A novel electronic key-controlled expander for precise asymmetric palatal expansion.

Abstract

Achieving precise, comfortable, and asymmetric maxillary expansion remains a clinical challenge in orthodontics. Conventional expanders, such as the Hyrax, depend on manual activation by caregivers, often leading to inaccurate screw turns, patient discomfort, mucosal injury, and inconsistent results. Moreover, their mechanical design limits controlled asymmetric expansion, reducing effectiveness in unilateral crossbites. This brief research report introduces a proof-of-concept electronic, key-controlled palatal expander designed to enhance precision, safety, and ease of use. The concept integrates an electronic activation system with a multi-keyhole design, allowing both symmetrical and asymmetrical expansion tailored to individual patient needs. To assess the device's mechanical behavior, a functional digital simulation was conducted using the finite element method (ANSYS 2024 R1, ANSYS Inc., USA). Activation of the center screw produced smooth, stable, and symmetric bilateral expansion, with a 1 mm screw advancement generating approximately 1.08 mm of lateral displacement. Selective activation of lateral keyholes yielded illustrative unilateral movement, with each 1 mm screw activation resulting in approximately 1.9 mm of displacement, demonstrating the device's potential for controlled asymmetric expansion under the modeled conditions. Currently at the conceptual and design stage, the device has not undergone bench or clinical testing. However, the mechanical simulation supports the feasibility of a digitally guided expander capable of delivering controlled and customizable expansion in theory while reducing reliance on caregiver-performed activations. This innovation may offer a safer and more precise alternative to conventional devices, although all proposed advantages remain preliminary and require experimental and clinical validation before clinical use.