What is Rapid Maxillary Expansion?

Rapid Maxillary Expansion (RME), is an orthodontic technique designed to widen the upper jaw when it’s too narrow. This procedure is particularly beneficial for children and adolescents whose upper jaw hasn’t fully developed or has grown disproportionately compared to the lower jaw.

The primary goal of RME is to create more space in the upper dental arch, which can address a variety of orthodontic issues. Unlike traditional orthodontic treatments that focus solely on moving teeth, RME works on the skeletal level, actually modifying the structure of the upper jaw itself.

The process involves using a special orthodontic appliance called an expander. This device is custom made for each patient and is fixed to the upper molars. It cannot be removed by the patient, ensuring consistent treatment. The expander applies gentle, constant pressure to gradually separate the two halves of the upper jawbone, which are naturally divided by a suture in the middle of the palate.

As the name suggests, this expansion happens relatively quickly – typically over a few weeks to months. During this time, new bone forms in the gap created by the expansion, effectively widening the upper jaw. This newly created space allows for better alignment of teeth and can improve the overall bite structure.

It’s important to note that RME is not just about creating a wider smile. The benefits of this treatment can extend beyond aesthetics, potentially improving breathing, speech, and even facial symmetry. As we look deeper into this topic, we’ll explore these benefits in more detail, helping you understand why orthodontists might recommend this treatment for certain patients.

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The Implications of a Smaller Upper Jaw

While some might overlook a minor deviation in jaw size, particularly in young children, a smaller upper jaw could lead to significant problems later in life.

These potential issues include:

• Misalignment of the jaw, leading to speech and chewing difficulties.
• Increased probability of teeth crowding and misalignment, necessitating orthodontic intervention.
• Greater wear and tear on teeth due to deviation in the lower jaw.
• Damage to the surrounding tissue supporting the teeth.
• A higher risk of temporal mandibular joint dysfunction.

The primary objective of RME is to prevent these complications from arising.

Science Behind Rapid Maxillary Expansion

To fully understand the effectiveness of Rapid Maxillary Expansion, it is crucial to understand the science that underpins this orthodontic technique. RME capitalises on the unique structure of the upper jaw and the natural growth processes of the human body.

The upper jaw, or maxilla, is actually composed of two separate bones that meet in the middle of the palate. This meeting point is called the mid palatal suture. In children and young adolescents, this suture hasn’t yet fused, allowing for some flexibility in the structure of the upper jaw. RME takes advantage of this natural separation to achieve its goals.

When an orthodontist applies an expander device, it exerts a controlled force on the teeth and palate. This force is significantly stronger than what’s used in traditional orthodontic treatments. While conventional braces might use forces between 12-150 grams, an RME appliance can apply forces ranging from 900 to 4500 grams. This substantial force is necessary to overcome the resistance of the facial bones and actually separate the two halves of the maxilla.

As the expander is activated (usually through regular adjustments made at home), it gradually pushes the two halves of the maxilla apart. This separation triggers a biological process known as distraction osteogenesis. In simple terms, this means that as the bones are pulled apart, the body responds by creating new bone to fill the gap.

The process of bone formation in RME occurs in three stages:

• Latency Phase
  This is the initial period after the expander is activated. During this time, the body begins to respond to the applied force, but no visible changes occur yet.
• Active Distraction Phase
  This is when the actual separation of the maxillary bones occurs. New bone begins to form in the widening gap.
• Consolidation Phase
  After the desired expansion is achieved, the appliance is left in place to allow the newly formed bone to mature and stabilise.

It’s worth noting that the expansion achieved through the appliance is not a one to one ratio with the actual skeletal expansion. Typically, for every 3mm of expansion in the appliance, about 1mm of skeletal expansion is achieved. This is due to the resistance offered by the surrounding facial structures.

Understanding this science helps explain why RME is most effective in younger patients. As individuals age, the mid palatal suture begins to close and interlock, making it more resistant to expansion. This is why orthodontists often recommend early intervention when RME is deemed necessary.

