Frankel FR-IV

The Frankel FR-IV is specifically designed for anterior open bite cases. Extended buccal shields provide enhanced vertical control of posterior segments, and bite blocks prevent tongue interposition between anterior teeth.

• Extended Buccal Shields — Longer vertical extension than FR-I/II/III for posterior control • Anterior Bite Blocks — Acrylic platforms preventing tongue thrust between incisors • Lip Pads — Lower lip pads (same as FR-I) • Palatal Bow — 1.2mm SS wire • Labial Bow — 1.0mm SS wire on maxillary incisors

Extended buccal shields provide greater control of posterior vertical dimension. The anterior bite blocks physically prevent tongue posturing between anterior teeth — addressing one of the primary etiologies of open bite. Combined with the tissue-borne shield mechanism, the FR-IV addresses open bite through both skeletal and functional pathways.

1. Full vestibular depth impressions (critical for extended shields) 2. Construction bite: Slight vertical opening, no sagittal shift 3. 3D-print models 4. Wax extended shields — 2-3mm longer than standard FR-I 5. Position anterior bite blocks at prescribed thickness 6. Flask, process, trim extended shields carefully 7. QC: Shield extension measurement, bite block thickness, tongue clearance

• All FR-I material standards apply • Shield extension: 2-3mm longer than FR-I standard • Bite blocks: Minimum 2mm PMMA, smooth surface • QC: Extended shield measurement, bite block verification, tongue space test