Procedure for a surgical palatal expansion
Surgical palatal expansion is only necessary if the growth plate in the middle of the upper jaw is already ossified. This is the case in adults. Therefore, surgical palatal expansion is not performed in children, since conventional therapy with a special apparatus is sufficient to generate a growth of 5mm.
The surgical procedure is performed by weakening the already ossified growth plate. This operation is performed minimally invasively under local anesthesia. Furthermore, another surgical route can be chosen, which is performed under intubation anesthesia.
This becomes necessary if a simple weakening is not sufficient. The upper jaw is surgically separated from the midface with the so-called LeFort 1- Osteotomy. An orthodontic appliance is inserted before the operation and the oral surgeon can expand it by a few millimeters after the operation by turning a screw.
The appliance, the so-called Hyrax screw, is also used in cases of palatal expansion without surgery. Distraction osteogenesis can be the treatment of choice if the teeth are not to be subjected to such force by the Hyrax screw. In this case, an orthodontic appliance is chosen which expands directly on the palate by means of screws and does not stress the teeth.
The so-called transpalatal distractor is inserted across the palatal suture and can enlarge the palate centrally and evenly in width. The transpalatal distractor and the Hyrax screw are worn for three to four months until sufficient widening is achieved and then removed. Regardless of which appliance is used, whether fixed or removable, the mechanism is always the same: The upper jaw is expanded piece by piece.
In the middle of the appliance there is a screw which is unscrewed by turning it with a key. This creates a force that creates movement. This force can cause pain and strong pressure, because the teeth do not know such a load.
Orthodontists therefore advise to take a painkiller before each new rotation and further application of force in order to better bear the pain, which is initially the greatest.However, the pain decreases constantly as soon as the movement is done, the teeth “get used” to the effort, so to speak. Therefore, after some time, pain relief will no longer be necessary, as the pain becomes bearable and quickly subsides. When using the Hyrax screw, there is always the risk of the teeth tilting.
By anchoring the screw to the first molars and the first premolars on both sides, tilting can always occur, since the complete force is transferred to the teeth. To counteract this problem, the transpalatal distractor is used. This distractor is not supported by the teeth, which protects the teeth, since it only exerts force on the palate and thus directly on the bone.
However, there is always the risk of recurrence with both appliances. As soon as the widening is completed and the appliances are removed, a receding movement may occur. 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 entire facial relations and which the patient must be aware of in advance. In principle, there is a risk that scarring remains or facial nerves are damaged during the operation and that a loss of sensation in facial areas occurs. Furthermore, anaesthesia always carries a risk with side effects. However, the complication rate during surgery is low.
