Appliances for functional jaw orthopedics
Last update 09.12.2019

For an impression of the art of functional jaw orthopedics with removable appliances (German: FKO), see these 2 sentences which I found elsewhere, in a materials research journal:
Nature is still doing all the work in creating (..). We´re just politely asking it to do it in a particular location with a defined order and configuration“.
FKO utilizes exclusively the forces of the patient´s mouth muscles, and it corrects the muscular functions. Particular non-rigid appliances even stimulate jaw movements by the so-called „chewing gum effect“. These forces are controlled by the patient. Functional appliances re-direct them for bite correction, for growing all teeth in plane, and some special appliances also for gain of space by stimulation of growth, or for correction of individual teeth.

Pain and possible damage, which threaten when applying „artificial“ forces especially by fixed appliances, are prevented. It is emphasized that the somehow „self-grown“ results of FKO are well stable against relapse. Some more English examples are in the case examples.

Bite jumper plates

Doing dental corrections and bite shift simultaneously with these appliances allows time-efficient therapy even of older teenagers.
Jähnig´s modern „Göttingen“ type is shown above, which is very versatile and with high comfort. The mobile bite jumper yokes are at the outsides. Inside, any kinds of springs and screws can be included into the plates, for any further correction which is desired. The plates are detachable, e.g. to wear one of them for additional hours per day, if required. See case example for more.
For this kind of bite jumper plate, also a headgear effect is reported. In contrast to the activator (see below), it acts more on the upper than on the lower jaw. The forces along the yokes are of similar size and direction to those of a high-pull headgear!

Double and single (lightweight) bite back-shift plate

Bite back shift plates are intra-oral appliances in quite conventional style to treat the rarer class III (progenic) cases. That means, they do the opposite of the before-mentioned bite jumper plates, and this is more difficult: try yourself, how far can you shift your lower jaw forward, but how far only pull it backward?
Unfortunately, gentle methods of treatment vanish for these patients (also the less conventional FR 3, Bimler C and Function Harmonizer, see all below), even if they show up well in time. All these appliances keep not only the lower jaw back and enhance the forward growth of the upper, but can also provide an upper expansion (simultaneously), which most of the progenic cases require. The bite back shift plates use just a standard large expansion screw for this.

The task of shifting back the lower jaw by small steps is solved in the double version by Sander´s commercial kit: in the upper plate a pair of downward directed lateral rods, and in the lower a pair of lateral supports which keep the upper rods in front of them. Or viewed from the lower jaw, this is held back by the upper plate. Some sideward distance permits the use of the expansion screws. Now the lower supports can be screwed forward, giving the lower jaw a back-shift little by little, whereas the counter-force acts on the upper jaw.

The 4-element bite back shift single plate leaves much more space for the tongue. As the first element, a re-adjustable downward bow holds the lower jaw back (compare with „ expl. of cases“> Early treatment of class III). Next, an expansion screw is for gain of jaw width. Then for gain of frontal jaw length, protrusion springs push the incisors from inside, and the outer shields, which are somewhat small here, stem from the FR 3 (see below) and are to stimulate the bone growth in the height of the roots.

Well-shaped activator

The shown specimen reaches deep in the lower jaw, and snaps in there, for its sure guidance especially during sleep. In the upper jaw, however, the plastic body is largely reduced. By this, it hinders speech less than most upper plate appliances. It performs not only bite jumping, but allows also vertical equilibration of deep or open bite, if it is properly machined after casting.

Class 3 activator

The well-proven type of this robust appliance shown here is horizontally divided. A specialized screw element connects upper and lower part. It is somewhat bulky, but provides a successive lower backshift. Thus, it guides the lower jaw little by little to a normal bite, if the upper jaw is already well-shaped.
The example here has a class III occlusion, whereas the deviation of the midline is just due to migration of the upper incisors and not caused by lateral bite deviation.
In contrast to the above-shown bite back-shift plate, which is not as robust and which requires more specialized parts, this class III activator cannot provide upper expansion. However, it may be well-suited to continue a treatment after class III plates have shaped matching arches, but not yet normalized the jaw positions.

Special upper expansion screws are available for standard activators, which can also be crafted for lower back-shift, but not a re-adjustable.
Frontally open class III activators with palatinal expansion screw and lip shields are used in combination with physiotherapy in a university in Thailand (see sources) to treat unselected class III patients successfully. More severe cases simply received in the course of their treatment a second or third specimen of this light appliance, which lacks an adjustable backshift

Improved bionators of 2 types

These are improved to stimulate jaw movements (chewing gum effect) and to convert their force to bite corrections. By this, even a treatment of children beyond their growth maximum remains promising.

Silicone rubber is added on the sides of the first (upper) specimen, for more efficient correction of an open bite.

The second specimen is a „reverse“ Bionator modification, for class 3 treatment (back shift of lower jaw). Correction is enhanced here by silicone rubber for a full-contact forward shift of the upper front (set-up technique).

