A Digitally Guided, Single-Visit Workflow for Miniscrew-Assisted Rapid Palatal Expansion: The YOM Technique

Miniscrew-assisted rapid palatal expansion (MARPE) extends non-surgical, predominantly skeletal expansion to skeletally mature patients. Its success depends on the palatal miniscrews achieving sound engagement in a safe site and on the expander and the screws fitting together accurately. Two sequences are described. In a bone-first sequence, the miniscrews are inserted first, commonly through a CAD/CAM (computer-aided design/computer-aided manufacturing) guide that controls trajectory and depth, after which the appliance must be fitted to the screws in the positions they actually occupy. In an appliance-first sequence, the expander is cemented first, and the miniscrews are inserted through its own holes, so the entry position is defined by the appliance while angulation and depth are left to the operator. This technical report describes the YOM technique, an appliance-first workflow in which guided insertion is applied. A single registered plan of superimposed cone-beam CT (CBCT) and intraoral scan data is used to design a metal-printed hybrid tooth- and bone-borne MARPE appliance together with a separate, removable surgical guide. The appliance is cemented first, and the guide is then indexed onto it so that its guide holes are coaxial with the appliance's miniscrew holes. The guide is intended to control the entry site, angulation, and insertion depth. Because the appliance is cemented before insertion, the screws need not be parallel, and each trajectory can be planned according to the bone available at that site. Appliance delivery and guided miniscrew insertion are completed at a single clinical appointment, without the appliance having to be adapted to the screws afterwards. The individual components of the workflow are established in the literature; what is described here is their integration. No patient data are reported, and the insertion accuracy achieved with this guide has not been compared with the plan.