Palatal expander – a dental appliance for the roof of the mouth: types, prices and recommendations
Author: Dr. Raluca Bădulescu
November 20, 2025There are many types of orthodontic problems, and some of them simply cannot be resolved with traditional braces alone. Sometimes, there isn’t enough space for the teeth to align properly, the jaw is narrower than it should be, or the bite is incorrect. A disjunction appliance is a special orthodontic device that plays an important role in the harmonious development of your smile.
If you’re wondering, ‘What exactly is a disjunction appliance and why is it needed?’, we invite you to find out in this article how a disjunction appliance works and why it can be a lifesaver for children, teenagers and adults alike.
What is a dental separator and how does it work?
The palatal expander is a fixed orthodontic appliance, also known as a ‘palatal expander’. Its role is to widen the upper jaw and thus facilitate the treatment of orthodontic problems such as crowded teeth or malocclusions.
The maxillary disjunction appliance, consisting of two parts connected by a central screw placed on the roof of the mouth, is fixed to the upper jaw. This screw is the “engine” of the entire process.
When the screw is activated (usually daily, as directed by the dentist), it exerts a gentle, constant force on the midpalatal suture – the natural line that joins the two halves of the upper jaw. This slow separation process allows the bone to expand, thereby widening the upper jaw and creating more space for the teeth to align correctly.
Types of circuit breakers
There are two types of disjunctors: the maxillary disjunctor and the mandibular disjunctor.
Maxillary expander
The maxillary expander is used to expand the maxilla, with a view to correcting posterior crossbite, alleviating dental crowding and widening the floor of the nasal cavity to improve nasal airflow.
Early intervention for maxillary expansion is an effective approach to correcting dental crowding in the maxilla, resulting in a shorter treatment duration and significantly better results compared to orthodontic treatment started at a later stage.
Mandibular disjunction
The mandibular disjunction appliance is an orthodontic device used to correct orthodontic problems in the lower jaw, particularly when it is too narrow or misaligned.
By applying controlled forces, it helps to widen the lower dental arch and improve the bite.
Dental expanders in children vs adults
Malocclusions are a common orthodontic problem that can affect oral health and general well-being. For this reason, the timing of orthodontic treatment plays a crucial role in achieving the best results.
Thus, the patient’s age makes a major difference: what works excellently in childhood or adolescence no longer has the same effect in adulthood. The explanation is that the bone sutures surrounding the upper jaw fuse and calcify as we grow. Once these sutures have fused and are fully calcified, the upper jaw can only be widened surgically.
Therefore, it is recommended that treatment with disjunctors be carried out early. It is best to have an orthodontic assessment by the age of 8 to see if expansion or any early interceptive treatment is necessary to avoid problems. The most common age for treatment with a disjunctor is between 8 and approximately 15 years.
For adult treatment, surgery on the jaw will be required to expand it.
When is a circuit breaker recommended?
If there is a discrepancy between the size of the upper and lower jaws, treatment with a disjunctor is required. A narrow upper jaw can cause bite problems and affect physical appearance.
Expanding the upper jaw can have a positive long-term impact on your life.
The main benefits of using a maxillary disjunctor:
- Correction of severe malocclusions
- Improvement of mild to moderate dental crowding
- Improvement of airflow through the nasal cavity
- Correction of facial harmony
How much does a jaw joint replacement cost?
The recommendation to start treatment with a disjunction appliance can be made by a specialist in Orthodontics and Dentofacial Orthopaedics following a specialist consultation.
To establish a correct diagnosis, the orthodontist will use the results of digital investigations, such as X-rays and digital scans of the dental arches. Based on this information, the specialist will create a personalised treatment plan and determine the appropriate type of disjunction device.
The cost of the disjunction appliance will be determined based on the orthodontic condition requiring correction and the type of device recommended. At DENT ESTET, for orthodontic treatment in children, the medical team recommends a classic disjunction appliance, whilst a skeletal-anchored disjunction appliance is used for adult patients.
The price of a classic disjunction appliance is approximately 2,700 RON.
Frequently asked questions about the maxillary disarticulator
What is a dental separator and what is its purpose?
A dental expander is a fixed appliance placed on the roof of the mouth, used to widen the jaw in order to correct orthodontic problems (crowded teeth, malocclusions).
How does the maxillary disjunction work in children?
The palatal expander gradually widens the palatal suture through daily activation using a special key. By widening the jaw, space is created for the permanent teeth, thereby preventing the need for complex treatment during adolescence.
What is the difference between a maxillary disjunction and a mandibular disjunction?
The maxillary disjunction appliance is a fixed appliance on the upper jaw that opens the palatal suture, whilst the mandibular disjunction appliance is removable and widens the lower jaw.
What dental problems does a maxillary disjunctor correct?
Posterior reverse occlusion is corrected, dental crowding is resolved, airflow through the nasal cavity is improved, and facial aesthetics are enhanced. The first results can be seen within the first few weeks.
How do you clean braces on the roof of your mouth?
Maintaining good oral hygiene is essential. It is recommended that you brush thoroughly twice a day using a toothbrush and toothpaste. It is also advisable to use a mouthwash to remove food particles from hard-to-reach areas.
Bibliography
- Palatal expanders: what are they and how do they work, https://orthodonticsaustralia.org.au, 2024
- Raed Moussa, Maria T. O'Reilly, John M. Close - Long-term stability of rapid palatal expander treatment and edgewise mechanotherapy, 1995
- Andrew J. Haas - Palatal expansion: Just the beginning of dentofacial orthopaedics, www.ajodo.org
- M. Alam, R. Elbeshbeish, H. Abutayyem, M. Sghaireen - Effectiveness of Early Intervention with Palatal Expansion Versus Late Orthodontic Treatment for Correcting Maxillary Crowding, 2024