Common plate appliances (here for lower jaw)

These two similar appliances exemplify the formerly widespread „active plate appliance“. It was not just an „expander“ to gain space, but allowed for dental straightening almost at the same time – if constructed and handled properly! H = anchoring clasps, D = expansion screws (which in fact require growth to work properly), here even in 2 directions E = spring for a tooth correction, shaped according to the desired movement, S = labial arch (a common element).
Most of the following appliances are based on this, but developped further.
In the second specimen, the anchoring clasps at the rear are slightly simpler, but the front is equipped more generously with protrusion springs for tidying up crowded teeth.

Find examples of full treatments with plates in the „case examples“ chapter. Hints for distinctive applications of Crozat and plate appliances are there in the sub-chapter about classical Crozat treatment.

DNA appliance ® (no image or central link here)
means day- and nighttime appliance: for children, teenagers and adults, 12 - 16 /24h lead painlessly to success. DNA as well alludes to the theory behind it, the utilization of epigenetic jaw and arch development, including the nasal pathways, so that it cures also certain cases of snoring.

Wrong: how a blocked canine tooth was kept trapped

This is a typical example of a poorly designed plate appliance. Treatment started in late mixed dentition, where the gap for one of the cuspids (canine or eye teeth) had much narrowed. But instead of re-expanding it little by little, the positions of the adjacent teeth were retained by this plate.
Since it has the screw elements in wrong positions, it wasted 2 precious years of growth and made the case severe. An attempt to obtain a second opinion in time failed, because the visited orthodontist was one of those who make all patients first wait until all milk teeth are gone. This strategy aggravates all cases more or less, which increases the profit for the orthodontist as well as the pain and damage that the late treatment does to the patients. The patient here was menaced by a common package of orthodontic extortion: mutilating extractions, or headgear, or expensive, but hampering large fixed installations (pendulum, distal jet) - and each of these combined with fixed bracket braces.
The rarer specialists of gentle treatment offered mainly Crozat appliances (see below), which are however rarely covered by public health insurance.

Plate utilities: crossed wire fingers to close frontal gap; pro-loop

Interspaced incisors are not crooked in a medical sense. Nevertheless, these little gaps may waste space which will later lack for the larger canine teeth (eye teeth, cuspids).
Plate appliances for „gappers“ can be equipped with adjustable wire fingers to close up the teeth. If, moreover, an expansion screw is used, this can close up wire fingers by the same distance, if they are embedded crosswise in the halves of the plate, as shown here.
Screwed expansion also stretches and flattens a common frontal arch wire spring, as shown below. This is helpful if incisors stick out.
Against the opposite case, if incisors grow inward (retruded) of the arch line, plate appliances can be equipped with protrusion springs, either one by one (see above under „Common plate appliances“), or in the shape of an inner arch with loops.
In the specimen for interceptive treatment shown here, this element should stretch back when the plate is expanded. However, if it would also be embedded with crossed ends, then expanding the plate should bend it in the desired forward direction. Such a plate design, out of standard materials, may replace a specialized component: the robust, but sometimes bulky 3-way screw of Bertoni (see below, for T-segmented plate expanders).

Plate with additional clasps (Voss plate): expansion, distalization, vampire canine teeth

To develop a narrow jaw or a crowding of side teeth into a healthy situation by means of a plate, this appliance requires screwed segments in the right positions. Moreover, it needs sufficient anchorage for efficient force transmission. Additional clasps at both sides of the screw prevent the plate from lifting off when it is screwed onward, to avoid that it loses its proper fit and that most of its force falls flat.
In this sense, the first photo shows a typical vampire canine teeth (eye teeth, cuspids) situation. The narrowed gaps have already been re-gained. This appears to be a Y plate (see below) with additional clasps on the 2s and 4s here, and with guide wires for the cuspids which are now free to grow down.
The next photo shows a used plate expander with additional clasps on the 2s. It had expanded the maxilla by approximately 5 mm even in this stage with no more milk teeth left. Also the green specimen under Plates for one-sided expansion against single-sided crossbite has additional clasps.
The b/w photo shows a successful re-distalization of 3 teeth which had migrated forward. This plate has a further screw for simultaneous expansion, which was not used here. Teeth often move forward when milk teeth are destroyed before their successors are ripe, and narrow the gap as is exemplified in the sequence below: the gap for the canine tooth is narrowed to 1/3! Just 1 milk molar is left, but when it falls, it will provide another 2 mm of space.
2 wire elements support this plate in the incisor region. It successfully regained the lacking space by its backward screwed (distal) segment. It was provided with a lining of fresh plastic material during this, to re-establish the neat fit which generally degrades when screwed segments are used to greater extent. This treatment was accomplished by an activator which had additional guide elements for the growing cuspid as well as for the bicuspids which appeared rotated due to excess of space.

