Double feed plate
The double feed plate is a functional orthodontic device for the treatment of tooth misalignments of Angle Class II anomalies . Functional orthodontics is understood to be the favorable influencing of skeletal structures by specifically influencing functional processes using removable regulating devices ( braces ).
Historical
The first attempts to treat Angle class II with a removable device were made by Kingsley in 1879. He constructed an upper jaw plate with an oblique frontal bite that forced the lower jaw into a ventral position with every bite . With this device he defined his idea of “jumping the bite”: In order to get from a full premolar distal occlusion to a neutral toothing, the lower jaw has to jump over a premolar width.
The concept of "jumping the bite" forms the basis for functional orthodontics. The most popular functional orthodontic device is a bimaxillary device, the activator . This was first introduced by Andresen in a preliminary stage and later (1935) by Andresen and Häupl as the classic activator of the Norwegian system.
In the 1940s, Petrik developed the classic system further by adding additional elements to the activator.
In the 1950s, further modifications emerged: Bimler (dentition former) and codfish (Kinetor) added a elastic elements. Balters ( Bionator ) and Klammt (open activator) skeletonized the voluminous plastic block. Fränkel moved the plastic base to the vestibular area and called the device a function regulator .
These devices have some undesirable side effects. For example, the desired bite correction occurs very slowly. In addition, activators are not suitable for fine-tuning teeth. This means that before treatment with an activator, either a pretreatment with Schwarz's plates is necessary or, after the functional orthodontic treatment, a multiband treatment is definitely necessary.
Double plate systems
The orthodontic double plate systems go back to AM Schwarz. In the middle of the 20th century, he cut through an Andresen-Häupl activator in such a way that a plastic lamella extending from the upper jaw slides along an inclined plane in the lower jaw. He called his treatment apparatus the "double undershot plate". A modification of this system was the "double overbite plate" with wire brackets, which should trigger a forward displacement of the lower jaw via the guide surface. AM Schwarz saw the advantage of this design in the fact that the wire brackets used could be activated later by the practitioner and thus the forward displacement of the lower jaw could be controlled. At that time, AM Schwarz did not provide any information about the desired inclination of the feed loops. The loops should only fit harmoniously to the lower jaw appliance. The bars should be long enough that they still have contact with the guide surface in the opposing jaw when the lower jaw is in the resting position.
A modification of Schwarz's construction was described by Müller in the 1960s, the "double plate with upper jaw spur guide". With this construction, the advancing bars are attached laterally in order to reduce the patient's speech impairment and to give the tongue more freedom of movement. On the other hand, sideways movements of the lower jaw are not possible. The frequent fractures and thus the increased susceptibility of the Müller apparatus to repair are seen as a further disadvantage.
Only more than 30 years after the development of the "double overbite plate" according to AM Schwarz were night sleep examinations carried out by Franz Günter Sander , which were of decisive importance for the construction of the Sander double feed plate (S-II apparatus). Apparatus is ascribed an important role both to the inclination of the metal bars of 60 ° ± 5 ° to the occlusal plane and to the bar length. According to Sander, both parameters are essential for successful treatment.
indication
Similar to all functional orthodontic devices, the main areas of application here are also Angle classes II / 1 and II / 2. However, the double feed plate is particularly suitable for patients who, in addition to correcting the distal toothing, also require skeletal changes.
Advantages of the double feed plate
- The double feed plate is widely accepted by patients, as they can speak very well in the mouth with this device.
- By attaching different retaining elements, it is also possible to achieve good anchoring in the reduced mixed dentition .
- The construction of the device in two separate plates makes it possible to carry out single tooth movements in the upper and lower jaw at the same time.
- Since stretching in the upper jaw and midline corrections can be carried out at the same time, pretreatment with active plates prior to the actual functional orthodontic therapy is superfluous.
- By combining it with extraoral devices, the effect of the double feed plate can be increased.
- There are good treatment results in a relatively short time.
literature
- Lisson, JA: The dentoalveolar and skeletal effect of the orthodontic double-plate appliance with feed loops for dysgnathies of Angle class II / 1 during mixed dentition - a clinical and radiological longitudinal examination , habilitation thesis, Hannover (2000)
- Sander, FG: The double feed plate - an excellent treatment aid. Dental-Labor 6: 750-758 (1988)
- Sander, FG: Indication for the use of the double feed plate Prakt. Orthodontist. 2: 209-222 (1988)
- Wendler, S., Tränkmann J., Lisson, JA: On the treatment effect in the therapy of children with Angle-II, 1-occlusion with the double feed plate in the prepubertal and pubertal phase , J Orofac Orthop, 67, 105- 15 (2006)