X-twitter Instagram
Wimbledon Orthodontic Laboratory
Make an Enquiry

Twin Block

The Twin Block is a removable functional appliance used in growing patients to correct Class II malocclusions. We make Twin Blocks to your prescription, from your digital scan or impression and construction bite.

What is a Twin Block Appliance?

A Twin Block consists of separate upper and lower removable appliances with occlusal bite blocks. The blocks meet at an inclined plane, angled at about 70°, which guides the mandible forward into the construction bite position when the patient closes. Because it is worn full-time, including during eating, it uses the functional forces of occlusion to encourage correction of the skeletal and dental relationship during growth.

When Is a Twin Block Prescribed?

Twin block functional appliance with clear acrylic upper and lower blocks on white study models, lab-made for orthodontists
  • Class II Division 1 malocclusion: to reduce an increased overjet with a retrusive mandible in a growing patient.
  • Class II Division 2 malocclusion: often after the upper incisors have been proclined, for example with a sectional or upper removable appliance phase.
  • Interceptive and two-phase treatment: as a functional phase before fixed appliances.

What We Make to Your Prescription

Please send upper and lower scans or impressions with a construction bite registered in the protrusive position you require. A prescription can specify:

Dental technician holding a plaster model of teeth
Smiling child in a dental chair
  • Construction bite: forward posture and vertical opening
  • Bite block height and the inclined plane position
  • Clasps: Adams clasps, ball clasps or delta clasps on the teeth you choose
  • Labial bow (upper and/or lower), if required
  • Midline expansion screw in the upper appliance
  • Springs, for example for incisor proclination
  • Acrylic colour: clear acrylic is shown, and a wide variety of colours and designs is available

If any part of the design is unclear, we will contact you before manufacture. Turnaround is about two weeks from receipt of your scan or impression.

Other Appliances

Need help?

Unable to find what you’re looking for? or need further information?

Contact Us