No lobby acts for proven and economic techniques like this one. In contrast, manufacturers of countless fixed distalizers and „bone piercing“ (micro-implantat anchorage) engage reputable speakers for courses to promote these risky and forced techniques, which endanger children as well as adults.

Y plates, Z plates, Bertoni plates

Due to their large roots, cuspids (canine oe eye teeth) are important teeth, but often develop later than both their neighbors. Space can lack for them in case of insufficient jaw growth or premature loss of milk teeth. Then they often grow off-site, mostly before, rarer behind the main row of teeth.
Treatment would be easier when not waiting so long.
Y and Z plates use 2 common screws to regain this space. Narrowed gaps can nicely be expanded by the plastic ends of the screwed segments. These have to be shortened little by little when the tooth grows in or is being aligned.
The Y-shaped segmentation of the colourful upper specimen causes expansion as well as stretching of the jaw. This is a light case, whereas the harder case in the mouth photo in vampire canine teeth above obviously also uses a Y or Z plate: screw elements inside of the narrowed gaps had already re-gained them by expansion and stretching.

The following specimens (yellow and violet-from-b/w) have their screws more distally placed. They finger into the cuspid position by a Z-shaped 3-segmentation of the plate. By their rather sagittal direction, the gap is opened mainly by stretching and distalization.
Y and Z plates differ less in the lower jaw (pink specimen). The screws can be placed more or less frontally there.

The indication for the Y plate overlaps with that of the more recent Bertoni screw (3-way-screw). The green plate shown below contains it, and moreover 2 distal screws, so that this plate has 5 segments! Nevertheless it is not bulky, and is even more versatile than a Y or Z plate to shape the dental arch.
In addition, it is equipped to derotate the canine teeth, which are rotated by narrowing, already while the space for them is under way to be recovered. Such details make the difference between high-value plates for removable treatment and plates which are just preparing for fixed braces. 3- or 4-way screw elements also exist for lower jaw plates.

Such plates as shown here were proven for treatment of children and, by taking some more time, also for teenagers. Nowadays, they fall into oblivion, irrespective that they offer a way out of the frequent bad business which is exemplified above under Wrong .. canine tooth had to stay trapped: only treatment with extractions or with a headgear was offered there, or sometimes with more expensive, hindering fixed appliances under the palate (Pendulum, Distal jet), or even piercing mini implants (micro screws, micro pins) through the flesh into the bone, which imposes a considerable risk of persistent bone inflammations to the patient.

Molar distalization by screwed segments: (pre-prosthetic) adult treatment; impacted canine teeth

A) Special element included: double screw with 2 independent segments in series:
The symmetrical blue plate contains this element on both sides. All 4 premolars lack in this adult upper jaw: 2 had been sacrified for orthodontic treatment long ago, and 2 were destroyed more recently. These latter should now be replaced, but the molar teeth have already migrated forward and narrowed the gaps too much. Therefore, the screwed segments should recover sufficient gaps. The enlarged image with the red arrows shows that the front segment is to shift towards the fixed position of the screw heads, while the rear segment is to shift away from it. A jagged anchor for this long element can be seen embedded in the plastic behind the incisors.

B) 2 small standard expansion screws, aligned in series: In the next, 25-yr case, the canine teeth stayed impacted in the jawbone.
Sufficient space was created for them with the violet distal plate shown here and a subsequent one, by pushing teeth forward and others backward. The big molar teeth had to be pushed individually, each with its own screwed segment of the plate, 1 on the right and 2 on the left hand side here. Thus, the second-but-last molar can be shifted individually, if the more frontal screw is opened and the rear screw closed by the same amount.
After enough space was provided, one canine tooth grew in by itself, whereas the other had to be cut free and pulled out slowly, by glueing a hook to it and connecting it with a rubber band to a corresponding hook at the appliance. A formerly common procedure, to which Crozat appliances (see below) are also suitable.

The lower plate shown on the right side is similarly built, to help the canine tooth out of crowding. Photos from top to bottom are taken for illustration (in treatment, both segments should rather be alternated in smaller steps):
1) at start, no length expansion
2) rear segment length expanded (distalize molars 6 and 7)
3) middle segment length expanded, rear segment equivalently re-contracted (push back 4 and 5 and shift a frontal wire along which contacts the canine).
For better guidance, these both segments have plastic-fitted clasps.

