Comparison between conventional Twin block and a modified Essix twin block in adolescents with Class II malocclusion

Objective: To compare the changes in dento-skeletal structures between the conventional twin block and the modified Essix twin block and also to assess the patient's compliance with both the appliances. Material and Methods: A total of 14 female patients in the age group of 10 to 13 years were selected. They were divided into two groups, Group 1 was given the conventional twin block and the other group was given the modified Essix twin block. Lateral cephalograms were taken at two stagespre-treatment and post treatment (after the completion of myofunctional therapy, 11 months). At the end of the functional treatment the patient's were asked to fill a questionnaire regarding the usage with both types of appliances. Results: The conventional twin block showed slightly greater retroclination of upper incisors SNA increased post treatment in the Essix group but remained nearly constant in the conventional group. The increase in SNB and ANB as well as beta angle change was greater in the Essix group. The Essix group also showed greater proclination of the lower incisors as an adverse effect. The Jarabaks ratio appeared to increase in the Essix patients whereas in the conventional group it decreased. From the questionnaire it was clear that the patients found the Essix twin block more comfortable, esthetic. Conclusion: The Essix twin block produces a greater advancement of the mandibular apical base and more favorable direction of growth. It also shows prospects of better patient acceptability and compliance. The observed dentoskeletal effects indicate that the appliance may be particularly beneficial in patients with an anterio-posteriorly normal maxilla and a vertical growth pattern.