When Rapid Maxillary Expansion is Recommended

Rapid Maxillary Expansion is an orthodontic procedure that may not be appropriate for every patient. Orthodontists evaluate multiple factors before recommending RME. Recognising these indications can assist patients and parents in understanding why this treatment may be recommended in specific situations.

Crossbite Correction
One of the primary indications for RME is the presence of a posterior crossbite. This occurs when the upper back teeth sit inside the lower back teeth when biting down. A crossbite can lead to asymmetrical jaw growth if left untreated, potentially causing facial asymmetry and functional issues.

RME effectively widens the upper jaw, allowing the upper teeth to properly align with the lower teeth. This not only improves the bite but can also prevent long term complications associated with crossbites.

Crowding and Space Creation
In cases where there’s significant crowding in the upper arch, RME can be an effective solution. By widening the upper jaw, RME creates additional space for teeth to align properly. This can sometimes reduce or eliminate the need for tooth extractions in orthodontic treatment plans.

The extra space created by RME can be particularly beneficial when planning for the eruption of permanent teeth in growing children. It provides room for these teeth to come in more naturally aligned, potentially simplifying future orthodontic work.

Breathing Improvements
Interestingly, RME can have positive effects on breathing. A narrow upper jaw can sometimes contribute to restricted nasal airways. By widening the upper jaw, RME can indirectly expand the nasal cavity, potentially improving nasal breathing.

This aspect of RME has garnered attention in recent years, especially in discussions about sleep disordered breathing in children. While more research is needed, some studies suggest that RME might play a role in managing certain breathing issues.

Arch Form Correction
RME can help in correcting a narrow, V shaped upper arch. Ideally, the upper arch should have a broad, U shaped form. A narrow arch can lead to functional issues and may not provide adequate space for the tongue, potentially affecting speech and swallowing.

By expanding the upper jaw, RME helps achieve a more ideal arch form, which can improve overall oral function and aesthetics.

Preparation for Other Orthodontic Treatments
In some cases, RME is used as a preparatory step for other orthodontic treatments. Widening the upper jaw can create a more favorable environment for subsequent procedures, such as aligning teeth with braces or clear aligners.

Addressing Functional Shifts
Sometimes, a narrow upper jaw can cause the lower jaw to shift to one side when biting down. This functional shift can lead to asymmetrical jaw growth and potential TMJ (temporomandibular joint) issues. RME can help correct this by allowing the jaws to come together in a more balanced, centered position.

Aesthetic Considerations
While not the primary focus, RME can have positive effects on facial aesthetics. By widening the upper jaw, it can provide better support for the cheeks and lips, potentially improving the overall facial profile.

It’s important to note that the decision to use RME is always based on a comprehensive orthodontic assessment. Factors such as the patient’s age, skeletal maturity, the severity of the jaw discrepancy, and overall oral health are all taken into consideration.

Moreover, RME is often most effective when implemented at the right time in a child’s growth. This is typically before or during the pubertal growth spurt, when the mid-palatal suture is still flexible enough to be separated relatively easily.

Understanding these indications helps patients and parents appreciate why an orthodontist might recommend RME. It’s not just about creating a wider smile – it’s about addressing functional issues, improving oral health, and setting the stage for optimal dental and facial development.

The Ideal Timing for RME

The best time to commence RME treatment is during childhood, ideally between the ages of 8 and 10. This timing is critical as the upper jawbone comprises two bones connected by a single suture that doesn’t fully close until the early teenage years. Thus, starting the treatment at a young age, while the jaw is still growing and malleable, can lead to more effective and lasting results.

Design and Functionality of the RME Appliance

Rapid Maxillary Expansion treatment relies on a specialised appliance to achieve expansion. Knowing how this device works can help patients and parents feel more at ease with the process.

