A systematic review and meta-analysis of 7 randomized controlled trials compared two common braces used to correct Class II malocclusion (an overbite where the upper jaw sticks out) in growing patients up to age 16. The analysis included 548 participants and looked at how well each appliance worked on the teeth, jaw bones, and soft tissues.
The results showed that the Herbst appliance had a small but significant advantage over the Twin Block for improving the mentolabial angle (the curve between the lower lip and chin) and the molar relationship (how the upper and lower back teeth fit together). However, both appliances were effective overall.
No safety information was reported in the studies, so it is not clear if one appliance caused more discomfort or side effects. The review also did not report any limitations, but as a meta-analysis, it combines results from multiple studies and cannot provide individual patient data.
For parents and teens considering treatment, both appliances are good options. The Herbst may offer modest benefits for certain measurements, but the choice should also consider comfort, appearance, and how well the patient can adapt to wearing the appliance.