Palatal widening, also known as maxillary expansion, is a common orthodontic procedure designed to correct an upper jaw that is too narrow for the rest of the facial structure. The goal is to create adequate space within the upper arch, the bone structure housing the upper teeth and forming the roof of the mouth. This process aims to bring the upper and lower jaws into proper alignment, ensuring the teeth fit together correctly. Successful expansion improves dental function and contributes to better overall health.
Symptoms Requiring Palate Widening
A narrow upper jaw manifests through several noticeable signs that often prompt expansion therapy. One frequent indicator is dental crowding, where insufficient arch space causes permanent teeth to overlap or become impacted, leading to misalignment. Another common sign is a posterior crossbite, where the upper back teeth bite inside the lower back teeth instead of slightly outside them. This improper bite relationship can cause uneven wear on tooth surfaces and lead to jaw joint discomfort. Furthermore, a constricted palate can compromise the nasal passage above it, contributing to functional issues like habitual mouth breathing, snoring, or other sleep-related breathing disorders.
Non-Surgical Expansion in Children
Palatal expansion is easiest and most effective when performed in growing patients, generally between the ages of seven and fourteen. This is because the maxilla, or upper jaw, is formed of two halves joined by the midpalatal suture. In children, this fibrous suture is not yet fully fused, making the bone structure pliable and responsive to orthopedic force.
The standard appliance is a Rapid Palatal Expander (RPE), a fixed device cemented to the upper back teeth. The RPE contains a central screw mechanism that the patient or guardian activates daily using a small key. Each turn applies gentle, continuous pressure across the two halves of the upper jaw, gradually separating the suture.
The active expansion phase usually lasts only a few weeks, depending on the required width increase. A visible sign that the expansion is working is the formation of a temporary gap between the upper front teeth, indicating skeletal separation. Once the necessary expansion is achieved, the device is left in place without further activation to stabilize the new bone position.
Surgical and Advanced Expansion in Adults
In older adolescents and adults, the midpalatal suture has fully fused and mineralized, creating a rigid, single bone structure. Attempting expansion with a traditional RPE on a fused palate would primarily result in the tipping of the anchor teeth rather than true skeletal widening. Therefore, expansion requires different, more complex techniques to overcome the resistance of the mature bone.
One established method is Surgically Assisted Rapid Palatal Expansion (SARPE), a procedure combining orthodontics with oral surgery. An oral surgeon performs small cuts, called osteotomies, in the surrounding bones of the maxilla to surgically weaken resistance points. Immediately following the surgery, a fixed expander is activated over several weeks to achieve the desired widening.
A less invasive alternative is Micro-implant Assisted Rapid Palatal Expansion (MARPE), which avoids major surgery. This technique utilizes an expander anchored directly to the palatal bone using temporary anchorage devices (TADs), or miniscrews. By anchoring directly into the skeleton, MARPE can apply the necessary force to open the fused suture, making it a viable non-surgical option for many young adults.
The Retention Phase and Long-Term Results
Once the active phase of widening is complete, the process transitions into a retention phase to ensure the stability of the new jaw position. The active expander is secured, often by tying off the central screw, and remains in the mouth as a passive retainer for several months. This period allows the body to fill the newly created space at the midpalatal suture with new bone tissue, a process called distraction osteogenesis.
The passive retention phase typically lasts between three and six months, providing sufficient time for the new bone to mineralize and solidify the expansion. Without this stabilization period, the maxilla would be prone to relapse, moving back toward its original, narrow position. After the fixed retainer is removed, patients transition to a removable retainer, which must be worn long-term to prevent the gradual return of crowding or bite issues.
Successful palatal widening provides several long-term benefits beyond simply straightening teeth. The expansion creates a broader, more stable dental arch, which is less likely to suffer from relapse than arches corrected solely through tooth movement. Widening the palate also increases the width of the floor of the nasal cavity, promoting improved nasal airflow and supporting healthier breathing patterns.