Palate Expansion - You Should Know That!
definition
A palatal dilation is an orthodontic treatment that stimulates the growth of the upper jaw when the upper jaw is too narrow. The palate is the fusion of two bones that are connected in the middle by a natural growth plate. If the development of the upper jaw is disturbed, the growth of the upper jaw stops while the lower jaw continues to grow. The result is that the upper jaw is too narrow, the teeth are poorly interlocked and the upper jaw teeth have far too little space.
Orthodontics is now trying to stimulate the expansion of the width of the upper jaw again by expanding the palate. In children, the advantage here is that the growth plate in the middle of the upper jaw is not yet completely ossified and thus enables movement and growth in a relatively short period of time.
Why is a palatal expansion necessary?
A too narrow upper jaw due to a lack of growth is not only a dental problem. The patient can experience severe discomfort when breathing through the nose, as the palate is the bottom of the nose and the lack of growth makes breathing difficult. The nasal airways are simply narrowed by the smaller upper jaw, so that hardly any air can pass through.
A crowding in the upper jaw can arise as there is not enough space for the permanent teeth due to the narrow shape. The teeth are often nested and can tilt in different directions.
Furthermore, it can happen that the lower jaw teeth exceed the upper jaw teeth due to their further growth. Then either a head bite occurs, in which the cusps of the upper and lower teeth stand on one another and do not interlock, or a cross bite. The crossbite describes the condition when the lower jaw teeth are further out than the upper jaw teeth, which are supposed to be.
Upper anterior teeth that are strongly directed forward can also arise from the growth of the lower jaw and the lack of upper jaw growth when the lower anterior teeth push the upper anterior teeth forward and upward through the growth movement.
All of the reasons mentioned are indications for a palatal expansion.
Sequence of an operative palatal expansion
Surgical expansion of the palate is only necessary if the growth plate in the middle of the upper jaw is already ossified. This is the case with adults. Therefore, surgical expansion of the palate is not performed in children, as conventional therapy with a special device is sufficient to generate a growth of 5mm.
The procedure for the surgical treatment is carried out by weakening the already ossified growth plate. This operation is performed in a minimally invasive manner under local anesthesia.
Another surgical method can also be selected, which is performed under intubation anesthesia. This becomes necessary when a simple weakening is not enough. The upper jaw is surgically separated from the midface with the so-called LeFort 1 osteotomy.
An orthodontic appliance is used before the operation and the oral surgeon can stretch it by a few millimeters after the operation by turning a screw. The apparatus, the so-called Hyrax - Screw is also used in cases of palatal expansion without surgical intervention.
If the teeth are not expected to be subjected to so much force from the Hyrax screw, distraction osteogenesis can be the treatment of choice. An orthodontic appliance is chosen that expands directly on the palate with screws and does not stress the teeth.
The so-called transpalatal distractor is inserted across the palatal suture and can expand the width of the palate evenly and centrally. The transpalatal distractor and the Hyrax screw are worn for three to four months until sufficient widening is achieved and then removed.
Pain with palatal expansion
Regardless of the appliance, whether fixed or removable, the mechanism is always the same: the upper jaw is expanded bit by bit.
In the middle of the apparatus there is a screw that is unscrewed by turning it with a key. This creates a force that creates a movement. This force can cause pain and strong pressure, since the teeth are not exposed to such a load.
Orthodontists therefore recommend taking a pain reliever before each new rotation and further force exertion in order to better endure the pain that is initially greatest. The pain is constantly decreasing as soon as the movement has taken place, the teeth “get used” to the effort, so to speak. Therefore, after a while, pain relief will no longer be necessary, as the pain becomes bearable and quickly recedes.
What are the risks?
When using the Hyrax screw there is always the risk of the teeth tilting. Due to the anchoring to the first molars and the first premolars on both sides, tilting can always occur, as the entire force is transferred to the teeth.
The transpalatal distractor is used to counteract this problem. This is not supported dentally, which is gentle on the teeth, since it only exerts force on the palate and thus directly on the bone. With both devices, however, there is always the risk of recurrence. Backward movement may occur once the widening is complete and the appliances are removed. However, this risk is higher in percentage terms with the Hyrax screw than with distraction osteogenesis.
