Has MARPE Found Its Place?

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Has MARPE Found Its Place?

Join me for our first podcast of 2026 looking at Miniscrew Assisted Expansion, and where this treatment modality currently stands in clinical practice. With discussions of different designs (MSE Vs MARPE), rapid and slow activation protocols, orthopaedic effects, and predictors of success.   This podcast is a summary based on an excellent lecture from Angle-Net by Daniele Cantarella and Benedict Wilmes.

01:18 – MSE vs MARPE designs: key differences
03:55 – Anchorage, bone quality, and force delivery
05:29 – Skeletal effects: parallel suture split and expansion amounts
06:42 – Asymmetry, resistance areas, and biomechanics
07:00 – Class III correction: where MARPE really adds value
09:26 – Rapid vs slow activation and what actually happens to bone
10:28 – Predicting success: age limits, failure rates, and when to consider surgery

Design MSE Vs MARPE

• Number and location of TADs
  • MSE 4 miniscrews introduced Won Moon 2012
    • Miniscrew bicortical
    • Position
      • Posterior region maxilla – Cantarella Progress 2017
      • Closest proximity with greatest resistance = zygomatic buttress and pterygopalatine suture
      • Expansion force acts close to CoR – bi-zygomatic line 1^st molar
      • Miniscrews parallel to nasal septum
      • Expansion force acts perpendicular to midpalatal suture
      • Bone less than 2mm = additional TADs laterally or anteriorly
    • MARPE
      • Bone first approach
      • Use of ideal sites – mid-palate ‘T-zone premolar region Wilmes 2016 and confirmed by Chang 2021 (6-9mm)
      • FEM showed 500g of force can be distributed from 2 x TADs in the T zone Ludwig 2013
      • Thin bone posterior maxilla, offers little anchorage, no TADs posterior maxilla

• Appliance
  • MSE Appliance comes as a 1 piece, with the screw and eyelets for TAD position
    • = TADs will always fit the appliance, as appliance first, TADs second
    • Restricted position of the TADs by the appliance
  • MARPE
    • TAD inserted first into ideal bone, followed by fabrication of appliance
    • Risk of mismatch of appliance and design

Bone-borne only Vs arms to first molars

• MSE and MARPE both designs
  • Arms to 1^st molars to maintain position of appliance
    • After active expansion remove arms to 6s, maintain miniscrews
    • (Prevent dental tipping)
  • No arms
    • Less dental tipping
    • Risk of appliance rotating

Miniscrew Expansion Effects

• Parallel split of mid palatal suture
  • MSE 4.3 mm posterior 4.8 mm anterior, Cantarella 2017
  • MARPE 3.5 mm (average) Garib 2021
• Split of pterygopalatine suture in 53% Cantarella 2017
• Asymmetric changes, average 1.1mm
  • Difference in density and geometry = symmetric forces still result in asymmetric Cantarella 2017

Class 3 use with MARPE

• MARPE Vs RME Ergul 2025 AJODO
  • Greater skeletal protraction AP MARPE 1.6mm
  • Greater vertical control MARPE 1.2 degrees, less clockwise rotation of mandible
• Consensus statement Franchi 2025 recommend Alt-RAMEC Alternate Rapid Maxillary Expansion and Constriction 1 week expand 1mm per day, 1 week constriction 1mm per day, alternate for 5-8 weeks (Eric Liou 2014 JCO)
• Bicortical engagement due to forces required 500g+ Lee 2017 AJODO
  • Monocortical deformation 4.5 degrees
  • Bicortical deformation 1.8 degrees

Activation protocol

• Rapid: 1-2 turns per day
  • Based on conventional RME / SARPE
• Slow: Miniscrew Assistant Slow Palatal Expansion MARSE Arveda, Aghazada 2025
  • Equal skeletal expansion
  • Smaller diastema
  • Less discomfort and side effects? – yet to be proven
    • Questions if adaptation of distraction or bone bending and suture separation

Predictable expansion with MARPE?

• CBCT classification of mid palatal suture not reliable Angelleri 2013, Isfeld 2019
  • Bone bending – due to bone elasticity

AGE PROTOCOL Haas 2022

• Hyrax – Before puberty Bazargani 2023
• MARPE – After puberty until 25 Males, 30 Females Haichao 2021
  • 20-30 years males 80%
  • 20-30 years females 94%
• MISMARPE – Above 25 males, above 30 females
  • MARPE success 30-37 = 20% Olivera 2021

MISMARPE – minimally invasive surgery miniscrew assisted rapid palatal expansion Haas 2021