The general shape of Bionators is intended to correct lip and tongue functions, and like all 1-piece appliances, to enhance nose breathing. Correct functions should lead to correct jaw development.

The Biognathor, a functional appliance for adults

The Biognathor is a double-decker appliance that has been reduced to the essential, and this is made in high quality for longtime treatment. It is well-suited to be worn at work, because frontally open, and the surrounding wire element, which was taken from Balters´ bionator, can here be detached. For an overview with 9 more images click here [266kB pdf].
It alleviates bruxing, jaw joint disorders and tense muscles caused by this especially under stress. In contrast to common splints, it does not snap in, but teaches a reflex of release, which already brings relief.
Moreover, it helps against those malfunctions which are associated with improper development and ripening of the orofacial system, like wrong swallowing, mouth breathing or poor posture of the lips or lower jaw.

The Biognathor can also aim to achieve a functional bite shift, which is done by influencing the jaw development, even in adult treatment. This is vehemently doubted by protagonists of jaw surgery, whereas manufacturers and protagonists of Herbst appliances and likewise fetters nevertheless advertise their success in adult treatment.
Indeed, adult bone comprises some degradation and fresh formation of bone material. Form follows function.

For any application of the Biognathor, its effect should be amplified by physiotherapy. Individually selected exercises with simple items according to Padovan, Brazil, have been proven successful here.
A likewise amplification of uncomplicated, rigid functional appliances by well-targeted daily exercises was reported in Thailand. There, unselected patients in the age of 7 to 15 (!) yr were cured from progenic bite, which is particularly widespread in this population, by 6 to 24 months of this economic treatment.
Guided self-treatment is also among the various appliances with chewing gum effect which are displayed in this chapter. They stimulate muscular exercise by themselves, but this is less specific and rather in the sense of general stimulation of jaw development and nose breathing.
It is true that functional bite shift in adults has no 100% expectancy of success. But on the other hand, since such appliances as the comfortable Biognathor cause neither pain nor risk, the attempt should not be excluded in advance. More research on this field would be desirable.

Muscle force jaw shaper, unbreakable

Prefabricated appliance that uses strong chewing-gum effect, as described under Dentosophie . By this, it is not only well-suited and economic for early and interceptive treatment, but can also make the teeth of severe and late cases move.
Can be purchased through me (see main menu, right column) and exists in 4 shapes with continuous sizes, against
(1) lack of space with normal or backward jaw position
(2) covered bite (3) lower jaw too much forward
(4) upper jaw too narrow (unavailable from other manufacturers).

Bracco´s function generating bite of Turin

The series of function generating bite appliances (FGBs) marks a progress in chewing-gum effect orofacial orthopedics. Such appliances (see also Muscle force jaw shaper, and Bimler) require just little daytime wear, which in favour of those children who are rarely at home during daytime.
FGBs don´t break easily and remain usable while milk teeth are replacing. They are
hygienic, quite comfortable and are intended for early treatment (from 3 years on) and for interceptive treatment in mixed dentition. Patients with a covered bite can still profit in permanent dentition from appropriate FGBs which allow to tap muscular forces for dental alignment.

The school of Turin (Torino) has developped an old type of appliance further, which had survived somewhere in southern Europe, and diversified it to the FGBs and analyzes their muscular effects.

Already a basic kind of FGB cures unilateral crossbite (due to narrow upper jaw) in 7- to 10-yr children rather quickly and painlessly. Moreover, it normalizes the chewing movements on this side, for both hard and soft samples. In contrast to this holistic effect, orthodontists in USA (2001) found no reduction of odd chewing patterns when unilateral crossbite was early treated with rapid maxillary expansion.

The basic FGB leaves the lower jaw free. 1 Pair of side springs for support and expansion and 1 pair of wing carriers emerge from its central body. The wings consist of outer plastic bodies and thin metal sheets out of special resilient steel, which can be chewed: chewing-gum effect in durable, hygienic material. In resting position, neither these lateral planes should touch the teeth, nor the central body should touch the palate. Instead, the resilient appliance is held by the tongue against the inside of the upper arch. Frontally, the wing bodies are connected by at least an upper or a lower bow. This can have special bendings, if required, as in the red specimen shown here, which has 4 sturdy protrusion springs (for pushing) in addition to the basic elements.
The specimen shown next is a type of a class 3 FGB, since its frontal elements resemble those of Fränkel´s function regulator 3. In addition, it has a frontal bite plane, which emerges from the central body and is rather part of appliances against deep bite or covered bite (FGB-D). There, it can even be double, for severe cases.
Against class 2 malocclusions, FGBs are equipped with lower lip shields or tongue lifters. Thus, the jaw is guided to its healthy position without lasting force on teeth. In special cases, the lateral planes can be inclined or bent, to stimulate those particular muscles which act against the particular unhealthy jaw development, e.g. a bad vertical face growth, without any need for hard methods.

