MARPE & Maxillary Expansion
MARPE & Maxillary Expansion in Auckland — Treating a Genuinely Narrow Upper Jaw
A narrow upper jaw can present with a posterior crossbite, crowding, a constricted smile, a functional jaw shift or other clinical signs. Tooth position alone does not always reveal whether the underlying problem is dental, skeletal or both. The first step is therefore a specialist diagnosis—not an assumption that every narrow-looking arch requires skeletal expansion.
Where true maxillary constriction is present, the appropriate pathway may be conventional tooth-borne expansion, a hybrid appliance, miniscrew-assisted rapid palatal expansion (MARPE), or surgically assisted expansion. The recommendation depends on age, skeletal maturity, anatomy, severity, goals and the evidence relevant to the individual case.
At Parnell Orthodontics, maxillary expansion is approached as a diagnostic problem first. The appropriate expansion pathway — conventional, hybrid, mini-implant-assisted, or surgically assisted — depends on the patient's age, skeletal maturity, the degree of constriction, and the state of the mid-palatal suture.
Dr Adith has published multiple peer-reviewed research articles on bone-borne expansion. He utilises the AXEOS 3D CBCT imaging when clinically indicated, to assess the suture and surrounding anatomy before recommending any pathway. No expansion appliance is recommended without a thorough diagnostic workup first.
Understanding the Mid-Palatal Suture
The upper jaw (maxilla) develops from two halves joined at the midpalatal suture. In children and younger adolescents, this suture is generally less mature, so conventional expansion may be more predictable. With increasing skeletal maturity, resistance to expansion usually increases and additional anchorage or surgical assistance may be required.
Clinical examination and two-dimensional imaging may be sufficient in some cases. CBCT is used only when a specific clinical question requires three-dimensional information and the expected benefit justifies the radiation exposure.
Expansion Pathways available at Parnell Orthodontics:
1. Conventional tooth-borne palatal expansion uses a fixed expander bonded to the upper posterior teeth. It is effective and well-tolerated in children and young teenagers with an open suture. The expander is activated by the patient or parent daily, progressively widening the upper jaw over a period of weeks, after which the appliance is left in place to allow new bone to fill the expanded suture. This is the most established and widely used pathway for younger patients.
2. Miniscrew-Assisted Rapid Palatal Expansion (MARPE) is a contemporary technique used to widen a narrow upper jaw. Unlike conventional expanders, which obtain their support mainly from the teeth, MARPE uses small titanium miniscrews placed in the palate to transfer some of the expansion forces directly to the supporting bone.
MARPE is generally considered for selected older adolescents and adults who have progressed beyond the stage at which predictable expansion can be achieved using a conventional tooth-borne appliance alone. This often becomes relevant during the teenage years as the midpalatal suture gradually matures and becomes more resistant to expansion. MARPE can also be successful in appropriately selected young adults, although its predictability may gradually reduce with increasing age and skeletal maturity.
MARPE appliances may be designed in two principal ways:
• Hybrid or tooth–bone-borne MARPE: The appliance is supported by both the teeth and two or four palatal miniscrews. The additional skeletal anchorage reduces unwanted tipping and loading of the supporting teeth, allowing a more parallel expansion of the upper jaw with fewer dental side effects. This is the design most commonly used.
• Completely bone-borne MARPE: The appliance is anchored to four palatal miniscrews without relying on the teeth for support. This may be selected when more purely skeletal expansion is required or when minimising dental loading is particularly important.
The most appropriate design depends on the patient’s age, palatal anatomy, bone availability, dental condition and degree of sutural maturation. Age alone does not determine whether MARPE will be successful. A detailed clinical examination, digital dental scans and, where appropriate, CBCT imaging are used to assess the midpalatal suture and available palatal bone before treatment is recommended.
Dr Adith Venugopal has published research relating to bone-borne expansion and treatment planning. He uses digital 3D CBCT planning to evaluate the palate and optimise miniscrew positioning and appliance design for each patient. This personalised approach aims to improve the predictability of expansion while reducing unwanted effects on the teeth and surrounding structures.
MARPE has increased the number of older adolescents and adults who may be treated without surgery; however, it is not suitable for every patient.! When the mid-palatal suture is highly mature or interlocked, predictable nonsurgical expansion is unlikely, Surgically Assisted Rapid Palatal Expansion, or SARPE, may be a more appropriate option.
The final recommendation is therefore based on careful individual diagnosis rather than age alone.
3. Surgically Assisted Rapid Palatal Expansion (SARPE) is the indicated pathway when the suture is fully fused. That's typically in adults over 25 to 30, and where the degree of constriction is significant. A brief surgical procedure releases the mid-palatal suture and adjacent bony structures, after which a palatal expander is used to achieve the desired expansion.
SARPE is performed in collaboration with an oral and maxillofacial surgeon and is coordinated as part of a comprehensive orthodontic treatment plan managed by Dr Adith coordinating with eh Oral Surgeon.. SARPE can produce predictable, stable expansion in patients who cannot achieve adequate results through any non-surgical means.
What Does Treatment Involve?
Every maxillary expansion case at Parnell Orthodontics begins with a comprehensive clinical assessment and, where clinically indicated, CBCT imaging to evaluate the mid-palatal suture, bone quality, nasal cavity anatomy, and tooth root positions. This diagnostic information directly determines which expansion pathway is recommended. The findings and all treatment options are explained in full before any decision is made. Where surgery is involved, Dr Adith coordinates directly with the referring or treating oral surgeon to ensure the orthodontic and surgical phases are sequenced correctly for the best possible outcome.
Expansion treatment is typically followed by a retention period during which the expanded suture fills with new bone, and then by comprehensive orthodontic treatment to align the teeth within the newly widened arch. The total treatment timeline varies significantly depending on the pathway chosen and the individual patient.
Meet our Specialist Orthodontist ...
Dr. Adith Venugopal
Dr Adith Venugopal is a DCNZ-registered specialist orthodontist and Senior Lecturer at the University of Otago Faculty of Dentistry with published peer-reviewed research in bone-borne palatal expansion and virtual 3D expansion planning. He is one of the most published clinician-researchers in TAD-based and skeletal anchorage orthodontics internationally. Every expansion case at Parnell Orthodontics is personally planned and managed by Dr Adith using CBCT-informed diagnostic assessment.
