Maxillary expansion and the mid-palatal suture: A revised review

Abstract

The age at which maxillary expansion is undertaken plays a pivotal role in altering the transverse dimension of the maxilla through the separation of the mid-palatal suture. Selecting an appropriate patient at the correct developmental stage can significantly enhance treatment outcomes. Notably, early intervention during mixed dentition, coupled with the proper expansion appliance and protocol, greatly influences skeletal changes in the maxilla. This is particularly evident in cases involving correction of posterior crossbites or arch crowding. Clinicians often base appliance selection on clinical experience, patient age, and malocclusion severity. Palatal growth is generally near completion by ages 6 to 9, and as the suture becomes increasingly interdigitated, separation becomes more difficult post-puberty. However, with sufficient force, separation can still occur. Maxillary expansion is commonly indicated for conditions such as posterior crossbites, distal molar repositioning, skeletal anchorage procedures, bone graft support, and mild maxillary crowding. This review evaluates the influence of age on expansion efficacy, highlighting that younger patients with less suture maturity experience greater skeletal response. While sex does not significantly impact clinical outcomes, both age and suture development are critical in planning personalized and effective expansion strategies.