Twin Block Appliance for Skeletal Class II Mandibular Retrognathism

Twin Block Appliance

Product Features:

Indicated for growing patients with skeletal Class II mandibular retrognathism, with or without maxillary prognathism. Expansion screw can be added for narrow arch. Removable and fixed types are available; reverse Twin Block is designed for Class III malocclusion. The upper and lower guiding plates form 70° inclined surfaces. Occlusal force is transmitted to the jaws via the inclines to advance the mandible and restrain forward growth of maxilla, correcting sagittal discrepancy. Lateral and forward mandibular movements are permitted during wear.

Note:

Wear as instructed by the clinician. Full-time wear is required after adaptation, and wearing during meals is acceptable.

Cleaning method is the same as removable orthodontic appliances.

The bite pads can be adjusted gradually after adaptation. Trim the maxillary bite pad first; trim the mandibular bite pad after posterior occlusion is established. Take care not to damage the guiding inclines during trimming, otherwise mandibular advancement effect will be compromised.

Model requirement: Maxillary and mandibular models with wax bite registration.

Occlusal reconstruction: Mandibular advancement is generally 5–8 mm. Anterior bite opening is about 2 mm, and approximately 5–6 mm at the first premolar region, creating a 2 mm space at molars to facilitate eruption of lower posterior teeth and reduce deep bite. If overjet exceeds 10 mm, staged mandibular advancement is needed, and Twin Block with adjustable guiding surfaces is recommended.