A palate expander is an orthodontic device used to widen the upper jaw (maxilla) by applying continuous pressure to the palate. This pressure is intended to separate the two halves of the upper jawbone. While most commonly used in children whose bones are still growing, palate expansion is a viable field in adult orthodontics. Achieving skeletal widening in a fully matured jaw requires specialized techniques, as the biological challenges are fundamentally different from pediatric cases.
Why Adult Palate Expansion Requires Specialized Techniques
The fundamental difference between a child’s jaw and an adult’s jaw lies in the midpalatal suture, the joint running down the center of the roof of the mouth. In children, this suture is flexible connective tissue, allowing a traditional expander to easily separate the maxilla, resulting in true skeletal expansion.
In adults, the midpalatal suture is fully fused through ossification, creating a significant barrier resistant to orthopedic expansion forces. If a traditional, tooth-supported expander is used on a skeletally mature adult, the force is usually insufficient to separate the bone.
Instead of skeletal widening, the force often pushes the teeth outward, a movement known as dental tipping. This tipping is an undesirable side effect that can damage the teeth and surrounding tissues without correcting the underlying narrow jaw problem. To achieve true skeletal expansion in an adult, the treatment must overcome the fused suture and bony resistance.
Surgical and Non-Surgical Expansion Methods
Because the goal is to separate the fused maxilla, adult treatment options are divided into approaches that either mechanically weaken the bony resistance or apply force directly to the bone. The first major approach is Surgically Assisted Rapid Palatal Expansion (SARPE), typically reserved for older adults or those requiring significant expansion. This procedure involves a surgeon performing minor osteotomies (bone cuts) around the maxilla, including the fused midpalatal suture.
The surgical cuts weaken the bony resistance, allowing a conventional, tooth-supported expander to separate the maxilla skeletally over several weeks. While it is a more invasive procedure, SARPE is a predictable method for achieving significant skeletal expansion in mature jaws. After surgery, the patient activates the expander daily, and new bone growth fills the resulting gap.
A less invasive alternative is the use of bone-anchored expanders, often referred to as Miniscrew-Assisted Rapid Palatal Expansion (MARPE) or Maxillary Skeletal Expanders (MSE). These techniques utilize Temporary Anchorage Devices (TADs)—small titanium screws anchored directly into the palatal bone. The expander attaches to these screws, delivering the expansion force directly to the bone and bypassing the teeth entirely.
By applying force directly to the bone, MARPE/MSE can sometimes successfully open the midpalatal suture without requiring the more extensive osteotomies of SARPE. This technique is often effective in younger adults whose sutures may not be as densely fused. Direct skeletal anchorage minimizes the risk of dental tipping and focuses the force on achieving true orthopedic widening.
Expected Outcomes and Treatment Duration
Adult palate expansion primarily corrects a transverse maxillary deficiency (a narrow upper jaw). The most common result is correcting a posterior crossbite, where the upper back teeth bite inside the lower back teeth. Widening the arch also creates space, which can alleviate dental crowding and potentially prevent the need for tooth extractions during subsequent orthodontic treatment.
Another outcome is the potential improvement in nasal breathing. Since the floor of the nasal cavity is the roof of the mouth, widening the maxilla can increase the volume of the nasal airway. This can help patients who struggle with chronic mouth breathing or snoring. The maximum width depends on the individual’s anatomy, but both SARPE and MARPE aim for stable, functional expansion.
Adult expansion involves distinct phases spanning many months. The active expansion phase, where the patient turns the device, usually takes three to six months, though SARPE can be shorter due to surgical assistance. Following active widening, a retention phase begins. The expander is kept in place to stabilize the new width while new bone fills the gap created in the suture.
This retention period typically lasts an additional four to six months to ensure the skeletal change is stable before appliance removal. Once the maxilla is widened and stabilized, the patient enters the final stage of comprehensive orthodontic treatment. This involves using braces or clear aligners to align the teeth within the newly expanded arch, a process that often takes an additional six months to two years.