Class III Twin Blocks: a case series

Abstract

Objective: To evaluate the use of Class III Twin Blocks for the early treatment of Class III malocclusion.

Design: Retrospective analysis.

Subjects and Method: 14 subjects were consecutively treated with a modified version of the Class III Twin Block appliance. Lateral cephalometric radiographs taken at the start and end of treatment were assessed digitally.

Results: The mean age of subjects was 10 years and mean treatment time was 6.6 months. The cephalometric analysis of changes during treatment shows proclination of the upper incisors [mean 5.1°, SD 5.1], retroclination of the lower incisors [mean −4.5°, SD 3.9], reduction in angle SNB [mean −1.3°, SD 1.8] and an increase in the maxillary/ mandibular planes angle (mean 2.1°, SD 2.2]. Average cephalometric digitizations and photographs of a clinical case are shown.

Conclusions: Class III Twin Blocks can be used successfully for early treatment of Class III malocclusion. A randomly allocated prospective study is required to fully evaluate the efficacy of this appliance.

Keywords:

• Class III
• Twin Blocks
• Function Regulator III

Acknowledgments

We would like to thank Mr Nigel Taylor from the Royal Surrey County Hospital, Guildford, who was involved in the treatment of some subjects, and Dr David Moles from the Eastman Dental Institute, London, for statistical advice.