MINISCREW-ASSISTED RAPID PALATAL EXPANSION

👶 In Younger Patients

• The midpalatal suture is not yet fused and has minimal interdigitation.

• Tooth-borne expanders (like traditional Hyrax or Invisalign palatal expanders) are usually effective.

• The expansion results in a favourable amount of skeletal change—the two halves of the maxilla separate.

Midpalatal suture maturation: classification method for individual assessment before rapid maxillary expansion (Angelieri et.al., 2013)

🧑 In Older Patients

• With age, the midpalatal suture becomes increasingly interdigitated and eventually fuses.

• Using dental-supported expanders alone in these patients:

  • Can cause significant dental tipping rather than skeletal expansion.

  • May lead to periodontal issues, root resorption, or relapse.

🪛 Role of Miniscrews (TADs)

• Applies expansion force directly to the palatal bone, not through the teeth.

• Increases the likelihood of opening the midpalatal suture in adults. Achieves more true skeletal expansion.

• Minimizes dental tipping and root side effects.

 🦷 Dental (Teeth) Changes

• Significant maxillary width increase observed at the premolar and molar regions (Chun et al., 2022) –

  • Crossbite correction

• Expansion typically gains about 5–6 mm of space, which can be used for:

  • Retraction of anterior teeth

  • Relieve upper arch crowding

🦴 Skeletal (Jaw) Changes with MARPE

MARPE (Miniscrew-Assisted Rapid Palatal Expansion) works by opening the midpalatal suture—the seam where the two halves of the upper jaw meet. This expansion also affects other circummaxillary sutures.

Visual cues of expansion:

📸 (Lower right image): A space between the upper front teeth—known as a median diastema—often develops during treatment. This gap is a positive indicator that the midpalatal suture has successfully separated.

📸 (Left image): The suture opening may also extend upward toward the nasal cavity, which has been associated with improved nasal airflow and reduced airway resistance in the short term—particularly when using hybrid MARPE designs (supported by both teeth and bone screws).(Prévé & Alcázar, 2022) (Liu et al., 2023)

📸 (Upper right image): The maxilla is also displaced downward and forward, resulting in a lowered palatal vault. This skeletal movement can be especially helpful in Skeletal Class III cases, where the upper jaw is underdeveloped.

• The principles of expansion remain the same—aiming to gain dental space, modify skeletal structure, and potentially improve airway function.

• However, in older adolescents and adults, the midpalatal suture becomes more interdigitated and resistant to separation.

• As a result, greater force is required to achieve skeletal expansion.

There are many variations of MARPE (Miniscrew-Assisted Rapid Palatal Expansion) appliances—each with their own pros and cons, depending on age, anatomy, and treatment goals.

Hybrid MARPE (MSE – Maxillary Skeletal Expander used at MyBracesClinic)

• Combines 2 molar bands with 4 palatal miniscrews
• Offers a balance of stability and skeletal expansion

🔍 Planning Phase

• CBCT + Intraoral Scan
  → Assess bone thickness, suture morphology, and dental anatomy

• Treatment Design
  → Plan ideal miniscrew insertion sites (position, length, and angulation)
  → Customize expander based on anatomy and force requirements

🦷 Day 0: Expander Delivery

• Cementation of Expander

• Miniscrew Insertion under local anesthesia (LA)

• Turning Instructions

  • Demonstrate screw activation

  • Provide written and/or video guidance

  • Emphasize turning schedule and signs to monitor (e.g. discomfort, spacing)

🔁 Review Day (after ~2 week of turning)

• Check Progress

  • Midline diastema

  • Fit and comfort

  • Radiographic/clinical suture opening if needed

• Begin Consolidation Phase

  • Stop turning once desired expansion is achieved

  • Maintain expander in place to stabilize suture (typically 3–6 months)

😁 Post-Expansion Phase

• Bond Braces or

• Intraoral Scan for Invisalign