Conventional Versus 3D-Printed Twin Block Appliances in Growth Modification of Class II Malocclusion (Comparative Clinical Study)

Aim: To evaluate the effects of treatment using both conventional and 3D-printed Twin Block appliances for growth modification in Class II malocclusion.Background: Twin blocks are removable devices commonly used for treating Class II malocclusion. As functional appliances, they’re great for guiding craniofacial growth during a person’s developmental years. They work by harnessing nearby muscle forces to create changes in both the skeleton and teeth. Designed as a tooth- and tissue-borne appliance, the twin block makes the most of orthopedic forces. Since their introduction, they’ve become a popular orthodontic choice thanks to quick results, the ability to maintain normal oral functions, and comfort that supports long-term wear—boosting both motivation and compliance.Patients and methods: Pre-treatment (T1) and post-treatment (T2) lateral cephalograms of 10 patients treated with a conventional Twin Block appliance for class II malocclusion were compared to those of 10 patients treated with a 3D-printed Twin Block appliance for a 6-month follow-up period. Both groups were evaluated for dentoskeletal and soft tissue changes using various angular and linear geometric measurements, and differences between pre- and post-treatment were analyzed with a paired t-test.Results: The cephalometric analysis showed that the Twin Block appliance encouraged mandibular growth. Patients using it experienced a significant (p < 0.001) boost in mandibular length and lower facial height in both groups, with no significant differences between the two groups. All dental angular and linear measurements also changed notably from before to after treatment in each group. Similarly, there was improvement in the facial profile; thus, mean soft tissue measurements improved significantly over the treatment period, but there were no significant differences between the two groups Conclusion: Results of this study show that the Twin Block appliance is effective for treating Class II malocclusion, whether using a conventional or 3-D printed device. This effectiveness comes from the combined benefits of skeletal and dentoalveolar changes in both arches. Future research with larger sample sizes, 3D imaging, and long-term follow-ups could provide a clearer picture of how different functional appliances perform.