Trial design
RECRUITMENT
This study was a prospective, single-centre, single-arm trial and investigated facial expressions before (T0) and 4 months after orthognathic surgery (T1). It was approved by the institutional ethics committee (application number 13/2/19) in accordance with the Declaration of Helsinki. All participants gave written informed consent to take part in the study. The trial was registered before recruitment started (DRKS00017206). No changes occurred after trial commencement.