measures of jaw movements.

Semi-adjustable articulators

In the semi-adjustable articulators one of the values ​​, either the Bennett angle or the condylar inclination is adjustable.

Fully adjustable articulators

Fully adjustable articulators can be adjusted according to individual patient measurements. For this particular patient measurements for joint -related articulation of the models are necessary. What is essential is the provision of the hinge axis, an imaginary line connecting the passage points of the axis of rotation of the jaw joint through the skin. The fully adjustable articulators are used for the diagnosis of position and movement of the opposing dental arches and production of lab-fabricated restorations from inlays to tooth replacement. In both cases, the goal is a more natural transfer of the oral situation.

The various models differ in the setting of individual adjustment of the Bennett angle, condylar inclination, terminal hinge axis, anterior guidance. The incisal guide is interchangeable and thus the angle of repose customizable. Wherein the lateral movement of the mandible is carried out a displacement of the condyles. A distinction is made between immidiate side shift and progressive side shift.

After the Articulation of the upper model is in accordance with the jaw relation (formerly bite ) mounted the lower jaw model to the patient.

Arcon articulators

Furthermore, a distinction so-called non - Arcon and Arcon articulators. In the former, the design of the device is reversed as for the human jaw ( condyles are mounted in the articulator ), in the latter case the structure corresponds to the human anatomy of the temporomandibular joint. However, this has no effect on the function, as the relative movement of the lower jaw to the upper jaw for both technical approaches is the same. The motion sequence is reversed in non- arcon articulators in the articulator to the natural process and therefore used to.

Mittelwertartikulatoren non- Arcon devices with a Kondylenmittelpunktsabstand of 10-11 centimeters ( 10.5 in average mostly cm) and an insertable guide pin ( Incisal ), indicating an incisal point with a distance of 10-11 centimeters also to the Kondylenmittelpunkten are normally distributed (in see Bonwill triangle). The occlusal plane is aligned parallel to the plane of the table and the top edge of the articulator, so this represents the Camper's plane. The angle between the line connecting the incisal reference point and the Kondylenmittelpunkten one hand and the occlusal plane and the Camper's plane on the other hand thus represents the Balkwill angle of 20 ° to 25 °. These angles are alternate angles equal, and thus due to the parallelism of the occlusal plane and Camper shear plane. Thus, the model is aligned with the articulation that it applied to the incisal point to the reference mandrel and the occlusal plane is oriented horizontally (parallel to the table top ), and the median plane of the model perpendicular to Kondylenverbindungslinie.