Crozat appliances

are the oldest system of removable braces, invented and developped to mastery in the 1920ies, before plastic era. Wire elements of different thicknesses were soldered together to light, hygienic appliances which are well-suited for full-time wear, in particular for adult and pre-prosthetic treatment, and if teeth or gums have already damages.
Experts performed full treatments with these appliances, not restricted to simple cases, since they can widen and lengthen the arches and correct individual teeth. A limited expansion of the upper jaw is still possible in adults – slowly, but with these appliances with little discomfort.

Inspite of all the orthodontic „late cases“ (= teenagers and adults), this gentle and proven method is hardly reported anywhere in the mass media.
Rather, orthodontic implants are systematically disseminated in congress-filling manner as a high-profit invasive technique, but endanger the patient with persistent bone inflammations (see below under „Less discomfortable additives..“ for more about it).
Find Crozat cases and details of this method in the „case examples“ chapter.

Hybrid type and upgraded Crozats

Hybrids between Crozat and plate appliances can be built economically from common materials without soldering or welding. E.g. the blue lightweight spring expander in the upper photo. There, small plastic wings bear common clasps (anchors) and are connected by a thicker wire spring. Even prefabricated parts which are intended for fixed use (lingual arch, palatal bar, quad helix ...) could be adapted for this, to make their use friendlier.

Normal Crozats have just 2 clasps, which are in the molar region. Because they were originally intended to give teeth just stimuli in the desired directions, and to leave them otherwise free to find their anatomically functional positions. Of course, Crozats can be built with more clasps, but that could hamper this original intention. In some cases it cannot be foreseen if 2 clasps would be enough. The lower photo shows an upgraded Crozat. Before, its anchorage had turned out to be insufficient. Occlusal extensions were also desired to treat a crossbite. They were added out of plastic material, and additional clasps embedded in them.

Lightweight expanders with screw or spring instead of quadhelix or other fixed expanders

Removable expanders can be built such that they do not hinder speech, because leaving the frontal palate free, and that they are little visible when worn. In the upper specimen, plastic snaps over the side teeth instead of clasps. This is also suited for slow expansion in permanent dentition (upper jaw still expandable up to 4-6 mm). It could also be made by thermoforming of plastic sheet. For children whose side teeth are changing, on the other hand, ordinary clasps are preferable.

Continuous force can either be provided by a screw with an included spring, which is a specialized part, or by simple wire loops in spring expanders as shown below with various clasps. The strength or thickness of their spring can be varied, and also the position where it leaves the plastic wings. For details on this, also for the lower jaw, see Lightweight prototypes chapter.
Even more than 4 -5 mm width can be gained in children by removable expanders, with no need of splitting the palatal suture, fixed quad helix or other cruel treatment. Such widespread forced methods neclect loving care (find victims´ reports in the „Less disturbing kinds“-chapter), but are favoured by orthodontic manufacturers of many profitable prefabricated parts. These force the dentitions of individual humans into uniform shape.

If the molars are too conical or not yet fully erupted, so that these appliances fit too loosely, then tiny white attachments could be glued to them, which are now widespread in aligner orthodontics. In contrast to bands or brackets, they neither hurt the flesh, nor hamper cleaning these teeth far inside the mouth. The appliance would snap in firmly on these attachments, like an aligner splint (see below).

Plates for single-sided expansion (indeed!)

with an approximate force distribution of 2/3 to 1/3, to correct a one-sided crossbite that has already grown-in. For one-sided crossbite in early state (muscular crossbite), a simple expansion plate would often be sufficient (force distribution of 1/2 to 1/2).
A solution from old literature, the 1/4 – 3/4 divided activator (double decker appliance), would be larger scale. The fixed, pre-fabricated quad helix, in contrast, disturbs swallowing, speech and chewing (see examples in the „less disturbing kinds...“ chapter). Moreover, it has more relapses than expansion plates have.

Both specimens shown here are asymmetrically divided.
The green belonged to a 8-yr girl who was menaced with rapid palatal expansion (RPE) elsewhere. To unlock the wrong occlusion, this plate extends over the side teeth. Additional clasps assure a good grip, and the large expansion screw bears an included spring to deliver a continuous force. Simultaneously, 3 protrusion springs are to widen the frontal arch, and a finger spring is to re-gain the narrowed space for a growing canine tooth.
The yellow specimen, which could also be equipped with further elements, has a simple, big expansion screw and another solution for a more continuous force delivery: the contact zone to the teeth which are in crossbite consists of silicone rubber.

