Revise and Review: Retention After Rapid Maxillary Expansion (RME)

Post-expansion relapse is a known risk due to dental tipping, soft tissue recoil, and delayed skeletal stabilisation. The available methods are:

1. Traditional Retention Methods

A. Passive Transpalatal Arch (TPA):

• Common choice for 3–6 months post-RME

• Maintains transverse gains (Karaman et al., 2002)

B. Expander Left In Place:

• Haas or Hyrax used passively for 3–6 months

• Prevents early relapse (Zimring & Isaacson, 1965)

• May hinder hygiene

C. Hawley Retainer:

• Removable option requiring compliance

• Limited evidence for skeletal retention (Vega et al., 2011)

D.. Full-Coverage PFR (Alkhal et al. 2022)

• Full-Coverage (PFR) 1 mm thickness covers the entire posterior occlusal surface and the palate.

• Shows significantly less relapse in transverse dimension after RME compared to TPA or traditional fixed retainers.

• Adds vertical and rotational control of molars.

• Recommended for 6–12 months of retention.

2. MARPE/SARPE Considerations (Cantarella et al. 2018)

• Skeletal expansion using MARPE needs longer retention (≥6 months) with either MARPE in situ or bone-supported appliance.

• Sutural healing is slower in adults.

General Recommendations

A. Retention Duration:

• Minimum: 3–6 months

• Optimal: 6–12 months for bony stabilisation (Baik et al., 2004; Baysal et al., 2012)

B.Long-Term:

• Mild relapse still possible over 2+ years (Gurel et al., 2013)

• Overcorrection advised

What’s your preferred method of post-expansion retention, and have you tried full coverage PFR yet?

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