Furthermore, it should not be ignored that the patient looks different after the treatment. The upper jaw becomes wider, which changes the overall face relations and what the patient must be aware of in advance.
In the case of surgical expansion of the palate, there is a general risk that scarring will remain or that facial nerves will be damaged during the operation and that there will be a loss of sensation in facial areas. Furthermore, the anesthesia always carries a risk with side effects. However, the complication rate in the operations is low.
What is a palatal dilation appliance?
The palatal expansion device is a synonym for a Hyrax screw as an orthodontic device, which helps to expand the upper jaw. The Hyrax screw consists of a screw that is placed in the middle of the palatal suture. Four “little arms” go from this screw to the teeth and are attached with cast clips either to the molars and all premolars or to just one premolar on each side.
By turning the screw with a wrench, the screw is expanded and the four arms of the appliance are moved away from the roof of the mouth. This causes the teeth to move outwards and the upper jaw is stimulated to form new jaws.
Another form of the palatal expansion appliance is the quadhelix, which is located in the palate area, similar to the Hyrax screw. There is no screw in the center of the growth plate, but four loops that give the device its name. Furthermore, with the Quadhelix there is a wire bracket on the palate side of each tooth that is to be moved. The quadhelix is fixed by banding the first two molars.
Both palatal expanders (with Hyrax or Quadhelix) belong to the range of removable braces.
Read more about this under: Loose braces
Another variant of the palatal expansion device is the transpalatal distractor, which is only inserted directly on the palate and does not touch the teeth. It is anchored directly in the bone and is therefore not removable.
Reasons for a palatal expansion
But what causes the missing upper jaw growth? The factors for this are different.
- The largest proportion is due to excessive use of non-physiological pacifiers and feeding bottles. A too large attachment or too long use can cause the growth disturbance.
- A third of stunted growth are genetic and arise without any malfunction.
- Another cause is thumb sucking. By constantly sucking and pulling on a finger, the growth of the upper jaw is inhibited and the teeth and palate are misaligned.
- Furthermore, restricted nasal breathing and thus constant mouth breathing can also be a cause.
- Incorrect swallowing pattern: Swallowing is a complex process involving many muscles.
As the milk teeth erupt, the child's swallowing pattern usually changes in such a way that the tongue presses against the roof of the mouth.
If no contact is made with the palate due to incorrect swallowing, the growth stimulus on the upper jaw is missing and it lags behind in growth.
Is that still possible with adults?
In principle, palatal expansion is also possible in adults, but it is more difficult and protracted than in children, in whom growth has not yet ended.
In adults, the growth plate in the middle of the upper jaw, the so-called sutura palatina mediana, is already ossified. Therefore, this must first be surgically weakened to enable movement of the upper jaw and thus a widening.
If the weakening alone is not sufficient, a LeFort 1 osteotomy is connected and the upper jaw is widened with a Hyrax screw. Furthermore, the osteotomy can also be combined with a distraction screw if the maxillary teeth are not to be subjected to so much stress.
What alternative to palatal expansion is there?
There are hardly any alternatives to palatal expansion, as the concept always leads to the target model by widening the upper jaw. A removable appliance can be used to expand the palate, but this only works in children who have not yet completed their growth. As a result, surgical expansion of the palate is hardly necessary in children.
Furthermore, the fixed palatal expansion device is the most frequently used variant, which achieves success in a very short time and also, combined with the surgical weakening of the growth plate in the adult dentition, also achieves a positive therapeutic result. Treatment in adults usually takes longer due to the surgical component.
Cost of palatal expansion
The costs for a palatal expansion depend on the individual case, the size of the deficit and the planned therapy.
While children can usually only be treated with removable equipment, with therapy costing around 500 to 1000 euros, adult treatment with surgery can exceed 5000 euros. Since orthodontics is a purely private service for adults, it is usually only half as expensive for children and adolescents up to the age of 18 or is covered entirely by health insurance.
For an exact cost clarification, you should consult the treating orthodontist and the health insurance company, who will usually prepare a cost estimate.
What changes in the face can be expected?
Widening the palate changes the face and the individual proportions, but the changes are often hardly visible to other people. The widening of the upper jaw causes the mouth and the lip area to appear wider, and the smile also appears wider. Furthermore, the bottom of the nose is also widened, which can enlarge the nose vertically.
