Palatal Expander
An orthodontic appliance, fixed or removable, designed to widen the maxillary arch by applying lateral forces to separate the mid-palatal suture.
Full Definition
Palatal expanders include rapid maxillary expanders (RME), slow maxillary expanders, and removable expansion plates. Fixed versions (e.g., Hyrax, bonded RME) are cemented to the teeth or palate and activated by the patient or clinician using a key to turn a central expansion screw. The expansion is typically measured in millimetres per activation turn and documented in the patient record. Editors should note that the terms 'palatal expander', 'maxillary expander', and 'rapid maxillary expansion (RME) appliance' are used interchangeably in the literature, but the clinical record should be internally consistent. The expansion screw and activation protocol must be described precisely in patient instruction leaflets.
Usage
Usage note: Specify whether the appliance is fixed or removable, and state the activation protocol (turns per day and mm per turn) in patient-facing documents.
In Context
- "A bonded rapid maxillary expander was fitted and the activation protocol explained to the parent." — Clinical notes
- "Patient instructions for the palatal expander specified one quarter-turn activation twice daily." — Patient instruction leaflet