Plate with spring bolt screws

By use of a reamer, the tiny spring-bolt screws can be inserted later into a plate appliance, e.g. if changing teeth appear too much inward.
In the example here, a young cleft-palate patient with 45° twisted incisors profits from skillful removable treatment. The screws act from inside and the frontal wire from outside to untwist these teeth. Note also that the expansion screw is already expanded by about 5 mm!
In the following picture, the left one of the frontal screws has been re-inserted, to re-adapt its direction to the proceeding alignment.

This example demonstrates that even a cleft-palate child is not condemned to palatal splitting and other painful fixed stuff, if the treatment is continuous.
Find more details in the „expl. of cases“ chapter.

Plates equipped with silicone rubber for „complicated“ tooth correction

If sufficient space has been provided, this rational technique can correct teeth which are in the row but nevertheless not straight, that means tilted (around 3 axes possible).
This appliance is mainly a plate, with a rigid body and clasps (and screws would also be possible). It should provide a framework around those (tilted) teeth which are to align. On the plaster model, these are then cut out and re-fixed in aligned positions (setup / aligner techniques). Silicone rubber is molded around them onto the outer framework and the distant inner plate border.

Such plates are smaller than the common elastic „positioners“, which are mainly used when fixed braces gave no good result, but can also be applied independently.
Moreover, such a plate would allow larger alignments / untwistings by modification: stepwise alignment of the plaster model and subsequent renewal of just the silicone rubber parts, which is easy.

2 more examples for silicone rubber bearing plates and splints: 1 fine and 1 wide alignment by W. Paulus.

Less discomfortable additives for fixed braces

Many add-on parts for US style multibracket techniques pay little attention to patient comfort, because the patient, especially if a child, has no other choice anyway. In addition, they hamper oral hygiene.
Later on, the profitable international orthodontic business began to spread further orthodontic armament in form of little mini implants (mini pin, micro screw, mini screw, ...), which are pierced through the flesh into the bone, for all type of better fixation of fixed braces. Since they create a highway for bacteria into the bone, where inflammations are difficult to cure, their unneccessary use endangers adults and children. In contrast, they are completely useless for removable techniques! But nevertheless, removables have largely been abandonned.

Solutions with less discomfort or danger are obvious to those who are familiar with removable techniques. For single jaw treatment, no functional, but just plate appliance technique can already help a lot. The images show a speech-friendly, frontally open design of such an add-on plate, and 2 solutions to snap it in: silicone rubber to fixed buttons, or ball head clasps and outer grips for removal. Common orthodontic tasks to apply it:
-Maintain jaw width or position of last molars: simple blank plate to wear at night or part-time. Instead of head gear, lip bumper, nance appliance, palatal arch or other disturbing stuff.
-Expansion: screw, fan screw or spring expander (find more about this under Lightweight prototypes). Instead of quad helix or splitting the palatal suture (for these, see victims´ reports in the „less disturbing kinds of braces“ chapter).
-Protrusion of incisors: plate with protrusion springs / screws instead of disturbing lingual arches.
-Distalization (backward shift) of molars: segmented plate with distal screws, instead of headgear, lip bumper, pendulum, distal-jet or other fixed instruments.

Concerning bite correction and vertical deviations (deep bite, open bite), prefabricated functional trainers are available, also such which are compatible with multibracket appliances (T4B = trainer for braces).
1) Class II overjet, also with increased overbite (deep bite), can be corrected by sustained use of such trainers for 1 – 3 years, instead of hampering Herbst appliances or other bulky, unhygienic fixed parts.
2) More rapidly, a covered or deep bite can be levelled out painlessly. The required vertical forces are easily provided by biting on the trainer, instead of fixed bite blocks which extremely hamper any mastication (and subsequent digestion).
Apart from the T4B, which resembles the Muscle force Jaw shaper in shape (find instructions under Kaukraft Kiefer-Former), but has grooves for fixed braces, a thicker fixed-compatible trainer for covered bite is available. In contrast, the covered-bite type of the Jaw shaper allows the patient to keep an arch shape which is somewhat more tapering than standard.