Source:  Hyrax Expander

Basic Design
The RME appliance, often referred to as a palatal expander, is a custom made orthodontic device designed to fit precisely in the patient’s mouth. While there are several variations in design, most RME appliances share some common features:

• Expansion Screw
  This is the central component of the appliance. It’s a specially designed screw mechanism that, when activated, pushes the two halves of the appliance apart.
• Metal Bands or Plastic Splint
  These are used to anchor the appliance to the upper molars. Some designs use metal bands cemented to the teeth, while others employ a plastic splint that covers the teeth.
• Metal Framework
  This connects the expansion screw to the bands or splint, distributing the force across the palate.
• Key
  A small, removable key is provided to activate the expansion screw. This is typically used by the patient or parent at home, following the orthodontist’s instructions.

Types of RME Appliances
There are several types of RME appliances, each with its own advantages:

• Hyrax Expander: This is one of the most common types. It features a central screw with four arms that attach to bands on the first premolars and first molars.
• Haas Expander: Similar to the Hyrax, but with an acrylic pad that rests against the palate, theoretically distributing forces more evenly.
• Bonded Expander: Instead of bands, this type uses a clear acrylic splint that covers the biting surfaces of the back teeth.
• Mini-Screw Assisted Rapid Palatal Expander (MARPE): A newer design that incorporates mini-implants for additional anchorage, often used in older patients.

How the Appliance Works
The RME appliance works on the principle of gradual, controlled force application. Here’s a step by step breakdown of its function:

• Installation
  The orthodontist custom fits and cements the appliance to the upper molars.
• Activation
  Following the orthodontist’s instructions, the patient or parent uses the key to turn the expansion screw, typically once or twice daily.
• Force Application
  Each turn of the screw applies a small amount of lateral force, gradually pushing the two halves of the maxilla apart.
• Bone Separation
  Over time, this force overcomes the resistance of the mid palatal suture, causing the two halves of the upper jaw to separate.
• New Bone Formation
  As the bones separate, the body responds by forming new bone in the widening gap.
• Stabilisation
  Once the desired expansion is achieved, the appliance is left in place for several months to allow the new bone to mature and stabilise.

Lifestyle Adjustments During RME Treatment

While undergoing RME treatment, patients can continue with their regular routines, with some minor adjustments. It is advised to avoid certain types of food and beverages, particularly hard, sticky, or sugary items that might dislodge the appliance or promote tooth decay. A diet of softer foods is often recommended during the initial adjustment period.

Regular appointments with the orthodontist are crucial during the treatment phase. These appointments allow the orthodontist to monitor the progress of the treatment and make any necessary adjustments to the appliance.

Benefits of Rapid Maxillary Expansion

Rapid Maxillary Expansion offers a range of benefits that extend beyond just widening the smile. Understanding these advantages can help patients and parents appreciate the value of this orthodontic treatment. Let’s explore the multifaceted benefits of RME in detail.

Improved Dental Alignment 
One of the primary benefits of RME is its ability to create space for proper dental alignment:

• Reduced Crowding
  By widening the upper jaw, RME creates additional space for teeth to align naturally. This can sometimes eliminate the need for tooth extractions in orthodontic treatment plans.
• Correction of Crossbites
  RME effectively addresses posterior crossbites, where upper back teeth sit inside the lower back teeth when biting down. Correcting this misalignment can prevent asymmetrical jaw growth and potential TMJ issues.
• Enhanced Arch Form
  RME helps achieve a more ideal U-shaped arch form, which can improve overall dental function and aesthetics.

Facial Aesthetics

RME can have positive effects on facial appearance such as:

• Wider Smile
  The expansion of the upper jaw can lead to a broader, more aesthetically pleasing smile.
• Improved Facial Symmetry
  By addressing crossbites and promoting more balanced jaw growth, RME can enhance overall facial symmetry.
• Better Cheek and Lip Support
  The widened upper jaw provides better support for the cheeks and upper lip, potentially improving the facial profile.