The healing effect of FGBs includes also the jaw joints, and they appear favorable to create growth for the wisdom teeth. But since they neither can carry screws nor interdental springs, they cannot open or close gaps orthodontically. In case of gaps of lacking permanent teeth, FGBs at early time favour the close up of the teeth from behind. Aligners can be used if dental alignment is desired after FGB treatment.

A shoe tree in the cheeks:
Fränkel´s function regulators 1 and 2

Between lips and teeth, our cheeks have quite large pockets. The plastic of the Fränkel appliances reaches into these pockets, up to their top and bottom. There, it stands 2-3 mm away from the jaw. By this, it makes our flesh pull at our jawbones. This stimulates their growth, depending on age of the patient, but even for difficult „vertical“ face growth. With neither risk of over-correction and subsequent relapse, nor risk of jaw joint damages or tooth damages. High longtime stability of the results has been reported. If treatment begins early, then not only expansions of up to 6 mm and stretching of the jaws and vertical correction can be achieved, but also space for the wisdom teeth can be created.
The small, frontal plastic shields of the Fränkel appliances are re-adjustable in their distance. So if the growing jaw has approached them, growth stimulation can be re-activated.

Function regulator 3

The FR3 is well-proven for treatment of class 3 (progenic) children. Few cases, however, are better addressed by appliances with chewing-gum effect. It stretches and widens only the upper jaw, where re-adjustment of the frontal shields is also possible. It holds the lower jaw back and hinders its growth (plastic fits tightly around it).
Note well that the space for the tongue is not reduced, which allows a development of a healty tongue function.
A Fränkel appliance
alone can help a child with jaw disorders to grow a healthy mouth for whole life.

Bimler appliances (find more details under „expl. of cases“)
Bimler A = basic type (for class I and II-1)

Bimler appliances are designed in 3 types, with several sub-types of each. All are constructed to be springy such that they encourage the patient to jaw movements, like a chewing gum does: the so-called chewing gum effect. Bimler appliances convert this muscular force not just in unspecific stimulation of jaw growth, but can be equipped to direct some force to individual teeth to correct their positions (see more in the case examples).
Just 2 strong wires hold the lower part of the Bimler appliances. They come out of the rear of the upper part , and if a bite shift is required, they can be bent forward stepwisely. For narrow jaws, the appliances are equipped with an expansion screw instead of the upper omega-shaped palatinal spring.

For Bimler treatment of children, the Bimler-A type is appropriate in 90% of these cases. The specimen shown here has an additional pair of springs in the upper cuspid region.

Bimler B appliance, against „covered bite“ (class II-2)

viewed from above, so that the two long wires which hold the lower frontal part are underneath it.
Converts the force of biting down to press the upper and lower incisors into the bone (intrusion), along with some uprighting of the uppers. By this, the vertical overbite is reduced, painlessly and also in adults, which was practised e.g. in the former German Democratic Republic. Likewise, the type against
covered bite among Bracco´s above-mentioned Turin appliances is still suitable for adults.
For courses, pre-fabs and documentation, see Addresses of manufacturers of custom-made Bimler appliances can also be obtained there.

Bimler C / progenic appliance (for class III cases)

5% of the European population have a more or less progenic bite. The Bimler C appliance, here viewed from above (find more in the case example), leaves for the tongue almost as much space as the above-mentioned FR 3 does, but is much less bulky in the cheeks and needs less of daily wearing time. In fact, daytime wear is only required at the beginning of the treatment.
By this, the Bimler C appliance allows an inexpensive longtime treatment which does not burden the patients, but is appropriate to the notorious persistence of progenic jaw growth. Similar to the before-mentioned lightweight back-shift plates, the Bimler C is equipped with a downward bow and with elements to widen nd stretch the upper jaw. Here, however, these are exclusively powered by jaw movements of the patients. Further, the Bimler-C screens the tongue from the lower front teeth, and the complete lower part can stepwisely be bent backward, if required.

Hangl´s Maxillator

Austrian appliance which unifies advantages of Karwetzky´s U-bow-activator in its lower part (simplicity, stability) and of Bimler appliances in the upper part (gentle lateral and forward expansion by „chewing gum effect“; open front = low speech hindrance).
The shown specimen bears additionally an adjustable lower lip bumper, to overcome a habit of lip sucking. Additional elements can be included if required. Those of the Bimler technique can be used in the upper part, whereas the lower part can be machined to allow e.g. in case of deep bite that the side teeth can grow in plane in a position where they match properly with the upper.

Stockfisch´s Kinetor

This old pioneer appliance is built from a pre-fabricated kit of replacable wire and tubing parts. It has a similar mode of action than the Bimlers, but is narrower inside. It stimulates chewing and demands moderate wear times (night + 2-3 hours per day). Jaw development can be influenced rapidly in 3 dimensions.

Sources of the images: see German version of this chapter