Lower exterior plate (buccal plate), e.g. for gap closure of a missing tooth

This appliance wears comfortably because without plastic parts inside. It is described in literature only for the lower jaw and has advantage for straightening inward tilted teeth and for gap closure with a traction screw. E.g. for those 5% of people whose premolars in position 5-below are not formed, if their respective milk molars could not be preserved. The coloured specimen is for demonstration.
Even nowadays it is told with commercial interest that this task would require fixed braces to perform properly. But look in the case reports for successful removable treatments of such gaps. Spontaneous gap narrowing by forward migration of the molars should be allowed before fitting an appliance. Moderate speed when screwing or light force when using springs (also Crozat appliances would work here) are crucial for a tilt-free gap closure.

The monochrome views show a specimen with an additional space creating screw between the crowded tooth 5 and 6 here on the right, and a traction screw to close a little gap on the opposite site.
A further application would be the contraction of the lower front e.g. if it had been expanded by tongue habits. With a frontal traction screw, and with elastic silicone joints in the canine region, such an appliance would contract the front, but not the whole arch.

Extrusion (elongation) of teeth / use of „shelves“ (tiny attachments)

To close an open bite after growth has finished, and if it has not just developped by muscular imbalance, the respective teeth need grips to apply a force in extruding direction (the image shows a dummy). But no need to make the grips broader than required to pose a spring wire on them. Such tiny, tooth-coloured „attachments“ do not irritate, nor hamper cleaning. They are common in active splint treatment (see below), for teeth which can otherwise not be grabbed sufficiently to direct the desired force to them.
Here, the attachments give a grip to the surrounding spring of a speech-friendly constructed open plate, so that its extrusion force can be transmitted. This principle can be transferred to extrude side teeth if required, and the plate can bear further elements e.g. an expansion screw. Compare with the discomfort of a common extrusion method: rubber bands stretched between brackets or buttons in upper and lower jaw.
Attachments can also be used to improve anchoring clasps in difficult cases e.g. when teeth are not fully erupted.

Intrusion (= pressing too long teeth more into the bone)

The specimen shown here is intended for rather „cosmetic“ intrusion of the incisors. More often, re-intrusion of single side teeth which have grown too long is required medically in pre-prosthetic treatment. Here, removable appliances are hygienic, especially for patients who have gum disease.
Intrusion plates need good anchorage at all other teeth, or extensions which allow to transmit the force of biting down just to the teeth which should be intruded. When anchoring teeth lack, also in children who lost many milk teeth at once, one-piece appliances could be a better choice, e.g. prefabricated trainers like the Muscle force Jaw shaper (see Kaukraft Kiefer-Former).

Active orthodontic splints, e.g. Invisalign or hand-crafted aligners

are rather for permanent dentition and are continuously developped further. They are no budget method, but comparison of their price between several systems often pays, or even between doctors offering the same system.
A set of many thin transparent aligner splints is generated, each of which is some 0.2 mm correcter than the previous. Adults should wear each aligner full-time for 2 weeks. Part-time wear will prolong the treatment, but may be straightforward for teenagers.
Some gain of space for crowded teeth is possible by narrowing (stripping, slicing) the teeth, as has been done in this example. In cases of open bite, little tooth-coloured attachments can be included, similar as in Extrusion (elongation) of teeth.
A combination of hard and softer splint materials can be helpful, because under continuous force, orthodontic movements proceed rapidly in the first 14 days and then slow down because the surrounding tissue exhausts. Certain dental laboratories provide hard-and-soft either as compound aligners, or as hard and soft aligners to wear in turns. Both would improve the recovery of the surrounding tissue from orthodontic strain, and thus make the treatment more comfortable and nevertheless fast.

See link list (in German) under „ALIGNER (Korrekturschienen)“ for recommendable international suppliers.

Plate with tongue attracting element

Tongue malfunctions can cause teeth / jaw disorders. Speech training can help more or less. The most violent method of tongue correction are fixed spikes!
In sharp contrast, this „comfortable-feeling“ appliance mimicks the morphology of the frontal palate by thin silicone rubber, to give the tongue an almost natural surrounding around a little hole, which is placed to attract the tip of the tongue to its correct position.
Such a plate could perform further development and alignment at the same time, e.g. with screws. If the incisors were tilted forward („protruded“) by tongue thrusting, they can be pushed back by tightening the frontal arch wire. For this, the rim of the plate has to be shortened there, of course.
From old text Headgear Plate: attaching a headgear to a removable plate spreads its heavy force much wider than the usual fixation to the first molars, which are menaced with root damage then (pain is always a warning!). Besides, some kinds of coupled plates or function regulators have similar effect as the headgear, but offer additional features for further tasks. Be aware that the headgear is historically old and primitive.