Breathing Improvements
An often overlooked benefit of RME is its potential impact on breathing.  They include:

• Increased Nasal Cavity Volume
  As the upper jaw expands, it can indirectly widen the nasal cavity, potentially improving nasal airflow.
• Potential Sleep Benefits
  Some studies suggest that RME may help alleviate symptoms of sleep-disordered breathing in children, though more research is needed in this area.
• Reduced Mouth Breathing
  Improved nasal breathing can reduce reliance on mouth breathing, which has various oral health benefits.

Functional Improvements
RME can enhance various aspects of oral function such as:

• Better Chewing Efficiency
  A properly aligned bite allows for more effective chewing and food processing.
• Improved Speech
  In some cases, RME can positively impact speech by providing more space for proper tongue positioning.
• Enhanced Swallowing Patterns
  A wider palate can allow for more natural tongue placement during swallowing.

Orthodontic Treatment Efficiency
RME can make subsequent orthodontic treatments more efficient.  As follows.

• Simplified Alignment
  By creating more space in the dental arch, RME can simplify the process of aligning teeth with braces or clear aligners.
• Reduced Treatment Time
  In some cases, the space created by RME can lead to shorter overall orthodontic treatment times.
• Potentially Fewer Extractions
  The additional space created by RME may reduce the need for tooth extractions in some orthodontic cases.

Oral Health
The benefits of RME can contribute to long-term oral health such as:

• Reduced Risk of Tooth Wear
  Proper alignment of teeth can reduce abnormal wear patterns.
• Improved Oral Hygiene
  Properly aligned teeth are often easier to clean, potentially reducing the risk of decay and gum disease.
• TMJ Health
  By addressing bite issues early, RME may help prevent future temporomandibular joint (TMJ) problems.

Psychological Benefits
While often overlooked, the psychological benefits of RME can be significant.  As follows:

• Increased Confidence
  Improvements in smile aesthetics and facial symmetry can boost self-esteem.
• Better Quality of Life
  Functional improvements in breathing and chewing can enhance overall quality of life.
• Preventive Mindset
  Early intervention with RME can instill a proactive approach to oral health care.

It’s important to note that while these benefits are significant, the specific outcomes can vary from patient to patient. The effectiveness of RME depends on various factors, including the patient’s age, the severity of the initial condition, and compliance with treatment protocols.

Understanding these diverse benefits helps put RME in perspective as more than just a teeth straightening procedure. It’s a comprehensive treatment that can have far reaching positive effects on a patient’s oral health, overall well being, and quality of life.

Risks and Complications

While Rapid Maxillary Expansion is generally a safe and effective treatment, there are potential risks and complications associated with the procedure.

One common issue is discomfort or pain associated with the pressure exerted by the expander. This is usually mild and can be managed with over the counter pain relievers.

In some cases, patients may experience an unwanted tilting of the molars or a temporary gap between the front teeth. These issues typically resolve as the treatment progresses or can be corrected with additional orthodontic measures. There is also a small risk of overexpansion, which could lead to problems with bite alignment or jaw function.

In rare instances, improper application of force or inadequate monitoring during treatment can lead to damage to the roots of the teeth or the supporting bone. This underscores the importance of working with a qualified and experienced orthodontist when undergoing RME treatment.

Remember, while RME has its limitations, it remains a valuable and effective treatment option for many patients. The key is to approach it with a clear understanding of both its benefits and potential drawbacks.

Conclusion

Rapid Maxillary Expansion is a powerful orthodontic treatment that can address a range of structural issues within the maxilla. It offers numerous benefits, from improved dental alignment to enhanced breathing, and can have a significant impact on a patient’s quality of life. As with any medical procedure, RME comes with potential risks, but with the guidance of a skilled orthodontist, these can be effectively managed.

For those considering Rapid Maxillary Expansion, I encourage you to consult with a qualified orthodontist to discuss your specific needs and goals. With the right care and commitment, the benefits of RME can be unlocked, leading to a healthier, happier life.