Double-Axis Maxillary Skeletal Expander Suggests Higher Expansion Efficiency in Early Activation: A Finite Element Analysis.

Abstract

Introduction: Conventional single-axis maxillary skeletal expanders (MSE) have some drawbacks, such as limited control over maxillary expansion and possible asymmetric expansion between the anterior nasal spine (ANS) and posterior nasal spine (PNS). This report introduces a double-axis maxillary skeletal expander (DAMSE) concept to overcome these drawbacks and enhance the efficiency of maxillary skeletal expansion.

Materials and methods: Five different DAMSE designs were compared with a conventional single-axis MSE. Finite element analysis was performed to analyse their expansion efficiency, stress magnitude and distribution occurring in a simplified bone model.

Results: DAMSE outperformed the single-axis MSE and provided better control over ANS and PNS expansion. During early activation, the highest expansion efficiency (31.7%) was achieved by DAMSE Model V, 13% more efficient than the single-axis MSE. This efficiency was increased to 100.8% by combining the DAMSE Model V with midpalatal suture surgery. However, with the simplified bone model, the current study could not demonstrate that DAMSE can resolve the issue of asymmetric expansion between ANS and PNS.

Conclusions: An appropriately designed DAMSE can be a promising tool for maxillary expansion treatment. DAMSE offers more efficient treatment than the conventional single-axis MSE while maintaining similar levels of patient comfort and invasiveness.